release: 0.2.5

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

.gitea/workflows/nix.yml

@@ -0,0 +1,46 @@
+name: Nix
+
+on:
+  - push
+  - pull_request
+
+jobs:
+  tests:
+    name: NixOS tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Install Nix
+        uses: cachix/install-nix-action@08dcb3a5e62fa31e2da3d490afc4176ef55ecd72 # v30
+        with:
+          # explicitly enable sandbox
+          install_options: --daemon
+          extra_nix_config: |
+            sandbox = true
+            system-features = nixos-test benchmark big-parallel kvm
+          enable_kvm: true
+
+      - name: Ensure environment
+        run: >-
+          apt-get update && apt-get install -y sqlite3
+        if: ${{ runner.os == 'Linux' }}
+
+      - name: Restore Nix store
+        uses: nix-community/cache-nix-action@v5
+        with:
+          primary-key: nix-${{ runner.os }}-${{ hashFiles('**/*.nix') }}
+          restore-prefixes-first-match: nix-${{ runner.os }}-
+
+      - name: Run tests
+        run: |
+          nix --print-build-logs --experimental-features 'nix-command flakes' flake check --all-systems
+          nix build --out-link "result" --print-out-paths --print-build-logs .#checks.x86_64-linux.nixos-tests
+
+      - name: Upload test output
+        uses: actions/upload-artifact@v3
+        with:
+          name: "result"
+          path: result/*
+          retention-days: 1

.gitea/workflows/release.yml

@@ -1,4 +1,4 @@
-name: release
+name: Create distribution
 
 on:
   push:
@@ -7,8 +7,26 @@ on:
 
 jobs:
   release:
+    name: Release
     runs-on: ubuntu-latest
+    container:
+      image: node:16-bookworm-slim
     steps:
+      - name: Get dependencies
+        run: >-
+          echo 'deb http://deb.debian.org/debian bookworm-backports main' >> /etc/apt/sources.list.d/backports.list &&
+          apt-get update &&
+          apt-get install -y
+          acl
+          git
+          gcc
+          pkg-config
+          libwayland-dev
+          wayland-protocols/bookworm-backports
+          libxcb1-dev
+          libacl1-dev
+        if: ${{ runner.os == 'Linux' }}
+
       - name: Checkout
         uses: actions/checkout@v4
         with:
@@ -19,24 +37,17 @@ jobs:
         with:
           go-version: '>=1.23.0'
 
-      - name: Get dependencies
+      - name: Go generate
         run: >-
-          apt-get update &&
-          apt-get install -y
-          gcc
-          pkg-config
-          libacl1-dev
-        if: ${{ runner.os == 'Linux' }}
+          go generate ./...
 
-      - name: Build for Linux
-        run: >-
-          sh -c "go build -v -ldflags '-s -w -X main.Version=${{ github.ref_name }}' -o bin/fortify &&
-          sha256sum --tag -b bin/fortify > bin/fortify.sha256"
+      - name: Build for release
+        run: FORTIFY_VERSION='${{ github.ref_name }}' ./dist/release.sh
 
       - name: Release
         id: use-go-action
         uses: https://gitea.com/actions/release-action@main
         with:
           files: |-
-            bin/**
+            dist/fortify-**
           api_key: '${{secrets.RELEASE_TOKEN}}'

.gitea/workflows/test.yml

@@ -1,4 +1,4 @@
-name: test
+name: Tests
 
 on:
   - push
@@ -6,8 +6,29 @@ on:
 
 jobs:
   test:
+    name: Go tests
     runs-on: ubuntu-latest
+    container:
+      image: node:16-bookworm-slim
     steps:
+      - name: Enable backports
+        run: >-
+          echo 'deb http://deb.debian.org/debian bookworm-backports main' >> /etc/apt/sources.list.d/backports.list
+        if: ${{ runner.os == 'Linux' }}
+
+      - name: Ensure environment
+        run: >-
+          apt-get update && apt-get install -y curl wget sudo libxml2
+        if: ${{ runner.os == 'Linux' }}
+
+      - name: Get dependencies
+        uses: awalsh128/cache-apt-pkgs-action@latest
+        with:
+          packages: acl git gcc pkg-config libwayland-dev wayland-protocols/bookworm-backports libxcb1-dev libacl1-dev
+          version: 1.0
+          #execute_install_scripts: true
+        if: ${{ runner.os == 'Linux' }}
+
       - name: Checkout
         uses: actions/checkout@v4
         with:
@@ -18,20 +39,24 @@ jobs:
         with:
           go-version: '>=1.23.0'
 
-      - name: Get dependencies
+      - name: Go generate
         run: >-
-          apt-get update &&
-          apt-get install -y
-          gcc
-          pkg-config
-          libacl1-dev
-        if: ${{ runner.os == 'Linux' }}
+          go generate ./...
 
       - name: Run tests
         run: >-
           go test ./...
 
-      - name: Build for Linux
+      - name: Build for test
+        id: build-test
         run: >-
-          sh -c "go build -v -ldflags '-s -w -X main.Version=${{ github.ref_name }}' -o bin/fortify &&
-          sha256sum --tag -b bin/fortify > bin/fortify.sha256"
+          FORTIFY_VERSION="$(git rev-parse --short HEAD)"
+          bash -c './dist/release.sh &&
+          echo "rev=$FORTIFY_VERSION" >> $GITHUB_OUTPUT'
+
+      - name: Upload test build
+        uses: actions/upload-artifact@v3
+        with:
+          name: "fortify-${{ steps.build-test.outputs.rev }}"
+          path: dist/fortify-*
+          retention-days: 1

.gitignore

@@ -22,4 +22,10 @@ go.work.sum
 # env file
 .env
 .idea
-.vscode
+.vscode
+
+# go generate
+security-context-v1-protocol.*
+
+# release
+/dist/fortify-*

README.md

@@ -1,7 +1,8 @@
 Fortify
 =======
 
-[![Go Reference](https://pkg.go.dev/badge/git.ophivana.moe/security/fortify.svg)](https://pkg.go.dev/git.ophivana.moe/security/fortify)
+[![Go Reference](https://pkg.go.dev/badge/git.gensokyo.uk/security/fortify.svg)](https://pkg.go.dev/git.gensokyo.uk/security/fortify)
+[![Go Report Card](https://goreportcard.com/badge/git.gensokyo.uk/security/fortify)](https://goreportcard.com/report/git.gensokyo.uk/security/fortify)
 
 Lets you run graphical applications as another user in a confined environment with a nice NixOS
 module to configure target users and provide launchers and desktop files for your privileged user.
@@ -14,24 +15,17 @@ Why would you want this?
 
 - It provides UID isolation on top of the standard application sandbox.
 
-There are a few different things to set up for this to work:
-
-- A set of users, each for a group of applications that should be allowed access to each other
-
-- A tool to switch users, currently sudo and machinectl are supported.
-
-- If you are running NixOS, the module in this repository can take care of launchers and desktop files in the privileged
-  user's environment, as well as packages and extra home-manager configuration for target users.
-
 If you have a flakes-enabled nix environment, you can try out the tool by running:
 
 ```shell
-nix run git+https://git.ophivana.moe/security/fortify -- -h
+nix run git+https://git.gensokyo.uk/security/fortify -- help
 ```
 
 ## Module usage
 
-The NixOS module currently requires home-manager and impermanence to function correctly.
+The NixOS module currently requires home-manager to function correctly.
+
+Full module documentation can be found [here](options.md).
 
 To use the module, import it into your configuration with
 
@@ -41,7 +35,7 @@ To use the module, import it into your configuration with
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
 
     fortify = {
-      url = "git+https://git.ophivana.moe/security/fortify";
+      url = "git+https://git.gensokyo.uk/security/fortify";
 
       # Optional but recommended to limit the size of your system closure.
       inputs.nixpkgs.follows = "nixpkgs";
@@ -68,112 +62,101 @@ This adds the `environment.fortify` option:
 {
   environment.fortify = {
     enable = true;
-    user = "nixos";
-    stateDir = "/var/lib/persist/module";
-    target = {
-      chronos = {
-        launchers = {
-          weechat.method = "sudo";
-          claws-mail.capability.pulse = false;
+    stateDir = "/var/lib/persist/module/fortify";
+    users = {
+      alice = 0;
+      nixos = 10;
+    };
 
-          discord = {
-            command = "vesktop --ozone-platform-hint=wayland";
-            share = pkgs.vesktop;
+    apps = [
+      {
+        name = "chromium";
+        id = "org.chromium.Chromium";
+        packages = [ pkgs.chromium ];
+        userns = true;
+        mapRealUid = true;
+        dbus = {
+          system = {
+            filter = true;
+            talk = [
+              "org.bluez"
+              "org.freedesktop.Avahi"
+              "org.freedesktop.UPower"
+            ];
           };
-
-          chromium.dbus = {
-            configSystem = {
-              filter = true;
+          session =
+            f:
+            f {
               talk = [
-                "org.bluez"
-                "org.freedesktop.Avahi"
-                "org.freedesktop.UPower"
-              ];
-            };
-            config = {
-              filter = true;
-              talk = [
-                "org.freedesktop.DBus"
                 "org.freedesktop.FileManager1"
                 "org.freedesktop.Notifications"
                 "org.freedesktop.ScreenSaver"
                 "org.freedesktop.secrets"
-                "org.kde.kwalletd5"    
+                "org.kde.kwalletd5"
                 "org.kde.kwalletd6"
-              ];   
+              ];
               own = [
                 "org.chromium.Chromium.*"
                 "org.mpris.MediaPlayer2.org.chromium.Chromium.*"
                 "org.mpris.MediaPlayer2.chromium.*"
               ];
-              call = {
-                "org.freedesktop.portal.*" = "*";
-              };
-              broadcast = {
-                "org.freedesktop.portal.*" = "@/org/freedesktop/portal/*";
-              };
+              call = { };
+              broadcast = { };
             };
-          };
         };
-        packages = with pkgs; [
-          weechat
-          claws-mail
-          vesktop
-          chromium
-        ];
-        persistence.directories = [
-          ".config/weechat"
-          ".claws-mail"
-          ".config/vesktop"
+      }
+      {
+        name = "claws-mail";
+        id = "org.claws_mail.Claws-Mail";
+        packages = [ pkgs.claws-mail ];
+        gpu = false;
+        capability.pulse = false;
+      }
+      {
+        name = "weechat";
+        packages = [ pkgs.weechat ];
+        capability = {
+          wayland = false;
+          x11 = false;
+          dbus = true;
+          pulse = false;
+        };
+      }
+      {
+        name = "discord";
+        id = "dev.vencord.Vesktop";
+        packages = [ pkgs.vesktop ];
+        share = pkgs.vesktop;
+        command = "vesktop --ozone-platform-hint=wayland";
+        userns = true;
+        mapRealUid = true;
+        capability.x11 = true;
+        dbus = {
+          session =
+            f:
+            f {
+              talk = [ "org.kde.StatusNotifierWatcher" ];
+              own = [ ];
+              call = { };
+              broadcast = { };
+            };
+          system.filter = true;
+        };
+      }
+      {
+        name = "looking-glass-client";
+        groups = [ "plugdev" ];
+        extraPaths = [
+          {
+            src = "/dev/shm/looking-glass";
+            write = true;
+          }
         ];
         extraConfig = {
           programs.looking-glass-client.enable = true;
         };
-      };
-    };
+      }
+    ];
   };
 }
 ```
-
-* `enable` determines whether the module should be enabled or not. Useful when sharing configurations between graphical
-  and headless systems. Defaults to `false`.
-
-* `user` specifies the privileged user with access to fortified applications.
-
-* `stateDir` is the path to your persistent storage location. It is directly passed through to the impermanence module.
-
-* `target` is an attribute set of submodules, where the attribute name is the username of the unprivileged target user.
-
-  The available options are:
-
-    * `packages`, the list of packages to make available in the target user's environment.
-
-    * `persistence`, user persistence attribute set passed to impermanence.
-
-    * `extraConfig`, extra home-manager configuration for the target user.
-
-    * `launchers`, attribute set where the attribute name is the name of the launcher.
-
-      The available options are:
-
-        * `command`, the command to run as the target user. Defaults to launcher name.
-
-        * `dbus.config`, D-Bus proxy custom configuration.
-
-        * `dbus.configSystem`, D-Bus system bus custom configuration, null to disable.
-
-        * `dbus.id`, D-Bus application id, has no effect if `dbus.config` is set.
-
-        * `dbus.mpris`, whether to enable MPRIS defaults, has no effect if `dbus.config` is set.
-
-        * `capability.wayland`, whether to share the Wayland socket.
-
-        * `capability.x11`, whether to share the X11 socket and allow connection.
-
-        * `capability.dbus`, whether to proxy D-Bus.
-
-        * `capability.pulse`, whether to share the PulseAudio socket and cookie.
-
-        * `share`, package containing desktop/icon files. Defaults to launcher name.
-
-        * `method`, the launch method for the sandboxed program, can be `"fortify"`, `"fortify-sudo"`, `"sudo"`.

acl/acl.go

@@ -0,0 +1,19 @@
+// Package acl implements simple ACL manipulation via libacl.
+package acl
+
+type Perms []Perm
+
+func (ps Perms) String() string {
+	var s = []byte("---")
+	for _, p := range ps {
+		switch p {
+		case Read:
+			s[0] = 'r'
+		case Write:
+			s[1] = 'w'
+		case Execute:
+			s[2] = 'x'
+		}
+	}
+	return string(s)
+}

acl/acl_getfacl_test.go

@@ -0,0 +1,156 @@
+package acl_test
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"os/exec"
+	"strconv"
+)
+
+type (
+	getFAclInvocation struct {
+		cmd *exec.Cmd
+		val []*getFAclResp
+		pe  []error
+	}
+
+	getFAclResp struct {
+		typ  fAclType
+		cred int32
+		val  fAclPerm
+
+		raw []byte
+	}
+
+	fAclPerm uintptr
+	fAclType uint8
+)
+
+const fAclBufSize = 16
+
+const (
+	fAclPermRead fAclPerm = 1 << iota
+	fAclPermWrite
+	fAclPermExecute
+)
+
+const (
+	fAclTypeUser fAclType = iota
+	fAclTypeGroup
+	fAclTypeMask
+	fAclTypeOther
+)
+
+func (c *getFAclInvocation) run(name string) error {
+	if c.cmd != nil {
+		panic("attempted to run twice")
+	}
+
+	c.cmd = exec.Command("getfacl", "--omit-header", "--absolute-names", "--numeric", name)
+
+	scanErr := make(chan error, 1)
+	if p, err := c.cmd.StdoutPipe(); err != nil {
+		return err
+	} else {
+		go c.parse(p, scanErr)
+	}
+
+	if err := c.cmd.Start(); err != nil {
+		return err
+	}
+
+	return errors.Join(<-scanErr, c.cmd.Wait())
+}
+
+func (c *getFAclInvocation) parse(pipe io.Reader, scanErr chan error) {
+	c.val = make([]*getFAclResp, 0, 4+fAclBufSize)
+
+	s := bufio.NewScanner(pipe)
+	for s.Scan() {
+		fields := bytes.SplitN(s.Bytes(), []byte{':'}, 3)
+		if len(fields) != 3 {
+			continue
+		}
+
+		resp := getFAclResp{}
+
+		switch string(fields[0]) {
+		case "user":
+			resp.typ = fAclTypeUser
+		case "group":
+			resp.typ = fAclTypeGroup
+		case "mask":
+			resp.typ = fAclTypeMask
+		case "other":
+			resp.typ = fAclTypeOther
+		default:
+			c.pe = append(c.pe, fmt.Errorf("unknown type %s", string(fields[0])))
+			continue
+		}
+
+		if len(fields[1]) == 0 {
+			resp.cred = -1
+		} else {
+			if cred, err := strconv.Atoi(string(fields[1])); err != nil {
+				c.pe = append(c.pe, err)
+				continue
+			} else {
+				resp.cred = int32(cred)
+				if resp.cred < 0 {
+					c.pe = append(c.pe, fmt.Errorf("credential %d out of range", resp.cred))
+					continue
+				}
+			}
+		}
+
+		if len(fields[2]) != 3 {
+			c.pe = append(c.pe, fmt.Errorf("invalid perm length %d", len(fields[2])))
+			continue
+		} else {
+			switch fields[2][0] {
+			case 'r':
+				resp.val |= fAclPermRead
+			case '-':
+			default:
+				c.pe = append(c.pe, fmt.Errorf("invalid perm %v", fields[2][0]))
+				continue
+			}
+			switch fields[2][1] {
+			case 'w':
+				resp.val |= fAclPermWrite
+			case '-':
+			default:
+				c.pe = append(c.pe, fmt.Errorf("invalid perm %v", fields[2][1]))
+				continue
+			}
+			switch fields[2][2] {
+			case 'x':
+				resp.val |= fAclPermExecute
+			case '-':
+			default:
+				c.pe = append(c.pe, fmt.Errorf("invalid perm %v", fields[2][2]))
+				continue
+			}
+		}
+
+		resp.raw = make([]byte, len(s.Bytes()))
+		copy(resp.raw, s.Bytes())
+		c.val = append(c.val, &resp)
+	}
+	scanErr <- s.Err()
+}
+
+func (r *getFAclResp) String() string {
+	if r.raw != nil && len(r.raw) > 0 {
+		return string(r.raw)
+	}
+
+	return "(user-initialised resp value)"
+}
+
+func (r *getFAclResp) equals(typ fAclType, cred int32, val fAclPerm) bool {
+	return r.typ == typ && r.cred == cred && r.val == val
+}

acl/acl_test.go

@@ -0,0 +1,125 @@
+package acl_test
+
+import (
+	"errors"
+	"os"
+	"path"
+	"reflect"
+	"testing"
+
+	"git.gensokyo.uk/security/fortify/acl"
+)
+
+const testFileName = "acl.test"
+
+var (
+	uid  = os.Geteuid()
+	cred = int32(os.Geteuid())
+)
+
+func TestUpdatePerm(t *testing.T) {
+	if os.Getenv("GO_TEST_SKIP_ACL") == "1" {
+		t.Log("acl test skipped")
+		t.SkipNow()
+	}
+
+	testFilePath := path.Join(t.TempDir(), testFileName)
+
+	if f, err := os.Create(testFilePath); err != nil {
+		t.Fatalf("Create: error = %v", err)
+	} else {
+		if err = f.Close(); err != nil {
+			t.Fatalf("Close: error = %v", err)
+		}
+	}
+	defer func() {
+		if err := os.Remove(testFilePath); err != nil {
+			t.Fatalf("Remove: error = %v", err)
+		}
+	}()
+
+	cur := getfacl(t, testFilePath)
+
+	t.Run("default entry count", func(t *testing.T) {
+		if len(cur) != 3 {
+			t.Fatalf("unexpected test file acl length %d", len(cur))
+		}
+	})
+
+	t.Run("default clear mask", func(t *testing.T) {
+		if err := acl.UpdatePerm(testFilePath, uid); err != nil {
+			t.Fatalf("UpdatePerm: error = %v", err)
+		}
+		if cur = getfacl(t, testFilePath); len(cur) != 4 {
+			t.Fatalf("UpdatePerm: %v", cur)
+		}
+	})
+
+	t.Run("default clear consistency", func(t *testing.T) {
+		if err := acl.UpdatePerm(testFilePath, uid); err != nil {
+			t.Fatalf("UpdatePerm: error = %v", err)
+		}
+		if val := getfacl(t, testFilePath); !reflect.DeepEqual(val, cur) {
+			t.Fatalf("UpdatePerm: %v, want %v", val, cur)
+		}
+	})
+
+	testUpdate(t, testFilePath, "r--", cur, fAclPermRead, acl.Read)
+	testUpdate(t, testFilePath, "-w-", cur, fAclPermWrite, acl.Write)
+	testUpdate(t, testFilePath, "--x", cur, fAclPermExecute, acl.Execute)
+	testUpdate(t, testFilePath, "-wx", cur, fAclPermWrite|fAclPermExecute, acl.Write, acl.Execute)
+	testUpdate(t, testFilePath, "r-x", cur, fAclPermRead|fAclPermExecute, acl.Read, acl.Execute)
+	testUpdate(t, testFilePath, "rw-", cur, fAclPermRead|fAclPermWrite, acl.Read, acl.Write)
+	testUpdate(t, testFilePath, "rwx", cur, fAclPermRead|fAclPermWrite|fAclPermExecute, acl.Read, acl.Write, acl.Execute)
+}
+
+func testUpdate(t *testing.T, testFilePath, name string, cur []*getFAclResp, val fAclPerm, perms ...acl.Perm) {
+	t.Run(name, func(t *testing.T) {
+		t.Cleanup(func() {
+			if err := acl.UpdatePerm(testFilePath, uid); err != nil {
+				t.Fatalf("UpdatePerm: error = %v", err)
+			}
+			if v := getfacl(t, testFilePath); !reflect.DeepEqual(v, cur) {
+				t.Fatalf("UpdatePerm: %v, want %v", v, cur)
+			}
+		})
+
+		if err := acl.UpdatePerm(testFilePath, uid, perms...); err != nil {
+			t.Fatalf("UpdatePerm: error = %v", err)
+		}
+		r := respByCred(getfacl(t, testFilePath), fAclTypeUser, cred)
+		if r == nil {
+			t.Fatalf("UpdatePerm did not add an ACL entry")
+		}
+		if !r.equals(fAclTypeUser, cred, val) {
+			t.Fatalf("UpdatePerm(%s) = %s", name, r)
+		}
+	})
+}
+
+func getfacl(t *testing.T, name string) []*getFAclResp {
+	c := new(getFAclInvocation)
+	if err := c.run(name); err != nil {
+		t.Fatalf("getfacl: error = %v", err)
+	}
+	if len(c.pe) != 0 {
+		t.Errorf("errors encountered parsing getfacl output\n%s", errors.Join(c.pe...).Error())
+	}
+	return c.val
+}
+
+func respByCred(v []*getFAclResp, typ fAclType, cred int32) *getFAclResp {
+	j := -1
+	for i, r := range v {
+		if r.typ == typ && r.cred == cred {
+			if j != -1 {
+				panic("invalid acl")
+			}
+			j = i
+		}
+	}
+	if j == -1 {
+		return nil
+	}
+	return v[j]
+}

acl/c.go

@@ -1,50 +1,95 @@
 package acl
 
+import "C"
 import (
 	"errors"
-	"fmt"
+	"runtime"
 	"syscall"
 	"unsafe"
 )
 
-//#include <stdlib.h>
-//#include <sys/acl.h>
-//#include <acl/libacl.h>
-//#cgo linux LDFLAGS: -lacl
-import "C"
+/*
+#cgo linux pkg-config: libacl
 
-type acl struct {
-	val   C.acl_t
-	freed bool
+#include <stdlib.h>
+#include <sys/acl.h>
+#include <acl/libacl.h>
+
+static acl_t _go_acl_get_file(const char *path_p, acl_type_t type) {
+	acl_t acl = acl_get_file(path_p, type);
+	free((void *)path_p);
+	return acl;
 }
 
-func aclGetFile(path string, t C.acl_type_t) (*acl, error) {
-	p := C.CString(path)
-	a, err := C.acl_get_file(p, t)
-	C.free(unsafe.Pointer(p))
+static int _go_acl_set_file(const char *path_p, acl_type_t type, acl_t acl) {
+	if (acl_valid(acl) != 0) {
+		return -1;
+	}
 
+	int ret = acl_set_file(path_p, type, acl);
+	free((void *)path_p);
+	return ret;
+}
+*/
+import "C"
+
+func getFile(name string, t C.acl_type_t) (*ACL, error) {
+	a, err := C._go_acl_get_file(C.CString(name), t)
 	if errors.Is(err, syscall.ENODATA) {
 		err = nil
 	}
-	return &acl{val: a, freed: false}, err
+
+	return newACL(a), err
 }
 
-func (a *acl) setFile(path string, t C.acl_type_t) error {
-	if C.acl_valid(a.val) != 0 {
-		return fmt.Errorf("invalid acl")
-	}
-
-	p := C.CString(path)
-	_, err := C.acl_set_file(p, t, a.val)
-	C.free(unsafe.Pointer(p))
+func (acl *ACL) setFile(name string, t C.acl_type_t) error {
+	_, err := C._go_acl_set_file(C.CString(name), t, acl.acl)
 	return err
 }
 
-func (a *acl) removeEntry(tt C.acl_tag_t, tq int) error {
+func newACL(a C.acl_t) *ACL {
+	acl := &ACL{a}
+	runtime.SetFinalizer(acl, (*ACL).free)
+	return acl
+}
+
+type ACL struct {
+	acl C.acl_t
+}
+
+func (acl *ACL) free() {
+	C.acl_free(unsafe.Pointer(acl.acl))
+
+	// no need for a finalizer anymore
+	runtime.SetFinalizer(acl, nil)
+}
+
+const (
+	Read    = C.ACL_READ
+	Write   = C.ACL_WRITE
+	Execute = C.ACL_EXECUTE
+
+	TypeDefault = C.ACL_TYPE_DEFAULT
+	TypeAccess  = C.ACL_TYPE_ACCESS
+
+	UndefinedTag = C.ACL_UNDEFINED_TAG
+	UserObj      = C.ACL_USER_OBJ
+	User         = C.ACL_USER
+	GroupObj     = C.ACL_GROUP_OBJ
+	Group        = C.ACL_GROUP
+	Mask         = C.ACL_MASK
+	Other        = C.ACL_OTHER
+)
+
+type (
+	Perm C.acl_perm_t
+)
+
+func (acl *ACL) removeEntry(tt C.acl_tag_t, tq int) error {
 	var e C.acl_entry_t
 
 	// get first entry
-	if r, err := C.acl_get_entry(a.val, C.ACL_FIRST_ENTRY, &e); err != nil {
+	if r, err := C.acl_get_entry(acl.acl, C.ACL_FIRST_ENTRY, &e); err != nil {
 		return err
 	} else if r == 0 {
 		// return on acl with no entries
@@ -52,7 +97,7 @@ func (a *acl) removeEntry(tt C.acl_tag_t, tq int) error {
 	}
 
 	for {
-		if r, err := C.acl_get_entry(a.val, C.ACL_NEXT_ENTRY, &e); err != nil {
+		if r, err := C.acl_get_entry(acl.acl, C.ACL_NEXT_ENTRY, &e); err != nil {
 			return err
 		} else if r == 0 {
 			// return on drained acl
@@ -84,16 +129,68 @@ func (a *acl) removeEntry(tt C.acl_tag_t, tq int) error {
 
 		// delete on match
 		if t == tt && q == tq {
-			_, err := C.acl_delete_entry(a.val, e)
+			_, err := C.acl_delete_entry(acl.acl, e)
 			return err
 		}
 	}
 }
 
-func (a *acl) free() {
-	if a.freed {
-		panic("acl already freed")
+func UpdatePerm(name string, uid int, perms ...Perm) error {
+	// read acl from file
+	a, err := getFile(name, TypeAccess)
+	if err != nil {
+		return err
 	}
-	C.acl_free(unsafe.Pointer(a.val))
-	a.freed = true
+	// free acl on return if get is successful
+	defer a.free()
+
+	// remove existing entry
+	if err = a.removeEntry(User, uid); err != nil {
+		return err
+	}
+
+	// create new entry if perms are passed
+	if len(perms) > 0 {
+		// create new acl entry
+		var e C.acl_entry_t
+		if _, err = C.acl_create_entry(&a.acl, &e); err != nil {
+			return err
+		}
+
+		// get perm set of new entry
+		var p C.acl_permset_t
+		if _, err = C.acl_get_permset(e, &p); err != nil {
+			return err
+		}
+
+		// add target perms
+		for _, perm := range perms {
+			if _, err = C.acl_add_perm(p, C.acl_perm_t(perm)); err != nil {
+				return err
+			}
+		}
+
+		// set perm set to new entry
+		if _, err = C.acl_set_permset(e, p); err != nil {
+			return err
+		}
+
+		// set user tag to new entry
+		if _, err = C.acl_set_tag_type(e, User); err != nil {
+			return err
+		}
+
+		// set qualifier (uid) to new entry
+		if _, err = C.acl_set_qualifier(e, unsafe.Pointer(&uid)); err != nil {
+			return err
+		}
+	}
+
+	// calculate mask after update
+	if _, err = C.acl_calc_mask(&a.acl); err != nil {
+		return err
+	}
+
+	// write acl to file
+	return a.setFile(name, TypeAccess)
 }

acl/export.go

@@ -1,106 +0,0 @@
-package acl
-
-import "unsafe"
-
-//#include <stdlib.h>
-//#include <sys/acl.h>
-//#include <acl/libacl.h>
-//#cgo linux LDFLAGS: -lacl
-import "C"
-
-const (
-	Read    = C.ACL_READ
-	Write   = C.ACL_WRITE
-	Execute = C.ACL_EXECUTE
-
-	TypeDefault = C.ACL_TYPE_DEFAULT
-	TypeAccess  = C.ACL_TYPE_ACCESS
-
-	UndefinedTag = C.ACL_UNDEFINED_TAG
-	UserObj      = C.ACL_USER_OBJ
-	User         = C.ACL_USER
-	GroupObj     = C.ACL_GROUP_OBJ
-	Group        = C.ACL_GROUP
-	Mask         = C.ACL_MASK
-	Other        = C.ACL_OTHER
-)
-
-type (
-	Perm  C.acl_perm_t
-	Perms []Perm
-)
-
-func (ps Perms) String() string {
-	var s = []byte("---")
-	for _, p := range ps {
-		switch p {
-		case Read:
-			s[0] = 'r'
-		case Write:
-			s[1] = 'w'
-		case Execute:
-			s[2] = 'x'
-		}
-	}
-	return string(s)
-}
-
-func UpdatePerm(path string, uid int, perms ...Perm) error {
-	// read acl from file
-	a, err := aclGetFile(path, TypeAccess)
-	if err != nil {
-		return err
-	}
-	// free acl on return if get is successful
-	defer a.free()
-
-	// remove existing entry
-	if err = a.removeEntry(User, uid); err != nil {
-		return err
-	}
-
-	// create new entry if perms are passed
-	if len(perms) > 0 {
-		// create new acl entry
-		var e C.acl_entry_t
-		if _, err = C.acl_create_entry(&a.val, &e); err != nil {
-			return err
-		}
-
-		// get perm set of new entry
-		var p C.acl_permset_t
-		if _, err = C.acl_get_permset(e, &p); err != nil {
-			return err
-		}
-
-		// add target perms
-		for _, perm := range perms {
-			if _, err = C.acl_add_perm(p, C.acl_perm_t(perm)); err != nil {
-				return err
-			}
-		}
-
-		// set perm set to new entry
-		if _, err = C.acl_set_permset(e, p); err != nil {
-			return err
-		}
-
-		// set user tag to new entry
-		if _, err = C.acl_set_tag_type(e, User); err != nil {
-			return err
-		}
-
-		// set qualifier (uid) to new entry
-		if _, err = C.acl_set_qualifier(e, unsafe.Pointer(&uid)); err != nil {
-			return err
-		}
-	}
-
-	// calculate mask after update
-	if _, err = C.acl_calc_mask(&a.val); err != nil {
-		return err
-	}
-
-	// write acl to file
-	return a.setFile(path, TypeAccess)
-}

cmd/finit/ipc/payload.go

@@ -1,14 +1,12 @@
 package init0
 
-const EnvInit = "FORTIFY_INIT"
+const Env = "FORTIFY_INIT"
 
 type Payload struct {
 	// target full exec path
 	Argv0 string
 	// child full argv
 	Argv []string
-	// wayland fd, -1 to disable
-	WL int
 
 	// verbosity pass through
 	Verbose bool

cmd/finit/main.go

@@ -1,69 +1,83 @@
-package init0
+package main
 
 import (
-	"encoding/gob"
 	"errors"
-	"flag"
 	"os"
 	"os/exec"
 	"os/signal"
 	"path"
-	"strconv"
 	"syscall"
 	"time"
 
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	init0 "git.gensokyo.uk/security/fortify/cmd/finit/ipc"
+	"git.gensokyo.uk/security/fortify/internal"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/proc"
 )
 
 const (
-	// time to wait for linger processes after death initial process
+	// time to wait for linger processes after death of initial process
 	residualProcessTimeout = 5 * time.Second
 )
 
 // everything beyond this point runs within pid namespace
 // proceed with caution!
 
-func doInit(fd uintptr) {
+func main() {
+	// sharing stdout with shim
+	// USE WITH CAUTION
 	fmsg.SetPrefix("init")
 
+	// setting this prevents ptrace
+	if err := internal.PR_SET_DUMPABLE__SUID_DUMP_DISABLE(); err != nil {
+		fmsg.Fatalf("cannot set SUID_DUMP_DISABLE: %s", err)
+		panic("unreachable")
+	}
+
+	if os.Getpid() != 1 {
+		fmsg.Fatal("this process must run as pid 1")
+		panic("unreachable")
+	}
+
 	// re-exec
-	if len(os.Args) > 0 && os.Args[0] != "fortify" && path.IsAbs(os.Args[0]) {
-		if err := syscall.Exec(os.Args[0], []string{"fortify", "init"}, os.Environ()); err != nil {
+	if len(os.Args) > 0 && (os.Args[0] != "finit" || len(os.Args) != 1) && path.IsAbs(os.Args[0]) {
+		if err := syscall.Exec(os.Args[0], []string{"finit"}, os.Environ()); err != nil {
 			fmsg.Println("cannot re-exec self:", err)
 			// continue anyway
 		}
 	}
 
-	var payload Payload
-	p := os.NewFile(fd, "config-stream")
-	if p == nil {
-		fmsg.Fatal("invalid config descriptor")
-	}
-	if err := gob.NewDecoder(p).Decode(&payload); err != nil {
-		fmsg.Fatal("cannot decode init payload:", err)
+	// receive setup payload
+	var (
+		payload    init0.Payload
+		closeSetup func() error
+	)
+	if f, err := proc.Receive(init0.Env, &payload); err != nil {
+		if errors.Is(err, proc.ErrInvalid) {
+			fmsg.Fatal("invalid config descriptor")
+		}
+		if errors.Is(err, proc.ErrNotSet) {
+			fmsg.Fatal("FORTIFY_INIT not set")
+		}
+
+		fmsg.Fatalf("cannot decode init setup payload: %v", err)
+		panic("unreachable")
 	} else {
-		// sharing stdout with parent
-		// USE WITH CAUTION
 		fmsg.SetVerbose(payload.Verbose)
+		closeSetup = f
 
 		// child does not need to see this
-		if err = os.Unsetenv(EnvInit); err != nil {
-			fmsg.Println("cannot unset", EnvInit+":", err)
+		if err = os.Unsetenv(init0.Env); err != nil {
+			fmsg.Printf("cannot unset %s: %v", init0.Env, err)
 			// not fatal
 		} else {
 			fmsg.VPrintln("received configuration")
 		}
 	}
 
-	// close config fd
-	if err := p.Close(); err != nil {
-		fmsg.Println("cannot close config fd:", err)
-		// not fatal
-	}
-
 	// die with parent
-	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, uintptr(syscall.SIGKILL), 0); errno != 0 {
-		fmsg.Fatal("prctl(PR_SET_PDEATHSIG, SIGKILL):", errno.Error())
+	if err := internal.PR_SET_PDEATHSIG__SIGKILL(); err != nil {
+		fmsg.Fatalf("prctl(PR_SET_PDEATHSIG, SIGKILL): %v", err)
 	}
 
 	cmd := exec.Command(payload.Argv0)
@@ -71,17 +85,16 @@ func doInit(fd uintptr) {
 	cmd.Args = payload.Argv
 	cmd.Env = os.Environ()
 
-	// pass wayland fd
-	if payload.WL != -1 {
-		if f := os.NewFile(uintptr(payload.WL), "wayland"); f != nil {
-			cmd.Env = append(cmd.Env, "WAYLAND_SOCKET="+strconv.Itoa(3+len(cmd.ExtraFiles)))
-			cmd.ExtraFiles = append(cmd.ExtraFiles, f)
-		}
-	}
-
 	if err := cmd.Start(); err != nil {
 		fmsg.Fatalf("cannot start %q: %v", payload.Argv0, err)
 	}
+	fmsg.Suspend()
+
+	// close setup pipe as setup is now complete
+	if err := closeSetup(); err != nil {
+		fmsg.Println("cannot close setup pipe:", err)
+		// not fatal
+	}
 
 	sig := make(chan os.Signal, 2)
 	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
@@ -122,6 +135,7 @@ func doInit(fd uintptr) {
 		close(done)
 	}()
 
+	// closed after residualProcessTimeout has elapsed after initial process death
 	timeout := make(chan struct{})
 
 	r := 2
@@ -129,9 +143,13 @@ func doInit(fd uintptr) {
 		select {
 		case s := <-sig:
 			fmsg.VPrintln("received", s.String())
+			fmsg.Resume() // output could still be withheld at this point, so resume is called
 			fmsg.Exit(0)
 		case w := <-info:
 			if w.wpid == cmd.Process.Pid {
+				// initial process exited, output is most likely available again
+				fmsg.Resume()
+
 				switch {
 				case w.wstatus.Exited():
 					r = w.wstatus.ExitStatus()
@@ -154,21 +172,3 @@ func doInit(fd uintptr) {
 		}
 	}
 }
-
-// Try runs init and stops execution if FORTIFY_INIT is set.
-func Try() {
-	if os.Getpid() != 1 {
-		return
-	}
-
-	if args := flag.Args(); len(args) == 1 && args[0] == "init" {
-		if s, ok := os.LookupEnv(EnvInit); ok {
-			if fd, err := strconv.Atoi(s); err != nil {
-				fmsg.Fatalf("cannot parse %q: %v", s, err)
-			} else {
-				doInit(uintptr(fd))
-			}
-			panic("unreachable")
-		}
-	}
-}

cmd/fshim/ipc/payload.go

@@ -0,0 +1,21 @@
+package shim0
+
+import (
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+)
+
+const Env = "FORTIFY_SHIM"
+
+type Payload struct {
+	// child full argv
+	Argv []string
+	// bwrap, target full exec path
+	Exec [2]string
+	// bwrap config
+	Bwrap *bwrap.Config
+	// sync fd
+	Sync *uintptr
+
+	// verbosity pass through
+	Verbose bool
+}

cmd/fshim/ipc/shim/shim.go

@@ -0,0 +1,137 @@
+package shim
+
+import (
+	"encoding/gob"
+	"errors"
+	"os"
+	"os/exec"
+	"os/signal"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	shim0 "git.gensokyo.uk/security/fortify/cmd/fshim/ipc"
+	"git.gensokyo.uk/security/fortify/internal"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/proc"
+)
+
+const shimSetupTimeout = 5 * time.Second
+
+// used by the parent process
+
+type Shim struct {
+	// user switcher process
+	cmd *exec.Cmd
+	// uid of shim target user
+	uid uint32
+	// string representation of application id
+	aid string
+	// string representation of supplementary group ids
+	supp []string
+	// fallback exit notifier with error returned killing the process
+	killFallback chan error
+	// shim setup payload
+	payload *shim0.Payload
+}
+
+func New(uid uint32, aid string, supp []string, payload *shim0.Payload) *Shim {
+	return &Shim{uid: uid, aid: aid, supp: supp, payload: payload}
+}
+
+func (s *Shim) String() string {
+	if s.cmd == nil {
+		return "(unused shim manager)"
+	}
+	return s.cmd.String()
+}
+
+func (s *Shim) Unwrap() *exec.Cmd {
+	return s.cmd
+}
+
+func (s *Shim) WaitFallback() chan error {
+	return s.killFallback
+}
+
+func (s *Shim) Start() (*time.Time, error) {
+	// start user switcher process and save time
+	var fsu string
+	if p, ok := internal.Check(internal.Fsu); !ok {
+		fmsg.Fatal("invalid fsu path, this copy of fshim is not compiled correctly")
+		panic("unreachable")
+	} else {
+		fsu = p
+	}
+	s.cmd = exec.Command(fsu)
+
+	var encoder *gob.Encoder
+	if fd, e, err := proc.Setup(&s.cmd.ExtraFiles); err != nil {
+		return nil, fmsg.WrapErrorSuffix(err,
+			"cannot create shim setup pipe:")
+	} else {
+		encoder = e
+		s.cmd.Env = []string{
+			shim0.Env + "=" + strconv.Itoa(fd),
+			"FORTIFY_APP_ID=" + s.aid,
+		}
+	}
+
+	if len(s.supp) > 0 {
+		fmsg.VPrintf("attaching supplementary group ids %s", s.supp)
+		s.cmd.Env = append(s.cmd.Env, "FORTIFY_GROUPS="+strings.Join(s.supp, " "))
+	}
+	s.cmd.Stdin, s.cmd.Stdout, s.cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
+	s.cmd.Dir = "/"
+
+	// pass sync fd if set
+	if s.payload.Bwrap.Sync() != nil {
+		fd := proc.ExtraFile(s.cmd, s.payload.Bwrap.Sync())
+		s.payload.Sync = &fd
+	}
+
+	fmsg.VPrintln("starting shim via fsu:", s.cmd)
+	fmsg.Suspend() // withhold messages to stderr
+	if err := s.cmd.Start(); err != nil {
+		return nil, fmsg.WrapErrorSuffix(err,
+			"cannot start fsu:")
+	}
+	startTime := time.Now().UTC()
+
+	// kill shim if something goes wrong and an error is returned
+	s.killFallback = make(chan error, 1)
+	killShim := func() {
+		if err := s.cmd.Process.Signal(os.Interrupt); err != nil {
+			s.killFallback <- err
+		}
+	}
+	defer func() { killShim() }()
+
+	// take alternative exit path on signal
+	sig := make(chan os.Signal, 2)
+	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		v := <-sig
+		fmsg.Printf("got %s after program start", v)
+		s.killFallback <- nil
+		signal.Ignore(syscall.SIGINT, syscall.SIGTERM)
+	}()
+
+	shimErr := make(chan error)
+	go func() { shimErr <- encoder.Encode(s.payload) }()
+
+	select {
+	case err := <-shimErr:
+		if err != nil {
+			return &startTime, fmsg.WrapErrorSuffix(err,
+				"cannot transmit shim config:")
+		}
+		killShim = func() {}
+	case <-time.After(shimSetupTimeout):
+		return &startTime, fmsg.WrapError(errors.New("timed out waiting for shim"),
+			"timed out waiting for shim")
+	}
+
+	return &startTime, nil
+}

cmd/fshim/main.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"errors"
+	"os"
+	"path"
+	"strconv"
+	"syscall"
+
+	init0 "git.gensokyo.uk/security/fortify/cmd/finit/ipc"
+	shim "git.gensokyo.uk/security/fortify/cmd/fshim/ipc"
+	"git.gensokyo.uk/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/internal"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/proc"
+)
+
+// everything beyond this point runs as unconstrained target user
+// proceed with caution!
+
+func main() {
+	// sharing stdout with fortify
+	// USE WITH CAUTION
+	fmsg.SetPrefix("shim")
+
+	// setting this prevents ptrace
+	if err := internal.PR_SET_DUMPABLE__SUID_DUMP_DISABLE(); err != nil {
+		fmsg.Fatalf("cannot set SUID_DUMP_DISABLE: %s", err)
+		panic("unreachable")
+	}
+
+	// re-exec
+	if len(os.Args) > 0 && (os.Args[0] != "fshim" || len(os.Args) != 1) && path.IsAbs(os.Args[0]) {
+		if err := syscall.Exec(os.Args[0], []string{"fshim"}, os.Environ()); err != nil {
+			fmsg.Println("cannot re-exec self:", err)
+			// continue anyway
+		}
+	}
+
+	// check path to finit
+	var finitPath string
+	if p, ok := internal.Path(internal.Finit); !ok {
+		fmsg.Fatal("invalid finit path, this copy of fshim is not compiled correctly")
+	} else {
+		finitPath = p
+	}
+
+	// receive setup payload
+	var (
+		payload    shim.Payload
+		closeSetup func() error
+	)
+	if f, err := proc.Receive(shim.Env, &payload); err != nil {
+		if errors.Is(err, proc.ErrInvalid) {
+			fmsg.Fatal("invalid config descriptor")
+		}
+		if errors.Is(err, proc.ErrNotSet) {
+			fmsg.Fatal("FORTIFY_SHIM not set")
+		}
+
+		fmsg.Fatalf("cannot decode shim setup payload: %v", err)
+		panic("unreachable")
+	} else {
+		fmsg.SetVerbose(payload.Verbose)
+		closeSetup = f
+	}
+
+	if payload.Bwrap == nil {
+		fmsg.Fatal("bwrap config not supplied")
+	}
+
+	// restore bwrap sync fd
+	if payload.Sync != nil {
+		payload.Bwrap.SetSync(os.NewFile(*payload.Sync, "sync"))
+	}
+
+	// close setup socket
+	if err := closeSetup(); err != nil {
+		fmsg.Println("cannot close setup pipe:", err)
+		// not fatal
+	}
+
+	var ic init0.Payload
+
+	// resolve argv0
+	ic.Argv = payload.Argv
+	if len(ic.Argv) > 0 {
+		// looked up from $PATH by parent
+		ic.Argv0 = payload.Exec[1]
+	} else {
+		// no argv, look up shell instead
+		var ok bool
+		if payload.Bwrap.SetEnv == nil {
+			fmsg.Fatal("no command was specified and environment is unset")
+		}
+		if ic.Argv0, ok = payload.Bwrap.SetEnv["SHELL"]; !ok {
+			fmsg.Fatal("no command was specified and $SHELL was unset")
+		}
+
+		ic.Argv = []string{ic.Argv0}
+	}
+
+	conf := payload.Bwrap
+
+	var extraFiles []*os.File
+
+	// serve setup payload
+	if fd, encoder, err := proc.Setup(&extraFiles); err != nil {
+		fmsg.Fatalf("cannot pipe: %v", err)
+	} else {
+		conf.SetEnv[init0.Env] = strconv.Itoa(fd)
+		go func() {
+			fmsg.VPrintln("transmitting config to init")
+			if err = encoder.Encode(&ic); err != nil {
+				fmsg.Fatalf("cannot transmit init config: %v", err)
+			}
+		}()
+	}
+
+	helper.BubblewrapName = payload.Exec[0] // resolved bwrap path by parent
+	if b, err := helper.NewBwrap(conf, nil, finitPath,
+		func(int, int) []string { return make([]string, 0) }); err != nil {
+		fmsg.Fatalf("malformed sandbox config: %v", err)
+	} else {
+		cmd := b.Unwrap()
+		cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
+		cmd.ExtraFiles = extraFiles
+
+		if fmsg.Verbose() {
+			fmsg.VPrintln("bwrap args:", conf.Args())
+		}
+
+		// run and pass through exit code
+		if err = b.Start(); err != nil {
+			fmsg.Fatalf("cannot start target process: %v", err)
+		} else if err = b.Wait(); err != nil {
+			fmsg.VPrintln("wait:", err)
+		}
+		if b.Unwrap().ProcessState != nil {
+			fmsg.Exit(b.Unwrap().ProcessState.ExitCode())
+		} else {
+			fmsg.Exit(127)
+		}
+	}
+}

cmd/fsu/main.go

@@ -1,25 +1,31 @@
 package main
 
 import (
-	"bufio"
+	"bytes"
+	"fmt"
 	"log"
 	"os"
 	"path"
+	"slices"
 	"strconv"
 	"strings"
 	"syscall"
 )
 
 const (
+	compPoison  = "INVALIDINVALIDINVALIDINVALIDINVALID"
 	fsuConfFile = "/etc/fsurc"
 	envShim     = "FORTIFY_SHIM"
 	envAID      = "FORTIFY_APP_ID"
+	envGroups   = "FORTIFY_GROUPS"
 
-	fpPoison = "INVALIDINVALIDINVALIDINVALIDINVALID"
+	PR_SET_NO_NEW_PRIVS = 0x26
 )
 
-// FortifyPath is the path to fortify, set at compile time.
-var FortifyPath = fpPoison
+var (
+	Fmain = compPoison
+	Fshim = compPoison
+)
 
 func main() {
 	log.SetFlags(0)
@@ -35,9 +41,16 @@ func main() {
 		log.Fatal("this program must not be started by root")
 	}
 
-	// validate compiled in fortify path
-	if FortifyPath == fpPoison || !path.IsAbs(FortifyPath) {
+	var fmain, fshim string
+	if p, ok := checkPath(Fmain); !ok {
 		log.Fatal("invalid fortify path, this copy of fsu is not compiled correctly")
+	} else {
+		fmain = p
+	}
+	if p, ok := checkPath(Fshim); !ok {
+		log.Fatal("invalid fshim path, this copy of fsu is not compiled correctly")
+	} else {
+		fshim = p
 	}
 
 	pexe := path.Join("/proc", strconv.Itoa(os.Getppid()), "exe")
@@ -45,7 +58,7 @@ func main() {
 		log.Fatalf("cannot read parent executable path: %v", err)
 	} else if strings.HasSuffix(p, " (deleted)") {
 		log.Fatal("fortify executable has been deleted")
-	} else if p != FortifyPath {
+	} else if p != fmain {
 		log.Fatal("this program must be started by fortify")
 	}
 
@@ -61,80 +74,81 @@ func main() {
 		uid += fid * 10000
 	}
 
-	// pass through setup path to shim
-	var shimSetupPath string
-	if s, ok := os.LookupEnv(envShim); !ok {
-		log.Fatal("FORTIFY_SHIM not set")
-	} else if !path.IsAbs(s) {
-		log.Fatal("FORTIFY_SHIM is not absolute")
-	} else {
-		shimSetupPath = s
-	}
-
 	// allowed aid range 0 to 9999
 	if as, ok := os.LookupEnv(envAID); !ok {
 		log.Fatal("FORTIFY_APP_ID not set")
-	} else if aid, err := strconv.Atoi(as); err != nil || aid < 0 || aid > 9999 {
+	} else if aid, err := parseUint32Fast(as); err != nil || aid < 0 || aid > 9999 {
 		log.Fatal("invalid aid")
 	} else {
 		uid += aid
 	}
 
+	// pass through setup fd to shim
+	var shimSetupFd string
+	if s, ok := os.LookupEnv(envShim); !ok {
+		// fortify requests target uid
+		// print resolved uid and exit
+		fmt.Print(uid)
+		os.Exit(0)
+	} else if len(s) != 1 || s[0] > '9' || s[0] < '3' {
+		log.Fatal("FORTIFY_SHIM holds an invalid value")
+	} else {
+		shimSetupFd = s
+	}
+
+	// supplementary groups
+	var suppGroups, suppCurrent []int
+
+	if gs, ok := os.LookupEnv(envGroups); ok {
+		if cur, err := os.Getgroups(); err != nil {
+			log.Fatalf("cannot get groups: %v", err)
+		} else {
+			suppCurrent = cur
+		}
+
+		// parse space-separated list of group ids
+		gss := bytes.Split([]byte(gs), []byte{' '})
+		suppGroups = make([]int, len(gss)+1)
+		for i, s := range gss {
+			if gid, err := strconv.Atoi(string(s)); err != nil {
+				log.Fatalf("cannot parse %q: %v", string(s), err)
+			} else if gid > 0 && gid != uid && gid != os.Getgid() && slices.Contains(suppCurrent, gid) {
+				suppGroups[i] = gid
+			} else {
+				log.Fatalf("invalid gid %d", gid)
+			}
+		}
+		suppGroups[len(suppGroups)-1] = uid
+	} else {
+		suppGroups = []int{uid}
+	}
+
+	// final bounds check to catch any bugs
+	if uid < 1000000 || uid >= 2000000 {
+		panic("uid out of bounds")
+	}
+
+	// careful! users in the allowlist is effectively allowed to drop groups via fsu
+
 	if err := syscall.Setresgid(uid, uid, uid); err != nil {
 		log.Fatalf("cannot set gid: %v", err)
 	}
+	if err := syscall.Setgroups(suppGroups); err != nil {
+		log.Fatalf("cannot set supplementary groups: %v", err)
+	}
 	if err := syscall.Setresuid(uid, uid, uid); err != nil {
 		log.Fatalf("cannot set uid: %v", err)
 	}
-	if err := syscall.Exec(FortifyPath, []string{"fortify", "shim"}, []string{envShim + "=" + shimSetupPath}); err != nil {
+	if _, _, errno := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, PR_SET_NO_NEW_PRIVS, 1, 0); errno != 0 {
+		log.Fatalf("cannot set no_new_privs flag: %s", errno.Error())
+	}
+	if err := syscall.Exec(fshim, []string{"fshim"}, []string{envShim + "=" + shimSetupFd}); err != nil {
 		log.Fatalf("cannot start shim: %v", err)
 	}
 
 	panic("unreachable")
 }
 
-func parseConfig(p string, puid int) (fid int, ok bool) {
-	// refuse to run if fsurc is not protected correctly
-	if s, err := os.Stat(p); err != nil {
-		log.Fatal(err)
-	} else if s.Mode().Perm() != 0400 {
-		log.Fatal("bad fsurc perm")
-	} else if st := s.Sys().(*syscall.Stat_t); st.Uid != 0 || st.Gid != 0 {
-		log.Fatal("fsurc must be owned by uid 0")
-	}
-
-	if r, err := os.Open(p); err != nil {
-		log.Fatal(err)
-		return -1, false
-	} else {
-		s := bufio.NewScanner(r)
-		var line int
-		for s.Scan() {
-			line++
-
-			// <puid> <fid>
-			lf := strings.SplitN(s.Text(), " ", 2)
-			if len(lf) != 2 {
-				log.Fatalf("invalid entry on line %d", line)
-			}
-
-			var puid0 int
-			if puid0, err = strconv.Atoi(lf[0]); err != nil || puid0 < 1 {
-				log.Fatalf("invalid parent uid on line %d", line)
-			}
-
-			ok = puid0 == puid
-			if ok {
-				// allowed fid range 0 to 99
-				if fid, err = strconv.Atoi(lf[1]); err != nil || fid < 0 || fid > 99 {
-					log.Fatalf("invalid fortify uid on line %d", line)
-				}
-				return
-			}
-		}
-		if err = s.Err(); err != nil {
-			log.Fatalf("cannot read fsurc: %v", err)
-		}
-		return -1, false
-	}
+func checkPath(p string) (string, bool) {
+	return p, p != compPoison && p != "" && path.IsAbs(p)
 }

cmd/fsu/parse.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"syscall"
+)
+
+func parseUint32Fast(s string) (int, error) {
+	sLen := len(s)
+	if sLen < 1 {
+		return -1, errors.New("zero length string")
+	}
+	if sLen > 10 {
+		return -1, errors.New("string too long")
+	}
+
+	n := 0
+	for i, ch := range []byte(s) {
+		ch -= '0'
+		if ch > 9 {
+			return -1, fmt.Errorf("invalid character '%s' at index %d", string([]byte{ch}), i)
+		}
+		n = n*10 + int(ch)
+	}
+	return n, nil
+}
+
+func parseConfig(p string, puid int) (fid int, ok bool) {
+	// refuse to run if fsurc is not protected correctly
+	if s, err := os.Stat(p); err != nil {
+		log.Fatal(err)
+	} else if s.Mode().Perm() != 0400 {
+		log.Fatal("bad fsurc perm")
+	} else if st := s.Sys().(*syscall.Stat_t); st.Uid != 0 || st.Gid != 0 {
+		log.Fatal("fsurc must be owned by uid 0")
+	}
+
+	if r, err := os.Open(p); err != nil {
+		log.Fatal(err)
+		return -1, false
+	} else {
+		s := bufio.NewScanner(r)
+		var line int
+		for s.Scan() {
+			line++
+
+			// <puid> <fid>
+			lf := strings.SplitN(s.Text(), " ", 2)
+			if len(lf) != 2 {
+				log.Fatalf("invalid entry on line %d", line)
+			}
+
+			var puid0 int
+			if puid0, err = parseUint32Fast(lf[0]); err != nil || puid0 < 1 {
+				log.Fatalf("invalid parent uid on line %d", line)
+			}
+
+			ok = puid0 == puid
+			if ok {
+				// allowed fid range 0 to 99
+				if fid, err = parseUint32Fast(lf[1]); err != nil || fid < 0 || fid > 99 {
+					log.Fatalf("invalid fortify uid on line %d", line)
+				}
+				return
+			}
+		}
+		if err = s.Err(); err != nil {
+			log.Fatalf("cannot read fsurc: %v", err)
+		}
+		return -1, false
+	}
+}

cmd/fuserdb/main.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"bytes"
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+	"path"
+	"strconv"
+
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+)
+
+func main() {
+	fmsg.SetPrefix("fuserdb")
+
+	const varEmpty = "/var/empty"
+
+	out := flag.String("o", "userdb", "output directory")
+	homeDir := flag.String("d", varEmpty, "parent of home directories")
+	shell := flag.String("s", "/sbin/nologin", "absolute path to subordinate user shell")
+	flag.Parse()
+
+	type user struct {
+		name string
+		fid  int
+	}
+
+	users := make([]user, len(flag.Args()))
+	for i, s := range flag.Args() {
+		f := bytes.SplitN([]byte(s), []byte{':'}, 2)
+		if len(f) != 2 {
+			fmsg.Fatalf("invalid entry at index %d", i)
+		}
+		users[i].name = string(f[0])
+		if fid, err := strconv.Atoi(string(f[1])); err != nil {
+			fmsg.Fatal(err.Error())
+		} else {
+			users[i].fid = fid
+		}
+	}
+
+	if err := os.MkdirAll(*out, 0755); err != nil && !errors.Is(err, os.ErrExist) {
+		fmsg.Fatalf("cannot create output: %v", err)
+	}
+
+	for _, u := range users {
+		fidString := strconv.Itoa(u.fid)
+		for aid := 0; aid < 10000; aid++ {
+			userName := fmt.Sprintf("u%d_a%d", u.fid, aid)
+			uid := 1000000 + u.fid*10000 + aid
+			us := strconv.Itoa(uid)
+			realName := fmt.Sprintf("Fortify subordinate user %d (%s)", aid, u.name)
+			var homeDirectory string
+			if *homeDir != varEmpty {
+				homeDirectory = path.Join(*homeDir, "u"+fidString, "a"+strconv.Itoa(aid))
+			} else {
+				homeDirectory = varEmpty
+			}
+
+			writeUser(userName, uid, us, realName, homeDirectory, *shell, *out)
+			writeGroup(userName, uid, us, nil, *out)
+		}
+	}
+
+	fmsg.Printf("created %d entries", len(users)*2*10000)
+	fmsg.Exit(0)
+}

cmd/fuserdb/payload.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"path"
+
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+)
+
+type payloadU struct {
+	UserName      string   `json:"userName"`
+	Uid           int      `json:"uid"`
+	Gid           int      `json:"gid"`
+	MemberOf      []string `json:"memberOf,omitempty"`
+	RealName      string   `json:"realName"`
+	HomeDirectory string   `json:"homeDirectory"`
+	Shell         string   `json:"shell"`
+}
+
+func writeUser(userName string, uid int, us string, realName, homeDirectory, shell string, out string) {
+	userFileName := userName + ".user"
+	if f, err := os.OpenFile(path.Join(out, userFileName), os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644); err != nil {
+		fmsg.Fatalf("cannot create %s: %v", userName, err)
+	} else if err = json.NewEncoder(f).Encode(&payloadU{
+		UserName:      userName,
+		Uid:           uid,
+		Gid:           uid,
+		RealName:      realName,
+		HomeDirectory: homeDirectory,
+		Shell:         shell,
+	}); err != nil {
+		fmsg.Fatalf("cannot serialise %s: %v", userName, err)
+	} else if err = f.Close(); err != nil {
+		fmsg.Printf("cannot close %s: %v", userName, err)
+	}
+	if err := os.Symlink(userFileName, path.Join(out, us+".user")); err != nil {
+		fmsg.Fatalf("cannot link %s: %v", userName, err)
+	}
+}
+
+type payloadG struct {
+	GroupName string   `json:"groupName"`
+	Gid       int      `json:"gid"`
+	Members   []string `json:"members,omitempty"`
+}
+
+func writeGroup(groupName string, gid int, gs string, members []string, out string) {
+	groupFileName := groupName + ".group"
+	if f, err := os.OpenFile(path.Join(out, groupFileName), os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644); err != nil {
+		fmsg.Fatalf("cannot create %s: %v", groupName, err)
+	} else if err = json.NewEncoder(f).Encode(&payloadG{
+		GroupName: groupName,
+		Gid:       gid,
+		Members:   members,
+	}); err != nil {
+		fmsg.Fatalf("cannot serialise %s: %v", groupName, err)
+	} else if err = f.Close(); err != nil {
+		fmsg.Printf("cannot close %s: %v", groupName, err)
+	}
+	if err := os.Symlink(groupFileName, path.Join(out, gs+".group")); err != nil {
+		fmsg.Fatalf("cannot link %s: %v", groupName, err)
+	}
+}

comp/_fortify

@@ -0,0 +1,51 @@
+#compdef fortify
+
+_fortify_app() {
+  _path_files -g "*.(json|ftfy)"
+}
+
+_fortify_run() {
+  _arguments \
+    '--id[App ID, leave empty to disable security context app_id]:id' \
+    '-a[Fortify application ID]: :_numbers' \
+    '-g[Groups inherited by the app process]: :_groups' \
+    '-d[Application home directory]: :_files -/' \
+    '-u[Passwd name within sandbox]: :_users' \
+    '--wayland[Share Wayland socket]' \
+    '-X[Share X11 socket and allow connection]' \
+    '--dbus[Proxy D-Bus connection]' \
+    '--pulse[Share PulseAudio socket and cookie]' \
+    '--dbus-config[Path to D-Bus proxy config file]: :_files -g "*.json"' \
+    '--dbus-system[Path to system D-Bus proxy config file]: :_files -g "*.json"' \
+    '--mpris[Allow owning MPRIS D-Bus path]' \
+    '--dbus-log[Force logging in the D-Bus proxy]'
+}
+
+(( $+functions[_fortify_commands] )) || _fortify_commands()
+{
+  local -a _fortify_cmds
+  _fortify_cmds=(
+    "app:Launch app defined by the specified config file"
+    "run:Configure and start a permissive default sandbox"
+    "ps:List active apps and their state"
+    "version:Show fortify version"
+    "license:Show full license text"
+    "template:Produce a config template"
+    "help:Show help message"
+  )
+  if (( CURRENT == 1 )); then
+    _describe -t commands 'fortify command' _fortify_cmds || compadd "$@"
+  else
+    local curcontext="$curcontext"
+    cmd="${${_fortify_cmds[(r)$words[1]:*]%%:*}}"
+    if (( $+functions[_fortify_$cmd] )); then
+      _fortify_$cmd
+    else
+      _message "no more options"
+    fi
+  fi
+}
+
+_arguments -C \
+  '-v[Verbose output]' \
+  '*::fortify command:_fortify_commands'

config.go

@@ -1,135 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"flag"
-	"fmt"
-
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/internal/app"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/system"
-)
-
-var (
-	printTemplate bool
-
-	confPath string
-
-	dbusConfigSession string
-	dbusConfigSystem  string
-	dbusID            string
-	mpris             bool
-	dbusVerbose       bool
-
-	userName    string
-	enablements [system.ELen]bool
-
-	launchMethodText string
-)
-
-func init() {
-	flag.BoolVar(&printTemplate, "template", false, "Print a full config template and exit")
-
-	// config file, disables every other flag here
-	flag.StringVar(&confPath, "c", "nil", "Path to full app configuration, or \"nil\" to configure from flags")
-
-	flag.StringVar(&dbusConfigSession, "dbus-config", "builtin", "Path to D-Bus proxy config file, or \"builtin\" for defaults")
-	flag.StringVar(&dbusConfigSystem, "dbus-system", "nil", "Path to system D-Bus proxy config file, or \"nil\" to disable")
-	flag.StringVar(&dbusID, "dbus-id", "", "D-Bus ID of application, leave empty to disable own paths, has no effect if custom config is available")
-	flag.BoolVar(&mpris, "mpris", false, "Allow owning MPRIS D-Bus path, has no effect if custom config is available")
-	flag.BoolVar(&dbusVerbose, "dbus-log", false, "Force logging in the D-Bus proxy")
-
-	flag.StringVar(&userName, "u", "chronos", "Passwd name of user to run as")
-	flag.BoolVar(&enablements[system.EWayland], "wayland", false, "Share Wayland socket")
-	flag.BoolVar(&enablements[system.EX11], "X", false, "Share X11 socket and allow connection")
-	flag.BoolVar(&enablements[system.EDBus], "dbus", false, "Proxy D-Bus connection")
-	flag.BoolVar(&enablements[system.EPulse], "pulse", false, "Share PulseAudio socket and cookie")
-}
-
-func init() {
-	methodHelpString := "Method of launching the child process, can be one of \"sudo\""
-	if os.SdBooted() {
-		methodHelpString += ", \"systemd\""
-	}
-
-	flag.StringVar(&launchMethodText, "method", "sudo", methodHelpString)
-}
-
-func tryTemplate() {
-	if printTemplate {
-		if s, err := json.MarshalIndent(app.Template(), "", "  "); err != nil {
-			fmsg.Fatalf("cannot generate template: %v", err)
-			panic("unreachable")
-		} else {
-			fmt.Println(string(s))
-		}
-		fmsg.Exit(0)
-	}
-}
-
-func loadConfig() *app.Config {
-	if confPath == "nil" {
-		// config from flags
-		return configFromFlags()
-	} else {
-		// config from file
-		c := new(app.Config)
-		if f, err := os.Open(confPath); err != nil {
-			fmsg.Fatalf("cannot access config file %q: %s", confPath, err)
-			panic("unreachable")
-		} else if err = json.NewDecoder(f).Decode(&c); err != nil {
-			fmsg.Fatalf("cannot parse config file %q: %s", confPath, err)
-			panic("unreachable")
-		} else {
-			return c
-		}
-	}
-}
-
-func configFromFlags() (config *app.Config) {
-	// initialise config from flags
-	config = &app.Config{
-		ID:      dbusID,
-		User:    userName,
-		Command: flag.Args(),
-		Method:  launchMethodText,
-	}
-
-	// enablements from flags
-	for i := system.Enablement(0); i < system.Enablement(system.ELen); i++ {
-		if enablements[i] {
-			config.Confinement.Enablements.Set(i)
-		}
-	}
-
-	// parse D-Bus config file from flags if applicable
-	if enablements[system.EDBus] {
-		if dbusConfigSession == "builtin" {
-			config.Confinement.SessionBus = dbus.NewConfig(dbusID, true, mpris)
-		} else {
-			if c, err := dbus.NewConfigFromFile(dbusConfigSession); err != nil {
-				fmsg.Fatalf("cannot load session bus proxy config from %q: %s", dbusConfigSession, err)
-			} else {
-				config.Confinement.SessionBus = c
-			}
-		}
-
-		// system bus proxy is optional
-		if dbusConfigSystem != "nil" {
-			if c, err := dbus.NewConfigFromFile(dbusConfigSystem); err != nil {
-				fmsg.Fatalf("cannot load system bus proxy config from %q: %s", dbusConfigSystem, err)
-			} else {
-				config.Confinement.SystemBus = c
-			}
-		}
-
-		// override log from configuration
-		if dbusVerbose {
-			config.Confinement.SessionBus.Log = true
-			config.Confinement.SystemBus.Log = true
-		}
-	}
-
-	return
-}

dbus/config_test.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/dbus"
 )
 
 func TestConfig_Args(t *testing.T) {

dbus/dbus.go

@@ -1,3 +1,4 @@
+// Package dbus wraps xdg-dbus-proxy and implements configuration and sandboxing of the underlying helper process.
 package dbus
 
 import (

dbus/dbus_test.go

@@ -5,8 +5,8 @@ import (
 	"strings"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/helper"
 )
 
 func TestNew(t *testing.T) {

dbus/proxy.go

@@ -6,8 +6,8 @@ import (
 	"io"
 	"sync"
 
-	"git.ophivana.moe/security/fortify/helper"
-	"git.ophivana.moe/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
 )
 
 // ProxyName is the file name or path to the proxy program.

dbus/run.go

@@ -9,9 +9,9 @@ import (
 	"strconv"
 	"strings"
 
-	"git.ophivana.moe/security/fortify/helper"
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/ldd"
+	"git.gensokyo.uk/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/ldd"
 )
 
 // Start launches the D-Bus proxy and sets up the Wait method.

dbus/samples_test.go

@@ -3,7 +3,7 @@ package dbus_test
 import (
 	"sync"
 
-	"git.ophivana.moe/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/dbus"
 )
 
 var samples = []dbusTestCase{

dbus/stub_test.go

@@ -3,7 +3,7 @@ package dbus_test
 import (
 	"testing"
 
-	"git.ophivana.moe/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper"
 )
 
 func TestHelperChildStub(t *testing.T) {

dist/fsurc.default

@@ -0,0 +1 @@
+1000 0

dist/install.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+cd "$(dirname -- "$0")" || exit 1
+
+install -vDm0755 "bin/fortify" "${FORTIFY_INSTALL_PREFIX}/usr/bin/fortify"
+install -vDm0755 "bin/fshim" "${FORTIFY_INSTALL_PREFIX}/usr/libexec/fortify/fshim"
+install -vDm0755 "bin/finit" "${FORTIFY_INSTALL_PREFIX}/usr/libexec/fortify/finit"
+install -vDm0755 "bin/fuserdb" "${FORTIFY_INSTALL_PREFIX}/usr/libexec/fortify/fuserdb"
+
+install -vDm6511 "bin/fsu" "${FORTIFY_INSTALL_PREFIX}/usr/bin/fsu"
+install -vDm0400 "fsurc.default" "${FORTIFY_INSTALL_PREFIX}/etc/fsurc"

dist/release.sh

@@ -0,0 +1,19 @@
+#!/bin/sh -e
+cd "$(dirname -- "$0")/.."
+VERSION="${FORTIFY_VERSION:-untagged}"
+pname="fortify-${VERSION}"
+out="dist/${pname}"
+
+mkdir -p "${out}"
+cp "README.md" "dist/fsurc.default" "dist/install.sh" "${out}"
+
+go build -v -o "${out}/bin/" -ldflags "-s -w
+  -X git.gensokyo.uk/security/fortify/internal.Version=${VERSION}
+  -X git.gensokyo.uk/security/fortify/internal.Fsu=/usr/bin/fsu
+  -X git.gensokyo.uk/security/fortify/internal.Finit=/usr/libexec/fortify/finit
+  -X main.Fmain=/usr/bin/fortify
+  -X main.Fshim=/usr/libexec/fortify/fshim" ./...
+
+rm -f "./${out}.tar.gz" && tar -C dist -czf "${out}.tar.gz" "${pname}"
+rm -rf "./${out}"
+sha512sum "${out}.tar.gz" > "${out}.tar.gz.sha512"

error.go

@@ -3,8 +3,8 @@ package main
 import (
 	"errors"
 
-	"git.ophivana.moe/security/fortify/internal/app"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 func logWaitError(err error) {

flake.lock

@@ -1,23 +1,45 @@
 {
   "nodes": {
+    "home-manager": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1733951536,
+        "narHash": "sha256-Zb5ZCa7Xj+0gy5XVXINTSr71fCfAv+IKtmIXNrykT54=",
+        "owner": "nix-community",
+        "repo": "home-manager",
+        "rev": "1318c3f3b068cdcea922fa7c1a0a1f0c96c22f5f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "ref": "release-24.11",
+        "repo": "home-manager",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1725361206,
-        "narHash": "sha256-/HTUg+kMaqBPGrcQBYboAMsQHIWIkuKRDldss/035Hc=",
+        "lastModified": 1734298236,
+        "narHash": "sha256-aWhhqY44xBjMoO9r5fyPp5u8tqUNWRZ/m/P+abMSs5c=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "2830c7c930311397d94c0b86a359c865c081c875",
+        "rev": "eb919d9300b6a18f8583f58aef16db458fbd7bec",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-unstable-small",
+        "ref": "nixos-24.11-small",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
+        "home-manager": "home-manager",
         "nixpkgs": "nixpkgs"
       }
     }

flake.nix

@@ -2,11 +2,20 @@
   description = "fortify sandbox tool and nixos module";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable-small";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11-small";
+
+    home-manager = {
+      url = "github:nix-community/home-manager/release-24.11";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs =
-    { self, nixpkgs }:
+    {
+      self,
+      nixpkgs,
+      home-manager,
+    }:
     let
       supportedSystems = [
         "aarch64-linux"
@@ -20,6 +29,55 @@
     {
       nixosModules.fortify = import ./nixos.nix;
 
+      checks = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgsFor.${system};
+
+          inherit (pkgs)
+            runCommandLocal
+            callPackage
+            nixfmt-rfc-style
+            deadnix
+            statix
+            ;
+        in
+        {
+          check-formatting =
+            runCommandLocal "check-formatting" { nativeBuildInputs = [ nixfmt-rfc-style ]; }
+              ''
+                cd ${./.}
+
+                echo "running nixfmt..."
+                nixfmt --check .
+
+                touch $out
+              '';
+
+          check-lint =
+            runCommandLocal "check-lint"
+              {
+                nativeBuildInputs = [
+                  deadnix
+                  statix
+                ];
+              }
+              ''
+                cd ${./.}
+
+                echo "running deadnix..."
+                deadnix --fail
+
+                echo "running statix..."
+                statix check .
+
+                touch $out
+              '';
+
+          nixos-tests = callPackage ./test.nix { inherit system self home-manager; };
+        }
+      );
+
       packages = forAllSystems (
         system:
         let
@@ -37,11 +95,58 @@
           buildInputs = with nixpkgsFor.${system}; self.packages.${system}.fortify.buildInputs;
         };
 
+        fhs = nixpkgsFor.${system}.buildFHSEnv {
+          pname = "fortify-fhs";
+          inherit (self.packages.${system}.fortify) version;
+          targetPkgs =
+            pkgs: with pkgs; [
+              go
+              gcc
+              pkg-config
+              acl
+              wayland
+              wayland-scanner
+              wayland-protocols
+              xorg.libxcb
+            ];
+          extraOutputsToInstall = [ "dev" ];
+          profile = ''
+            export PKG_CONFIG_PATH="/usr/share/pkgconfig:$PKG_CONFIG_PATH"
+          '';
+        };
+
         withPackage = nixpkgsFor.${system}.mkShell {
           buildInputs =
             with nixpkgsFor.${system};
             self.packages.${system}.fortify.buildInputs ++ [ self.packages.${system}.fortify ];
         };
+
+        generateDoc =
+          let
+            pkgs = nixpkgsFor.${system};
+            inherit (pkgs) lib;
+
+            doc =
+              let
+                eval = lib.evalModules {
+                  specialArgs = {
+                    inherit pkgs;
+                  };
+                  modules = [ ./options.nix ];
+                };
+                cleanEval = lib.filterAttrsRecursive (n: _: n != "_module") eval;
+              in
+              pkgs.nixosOptionsDoc { inherit (cleanEval) options; };
+            docText = pkgs.runCommand "fortify-module-docs.md" { } ''
+              cat ${doc.optionsCommonMark} > $out
+              sed -i '/*Declared by:*/,+1 d' $out
+            '';
+          in
+          nixpkgsFor.${system}.mkShell {
+            shellHook = ''
+              exec cat ${docText} > options.md
+            '';
+          };
       });
     };
 }

fst/config.go

@@ -1,23 +1,22 @@
-package app
+package fst
 
 import (
-	"os"
+	"errors"
 
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
+const fTmp = "/fortify"
+
 // Config is used to seal an *App
 type Config struct {
 	// D-Bus application ID
 	ID string `json:"id"`
-	// username of the target user to switch to
-	User string `json:"user"`
 	// value passed through to the child process as its argv
 	Command []string `json:"command"`
-	// string representation of the child's launch method
-	Method string `json:"method"`
 
 	// child confinement configuration
 	Confinement ConfinementConfig `json:"confinement"`
@@ -25,6 +24,16 @@ type Config struct {
 
 // ConfinementConfig defines fortified child's confinement
 type ConfinementConfig struct {
+	// numerical application id, determines uid in the init namespace
+	AppID int `json:"app_id"`
+	// list of supplementary groups to inherit
+	Groups []string `json:"groups"`
+	// passwd username in the sandbox, defaults to chronos
+	Username string `json:"username,omitempty"`
+	// home directory in sandbox, empty for outer
+	Inner string `json:"home_inner"`
+	// home directory in init namespace
+	Outer string `json:"home"`
 	// bwrap sandbox confinement configuration
 	Sandbox *SandboxConfig `json:"sandbox"`
 
@@ -47,10 +56,14 @@ type SandboxConfig struct {
 	UserNS bool `json:"userns,omitempty"`
 	// share net namespace
 	Net bool `json:"net,omitempty"`
+	// share all devices
+	Dev bool `json:"dev,omitempty"`
 	// do not run in new session
 	NoNewSession bool `json:"no_new_session,omitempty"`
-	// mediated access to wayland socket
-	Wayland bool `json:"wayland,omitempty"`
+	// map target user uid to privileged user uid in the user namespace
+	MapRealUID bool `json:"map_real_uid"`
+	// direct access to wayland socket
+	DirectWayland bool `json:"direct_wayland,omitempty"`
 
 	// final environment variables
 	Env map[string]string `json:"env"`
@@ -58,6 +71,8 @@ type SandboxConfig struct {
 	Filesystem []*FilesystemConfig `json:"filesystem"`
 	// symlinks created inside the sandbox
 	Link [][2]string `json:"symlink"`
+	// automatically set up /etc symlinks
+	AutoEtc bool `json:"auto_etc"`
 	// paths to override by mounting tmpfs over them
 	Override []string `json:"override"`
 }
@@ -77,9 +92,16 @@ type FilesystemConfig struct {
 
 // Bwrap returns the address of the corresponding bwrap.Config to s.
 // Note that remaining tmpfs entries must be queued by the caller prior to launch.
-func (s *SandboxConfig) Bwrap() *bwrap.Config {
+func (s *SandboxConfig) Bwrap(os linux.System) (*bwrap.Config, error) {
 	if s == nil {
-		return nil
+		return nil, errors.New("nil sandbox config")
+	}
+
+	var uid int
+	if !s.MapRealUID {
+		uid = 65534
+	} else {
+		uid = os.Geteuid()
 	}
 
 	conf := (&bwrap.Config{
@@ -93,11 +115,21 @@ func (s *SandboxConfig) Bwrap() *bwrap.Config {
 		AsInit:        true,
 
 		// initialise map
-		Chmod: make(map[string]os.FileMode),
+		Chmod: make(bwrap.ChmodConfig),
 	}).
-		SetUID(65534).SetGID(65534).
-		Procfs("/proc").DevTmpfs("/dev").Mqueue("/dev/mqueue").
-		Tmpfs("/dev/fortify", 4*1024)
+		SetUID(uid).SetGID(uid).
+		Procfs("/proc").
+		Tmpfs(fTmp, 4*1024)
+
+	if !s.Dev {
+		conf.DevTmpfs("/dev").Mqueue("/dev/mqueue")
+	} else {
+		conf.Bind("/dev", "/dev", false, true, true)
+	}
+
+	if !s.AutoEtc {
+		conf.Dir("/etc")
+	}
 
 	for _, c := range s.Filesystem {
 		if c == nil {
@@ -115,14 +147,35 @@ func (s *SandboxConfig) Bwrap() *bwrap.Config {
 		conf.Symlink(l[0], l[1])
 	}
 
-	return conf
+	if s.AutoEtc {
+		conf.Bind("/etc", fTmp+"/etc")
+
+		// link host /etc contents to prevent passwd/group from being overwritten
+		if d, err := os.ReadDir("/etc"); err != nil {
+			return nil, err
+		} else {
+			for _, ent := range d {
+				name := ent.Name()
+				switch name {
+				case "passwd":
+				case "group":
+
+				case "mtab":
+					conf.Symlink("/proc/mounts", "/etc/"+name)
+				default:
+					conf.Symlink(fTmp+"/etc/"+name, "/etc/"+name)
+				}
+			}
+		}
+	}
+
+	return conf, nil
 }
 
 // Template returns a fully populated instance of Config.
 func Template() *Config {
 	return &Config{
-		ID:   "org.chromium.Chromium",
-		User: "chronos",
+		ID: "org.chromium.Chromium",
 		Command: []string{
 			"chromium",
 			"--ignore-gpu-blocklist",
@@ -130,14 +183,20 @@ func Template() *Config {
 			"--enable-features=UseOzonePlatform",
 			"--ozone-platform=wayland",
 		},
-		Method: "sudo",
 		Confinement: ConfinementConfig{
+			AppID:    9,
+			Groups:   []string{"video"},
+			Username: "chronos",
+			Outer:    "/var/lib/persist/home/org.chromium.Chromium",
+			Inner:    "/var/lib/fortify",
 			Sandbox: &SandboxConfig{
-				Hostname:     "localhost",
-				UserNS:       true,
-				Net:          true,
-				NoNewSession: true,
-				Wayland:      false,
+				Hostname:      "localhost",
+				UserNS:        true,
+				Net:           true,
+				NoNewSession:  true,
+				MapRealUID:    true,
+				Dev:           true,
+				DirectWayland: false,
 				// example API credentials pulled from Google Chrome
 				// DO NOT USE THESE IN A REAL BROWSER
 				Env: map[string]string{
@@ -146,12 +205,15 @@ func Template() *Config {
 					"GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT",
 				},
 				Filesystem: []*FilesystemConfig{
-					{Src: "/nix"},
-					{Src: "/storage/emulated/0", Write: true, Must: true},
-					{Src: "/data/user/0", Dst: "/data/data", Write: true, Must: true},
-					{Src: "/var/tmp", Write: true},
+					{Src: "/nix/store"},
+					{Src: "/run/current-system"},
+					{Src: "/run/opengl-driver"},
+					{Src: "/var/db/nix-channels"},
+					{Src: "/home/chronos", Write: true, Must: true},
+					{Src: "/dev/dri", Device: true},
 				},
-				Link:     [][2]string{{"/dev/fortify/etc", "/etc"}},
+				Link:     [][2]string{{"/run/user/65534", "/run/user/150"}},
+				AutoEtc:  true,
 				Override: []string{"/var/run/nscd"},
 			},
 			SystemBus: &dbus.Config{

fst/id.go

@@ -0,0 +1,48 @@
+package fst
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"errors"
+	"fmt"
+)
+
+type ID [16]byte
+
+var (
+	ErrInvalidLength = errors.New("string representation must have a length of 32")
+)
+
+func (a *ID) String() string {
+	return hex.EncodeToString(a[:])
+}
+
+func NewAppID(id *ID) error {
+	_, err := rand.Read(id[:])
+	return err
+}
+
+func ParseAppID(id *ID, s string) error {
+	if len(s) != 32 {
+		return ErrInvalidLength
+	}
+
+	for i, b := range s {
+		if b < '0' || b > 'f' {
+			return fmt.Errorf("invalid char %q at byte %d", b, i)
+		}
+
+		v := uint8(b)
+		if v > '9' {
+			v = 10 + v - 'a'
+		} else {
+			v -= '0'
+		}
+		if i%2 == 0 {
+			v <<= 4
+		}
+		id[i/2] += v
+	}
+
+	return nil
+}

fst/id_test.go

@@ -0,0 +1,63 @@
+package fst_test
+
+import (
+	"errors"
+	"testing"
+
+	"git.gensokyo.uk/security/fortify/fst"
+)
+
+func TestParseAppID(t *testing.T) {
+	t.Run("bad length", func(t *testing.T) {
+		if err := fst.ParseAppID(new(fst.ID), "meow"); !errors.Is(err, fst.ErrInvalidLength) {
+			t.Errorf("ParseAppID: error = %v, wantErr =  %v", err, fst.ErrInvalidLength)
+		}
+	})
+
+	t.Run("bad byte", func(t *testing.T) {
+		wantErr := "invalid char '\\n' at byte 15"
+		if err := fst.ParseAppID(new(fst.ID), "02bc7f8936b2af6\n\ne2535cd71ef0bb7"); err == nil || err.Error() != wantErr {
+			t.Errorf("ParseAppID: error = %v, wantErr =  %v", err, wantErr)
+		}
+	})
+
+	t.Run("fuzz 16 iterations", func(t *testing.T) {
+		for i := 0; i < 16; i++ {
+			testParseAppIDWithRandom(t)
+		}
+	})
+}
+
+func FuzzParseAppID(f *testing.F) {
+	for i := 0; i < 16; i++ {
+		id := new(fst.ID)
+		if err := fst.NewAppID(id); err != nil {
+			panic(err.Error())
+		}
+		f.Add(id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7], id[8], id[9], id[10], id[11], id[12], id[13], id[14], id[15])
+	}
+
+	f.Fuzz(func(t *testing.T, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15 byte) {
+		testParseAppID(t, &fst.ID{b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15})
+	})
+}
+
+func testParseAppIDWithRandom(t *testing.T) {
+	id := new(fst.ID)
+	if err := fst.NewAppID(id); err != nil {
+		t.Fatalf("cannot generate app ID: %v", err)
+	}
+	testParseAppID(t, id)
+}
+
+func testParseAppID(t *testing.T, id *fst.ID) {
+	s := id.String()
+	got := new(fst.ID)
+	if err := fst.ParseAppID(got, s); err != nil {
+		t.Fatalf("cannot parse app ID: %v", err)
+	}
+
+	if *got != *id {
+		t.Fatalf("ParseAppID(%#v) = \n%#v, want \n%#v", s, got, id)
+	}
+}

fst/shared.go

@@ -0,0 +1,2 @@
+// Package fst exports shared fortify types.
+package fst

go.mod

@@ -1,3 +1,3 @@
-module git.ophivana.moe/security/fortify
+module git.gensokyo.uk/security/fortify
 
 go 1.22

helper/args_test.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper"
 )
 
 func Test_argsFD_String(t *testing.T) {

helper/bwrap.go

@@ -3,11 +3,13 @@ package helper
 import (
 	"errors"
 	"io"
+	"os"
 	"os/exec"
 	"strconv"
 	"sync"
 
-	"git.ophivana.moe/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/proc"
 )
 
 // BubblewrapName is the file name or path to bubblewrap.
@@ -19,6 +21,8 @@ type bubblewrap struct {
 
 	// bwrap pipes
 	p *pipes
+	// sync pipe
+	sync *os.File
 	// returns an array of arguments passed directly
 	// to the child process spawned by bwrap
 	argF func(argsFD, statFD int) []string
@@ -72,6 +76,10 @@ func (b *bubblewrap) StartNotify(ready chan error) error {
 		b.Cmd.Env = append(b.Cmd.Env, FortifyHelper+"=1", FortifyStatus+"=-1")
 	}
 
+	if b.sync != nil {
+		b.Cmd.Args = append(b.Cmd.Args, "--sync-fd", strconv.Itoa(int(proc.ExtraFile(b.Cmd, b.sync))))
+	}
+
 	if err := b.Cmd.Start(); err != nil {
 		return err
 	}
@@ -131,6 +139,7 @@ func NewBwrap(conf *bwrap.Config, wt io.WriterTo, name string, argF func(argsFD,
 		b.p = &pipes{args: args}
 	}
 
+	b.sync = conf.Sync()
 	b.argF = argF
 	b.name = name
 	if wt != nil {

helper/bwrap/config.go

@@ -68,13 +68,16 @@ type Config struct {
 	// (--as-pid-1)
 	AsInit bool `json:"as_init"`
 
+	// keep this fd open while sandbox is running
+	// (--sync-fd FD)
+	sync *os.File
+
 	/* unmapped options include:
 	    --unshare-user-try           Create new user namespace if possible else continue by skipping it
 	    --unshare-cgroup-try         Create new cgroup namespace if possible else continue by skipping it
 	    --userns FD                  Use this user namespace (cannot combine with --unshare-user)
 	    --userns2 FD                 After setup switch to this user namespace, only useful with --userns
 	    --pidns FD                   Use this pid namespace (as parent namespace if using --unshare-pid)
-		--sync-fd FD                 Keep this fd open while sandbox is running
 	    --exec-label LABEL           Exec label for the sandbox
 	    --file-label LABEL           File label for temporary sandbox content
 	    --file FD DEST               Copy from FD to destination DEST
@@ -92,6 +95,12 @@ type Config struct {
 	among which --args is used internally for passing arguments */
 }
 
+// Sync keep this fd open while sandbox is running
+// (--sync-fd FD)
+func (c *Config) Sync() *os.File {
+	return c.sync
+}
+
 type UnshareConfig struct {
 	// (--unshare-user)
 	// create new user namespace

helper/bwrap/config.set.go

@@ -136,3 +136,10 @@ func (c *Config) SetGID(gid int) *Config {
 	}
 	return c
 }
+
+// SetSync sets the sync pipe kept open while sandbox is running
+// (--sync-fd FD)
+func (c *Config) SetSync(s *os.File) *Config {
+	c.sync = s
+	return c
+}

helper/bwrap_test.go

@@ -7,8 +7,8 @@ import (
 	"strings"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/helper"
-	"git.ophivana.moe/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
 )
 
 func TestBwrap(t *testing.T) {

helper/direct_test.go

@@ -5,7 +5,7 @@ import (
 	"os"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper"
 )
 
 func TestDirect(t *testing.T) {

helper/helper.go

@@ -1,6 +1,4 @@
-/*
-Package helper runs external helpers and manages their status and args FDs.
-*/
+// Package helper runs external helpers with optional sandboxing and manages their status/args pipes.
 package helper
 
 import (

helper/helper_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"
 
-	"git.ophivana.moe/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper"
 )
 
 var (

helper/pipe.go

@@ -5,6 +5,8 @@ import (
 	"io"
 	"os"
 	"os/exec"
+
+	"git.gensokyo.uk/security/fortify/internal/proc"
 )
 
 type pipes struct {
@@ -47,24 +49,21 @@ func (p *pipes) pipe() error {
 }
 
 // calls pipe to create pipes and sets them up as ExtraFiles, returning their fd
-func (p *pipes) prepareCmd(cmd *exec.Cmd) (int, int, error) {
-	if err := p.pipe(); err != nil {
-		return -1, -1, err
+func (p *pipes) prepareCmd(cmd *exec.Cmd) (argsFd, statFd int, err error) {
+	argsFd, statFd = -1, -1
+	if err = p.pipe(); err != nil {
+		return
 	}
 
 	// save a reference of cmd for future use
 	p.cmd = cmd
 
-	// ExtraFiles: If non-nil, entry i becomes file descriptor 3+i.
-	argsFd := 3 + len(cmd.ExtraFiles)
-	cmd.ExtraFiles = append(cmd.ExtraFiles, p.argsP[0])
-
+	argsFd = int(proc.ExtraFile(cmd, p.argsP[0]))
 	if p.ready != nil {
-		cmd.ExtraFiles = append(cmd.ExtraFiles, p.statP[1])
-		return argsFd, argsFd + 1, nil
-	} else {
-		return argsFd, -1, nil
+		statFd = int(proc.ExtraFile(cmd, p.statP[1]))
 	}
+
+	return
 }
 
 func (p *pipes) readyWriteArgs() error {

helper/stub.go

@@ -10,8 +10,8 @@ import (
 	"syscall"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 // InternalChildStub is an internal function but exported because it is cross-package;

helper/stub_test.go

@@ -3,7 +3,7 @@ package helper_test
 import (
 	"testing"
 
-	"git.ophivana.moe/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper"
 )
 
 func TestHelperChildStub(t *testing.T) {

internal/app/app.go

@@ -2,14 +2,16 @@ package app
 
 import (
 	"sync"
+	"sync/atomic"
 
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/shim"
+	"git.gensokyo.uk/security/fortify/cmd/fshim/ipc/shim"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/linux"
 )
 
 type App interface {
 	// ID returns a copy of App's unique ID.
-	ID() ID
+	ID() fst.ID
 	// Start sets up the system and starts the App.
 	Start() error
 	// Wait waits for App's process to exit and reverts system setup.
@@ -17,15 +19,18 @@ type App interface {
 	// WaitErr returns error returned by the underlying wait syscall.
 	WaitErr() error
 
-	Seal(config *Config) error
+	Seal(config *fst.Config) error
 	String() string
 }
 
 type app struct {
+	// single-use config reference
+	ct *appCt
+
 	// application unique identifier
-	id *ID
+	id *fst.ID
 	// operating system interface
-	os internal.System
+	os linux.System
 	// shim process manager
 	shim *shim.Shim
 	// child process related information
@@ -36,7 +41,7 @@ type app struct {
 	lock sync.RWMutex
 }
 
-func (a *app) ID() ID {
+func (a *app) ID() fst.ID {
 	return *a.id
 }
 
@@ -53,7 +58,7 @@ func (a *app) String() string {
 	}
 
 	if a.seal != nil {
-		return "(sealed fortified app as uid " + a.seal.sys.user.Uid + ")"
+		return "(sealed fortified app as uid " + a.seal.sys.user.us + ")"
 	}
 
 	return "(unsealed fortified app)"
@@ -63,9 +68,30 @@ func (a *app) WaitErr() error {
 	return a.waitErr
 }
 
-func New(os internal.System) (App, error) {
+func New(os linux.System) (App, error) {
 	a := new(app)
-	a.id = new(ID)
+	a.id = new(fst.ID)
 	a.os = os
-	return a, newAppID(a.id)
+	return a, fst.NewAppID(a.id)
+}
+
+// appCt ensures its wrapped val is only accessed once
+type appCt struct {
+	val  *fst.Config
+	done *atomic.Bool
+}
+
+func (a *appCt) Unwrap() *fst.Config {
+	if !a.done.Load() {
+		defer a.done.Store(true)
+		return a.val
+	}
+	panic("attempted to access config reference twice")
+}
+
+func newAppCt(config *fst.Config) (ct *appCt) {
+	ct = new(appCt)
+	ct.done = new(atomic.Bool)
+	ct.val = config
+	return ct
 }

internal/app/app_nixos_test.go

@@ -1,278 +1,87 @@
 package app_test
 
 import (
-	"fmt"
-	"io/fs"
-	"os/user"
-	"strconv"
-
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/app"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 var testCasesNixos = []sealTestCase{
 	{
-		"nixos permissive defaults no enablements", new(stubNixOS),
-		&app.Config{
-			User:    "chronos",
-			Command: make([]string, 0),
-			Method:  "sudo",
-		},
-		app.ID{
-			0x4a, 0x45, 0x0b, 0x65,
-			0x96, 0xd7, 0xbc, 0x15,
-			0xbd, 0x01, 0x78, 0x0e,
-			0xb9, 0xa6, 0x07, 0xac,
-		},
-		system.New(150).
-			Ensure("/tmp/fortify.1971", 0701).
-			Ephemeral(system.Process, "/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac", 0701).
-			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir/150", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/150", acl.Read, acl.Write, acl.Execute).
-			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
-			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
-			Ephemeral(system.Process, "/run/user/1971/fortify/4a450b6596d7bc15bd01780eb9a607ac", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/4a450b6596d7bc15bd01780eb9a607ac", acl.Execute).
-			WriteType(system.Process, "/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/passwd", "chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n").
-			WriteType(system.Process, "/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/group", "fortify:x:65534:\n"),
-		(&bwrap.Config{
-			Net:      true,
-			UserNS:   true,
-			Clearenv: true,
-			SetEnv: map[string]string{
-				"HOME":              "/home/chronos",
-				"SHELL":             "/run/current-system/sw/bin/zsh",
-				"TERM":              "xterm-256color",
-				"USER":              "chronos",
-				"XDG_RUNTIME_DIR":   "/run/user/150",
-				"XDG_SESSION_CLASS": "user",
-				"XDG_SESSION_TYPE":  "tty"},
-			Chmod:         make(bwrap.ChmodConfig),
-			DieWithParent: true,
-			AsInit:        true,
-		}).SetUID(65534).SetGID(65534).
-			Procfs("/proc").DevTmpfs("/dev").Mqueue("/dev/mqueue").
-			Tmpfs("/dev/fortify", 4096).
-			Bind("/bin", "/bin", false, true).
-			Bind("/boot", "/boot", false, true).
-			Bind("/etc", "/dev/fortify/etc").
-			Bind("/home", "/home", false, true).
-			Bind("/lib", "/lib", false, true).
-			Bind("/lib64", "/lib64", false, true).
-			Bind("/nix", "/nix", false, true).
-			Bind("/root", "/root", false, true).
-			Bind("/srv", "/srv", false, true).
-			Bind("/sys", "/sys", false, true).
-			Bind("/usr", "/usr", false, true).
-			Bind("/var", "/var", false, true).
-			Bind("/run/agetty.reload", "/run/agetty.reload", false, true).
-			Bind("/run/binfmt", "/run/binfmt", false, true).
-			Bind("/run/booted-system", "/run/booted-system", false, true).
-			Bind("/run/credentials", "/run/credentials", false, true).
-			Bind("/run/cryptsetup", "/run/cryptsetup", false, true).
-			Bind("/run/current-system", "/run/current-system", false, true).
-			Bind("/run/host", "/run/host", false, true).
-			Bind("/run/keys", "/run/keys", false, true).
-			Bind("/run/libvirt", "/run/libvirt", false, true).
-			Bind("/run/libvirtd.pid", "/run/libvirtd.pid", false, true).
-			Bind("/run/lock", "/run/lock", false, true).
-			Bind("/run/log", "/run/log", false, true).
-			Bind("/run/lvm", "/run/lvm", false, true).
-			Bind("/run/mount", "/run/mount", false, true).
-			Bind("/run/NetworkManager", "/run/NetworkManager", false, true).
-			Bind("/run/nginx", "/run/nginx", false, true).
-			Bind("/run/nixos", "/run/nixos", false, true).
-			Bind("/run/nscd", "/run/nscd", false, true).
-			Bind("/run/opengl-driver", "/run/opengl-driver", false, true).
-			Bind("/run/pppd", "/run/pppd", false, true).
-			Bind("/run/resolvconf", "/run/resolvconf", false, true).
-			Bind("/run/sddm", "/run/sddm", false, true).
-			Bind("/run/store", "/run/store", false, true).
-			Bind("/run/syncoid", "/run/syncoid", false, true).
-			Bind("/run/system", "/run/system", false, true).
-			Bind("/run/systemd", "/run/systemd", false, true).
-			Bind("/run/tmpfiles.d", "/run/tmpfiles.d", false, true).
-			Bind("/run/udev", "/run/udev", false, true).
-			Bind("/run/udisks2", "/run/udisks2", false, true).
-			Bind("/run/utmp", "/run/utmp", false, true).
-			Bind("/run/virtlogd.pid", "/run/virtlogd.pid", false, true).
-			Bind("/run/wrappers", "/run/wrappers", false, true).
-			Bind("/run/zed.pid", "/run/zed.pid", false, true).
-			Bind("/run/zed.state", "/run/zed.state", false, true).
-			Symlink("/dev/fortify/etc/alsa", "/etc/alsa").
-			Symlink("/dev/fortify/etc/bashrc", "/etc/bashrc").
-			Symlink("/dev/fortify/etc/binfmt.d", "/etc/binfmt.d").
-			Symlink("/dev/fortify/etc/dbus-1", "/etc/dbus-1").
-			Symlink("/dev/fortify/etc/default", "/etc/default").
-			Symlink("/dev/fortify/etc/ethertypes", "/etc/ethertypes").
-			Symlink("/dev/fortify/etc/fonts", "/etc/fonts").
-			Symlink("/dev/fortify/etc/fstab", "/etc/fstab").
-			Symlink("/dev/fortify/etc/fuse.conf", "/etc/fuse.conf").
-			Symlink("/dev/fortify/etc/host.conf", "/etc/host.conf").
-			Symlink("/dev/fortify/etc/hostid", "/etc/hostid").
-			Symlink("/dev/fortify/etc/hostname", "/etc/hostname").
-			Symlink("/dev/fortify/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
-			Symlink("/dev/fortify/etc/hosts", "/etc/hosts").
-			Symlink("/dev/fortify/etc/inputrc", "/etc/inputrc").
-			Symlink("/dev/fortify/etc/ipsec.d", "/etc/ipsec.d").
-			Symlink("/dev/fortify/etc/issue", "/etc/issue").
-			Symlink("/dev/fortify/etc/kbd", "/etc/kbd").
-			Symlink("/dev/fortify/etc/libblockdev", "/etc/libblockdev").
-			Symlink("/dev/fortify/etc/locale.conf", "/etc/locale.conf").
-			Symlink("/dev/fortify/etc/localtime", "/etc/localtime").
-			Symlink("/dev/fortify/etc/login.defs", "/etc/login.defs").
-			Symlink("/dev/fortify/etc/lsb-release", "/etc/lsb-release").
-			Symlink("/dev/fortify/etc/lvm", "/etc/lvm").
-			Symlink("/dev/fortify/etc/machine-id", "/etc/machine-id").
-			Symlink("/dev/fortify/etc/man_db.conf", "/etc/man_db.conf").
-			Symlink("/dev/fortify/etc/modprobe.d", "/etc/modprobe.d").
-			Symlink("/dev/fortify/etc/modules-load.d", "/etc/modules-load.d").
-			Symlink("/proc/mounts", "/etc/mtab").
-			Symlink("/dev/fortify/etc/nanorc", "/etc/nanorc").
-			Symlink("/dev/fortify/etc/netgroup", "/etc/netgroup").
-			Symlink("/dev/fortify/etc/NetworkManager", "/etc/NetworkManager").
-			Symlink("/dev/fortify/etc/nix", "/etc/nix").
-			Symlink("/dev/fortify/etc/nixos", "/etc/nixos").
-			Symlink("/dev/fortify/etc/NIXOS", "/etc/NIXOS").
-			Symlink("/dev/fortify/etc/nscd.conf", "/etc/nscd.conf").
-			Symlink("/dev/fortify/etc/nsswitch.conf", "/etc/nsswitch.conf").
-			Symlink("/dev/fortify/etc/opensnitchd", "/etc/opensnitchd").
-			Symlink("/dev/fortify/etc/os-release", "/etc/os-release").
-			Symlink("/dev/fortify/etc/pam", "/etc/pam").
-			Symlink("/dev/fortify/etc/pam.d", "/etc/pam.d").
-			Symlink("/dev/fortify/etc/pipewire", "/etc/pipewire").
-			Symlink("/dev/fortify/etc/pki", "/etc/pki").
-			Symlink("/dev/fortify/etc/polkit-1", "/etc/polkit-1").
-			Symlink("/dev/fortify/etc/profile", "/etc/profile").
-			Symlink("/dev/fortify/etc/protocols", "/etc/protocols").
-			Symlink("/dev/fortify/etc/qemu", "/etc/qemu").
-			Symlink("/dev/fortify/etc/resolv.conf", "/etc/resolv.conf").
-			Symlink("/dev/fortify/etc/resolvconf.conf", "/etc/resolvconf.conf").
-			Symlink("/dev/fortify/etc/rpc", "/etc/rpc").
-			Symlink("/dev/fortify/etc/samba", "/etc/samba").
-			Symlink("/dev/fortify/etc/sddm.conf", "/etc/sddm.conf").
-			Symlink("/dev/fortify/etc/secureboot", "/etc/secureboot").
-			Symlink("/dev/fortify/etc/services", "/etc/services").
-			Symlink("/dev/fortify/etc/set-environment", "/etc/set-environment").
-			Symlink("/dev/fortify/etc/shadow", "/etc/shadow").
-			Symlink("/dev/fortify/etc/shells", "/etc/shells").
-			Symlink("/dev/fortify/etc/ssh", "/etc/ssh").
-			Symlink("/dev/fortify/etc/ssl", "/etc/ssl").
-			Symlink("/dev/fortify/etc/static", "/etc/static").
-			Symlink("/dev/fortify/etc/subgid", "/etc/subgid").
-			Symlink("/dev/fortify/etc/subuid", "/etc/subuid").
-			Symlink("/dev/fortify/etc/sudoers", "/etc/sudoers").
-			Symlink("/dev/fortify/etc/sysctl.d", "/etc/sysctl.d").
-			Symlink("/dev/fortify/etc/systemd", "/etc/systemd").
-			Symlink("/dev/fortify/etc/terminfo", "/etc/terminfo").
-			Symlink("/dev/fortify/etc/tmpfiles.d", "/etc/tmpfiles.d").
-			Symlink("/dev/fortify/etc/udev", "/etc/udev").
-			Symlink("/dev/fortify/etc/udisks2", "/etc/udisks2").
-			Symlink("/dev/fortify/etc/UPower", "/etc/UPower").
-			Symlink("/dev/fortify/etc/vconsole.conf", "/etc/vconsole.conf").
-			Symlink("/dev/fortify/etc/X11", "/etc/X11").
-			Symlink("/dev/fortify/etc/zfs", "/etc/zfs").
-			Symlink("/dev/fortify/etc/zinputrc", "/etc/zinputrc").
-			Symlink("/dev/fortify/etc/zoneinfo", "/etc/zoneinfo").
-			Symlink("/dev/fortify/etc/zprofile", "/etc/zprofile").
-			Symlink("/dev/fortify/etc/zshenv", "/etc/zshenv").
-			Symlink("/dev/fortify/etc/zshrc", "/etc/zshrc").
-			Bind("/tmp/fortify.1971/tmpdir/150", "/tmp", false, true).
-			Tmpfs("/tmp/fortify.1971", 1048576).
-			Tmpfs("/run/user", 1048576).
-			Tmpfs("/run/user/150", 8388608).
-			Bind("/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/passwd", "/etc/passwd").
-			Bind("/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/group", "/etc/group").
-			Tmpfs("/var/run/nscd", 8192),
-	},
-	{
-		"nixos permissive defaults chromium", new(stubNixOS),
-		&app.Config{
+		"nixos chromium direct wayland", new(stubNixOS),
+		&fst.Config{
 			ID:      "org.chromium.Chromium",
-			User:    "chronos",
-			Command: []string{"/run/current-system/sw/bin/zsh", "-c", "exec chromium "},
-			Confinement: app.ConfinementConfig{
+			Command: []string{"/nix/store/yqivzpzzn7z5x0lq9hmbzygh45d8rhqd-chromium-start"},
+			Confinement: fst.ConfinementConfig{
+				AppID: 1, Groups: []string{}, Username: "u0_a1",
+				Outer: "/var/lib/persist/module/fortify/0/1",
+				Sandbox: &fst.SandboxConfig{
+					UserNS: true, Net: true, MapRealUID: true, DirectWayland: true, Env: nil,
+					Filesystem: []*fst.FilesystemConfig{
+						{Src: "/bin", Must: true}, {Src: "/usr/bin", Must: true},
+						{Src: "/nix/store", Must: true}, {Src: "/run/current-system", Must: true},
+						{Src: "/sys/block"}, {Src: "/sys/bus"}, {Src: "/sys/class"}, {Src: "/sys/dev"}, {Src: "/sys/devices"},
+						{Src: "/run/opengl-driver", Must: true}, {Src: "/dev/dri", Device: true},
+					}, AutoEtc: true,
+					Override: []string{"/var/run/nscd"},
+				},
+				SystemBus: &dbus.Config{
+					Talk:   []string{"org.bluez", "org.freedesktop.Avahi", "org.freedesktop.UPower"},
+					Filter: true,
+				},
 				SessionBus: &dbus.Config{
 					Talk: []string{
-						"org.freedesktop.Notifications",
-						"org.freedesktop.FileManager1",
-						"org.freedesktop.ScreenSaver",
-						"org.freedesktop.secrets",
-						"org.kde.kwalletd5",
-						"org.kde.kwalletd6",
-						"org.gnome.SessionManager",
+						"org.freedesktop.FileManager1", "org.freedesktop.Notifications",
+						"org.freedesktop.ScreenSaver", "org.freedesktop.secrets",
+						"org.kde.kwalletd5", "org.kde.kwalletd6",
 					},
 					Own: []string{
 						"org.chromium.Chromium.*",
 						"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
 						"org.mpris.MediaPlayer2.chromium.*",
 					},
-					Call: map[string]string{
-						"org.freedesktop.portal.*": "*",
-					},
-					Broadcast: map[string]string{
-						"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
-					},
-					Filter: true,
-				},
-				SystemBus: &dbus.Config{
-					Talk: []string{
-						"org.bluez",
-						"org.freedesktop.Avahi",
-						"org.freedesktop.UPower",
-					},
+					Call: map[string]string{}, Broadcast: map[string]string{},
 					Filter: true,
 				},
 				Enablements: system.EWayland.Mask() | system.EDBus.Mask() | system.EPulse.Mask(),
 			},
-			Method: "systemd",
 		},
-		app.ID{
-			0xeb, 0xf0, 0x83, 0xd1,
-			0xb1, 0x75, 0x91, 0x17,
-			0x82, 0xd4, 0x13, 0x36,
-			0x9b, 0x64, 0xce, 0x7c,
+		fst.ID{
+			0x8e, 0x2c, 0x76, 0xb0,
+			0x66, 0xda, 0xbe, 0x57,
+			0x4c, 0xf0, 0x73, 0xbd,
+			0xb4, 0x6e, 0xb5, 0xc1,
 		},
-		system.New(150).
-			Ensure("/tmp/fortify.1971", 0701).
-			Ephemeral(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c", 0701).
+		system.New(1000001).
+			Ensure("/tmp/fortify.1971", 0711).
+			Ephemeral(system.Process, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1", 0711).
 			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir/150", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/150", acl.Read, acl.Write, acl.Execute).
+			Ensure("/tmp/fortify.1971/tmpdir/1", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/1", acl.Read, acl.Write, acl.Execute).
 			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
 			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
-			Ephemeral(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", acl.Execute).
-			WriteType(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/passwd", "chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n").
-			WriteType(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/group", "fortify:x:65534:\n").
-			Link("/run/user/1971/wayland-0", "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/wayland").
+			Ephemeral(system.Process, "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1", acl.Execute).
+			WriteType(system.Process, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/passwd", "u0_a1:x:1971:1971:Fortify:/var/lib/persist/module/fortify/0/1:/run/current-system/sw/bin/zsh\n").
+			WriteType(system.Process, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/group", "fortify:x:1971:\n").
+			Link("/run/user/1971/wayland-0", "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/wayland").
 			UpdatePermType(system.EWayland, "/run/user/1971/wayland-0", acl.Read, acl.Write, acl.Execute).
-			Link("/run/user/1971/pulse/native", "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse").
-			CopyFile("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie", "/home/ophestra/xdg/config/pulse/cookie").
-			MustProxyDBus("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", &dbus.Config{
+			Link("/run/user/1971/pulse/native", "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/pulse").
+			CopyFile("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/pulse-cookie", "/home/ophestra/xdg/config/pulse/cookie").
+			MustProxyDBus("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", &dbus.Config{
 				Talk: []string{
-					"org.freedesktop.Notifications",
-					"org.freedesktop.FileManager1",
-					"org.freedesktop.ScreenSaver",
-					"org.freedesktop.secrets",
-					"org.kde.kwalletd5",
-					"org.kde.kwalletd6",
-					"org.gnome.SessionManager",
+					"org.freedesktop.FileManager1", "org.freedesktop.Notifications",
+					"org.freedesktop.ScreenSaver", "org.freedesktop.secrets",
+					"org.kde.kwalletd5", "org.kde.kwalletd6",
 				},
 				Own: []string{
 					"org.chromium.Chromium.*",
 					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
 					"org.mpris.MediaPlayer2.chromium.*",
 				},
-				Call: map[string]string{
-					"org.freedesktop.portal.*": "*",
-				},
-				Broadcast: map[string]string{
-					"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
-				},
+				Call: map[string]string{}, Broadcast: map[string]string{},
 				Filter: true,
-			}, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", &dbus.Config{
+			}, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", &dbus.Config{
 				Talk: []string{
 					"org.bluez",
 					"org.freedesktop.Avahi",
@@ -280,313 +89,137 @@ var testCasesNixos = []sealTestCase{
 				},
 				Filter: true,
 			}).
-			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", acl.Read, acl.Write).
-			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", acl.Read, acl.Write),
+			UpdatePerm("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", acl.Read, acl.Write).
+			UpdatePerm("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", acl.Read, acl.Write),
 		(&bwrap.Config{
 			Net:      true,
 			UserNS:   true,
+			Chdir:    "/var/lib/persist/module/fortify/0/1",
 			Clearenv: true,
 			SetEnv: map[string]string{
-				"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/150/bus",
+				"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/1971/bus",
 				"DBUS_SYSTEM_BUS_ADDRESS":  "unix:path=/run/dbus/system_bus_socket",
-				"HOME":                     "/home/chronos",
-				"PULSE_COOKIE":             "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie",
-				"PULSE_SERVER":             "unix:/run/user/150/pulse/native",
+				"HOME":                     "/var/lib/persist/module/fortify/0/1",
+				"PULSE_COOKIE":             "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/pulse-cookie",
+				"PULSE_SERVER":             "unix:/run/user/1971/pulse/native",
 				"SHELL":                    "/run/current-system/sw/bin/zsh",
 				"TERM":                     "xterm-256color",
-				"USER":                     "chronos",
-				"WAYLAND_DISPLAY":          "/run/user/150/wayland-0",
-				"XDG_RUNTIME_DIR":          "/run/user/150",
+				"USER":                     "u0_a1",
+				"WAYLAND_DISPLAY":          "/run/user/1971/wayland-0",
+				"XDG_RUNTIME_DIR":          "/run/user/1971",
 				"XDG_SESSION_CLASS":        "user",
 				"XDG_SESSION_TYPE":         "tty",
 			},
 			Chmod:         make(bwrap.ChmodConfig),
+			NewSession:    true,
 			DieWithParent: true,
 			AsInit:        true,
-		}).SetUID(65534).SetGID(65534).
-			Procfs("/proc").DevTmpfs("/dev").Mqueue("/dev/mqueue").
-			Tmpfs("/dev/fortify", 4096).
-			Bind("/bin", "/bin", false, true).
-			Bind("/boot", "/boot", false, true).
-			Bind("/etc", "/dev/fortify/etc").
-			Bind("/home", "/home", false, true).
-			Bind("/lib", "/lib", false, true).
-			Bind("/lib64", "/lib64", false, true).
-			Bind("/nix", "/nix", false, true).
-			Bind("/root", "/root", false, true).
-			Bind("/srv", "/srv", false, true).
-			Bind("/sys", "/sys", false, true).
-			Bind("/usr", "/usr", false, true).
-			Bind("/var", "/var", false, true).
-			Bind("/run/agetty.reload", "/run/agetty.reload", false, true).
-			Bind("/run/binfmt", "/run/binfmt", false, true).
-			Bind("/run/booted-system", "/run/booted-system", false, true).
-			Bind("/run/credentials", "/run/credentials", false, true).
-			Bind("/run/cryptsetup", "/run/cryptsetup", false, true).
-			Bind("/run/current-system", "/run/current-system", false, true).
-			Bind("/run/host", "/run/host", false, true).
-			Bind("/run/keys", "/run/keys", false, true).
-			Bind("/run/libvirt", "/run/libvirt", false, true).
-			Bind("/run/libvirtd.pid", "/run/libvirtd.pid", false, true).
-			Bind("/run/lock", "/run/lock", false, true).
-			Bind("/run/log", "/run/log", false, true).
-			Bind("/run/lvm", "/run/lvm", false, true).
-			Bind("/run/mount", "/run/mount", false, true).
-			Bind("/run/NetworkManager", "/run/NetworkManager", false, true).
-			Bind("/run/nginx", "/run/nginx", false, true).
-			Bind("/run/nixos", "/run/nixos", false, true).
-			Bind("/run/nscd", "/run/nscd", false, true).
-			Bind("/run/opengl-driver", "/run/opengl-driver", false, true).
-			Bind("/run/pppd", "/run/pppd", false, true).
-			Bind("/run/resolvconf", "/run/resolvconf", false, true).
-			Bind("/run/sddm", "/run/sddm", false, true).
-			Bind("/run/store", "/run/store", false, true).
-			Bind("/run/syncoid", "/run/syncoid", false, true).
-			Bind("/run/system", "/run/system", false, true).
-			Bind("/run/systemd", "/run/systemd", false, true).
-			Bind("/run/tmpfiles.d", "/run/tmpfiles.d", false, true).
-			Bind("/run/udev", "/run/udev", false, true).
-			Bind("/run/udisks2", "/run/udisks2", false, true).
-			Bind("/run/utmp", "/run/utmp", false, true).
-			Bind("/run/virtlogd.pid", "/run/virtlogd.pid", false, true).
-			Bind("/run/wrappers", "/run/wrappers", false, true).
-			Bind("/run/zed.pid", "/run/zed.pid", false, true).
-			Bind("/run/zed.state", "/run/zed.state", false, true).
+		}).SetUID(1971).SetGID(1971).
+			Procfs("/proc").
+			Tmpfs("/fortify", 4096).
+			DevTmpfs("/dev").Mqueue("/dev/mqueue").
+			Bind("/bin", "/bin").
+			Bind("/usr/bin", "/usr/bin").
+			Bind("/nix/store", "/nix/store").
+			Bind("/run/current-system", "/run/current-system").
+			Bind("/sys/block", "/sys/block", true).
+			Bind("/sys/bus", "/sys/bus", true).
+			Bind("/sys/class", "/sys/class", true).
+			Bind("/sys/dev", "/sys/dev", true).
+			Bind("/sys/devices", "/sys/devices", true).
+			Bind("/run/opengl-driver", "/run/opengl-driver").
 			Bind("/dev/dri", "/dev/dri", true, true, true).
-			Symlink("/dev/fortify/etc/alsa", "/etc/alsa").
-			Symlink("/dev/fortify/etc/bashrc", "/etc/bashrc").
-			Symlink("/dev/fortify/etc/binfmt.d", "/etc/binfmt.d").
-			Symlink("/dev/fortify/etc/dbus-1", "/etc/dbus-1").
-			Symlink("/dev/fortify/etc/default", "/etc/default").
-			Symlink("/dev/fortify/etc/ethertypes", "/etc/ethertypes").
-			Symlink("/dev/fortify/etc/fonts", "/etc/fonts").
-			Symlink("/dev/fortify/etc/fstab", "/etc/fstab").
-			Symlink("/dev/fortify/etc/fuse.conf", "/etc/fuse.conf").
-			Symlink("/dev/fortify/etc/host.conf", "/etc/host.conf").
-			Symlink("/dev/fortify/etc/hostid", "/etc/hostid").
-			Symlink("/dev/fortify/etc/hostname", "/etc/hostname").
-			Symlink("/dev/fortify/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
-			Symlink("/dev/fortify/etc/hosts", "/etc/hosts").
-			Symlink("/dev/fortify/etc/inputrc", "/etc/inputrc").
-			Symlink("/dev/fortify/etc/ipsec.d", "/etc/ipsec.d").
-			Symlink("/dev/fortify/etc/issue", "/etc/issue").
-			Symlink("/dev/fortify/etc/kbd", "/etc/kbd").
-			Symlink("/dev/fortify/etc/libblockdev", "/etc/libblockdev").
-			Symlink("/dev/fortify/etc/locale.conf", "/etc/locale.conf").
-			Symlink("/dev/fortify/etc/localtime", "/etc/localtime").
-			Symlink("/dev/fortify/etc/login.defs", "/etc/login.defs").
-			Symlink("/dev/fortify/etc/lsb-release", "/etc/lsb-release").
-			Symlink("/dev/fortify/etc/lvm", "/etc/lvm").
-			Symlink("/dev/fortify/etc/machine-id", "/etc/machine-id").
-			Symlink("/dev/fortify/etc/man_db.conf", "/etc/man_db.conf").
-			Symlink("/dev/fortify/etc/modprobe.d", "/etc/modprobe.d").
-			Symlink("/dev/fortify/etc/modules-load.d", "/etc/modules-load.d").
+			Bind("/etc", "/fortify/etc").
+			Symlink("/fortify/etc/alsa", "/etc/alsa").
+			Symlink("/fortify/etc/bashrc", "/etc/bashrc").
+			Symlink("/fortify/etc/binfmt.d", "/etc/binfmt.d").
+			Symlink("/fortify/etc/dbus-1", "/etc/dbus-1").
+			Symlink("/fortify/etc/default", "/etc/default").
+			Symlink("/fortify/etc/ethertypes", "/etc/ethertypes").
+			Symlink("/fortify/etc/fonts", "/etc/fonts").
+			Symlink("/fortify/etc/fstab", "/etc/fstab").
+			Symlink("/fortify/etc/fuse.conf", "/etc/fuse.conf").
+			Symlink("/fortify/etc/host.conf", "/etc/host.conf").
+			Symlink("/fortify/etc/hostid", "/etc/hostid").
+			Symlink("/fortify/etc/hostname", "/etc/hostname").
+			Symlink("/fortify/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
+			Symlink("/fortify/etc/hosts", "/etc/hosts").
+			Symlink("/fortify/etc/inputrc", "/etc/inputrc").
+			Symlink("/fortify/etc/ipsec.d", "/etc/ipsec.d").
+			Symlink("/fortify/etc/issue", "/etc/issue").
+			Symlink("/fortify/etc/kbd", "/etc/kbd").
+			Symlink("/fortify/etc/libblockdev", "/etc/libblockdev").
+			Symlink("/fortify/etc/locale.conf", "/etc/locale.conf").
+			Symlink("/fortify/etc/localtime", "/etc/localtime").
+			Symlink("/fortify/etc/login.defs", "/etc/login.defs").
+			Symlink("/fortify/etc/lsb-release", "/etc/lsb-release").
+			Symlink("/fortify/etc/lvm", "/etc/lvm").
+			Symlink("/fortify/etc/machine-id", "/etc/machine-id").
+			Symlink("/fortify/etc/man_db.conf", "/etc/man_db.conf").
+			Symlink("/fortify/etc/modprobe.d", "/etc/modprobe.d").
+			Symlink("/fortify/etc/modules-load.d", "/etc/modules-load.d").
 			Symlink("/proc/mounts", "/etc/mtab").
-			Symlink("/dev/fortify/etc/nanorc", "/etc/nanorc").
-			Symlink("/dev/fortify/etc/netgroup", "/etc/netgroup").
-			Symlink("/dev/fortify/etc/NetworkManager", "/etc/NetworkManager").
-			Symlink("/dev/fortify/etc/nix", "/etc/nix").
-			Symlink("/dev/fortify/etc/nixos", "/etc/nixos").
-			Symlink("/dev/fortify/etc/NIXOS", "/etc/NIXOS").
-			Symlink("/dev/fortify/etc/nscd.conf", "/etc/nscd.conf").
-			Symlink("/dev/fortify/etc/nsswitch.conf", "/etc/nsswitch.conf").
-			Symlink("/dev/fortify/etc/opensnitchd", "/etc/opensnitchd").
-			Symlink("/dev/fortify/etc/os-release", "/etc/os-release").
-			Symlink("/dev/fortify/etc/pam", "/etc/pam").
-			Symlink("/dev/fortify/etc/pam.d", "/etc/pam.d").
-			Symlink("/dev/fortify/etc/pipewire", "/etc/pipewire").
-			Symlink("/dev/fortify/etc/pki", "/etc/pki").
-			Symlink("/dev/fortify/etc/polkit-1", "/etc/polkit-1").
-			Symlink("/dev/fortify/etc/profile", "/etc/profile").
-			Symlink("/dev/fortify/etc/protocols", "/etc/protocols").
-			Symlink("/dev/fortify/etc/qemu", "/etc/qemu").
-			Symlink("/dev/fortify/etc/resolv.conf", "/etc/resolv.conf").
-			Symlink("/dev/fortify/etc/resolvconf.conf", "/etc/resolvconf.conf").
-			Symlink("/dev/fortify/etc/rpc", "/etc/rpc").
-			Symlink("/dev/fortify/etc/samba", "/etc/samba").
-			Symlink("/dev/fortify/etc/sddm.conf", "/etc/sddm.conf").
-			Symlink("/dev/fortify/etc/secureboot", "/etc/secureboot").
-			Symlink("/dev/fortify/etc/services", "/etc/services").
-			Symlink("/dev/fortify/etc/set-environment", "/etc/set-environment").
-			Symlink("/dev/fortify/etc/shadow", "/etc/shadow").
-			Symlink("/dev/fortify/etc/shells", "/etc/shells").
-			Symlink("/dev/fortify/etc/ssh", "/etc/ssh").
-			Symlink("/dev/fortify/etc/ssl", "/etc/ssl").
-			Symlink("/dev/fortify/etc/static", "/etc/static").
-			Symlink("/dev/fortify/etc/subgid", "/etc/subgid").
-			Symlink("/dev/fortify/etc/subuid", "/etc/subuid").
-			Symlink("/dev/fortify/etc/sudoers", "/etc/sudoers").
-			Symlink("/dev/fortify/etc/sysctl.d", "/etc/sysctl.d").
-			Symlink("/dev/fortify/etc/systemd", "/etc/systemd").
-			Symlink("/dev/fortify/etc/terminfo", "/etc/terminfo").
-			Symlink("/dev/fortify/etc/tmpfiles.d", "/etc/tmpfiles.d").
-			Symlink("/dev/fortify/etc/udev", "/etc/udev").
-			Symlink("/dev/fortify/etc/udisks2", "/etc/udisks2").
-			Symlink("/dev/fortify/etc/UPower", "/etc/UPower").
-			Symlink("/dev/fortify/etc/vconsole.conf", "/etc/vconsole.conf").
-			Symlink("/dev/fortify/etc/X11", "/etc/X11").
-			Symlink("/dev/fortify/etc/zfs", "/etc/zfs").
-			Symlink("/dev/fortify/etc/zinputrc", "/etc/zinputrc").
-			Symlink("/dev/fortify/etc/zoneinfo", "/etc/zoneinfo").
-			Symlink("/dev/fortify/etc/zprofile", "/etc/zprofile").
-			Symlink("/dev/fortify/etc/zshenv", "/etc/zshenv").
-			Symlink("/dev/fortify/etc/zshrc", "/etc/zshrc").
-			Bind("/tmp/fortify.1971/tmpdir/150", "/tmp", false, true).
+			Symlink("/fortify/etc/nanorc", "/etc/nanorc").
+			Symlink("/fortify/etc/netgroup", "/etc/netgroup").
+			Symlink("/fortify/etc/NetworkManager", "/etc/NetworkManager").
+			Symlink("/fortify/etc/nix", "/etc/nix").
+			Symlink("/fortify/etc/nixos", "/etc/nixos").
+			Symlink("/fortify/etc/NIXOS", "/etc/NIXOS").
+			Symlink("/fortify/etc/nscd.conf", "/etc/nscd.conf").
+			Symlink("/fortify/etc/nsswitch.conf", "/etc/nsswitch.conf").
+			Symlink("/fortify/etc/opensnitchd", "/etc/opensnitchd").
+			Symlink("/fortify/etc/os-release", "/etc/os-release").
+			Symlink("/fortify/etc/pam", "/etc/pam").
+			Symlink("/fortify/etc/pam.d", "/etc/pam.d").
+			Symlink("/fortify/etc/pipewire", "/etc/pipewire").
+			Symlink("/fortify/etc/pki", "/etc/pki").
+			Symlink("/fortify/etc/polkit-1", "/etc/polkit-1").
+			Symlink("/fortify/etc/profile", "/etc/profile").
+			Symlink("/fortify/etc/protocols", "/etc/protocols").
+			Symlink("/fortify/etc/qemu", "/etc/qemu").
+			Symlink("/fortify/etc/resolv.conf", "/etc/resolv.conf").
+			Symlink("/fortify/etc/resolvconf.conf", "/etc/resolvconf.conf").
+			Symlink("/fortify/etc/rpc", "/etc/rpc").
+			Symlink("/fortify/etc/samba", "/etc/samba").
+			Symlink("/fortify/etc/sddm.conf", "/etc/sddm.conf").
+			Symlink("/fortify/etc/secureboot", "/etc/secureboot").
+			Symlink("/fortify/etc/services", "/etc/services").
+			Symlink("/fortify/etc/set-environment", "/etc/set-environment").
+			Symlink("/fortify/etc/shadow", "/etc/shadow").
+			Symlink("/fortify/etc/shells", "/etc/shells").
+			Symlink("/fortify/etc/ssh", "/etc/ssh").
+			Symlink("/fortify/etc/ssl", "/etc/ssl").
+			Symlink("/fortify/etc/static", "/etc/static").
+			Symlink("/fortify/etc/subgid", "/etc/subgid").
+			Symlink("/fortify/etc/subuid", "/etc/subuid").
+			Symlink("/fortify/etc/sudoers", "/etc/sudoers").
+			Symlink("/fortify/etc/sysctl.d", "/etc/sysctl.d").
+			Symlink("/fortify/etc/systemd", "/etc/systemd").
+			Symlink("/fortify/etc/terminfo", "/etc/terminfo").
+			Symlink("/fortify/etc/tmpfiles.d", "/etc/tmpfiles.d").
+			Symlink("/fortify/etc/udev", "/etc/udev").
+			Symlink("/fortify/etc/udisks2", "/etc/udisks2").
+			Symlink("/fortify/etc/UPower", "/etc/UPower").
+			Symlink("/fortify/etc/vconsole.conf", "/etc/vconsole.conf").
+			Symlink("/fortify/etc/X11", "/etc/X11").
+			Symlink("/fortify/etc/zfs", "/etc/zfs").
+			Symlink("/fortify/etc/zinputrc", "/etc/zinputrc").
+			Symlink("/fortify/etc/zoneinfo", "/etc/zoneinfo").
+			Symlink("/fortify/etc/zprofile", "/etc/zprofile").
+			Symlink("/fortify/etc/zshenv", "/etc/zshenv").
+			Symlink("/fortify/etc/zshrc", "/etc/zshrc").
+			Bind("/tmp/fortify.1971/tmpdir/1", "/tmp", false, true).
 			Tmpfs("/tmp/fortify.1971", 1048576).
 			Tmpfs("/run/user", 1048576).
-			Tmpfs("/run/user/150", 8388608).
-			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/passwd", "/etc/passwd").
-			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/group", "/etc/group").
-			Bind("/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/wayland", "/run/user/150/wayland-0").
-			Bind("/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse", "/run/user/150/pulse/native").
-			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie", "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie").
-			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", "/run/user/150/bus").
-			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", "/run/dbus/system_bus_socket").
+			Tmpfs("/run/user/1971", 8388608).
+			Bind("/var/lib/persist/module/fortify/0/1", "/var/lib/persist/module/fortify/0/1", false, true).
+			Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/passwd", "/etc/passwd").
+			Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/group", "/etc/group").
+			Bind("/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/wayland", "/run/user/1971/wayland-0").
+			Bind("/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/pulse", "/run/user/1971/pulse/native").
+			Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/pulse-cookie", "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/pulse-cookie").
+			Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", "/run/user/1971/bus").
+			Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", "/run/dbus/system_bus_socket").
 			Tmpfs("/var/run/nscd", 8192),
 	},
 }
-
-// fs methods are not implemented using a real FS
-// to help better understand filesystem access behaviour
-type stubNixOS struct {
-	lookPathErr map[string]error
-	usernameErr map[string]error
-}
-
-func (s *stubNixOS) Geteuid() int {
-	return 1971
-}
-
-func (s *stubNixOS) LookupEnv(key string) (string, bool) {
-	switch key {
-	case "SHELL":
-		return "/run/current-system/sw/bin/zsh", true
-	case "TERM":
-		return "xterm-256color", true
-	case "WAYLAND_DISPLAY":
-		return "wayland-0", true
-	case "PULSE_COOKIE":
-		return "", false
-	case "HOME":
-		return "/home/ophestra", true
-	case "XDG_CONFIG_HOME":
-		return "/home/ophestra/xdg/config", true
-	default:
-		panic(fmt.Sprintf("attempted to access unexpected environment variable %q", key))
-	}
-}
-
-func (s *stubNixOS) TempDir() string {
-	return "/tmp"
-}
-
-func (s *stubNixOS) LookPath(file string) (string, error) {
-	if s.lookPathErr != nil {
-		if err, ok := s.lookPathErr[file]; ok {
-			return "", err
-		}
-	}
-
-	switch file {
-	case "sudo":
-		return "/run/wrappers/bin/sudo", nil
-	case "machinectl":
-		return "/home/ophestra/.nix-profile/bin/machinectl", nil
-	default:
-		panic(fmt.Sprintf("attempted to look up unexpected executable %q", file))
-	}
-}
-
-func (s *stubNixOS) Executable() (string, error) {
-	return "/home/ophestra/.nix-profile/bin/fortify", nil
-}
-
-func (s *stubNixOS) Lookup(username string) (*user.User, error) {
-	if s.usernameErr != nil {
-		if err, ok := s.usernameErr[username]; ok {
-			return nil, err
-		}
-	}
-
-	switch username {
-	case "chronos":
-		return &user.User{
-			Uid:      "150",
-			Gid:      "101",
-			Username: "chronos",
-			HomeDir:  "/home/chronos",
-		}, nil
-	default:
-		return nil, user.UnknownUserError(username)
-	}
-}
-
-func (s *stubNixOS) ReadDir(name string) ([]fs.DirEntry, error) {
-	switch name {
-	case "/":
-		return stubDirEntries("bin", "boot", "dev", "etc", "home", "lib",
-			"lib64", "nix", "proc", "root", "run", "srv", "sys", "tmp", "usr", "var")
-	case "/run":
-		return stubDirEntries("agetty.reload", "binfmt", "booted-system",
-			"credentials", "cryptsetup", "current-system", "dbus", "host", "keys",
-			"libvirt", "libvirtd.pid", "lock", "log", "lvm", "mount", "NetworkManager",
-			"nginx", "nixos", "nscd", "opengl-driver", "pppd", "resolvconf", "sddm",
-			"store", "syncoid", "system", "systemd", "tmpfiles.d", "udev", "udisks2",
-			"user", "utmp", "virtlogd.pid", "wrappers", "zed.pid", "zed.state")
-	case "/etc":
-		return stubDirEntries("alsa", "bashrc", "binfmt.d", "dbus-1", "default",
-			"ethertypes", "fonts", "fstab", "fuse.conf", "group", "host.conf", "hostid",
-			"hostname", "hostname.CHECKSUM", "hosts", "inputrc", "ipsec.d", "issue", "kbd",
-			"libblockdev", "locale.conf", "localtime", "login.defs", "lsb-release", "lvm",
-			"machine-id", "man_db.conf", "modprobe.d", "modules-load.d", "mtab", "nanorc",
-			"netgroup", "NetworkManager", "nix", "nixos", "NIXOS", "nscd.conf", "nsswitch.conf",
-			"opensnitchd", "os-release", "pam", "pam.d", "passwd", "pipewire", "pki", "polkit-1",
-			"profile", "protocols", "qemu", "resolv.conf", "resolvconf.conf", "rpc", "samba",
-			"sddm.conf", "secureboot", "services", "set-environment", "shadow", "shells", "ssh",
-			"ssl", "static", "subgid", "subuid", "sudoers", "sysctl.d", "systemd", "terminfo",
-			"tmpfiles.d", "udev", "udisks2", "UPower", "vconsole.conf", "X11", "zfs", "zinputrc",
-			"zoneinfo", "zprofile", "zshenv", "zshrc")
-	default:
-		panic(fmt.Sprintf("attempted to read unexpected directory %q", name))
-	}
-}
-
-func (s *stubNixOS) Stat(name string) (fs.FileInfo, error) {
-	switch name {
-	case "/var/run/nscd":
-		return nil, nil
-	case "/run/user/1971/pulse":
-		return nil, nil
-	case "/run/user/1971/pulse/native":
-		return stubFileInfoMode(0666), nil
-	case "/home/ophestra/.pulse-cookie":
-		return stubFileInfoIsDir(true), nil
-	case "/home/ophestra/xdg/config/pulse/cookie":
-		return stubFileInfoIsDir(false), nil
-	default:
-		panic(fmt.Sprintf("attempted to stat unexpected path %q", name))
-	}
-}
-
-func (s *stubNixOS) Open(name string) (fs.File, error) {
-	switch name {
-	default:
-		panic(fmt.Sprintf("attempted to open unexpected file %q", name))
-	}
-}
-
-func (s *stubNixOS) Exit(code int) {
-	panic("called exit on stub with code " + strconv.Itoa(code))
-}
-
-func (s *stubNixOS) Paths() internal.Paths {
-	return internal.Paths{
-		SharePath:   "/tmp/fortify.1971",
-		RuntimePath: "/run/user/1971",
-		RunDirPath:  "/run/user/1971/fortify",
-	}
-}
-
-func (s *stubNixOS) SdBooted() bool {
-	return true
-}

internal/app/app_pd_test.go

@@ -0,0 +1,452 @@
+package app_test
+
+import (
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/system"
+)
+
+var testCasesPd = []sealTestCase{
+	{
+		"nixos permissive defaults no enablements", new(stubNixOS),
+		&fst.Config{
+			Command: make([]string, 0),
+			Confinement: fst.ConfinementConfig{
+				AppID:    0,
+				Username: "chronos",
+				Outer:    "/home/chronos",
+			},
+		},
+		fst.ID{
+			0x4a, 0x45, 0x0b, 0x65,
+			0x96, 0xd7, 0xbc, 0x15,
+			0xbd, 0x01, 0x78, 0x0e,
+			0xb9, 0xa6, 0x07, 0xac,
+		},
+		system.New(1000000).
+			Ensure("/tmp/fortify.1971", 0711).
+			Ephemeral(system.Process, "/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac", 0711).
+			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
+			Ensure("/tmp/fortify.1971/tmpdir/0", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/0", acl.Read, acl.Write, acl.Execute).
+			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
+			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
+			Ephemeral(system.Process, "/run/user/1971/fortify/4a450b6596d7bc15bd01780eb9a607ac", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/4a450b6596d7bc15bd01780eb9a607ac", acl.Execute).
+			WriteType(system.Process, "/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/passwd", "chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n").
+			WriteType(system.Process, "/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/group", "fortify:x:65534:\n"),
+		(&bwrap.Config{
+			Net:      true,
+			UserNS:   true,
+			Clearenv: true,
+			Chdir:    "/home/chronos",
+			SetEnv: map[string]string{
+				"HOME":              "/home/chronos",
+				"SHELL":             "/run/current-system/sw/bin/zsh",
+				"TERM":              "xterm-256color",
+				"USER":              "chronos",
+				"XDG_RUNTIME_DIR":   "/run/user/65534",
+				"XDG_SESSION_CLASS": "user",
+				"XDG_SESSION_TYPE":  "tty"},
+			Chmod:         make(bwrap.ChmodConfig),
+			DieWithParent: true,
+			AsInit:        true,
+		}).SetUID(65534).SetGID(65534).
+			Procfs("/proc").
+			Tmpfs("/fortify", 4096).
+			DevTmpfs("/dev").Mqueue("/dev/mqueue").
+			Bind("/bin", "/bin", false, true).
+			Bind("/boot", "/boot", false, true).
+			Bind("/home", "/home", false, true).
+			Bind("/lib", "/lib", false, true).
+			Bind("/lib64", "/lib64", false, true).
+			Bind("/nix", "/nix", false, true).
+			Bind("/root", "/root", false, true).
+			Bind("/srv", "/srv", false, true).
+			Bind("/sys", "/sys", false, true).
+			Bind("/usr", "/usr", false, true).
+			Bind("/var", "/var", false, true).
+			Bind("/run/agetty.reload", "/run/agetty.reload", false, true).
+			Bind("/run/binfmt", "/run/binfmt", false, true).
+			Bind("/run/booted-system", "/run/booted-system", false, true).
+			Bind("/run/credentials", "/run/credentials", false, true).
+			Bind("/run/cryptsetup", "/run/cryptsetup", false, true).
+			Bind("/run/current-system", "/run/current-system", false, true).
+			Bind("/run/host", "/run/host", false, true).
+			Bind("/run/keys", "/run/keys", false, true).
+			Bind("/run/libvirt", "/run/libvirt", false, true).
+			Bind("/run/libvirtd.pid", "/run/libvirtd.pid", false, true).
+			Bind("/run/lock", "/run/lock", false, true).
+			Bind("/run/log", "/run/log", false, true).
+			Bind("/run/lvm", "/run/lvm", false, true).
+			Bind("/run/mount", "/run/mount", false, true).
+			Bind("/run/NetworkManager", "/run/NetworkManager", false, true).
+			Bind("/run/nginx", "/run/nginx", false, true).
+			Bind("/run/nixos", "/run/nixos", false, true).
+			Bind("/run/nscd", "/run/nscd", false, true).
+			Bind("/run/opengl-driver", "/run/opengl-driver", false, true).
+			Bind("/run/pppd", "/run/pppd", false, true).
+			Bind("/run/resolvconf", "/run/resolvconf", false, true).
+			Bind("/run/sddm", "/run/sddm", false, true).
+			Bind("/run/store", "/run/store", false, true).
+			Bind("/run/syncoid", "/run/syncoid", false, true).
+			Bind("/run/system", "/run/system", false, true).
+			Bind("/run/systemd", "/run/systemd", false, true).
+			Bind("/run/tmpfiles.d", "/run/tmpfiles.d", false, true).
+			Bind("/run/udev", "/run/udev", false, true).
+			Bind("/run/udisks2", "/run/udisks2", false, true).
+			Bind("/run/utmp", "/run/utmp", false, true).
+			Bind("/run/virtlogd.pid", "/run/virtlogd.pid", false, true).
+			Bind("/run/wrappers", "/run/wrappers", false, true).
+			Bind("/run/zed.pid", "/run/zed.pid", false, true).
+			Bind("/run/zed.state", "/run/zed.state", false, true).
+			Bind("/etc", "/fortify/etc").
+			Symlink("/fortify/etc/alsa", "/etc/alsa").
+			Symlink("/fortify/etc/bashrc", "/etc/bashrc").
+			Symlink("/fortify/etc/binfmt.d", "/etc/binfmt.d").
+			Symlink("/fortify/etc/dbus-1", "/etc/dbus-1").
+			Symlink("/fortify/etc/default", "/etc/default").
+			Symlink("/fortify/etc/ethertypes", "/etc/ethertypes").
+			Symlink("/fortify/etc/fonts", "/etc/fonts").
+			Symlink("/fortify/etc/fstab", "/etc/fstab").
+			Symlink("/fortify/etc/fuse.conf", "/etc/fuse.conf").
+			Symlink("/fortify/etc/host.conf", "/etc/host.conf").
+			Symlink("/fortify/etc/hostid", "/etc/hostid").
+			Symlink("/fortify/etc/hostname", "/etc/hostname").
+			Symlink("/fortify/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
+			Symlink("/fortify/etc/hosts", "/etc/hosts").
+			Symlink("/fortify/etc/inputrc", "/etc/inputrc").
+			Symlink("/fortify/etc/ipsec.d", "/etc/ipsec.d").
+			Symlink("/fortify/etc/issue", "/etc/issue").
+			Symlink("/fortify/etc/kbd", "/etc/kbd").
+			Symlink("/fortify/etc/libblockdev", "/etc/libblockdev").
+			Symlink("/fortify/etc/locale.conf", "/etc/locale.conf").
+			Symlink("/fortify/etc/localtime", "/etc/localtime").
+			Symlink("/fortify/etc/login.defs", "/etc/login.defs").
+			Symlink("/fortify/etc/lsb-release", "/etc/lsb-release").
+			Symlink("/fortify/etc/lvm", "/etc/lvm").
+			Symlink("/fortify/etc/machine-id", "/etc/machine-id").
+			Symlink("/fortify/etc/man_db.conf", "/etc/man_db.conf").
+			Symlink("/fortify/etc/modprobe.d", "/etc/modprobe.d").
+			Symlink("/fortify/etc/modules-load.d", "/etc/modules-load.d").
+			Symlink("/proc/mounts", "/etc/mtab").
+			Symlink("/fortify/etc/nanorc", "/etc/nanorc").
+			Symlink("/fortify/etc/netgroup", "/etc/netgroup").
+			Symlink("/fortify/etc/NetworkManager", "/etc/NetworkManager").
+			Symlink("/fortify/etc/nix", "/etc/nix").
+			Symlink("/fortify/etc/nixos", "/etc/nixos").
+			Symlink("/fortify/etc/NIXOS", "/etc/NIXOS").
+			Symlink("/fortify/etc/nscd.conf", "/etc/nscd.conf").
+			Symlink("/fortify/etc/nsswitch.conf", "/etc/nsswitch.conf").
+			Symlink("/fortify/etc/opensnitchd", "/etc/opensnitchd").
+			Symlink("/fortify/etc/os-release", "/etc/os-release").
+			Symlink("/fortify/etc/pam", "/etc/pam").
+			Symlink("/fortify/etc/pam.d", "/etc/pam.d").
+			Symlink("/fortify/etc/pipewire", "/etc/pipewire").
+			Symlink("/fortify/etc/pki", "/etc/pki").
+			Symlink("/fortify/etc/polkit-1", "/etc/polkit-1").
+			Symlink("/fortify/etc/profile", "/etc/profile").
+			Symlink("/fortify/etc/protocols", "/etc/protocols").
+			Symlink("/fortify/etc/qemu", "/etc/qemu").
+			Symlink("/fortify/etc/resolv.conf", "/etc/resolv.conf").
+			Symlink("/fortify/etc/resolvconf.conf", "/etc/resolvconf.conf").
+			Symlink("/fortify/etc/rpc", "/etc/rpc").
+			Symlink("/fortify/etc/samba", "/etc/samba").
+			Symlink("/fortify/etc/sddm.conf", "/etc/sddm.conf").
+			Symlink("/fortify/etc/secureboot", "/etc/secureboot").
+			Symlink("/fortify/etc/services", "/etc/services").
+			Symlink("/fortify/etc/set-environment", "/etc/set-environment").
+			Symlink("/fortify/etc/shadow", "/etc/shadow").
+			Symlink("/fortify/etc/shells", "/etc/shells").
+			Symlink("/fortify/etc/ssh", "/etc/ssh").
+			Symlink("/fortify/etc/ssl", "/etc/ssl").
+			Symlink("/fortify/etc/static", "/etc/static").
+			Symlink("/fortify/etc/subgid", "/etc/subgid").
+			Symlink("/fortify/etc/subuid", "/etc/subuid").
+			Symlink("/fortify/etc/sudoers", "/etc/sudoers").
+			Symlink("/fortify/etc/sysctl.d", "/etc/sysctl.d").
+			Symlink("/fortify/etc/systemd", "/etc/systemd").
+			Symlink("/fortify/etc/terminfo", "/etc/terminfo").
+			Symlink("/fortify/etc/tmpfiles.d", "/etc/tmpfiles.d").
+			Symlink("/fortify/etc/udev", "/etc/udev").
+			Symlink("/fortify/etc/udisks2", "/etc/udisks2").
+			Symlink("/fortify/etc/UPower", "/etc/UPower").
+			Symlink("/fortify/etc/vconsole.conf", "/etc/vconsole.conf").
+			Symlink("/fortify/etc/X11", "/etc/X11").
+			Symlink("/fortify/etc/zfs", "/etc/zfs").
+			Symlink("/fortify/etc/zinputrc", "/etc/zinputrc").
+			Symlink("/fortify/etc/zoneinfo", "/etc/zoneinfo").
+			Symlink("/fortify/etc/zprofile", "/etc/zprofile").
+			Symlink("/fortify/etc/zshenv", "/etc/zshenv").
+			Symlink("/fortify/etc/zshrc", "/etc/zshrc").
+			Bind("/tmp/fortify.1971/tmpdir/0", "/tmp", false, true).
+			Tmpfs("/tmp/fortify.1971", 1048576).
+			Tmpfs("/run/user", 1048576).
+			Tmpfs("/run/user/65534", 8388608).
+			Bind("/home/chronos", "/home/chronos", false, true).
+			Bind("/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/passwd", "/etc/passwd").
+			Bind("/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac/group", "/etc/group").
+			Tmpfs("/var/run/nscd", 8192),
+	},
+	{
+		"nixos permissive defaults chromium", new(stubNixOS),
+		&fst.Config{
+			ID:      "org.chromium.Chromium",
+			Command: []string{"/run/current-system/sw/bin/zsh", "-c", "exec chromium "},
+			Confinement: fst.ConfinementConfig{
+				AppID:    9,
+				Groups:   []string{"video"},
+				Username: "chronos",
+				Outer:    "/home/chronos",
+				SessionBus: &dbus.Config{
+					Talk: []string{
+						"org.freedesktop.Notifications",
+						"org.freedesktop.FileManager1",
+						"org.freedesktop.ScreenSaver",
+						"org.freedesktop.secrets",
+						"org.kde.kwalletd5",
+						"org.kde.kwalletd6",
+						"org.gnome.SessionManager",
+					},
+					Own: []string{
+						"org.chromium.Chromium.*",
+						"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+						"org.mpris.MediaPlayer2.chromium.*",
+					},
+					Call: map[string]string{
+						"org.freedesktop.portal.*": "*",
+					},
+					Broadcast: map[string]string{
+						"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
+					},
+					Filter: true,
+				},
+				SystemBus: &dbus.Config{
+					Talk: []string{
+						"org.bluez",
+						"org.freedesktop.Avahi",
+						"org.freedesktop.UPower",
+					},
+					Filter: true,
+				},
+				Enablements: system.EWayland.Mask() | system.EDBus.Mask() | system.EPulse.Mask(),
+			},
+		},
+		fst.ID{
+			0xeb, 0xf0, 0x83, 0xd1,
+			0xb1, 0x75, 0x91, 0x17,
+			0x82, 0xd4, 0x13, 0x36,
+			0x9b, 0x64, 0xce, 0x7c,
+		},
+		system.New(1000009).
+			Ensure("/tmp/fortify.1971", 0711).
+			Ephemeral(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c", 0711).
+			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
+			Ensure("/tmp/fortify.1971/tmpdir/9", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/9", acl.Read, acl.Write, acl.Execute).
+			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
+			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
+			Ephemeral(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", acl.Execute).
+			WriteType(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/passwd", "chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n").
+			WriteType(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/group", "fortify:x:65534:\n").
+			Ensure("/tmp/fortify.1971/wayland", 0711).
+			Wayland("/tmp/fortify.1971/wayland/ebf083d1b175911782d413369b64ce7c", "/run/user/1971/wayland-0", "org.chromium.Chromium", "ebf083d1b175911782d413369b64ce7c").
+			Link("/run/user/1971/pulse/native", "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse").
+			CopyFile("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie", "/home/ophestra/xdg/config/pulse/cookie").
+			MustProxyDBus("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", &dbus.Config{
+				Talk: []string{
+					"org.freedesktop.Notifications",
+					"org.freedesktop.FileManager1",
+					"org.freedesktop.ScreenSaver",
+					"org.freedesktop.secrets",
+					"org.kde.kwalletd5",
+					"org.kde.kwalletd6",
+					"org.gnome.SessionManager",
+				},
+				Own: []string{
+					"org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.chromium.*",
+				},
+				Call: map[string]string{
+					"org.freedesktop.portal.*": "*",
+				},
+				Broadcast: map[string]string{
+					"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
+				},
+				Filter: true,
+			}, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", &dbus.Config{
+				Talk: []string{
+					"org.bluez",
+					"org.freedesktop.Avahi",
+					"org.freedesktop.UPower",
+				},
+				Filter: true,
+			}).
+			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", acl.Read, acl.Write).
+			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", acl.Read, acl.Write),
+		(&bwrap.Config{
+			Net:      true,
+			UserNS:   true,
+			Chdir:    "/home/chronos",
+			Clearenv: true,
+			SetEnv: map[string]string{
+				"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/65534/bus",
+				"DBUS_SYSTEM_BUS_ADDRESS":  "unix:path=/run/dbus/system_bus_socket",
+				"HOME":                     "/home/chronos",
+				"PULSE_COOKIE":             "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie",
+				"PULSE_SERVER":             "unix:/run/user/65534/pulse/native",
+				"SHELL":                    "/run/current-system/sw/bin/zsh",
+				"TERM":                     "xterm-256color",
+				"USER":                     "chronos",
+				"WAYLAND_DISPLAY":          "/run/user/65534/wayland-0",
+				"XDG_RUNTIME_DIR":          "/run/user/65534",
+				"XDG_SESSION_CLASS":        "user",
+				"XDG_SESSION_TYPE":         "tty",
+			},
+			Chmod:         make(bwrap.ChmodConfig),
+			DieWithParent: true,
+			AsInit:        true,
+		}).SetUID(65534).SetGID(65534).
+			Procfs("/proc").
+			Tmpfs("/fortify", 4096).
+			DevTmpfs("/dev").Mqueue("/dev/mqueue").
+			Bind("/bin", "/bin", false, true).
+			Bind("/boot", "/boot", false, true).
+			Bind("/home", "/home", false, true).
+			Bind("/lib", "/lib", false, true).
+			Bind("/lib64", "/lib64", false, true).
+			Bind("/nix", "/nix", false, true).
+			Bind("/root", "/root", false, true).
+			Bind("/srv", "/srv", false, true).
+			Bind("/sys", "/sys", false, true).
+			Bind("/usr", "/usr", false, true).
+			Bind("/var", "/var", false, true).
+			Bind("/run/agetty.reload", "/run/agetty.reload", false, true).
+			Bind("/run/binfmt", "/run/binfmt", false, true).
+			Bind("/run/booted-system", "/run/booted-system", false, true).
+			Bind("/run/credentials", "/run/credentials", false, true).
+			Bind("/run/cryptsetup", "/run/cryptsetup", false, true).
+			Bind("/run/current-system", "/run/current-system", false, true).
+			Bind("/run/host", "/run/host", false, true).
+			Bind("/run/keys", "/run/keys", false, true).
+			Bind("/run/libvirt", "/run/libvirt", false, true).
+			Bind("/run/libvirtd.pid", "/run/libvirtd.pid", false, true).
+			Bind("/run/lock", "/run/lock", false, true).
+			Bind("/run/log", "/run/log", false, true).
+			Bind("/run/lvm", "/run/lvm", false, true).
+			Bind("/run/mount", "/run/mount", false, true).
+			Bind("/run/NetworkManager", "/run/NetworkManager", false, true).
+			Bind("/run/nginx", "/run/nginx", false, true).
+			Bind("/run/nixos", "/run/nixos", false, true).
+			Bind("/run/nscd", "/run/nscd", false, true).
+			Bind("/run/opengl-driver", "/run/opengl-driver", false, true).
+			Bind("/run/pppd", "/run/pppd", false, true).
+			Bind("/run/resolvconf", "/run/resolvconf", false, true).
+			Bind("/run/sddm", "/run/sddm", false, true).
+			Bind("/run/store", "/run/store", false, true).
+			Bind("/run/syncoid", "/run/syncoid", false, true).
+			Bind("/run/system", "/run/system", false, true).
+			Bind("/run/systemd", "/run/systemd", false, true).
+			Bind("/run/tmpfiles.d", "/run/tmpfiles.d", false, true).
+			Bind("/run/udev", "/run/udev", false, true).
+			Bind("/run/udisks2", "/run/udisks2", false, true).
+			Bind("/run/utmp", "/run/utmp", false, true).
+			Bind("/run/virtlogd.pid", "/run/virtlogd.pid", false, true).
+			Bind("/run/wrappers", "/run/wrappers", false, true).
+			Bind("/run/zed.pid", "/run/zed.pid", false, true).
+			Bind("/run/zed.state", "/run/zed.state", false, true).
+			Bind("/dev/dri", "/dev/dri", true, true, true).
+			Bind("/etc", "/fortify/etc").
+			Symlink("/fortify/etc/alsa", "/etc/alsa").
+			Symlink("/fortify/etc/bashrc", "/etc/bashrc").
+			Symlink("/fortify/etc/binfmt.d", "/etc/binfmt.d").
+			Symlink("/fortify/etc/dbus-1", "/etc/dbus-1").
+			Symlink("/fortify/etc/default", "/etc/default").
+			Symlink("/fortify/etc/ethertypes", "/etc/ethertypes").
+			Symlink("/fortify/etc/fonts", "/etc/fonts").
+			Symlink("/fortify/etc/fstab", "/etc/fstab").
+			Symlink("/fortify/etc/fuse.conf", "/etc/fuse.conf").
+			Symlink("/fortify/etc/host.conf", "/etc/host.conf").
+			Symlink("/fortify/etc/hostid", "/etc/hostid").
+			Symlink("/fortify/etc/hostname", "/etc/hostname").
+			Symlink("/fortify/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
+			Symlink("/fortify/etc/hosts", "/etc/hosts").
+			Symlink("/fortify/etc/inputrc", "/etc/inputrc").
+			Symlink("/fortify/etc/ipsec.d", "/etc/ipsec.d").
+			Symlink("/fortify/etc/issue", "/etc/issue").
+			Symlink("/fortify/etc/kbd", "/etc/kbd").
+			Symlink("/fortify/etc/libblockdev", "/etc/libblockdev").
+			Symlink("/fortify/etc/locale.conf", "/etc/locale.conf").
+			Symlink("/fortify/etc/localtime", "/etc/localtime").
+			Symlink("/fortify/etc/login.defs", "/etc/login.defs").
+			Symlink("/fortify/etc/lsb-release", "/etc/lsb-release").
+			Symlink("/fortify/etc/lvm", "/etc/lvm").
+			Symlink("/fortify/etc/machine-id", "/etc/machine-id").
+			Symlink("/fortify/etc/man_db.conf", "/etc/man_db.conf").
+			Symlink("/fortify/etc/modprobe.d", "/etc/modprobe.d").
+			Symlink("/fortify/etc/modules-load.d", "/etc/modules-load.d").
+			Symlink("/proc/mounts", "/etc/mtab").
+			Symlink("/fortify/etc/nanorc", "/etc/nanorc").
+			Symlink("/fortify/etc/netgroup", "/etc/netgroup").
+			Symlink("/fortify/etc/NetworkManager", "/etc/NetworkManager").
+			Symlink("/fortify/etc/nix", "/etc/nix").
+			Symlink("/fortify/etc/nixos", "/etc/nixos").
+			Symlink("/fortify/etc/NIXOS", "/etc/NIXOS").
+			Symlink("/fortify/etc/nscd.conf", "/etc/nscd.conf").
+			Symlink("/fortify/etc/nsswitch.conf", "/etc/nsswitch.conf").
+			Symlink("/fortify/etc/opensnitchd", "/etc/opensnitchd").
+			Symlink("/fortify/etc/os-release", "/etc/os-release").
+			Symlink("/fortify/etc/pam", "/etc/pam").
+			Symlink("/fortify/etc/pam.d", "/etc/pam.d").
+			Symlink("/fortify/etc/pipewire", "/etc/pipewire").
+			Symlink("/fortify/etc/pki", "/etc/pki").
+			Symlink("/fortify/etc/polkit-1", "/etc/polkit-1").
+			Symlink("/fortify/etc/profile", "/etc/profile").
+			Symlink("/fortify/etc/protocols", "/etc/protocols").
+			Symlink("/fortify/etc/qemu", "/etc/qemu").
+			Symlink("/fortify/etc/resolv.conf", "/etc/resolv.conf").
+			Symlink("/fortify/etc/resolvconf.conf", "/etc/resolvconf.conf").
+			Symlink("/fortify/etc/rpc", "/etc/rpc").
+			Symlink("/fortify/etc/samba", "/etc/samba").
+			Symlink("/fortify/etc/sddm.conf", "/etc/sddm.conf").
+			Symlink("/fortify/etc/secureboot", "/etc/secureboot").
+			Symlink("/fortify/etc/services", "/etc/services").
+			Symlink("/fortify/etc/set-environment", "/etc/set-environment").
+			Symlink("/fortify/etc/shadow", "/etc/shadow").
+			Symlink("/fortify/etc/shells", "/etc/shells").
+			Symlink("/fortify/etc/ssh", "/etc/ssh").
+			Symlink("/fortify/etc/ssl", "/etc/ssl").
+			Symlink("/fortify/etc/static", "/etc/static").
+			Symlink("/fortify/etc/subgid", "/etc/subgid").
+			Symlink("/fortify/etc/subuid", "/etc/subuid").
+			Symlink("/fortify/etc/sudoers", "/etc/sudoers").
+			Symlink("/fortify/etc/sysctl.d", "/etc/sysctl.d").
+			Symlink("/fortify/etc/systemd", "/etc/systemd").
+			Symlink("/fortify/etc/terminfo", "/etc/terminfo").
+			Symlink("/fortify/etc/tmpfiles.d", "/etc/tmpfiles.d").
+			Symlink("/fortify/etc/udev", "/etc/udev").
+			Symlink("/fortify/etc/udisks2", "/etc/udisks2").
+			Symlink("/fortify/etc/UPower", "/etc/UPower").
+			Symlink("/fortify/etc/vconsole.conf", "/etc/vconsole.conf").
+			Symlink("/fortify/etc/X11", "/etc/X11").
+			Symlink("/fortify/etc/zfs", "/etc/zfs").
+			Symlink("/fortify/etc/zinputrc", "/etc/zinputrc").
+			Symlink("/fortify/etc/zoneinfo", "/etc/zoneinfo").
+			Symlink("/fortify/etc/zprofile", "/etc/zprofile").
+			Symlink("/fortify/etc/zshenv", "/etc/zshenv").
+			Symlink("/fortify/etc/zshrc", "/etc/zshrc").
+			Bind("/tmp/fortify.1971/tmpdir/9", "/tmp", false, true).
+			Tmpfs("/tmp/fortify.1971", 1048576).
+			Tmpfs("/run/user", 1048576).
+			Tmpfs("/run/user/65534", 8388608).
+			Bind("/home/chronos", "/home/chronos", false, true).
+			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/passwd", "/etc/passwd").
+			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/group", "/etc/group").
+			Bind("/tmp/fortify.1971/wayland/ebf083d1b175911782d413369b64ce7c", "/run/user/65534/wayland-0").
+			Bind("/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse", "/run/user/65534/pulse/native").
+			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie", "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/pulse-cookie").
+			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", "/run/user/65534/bus").
+			Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", "/run/dbus/system_bus_socket").
+			Tmpfs("/var/run/nscd", 8192),
+	},
+}

internal/app/app_stub_test.go

@@ -0,0 +1,153 @@
+package app_test
+
+import (
+	"fmt"
+	"io"
+	"io/fs"
+	"os/user"
+	"strconv"
+
+	"git.gensokyo.uk/security/fortify/internal/linux"
+)
+
+// fs methods are not implemented using a real FS
+// to help better understand filesystem access behaviour
+type stubNixOS struct {
+	lookPathErr map[string]error
+	usernameErr map[string]error
+}
+
+func (s *stubNixOS) Geteuid() int {
+	return 1971
+}
+
+func (s *stubNixOS) LookupEnv(key string) (string, bool) {
+	switch key {
+	case "SHELL":
+		return "/run/current-system/sw/bin/zsh", true
+	case "TERM":
+		return "xterm-256color", true
+	case "WAYLAND_DISPLAY":
+		return "wayland-0", true
+	case "PULSE_COOKIE":
+		return "", false
+	case "HOME":
+		return "/home/ophestra", true
+	case "XDG_CONFIG_HOME":
+		return "/home/ophestra/xdg/config", true
+	default:
+		panic(fmt.Sprintf("attempted to access unexpected environment variable %q", key))
+	}
+}
+
+func (s *stubNixOS) TempDir() string {
+	return "/tmp"
+}
+
+func (s *stubNixOS) LookPath(file string) (string, error) {
+	if s.lookPathErr != nil {
+		if err, ok := s.lookPathErr[file]; ok {
+			return "", err
+		}
+	}
+
+	switch file {
+	case "sudo":
+		return "/run/wrappers/bin/sudo", nil
+	case "machinectl":
+		return "/home/ophestra/.nix-profile/bin/machinectl", nil
+	default:
+		panic(fmt.Sprintf("attempted to look up unexpected executable %q", file))
+	}
+}
+
+func (s *stubNixOS) Executable() (string, error) {
+	return "/home/ophestra/.nix-profile/bin/fortify", nil
+}
+
+func (s *stubNixOS) LookupGroup(name string) (*user.Group, error) {
+	switch name {
+	case "video":
+		return &user.Group{Gid: "26", Name: "video"}, nil
+	default:
+		return nil, user.UnknownGroupError(name)
+	}
+}
+
+func (s *stubNixOS) ReadDir(name string) ([]fs.DirEntry, error) {
+	switch name {
+	case "/":
+		return stubDirEntries("bin", "boot", "dev", "etc", "home", "lib",
+			"lib64", "nix", "proc", "root", "run", "srv", "sys", "tmp", "usr", "var")
+	case "/run":
+		return stubDirEntries("agetty.reload", "binfmt", "booted-system",
+			"credentials", "cryptsetup", "current-system", "dbus", "host", "keys",
+			"libvirt", "libvirtd.pid", "lock", "log", "lvm", "mount", "NetworkManager",
+			"nginx", "nixos", "nscd", "opengl-driver", "pppd", "resolvconf", "sddm",
+			"store", "syncoid", "system", "systemd", "tmpfiles.d", "udev", "udisks2",
+			"user", "utmp", "virtlogd.pid", "wrappers", "zed.pid", "zed.state")
+	case "/etc":
+		return stubDirEntries("alsa", "bashrc", "binfmt.d", "dbus-1", "default",
+			"ethertypes", "fonts", "fstab", "fuse.conf", "group", "host.conf", "hostid",
+			"hostname", "hostname.CHECKSUM", "hosts", "inputrc", "ipsec.d", "issue", "kbd",
+			"libblockdev", "locale.conf", "localtime", "login.defs", "lsb-release", "lvm",
+			"machine-id", "man_db.conf", "modprobe.d", "modules-load.d", "mtab", "nanorc",
+			"netgroup", "NetworkManager", "nix", "nixos", "NIXOS", "nscd.conf", "nsswitch.conf",
+			"opensnitchd", "os-release", "pam", "pam.d", "passwd", "pipewire", "pki", "polkit-1",
+			"profile", "protocols", "qemu", "resolv.conf", "resolvconf.conf", "rpc", "samba",
+			"sddm.conf", "secureboot", "services", "set-environment", "shadow", "shells", "ssh",
+			"ssl", "static", "subgid", "subuid", "sudoers", "sysctl.d", "systemd", "terminfo",
+			"tmpfiles.d", "udev", "udisks2", "UPower", "vconsole.conf", "X11", "zfs", "zinputrc",
+			"zoneinfo", "zprofile", "zshenv", "zshrc")
+	default:
+		panic(fmt.Sprintf("attempted to read unexpected directory %q", name))
+	}
+}
+
+func (s *stubNixOS) Stat(name string) (fs.FileInfo, error) {
+	switch name {
+	case "/var/run/nscd":
+		return nil, nil
+	case "/run/user/1971/pulse":
+		return nil, nil
+	case "/run/user/1971/pulse/native":
+		return stubFileInfoMode(0666), nil
+	case "/home/ophestra/.pulse-cookie":
+		return stubFileInfoIsDir(true), nil
+	case "/home/ophestra/xdg/config/pulse/cookie":
+		return stubFileInfoIsDir(false), nil
+	default:
+		panic(fmt.Sprintf("attempted to stat unexpected path %q", name))
+	}
+}
+
+func (s *stubNixOS) Open(name string) (fs.File, error) {
+	switch name {
+	default:
+		panic(fmt.Sprintf("attempted to open unexpected file %q", name))
+	}
+}
+
+func (s *stubNixOS) Exit(code int) {
+	panic("called exit on stub with code " + strconv.Itoa(code))
+}
+
+func (s *stubNixOS) Stdout() io.Writer {
+	panic("requested stdout")
+}
+
+func (s *stubNixOS) Paths() linux.Paths {
+	return linux.Paths{
+		SharePath:   "/tmp/fortify.1971",
+		RuntimePath: "/run/user/1971",
+		RunDirPath:  "/run/user/1971/fortify",
+	}
+}
+
+func (s *stubNixOS) Uid(aid int) (int, error) {
+	return 1000000 + 0*10000 + aid, nil
+}
+
+func (s *stubNixOS) SdBooted() bool {
+	return true
+}

internal/app/app_test.go

@@ -6,23 +6,24 @@ import (
 	"testing"
 	"time"
 
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/app"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 type sealTestCase struct {
 	name      string
-	os        internal.System
-	config    *app.Config
-	id        app.ID
+	os        linux.System
+	config    *fst.Config
+	id        fst.ID
 	wantSys   *system.I
 	wantBwrap *bwrap.Config
 }
 
 func TestApp(t *testing.T) {
-	testCases := append(testCasesNixos)
+	testCases := append(testCasesPd, testCasesNixos...)
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {

internal/app/export_test.go

@@ -1,12 +1,13 @@
 package app
 
 import (
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
-func NewWithID(id ID, os internal.System) App {
+func NewWithID(id fst.ID, os linux.System) App {
 	a := new(app)
 	a.id = &id
 	a.os = os

internal/app/id.go

@@ -1,17 +0,0 @@
-package app
-
-import (
-	"crypto/rand"
-	"encoding/hex"
-)
-
-type ID [16]byte
-
-func (a *ID) String() string {
-	return hex.EncodeToString(a[:])
-}
-
-func newAppID(id *ID) error {
-	_, err := rand.Read(id[:])
-	return err
-}

internal/app/launch.machinectl.go

@@ -1,57 +0,0 @@
-package app
-
-import (
-	"strings"
-
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-)
-
-func (a *app) commandBuilderMachineCtl(shimEnv string) (args []string) {
-	args = make([]string, 0, 9+len(a.seal.sys.bwrap.SetEnv))
-
-	// shell --uid=$USER
-	args = append(args, "shell", "--uid="+a.seal.sys.user.Username)
-
-	// --quiet
-	if !fmsg.Verbose() {
-		args = append(args, "--quiet")
-	}
-
-	// environ
-	envQ := make([]string, 0, len(a.seal.sys.bwrap.SetEnv)+1)
-	for k, v := range a.seal.sys.bwrap.SetEnv {
-		envQ = append(envQ, "-E"+k+"="+v)
-	}
-	// add shim payload to environment for shim path
-	envQ = append(envQ, "-E"+shimEnv)
-	args = append(args, envQ...)
-
-	// -- .host
-	args = append(args, "--", ".host")
-
-	// /bin/sh -c
-	if sh, err := a.os.LookPath("sh"); err != nil {
-		// hardcode /bin/sh path since it exists more often than not
-		args = append(args, "/bin/sh", "-c")
-	} else {
-		args = append(args, sh, "-c")
-	}
-
-	// build inner command expression ran as target user
-	innerCommand := strings.Builder{}
-
-	// apply custom environment variables to activation environment
-	innerCommand.WriteString("dbus-update-activation-environment --systemd")
-	for k := range a.seal.sys.bwrap.SetEnv {
-		innerCommand.WriteString(" " + k)
-	}
-	innerCommand.WriteString("; ")
-
-	// launch fortify as shim
-	innerCommand.WriteString("exec " + a.seal.sys.executable + " shim")
-
-	// append inner command
-	args = append(args, innerCommand.String())
-
-	return
-}

internal/app/launch.sudo.go

@@ -1,30 +0,0 @@
-package app
-
-import (
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-)
-
-const (
-	sudoAskPass = "SUDO_ASKPASS"
-)
-
-func (a *app) commandBuilderSudo(shimEnv string) (args []string) {
-	args = make([]string, 0, 8)
-
-	// -Hiu $USER
-	args = append(args, "-Hiu", a.seal.sys.user.Username)
-
-	// -A?
-	if _, ok := a.os.LookupEnv(sudoAskPass); ok {
-		fmsg.VPrintln(sudoAskPass, "set, adding askpass flag")
-		args = append(args, "-A")
-	}
-
-	// shim payload
-	args = append(args, shimEnv)
-
-	// -- $@
-	args = append(args, "--", a.seal.sys.executable, "shim")
-
-	return
-}

internal/app/seal.go

@@ -2,45 +2,35 @@ package app
 
 import (
 	"errors"
+	"fmt"
 	"io/fs"
-	"os/user"
 	"path"
+	"regexp"
 	"strconv"
 
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/shim"
-	"git.ophivana.moe/security/fortify/internal/state"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/state"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
-const (
-	LaunchMethodSudo uint8 = iota
-	LaunchMethodMachineCtl
-)
-
-var method = [...]string{
-	LaunchMethodSudo:       "sudo",
-	LaunchMethodMachineCtl: "systemd",
-}
-
 var (
 	ErrConfig = errors.New("no configuration to seal")
-	ErrUser   = errors.New("unknown user")
-	ErrLaunch = errors.New("invalid launch method")
-
-	ErrSudo       = errors.New("sudo not available")
-	ErrSystemd    = errors.New("systemd not available")
-	ErrMachineCtl = errors.New("machinectl not available")
+	ErrUser   = errors.New("invalid aid")
+	ErrHome   = errors.New("invalid home directory")
+	ErrName   = errors.New("invalid username")
 )
 
+var posixUsername = regexp.MustCompilePOSIX("^[a-z_]([A-Za-z0-9_-]{0,31}|[A-Za-z0-9_-]{0,30}\\$)$")
+
 // appSeal seals the application with child-related information
 type appSeal struct {
 	// app unique ID string representation
 	id string
-	// wayland mediation, disabled if nil
-	wl *shim.Wayland
+	// dbus proxy message buffer retriever
+	dbusMsg func(f func(msgbuf []string))
 
 	// freedesktop application ID
 	fid string
@@ -49,30 +39,28 @@ type appSeal struct {
 	// persistent process state store
 	store state.Store
 
-	// uint8 representation of launch method sealed from config
-	launchOption uint8
 	// process-specific share directory path
 	share string
 	// process-specific share directory path local to XDG_RUNTIME_DIR
 	shareLocal string
 
-	// path to launcher program
-	toolPath string
 	// pass-through enablement tracking from config
 	et system.Enablements
+	// wayland socket direct access
+	directWayland bool
 
 	// prevents sharing from happening twice
 	shared bool
 	// seal system-level component
 	sys *appSealSys
 
-	internal.Paths
+	linux.Paths
 
 	// protected by upstream mutex
 }
 
 // Seal seals the app launch context
-func (a *app) Seal(config *Config) error {
+func (a *app) Seal(config *fst.Config) error {
 	a.lock.Lock()
 	defer a.lock.Unlock()
 
@@ -96,55 +84,63 @@ func (a *app) Seal(config *Config) error {
 	seal.fid = config.ID
 	seal.command = config.Command
 
-	// parses launch method text and looks up tool path
-	switch config.Method {
-	case method[LaunchMethodSudo]:
-		seal.launchOption = LaunchMethodSudo
-		if sudoPath, err := a.os.LookPath("sudo"); err != nil {
-			return fmsg.WrapError(ErrSudo,
-				"sudo not found")
-		} else {
-			seal.toolPath = sudoPath
-		}
-	case method[LaunchMethodMachineCtl]:
-		seal.launchOption = LaunchMethodMachineCtl
-		if !a.os.SdBooted() {
-			return fmsg.WrapError(ErrSystemd,
-				"system has not been booted with systemd as init system")
-		}
-
-		if machineCtlPath, err := a.os.LookPath("machinectl"); err != nil {
-			return fmsg.WrapError(ErrMachineCtl,
-				"machinectl not found")
-		} else {
-			seal.toolPath = machineCtlPath
-		}
-	default:
-		return fmsg.WrapError(ErrLaunch,
-			"invalid launch method")
-	}
-
 	// create seal system component
 	seal.sys = new(appSealSys)
 
-	// look up fortify executable path
-	if p, err := a.os.Executable(); err != nil {
-		return fmsg.WrapErrorSuffix(err, "cannot look up fortify executable path:")
+	// mapped uid
+	if config.Confinement.Sandbox != nil && config.Confinement.Sandbox.MapRealUID {
+		seal.sys.mappedID = a.os.Geteuid()
 	} else {
-		seal.sys.executable = p
+		seal.sys.mappedID = 65534
 	}
+	seal.sys.mappedIDString = strconv.Itoa(seal.sys.mappedID)
+	seal.sys.runtime = path.Join("/run/user", seal.sys.mappedIDString)
 
-	// look up user from system
-	if u, err := a.os.Lookup(config.User); err != nil {
-		if errors.As(err, new(user.UnknownUserError)) {
-			return fmsg.WrapError(ErrUser, "unknown user", config.User)
-		} else {
-			// unreachable
-			panic(err)
-		}
+	// validate uid and set user info
+	if config.Confinement.AppID < 0 || config.Confinement.AppID > 9999 {
+		return fmsg.WrapError(ErrUser,
+			fmt.Sprintf("aid %d out of range", config.Confinement.AppID))
 	} else {
-		seal.sys.user = u
-		seal.sys.runtime = path.Join("/run/user", u.Uid)
+		seal.sys.user = appUser{
+			aid:      config.Confinement.AppID,
+			as:       strconv.Itoa(config.Confinement.AppID),
+			data:     config.Confinement.Outer,
+			home:     config.Confinement.Inner,
+			username: config.Confinement.Username,
+		}
+		if seal.sys.user.username == "" {
+			seal.sys.user.username = "chronos"
+		} else if !posixUsername.MatchString(seal.sys.user.username) {
+			return fmsg.WrapError(ErrName,
+				fmt.Sprintf("invalid user name %q", seal.sys.user.username))
+		}
+		if seal.sys.user.data == "" || !path.IsAbs(seal.sys.user.data) {
+			return fmsg.WrapError(ErrHome,
+				fmt.Sprintf("invalid home directory %q", seal.sys.user.data))
+		}
+		if seal.sys.user.home == "" {
+			seal.sys.user.home = seal.sys.user.data
+		}
+
+		// invoke fsu for full uid
+		if u, err := a.os.Uid(seal.sys.user.aid); err != nil {
+			return fmsg.WrapErrorSuffix(err,
+				"cannot obtain uid from fsu:")
+		} else {
+			seal.sys.user.uid = u
+			seal.sys.user.us = strconv.Itoa(u)
+		}
+
+		// resolve supplementary group ids from names
+		seal.sys.user.supp = make([]string, len(config.Confinement.Groups))
+		for i, name := range config.Confinement.Groups {
+			if g, err := a.os.LookupGroup(name); err != nil {
+				return fmsg.WrapError(err,
+					fmt.Sprintf("unknown group %q", name))
+			} else {
+				seal.sys.user.supp[i] = g.Gid
+			}
+		}
 	}
 
 	// map sandbox config to bwrap
@@ -152,16 +148,17 @@ func (a *app) Seal(config *Config) error {
 		fmsg.VPrintln("sandbox configuration not supplied, PROCEED WITH CAUTION")
 
 		// permissive defaults
-		conf := &SandboxConfig{
+		conf := &fst.SandboxConfig{
 			UserNS:       true,
 			Net:          true,
 			NoNewSession: true,
+			AutoEtc:      true,
 		}
 		// bind entries in /
 		if d, err := a.os.ReadDir("/"); err != nil {
 			return err
 		} else {
-			b := make([]*FilesystemConfig, 0, len(d))
+			b := make([]*fst.FilesystemConfig, 0, len(d))
 			for _, ent := range d {
 				p := "/" + ent.Name()
 				switch p {
@@ -170,11 +167,10 @@ func (a *app) Seal(config *Config) error {
 				case "/run":
 				case "/tmp":
 				case "/mnt":
-
 				case "/etc":
-					b = append(b, &FilesystemConfig{Src: p, Dst: "/dev/fortify/etc", Write: false, Must: true})
+
 				default:
-					b = append(b, &FilesystemConfig{Src: p, Write: true, Must: true})
+					b = append(b, &fst.FilesystemConfig{Src: p, Write: true, Must: true})
 				}
 			}
 			conf.Filesystem = append(conf.Filesystem, b...)
@@ -183,7 +179,7 @@ func (a *app) Seal(config *Config) error {
 		if d, err := a.os.ReadDir("/run"); err != nil {
 			return err
 		} else {
-			b := make([]*FilesystemConfig, 0, len(d))
+			b := make([]*fst.FilesystemConfig, 0, len(d))
 			for _, ent := range d {
 				name := ent.Name()
 				switch name {
@@ -191,7 +187,7 @@ func (a *app) Seal(config *Config) error {
 				case "dbus":
 				default:
 					p := "/run/" + name
-					b = append(b, &FilesystemConfig{Src: p, Write: true, Must: true})
+					b = append(b, &fst.FilesystemConfig{Src: p, Write: true, Must: true})
 				}
 			}
 			conf.Filesystem = append(conf.Filesystem, b...)
@@ -203,60 +199,29 @@ func (a *app) Seal(config *Config) error {
 		}
 		// bind GPU stuff
 		if config.Confinement.Enablements.Has(system.EX11) || config.Confinement.Enablements.Has(system.EWayland) {
-			conf.Filesystem = append(conf.Filesystem, &FilesystemConfig{Src: "/dev/dri", Device: true})
-		}
-		// link host /etc to prevent passwd/group from being overwritten
-		if d, err := a.os.ReadDir("/etc"); err != nil {
-			return err
-		} else {
-			b := make([][2]string, 0, len(d))
-			for _, ent := range d {
-				name := ent.Name()
-				switch name {
-				case "passwd":
-				case "group":
-
-				case "mtab":
-					b = append(b, [2]string{
-						"/proc/mounts",
-						"/etc/" + name,
-					})
-				default:
-					b = append(b, [2]string{
-						"/dev/fortify/etc/" + name,
-						"/etc/" + name,
-					})
-				}
-			}
-			conf.Link = append(conf.Link, b...)
+			conf.Filesystem = append(conf.Filesystem, &fst.FilesystemConfig{Src: "/dev/dri", Device: true})
 		}
 
 		config.Confinement.Sandbox = conf
 	}
-	seal.sys.bwrap = config.Confinement.Sandbox.Bwrap()
+	seal.directWayland = config.Confinement.Sandbox.DirectWayland
+	if b, err := config.Confinement.Sandbox.Bwrap(a.os); err != nil {
+		return err
+	} else {
+		seal.sys.bwrap = b
+	}
 	seal.sys.override = config.Confinement.Sandbox.Override
 	if seal.sys.bwrap.SetEnv == nil {
 		seal.sys.bwrap.SetEnv = make(map[string]string)
 	}
 
-	// create wayland struct and client wait channel if mediated wayland is enabled
-	// this field being set enables mediated wayland setup later on
-	if config.Confinement.Sandbox.Wayland {
-		seal.wl = shim.NewWayland()
-	}
-
 	// open process state store
 	// the simple store only starts holding an open file after first action
 	// store activity begins after Start is called and must end before Wait
-	seal.store = state.NewSimple(seal.RunDirPath, seal.sys.user.Uid)
+	seal.store = state.NewMulti(seal.RunDirPath)
 
-	// parse string UID
-	if u, err := strconv.Atoi(seal.sys.user.Uid); err != nil {
-		// unreachable unless kernel bug
-		panic("uid parse")
-	} else {
-		seal.sys.I = system.New(u)
-	}
+	// initialise system interface with full uid
+	seal.sys.I = system.New(seal.sys.user.uid)
 
 	// pass through enablements
 	seal.et = config.Confinement.Enablements
@@ -267,13 +232,11 @@ func (a *app) Seal(config *Config) error {
 	}
 
 	// verbose log seal information
-	fmsg.VPrintln("created application seal as user",
-		seal.sys.user.Username, "("+seal.sys.user.Uid+"),",
-		"method:", config.Method+",",
-		"launcher:", seal.toolPath+",",
-		"command:", config.Command)
+	fmsg.VPrintf("created application seal for uid %s (%s) groups: %v, command: %s",
+		seal.sys.user.us, seal.sys.user.username, config.Confinement.Groups, config.Command)
 
 	// seal app and release lock
 	a.seal = seal
+	a.ct = newAppCt(config)
 	return nil
 }

internal/app/share.dbus.go

@@ -3,9 +3,9 @@ package app
 import (
 	"path"
 
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 const (
@@ -22,8 +22,10 @@ func (seal *appSeal) shareDBus(config [2]*dbus.Config) error {
 	sessionPath, systemPath := path.Join(seal.share, "bus"), path.Join(seal.share, "system_bus_socket")
 
 	// configure dbus proxy
-	if err := seal.sys.ProxyDBus(config[0], config[1], sessionPath, systemPath); err != nil {
+	if f, err := seal.sys.ProxyDBus(config[0], config[1], sessionPath, systemPath); err != nil {
 		return err
+	} else {
+		seal.dbusMsg = f
 	}
 
 	// share proxy sockets

internal/app/share.display.go

@@ -4,10 +4,10 @@ import (
 	"errors"
 	"path"
 
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 const (
@@ -23,7 +23,7 @@ var (
 	ErrXDisplay = errors.New(display + " unset")
 )
 
-func (seal *appSeal) shareDisplay(os internal.System) error {
+func (seal *appSeal) shareDisplay(os linux.System) error {
 	// pass $TERM to launcher
 	if t, ok := os.LookupEnv(term); ok {
 		seal.sys.bwrap.SetEnv[term] = t
@@ -31,23 +31,36 @@ func (seal *appSeal) shareDisplay(os internal.System) error {
 
 	// set up wayland
 	if seal.et.Has(system.EWayland) {
+		var wp string
 		if wd, ok := os.LookupEnv(waylandDisplay); !ok {
 			return fmsg.WrapError(ErrWayland,
 				"WAYLAND_DISPLAY is not set")
-		} else if seal.wl == nil {
+		} else {
+			wp = path.Join(seal.RuntimePath, wd)
+		}
+
+		w := path.Join(seal.sys.runtime, "wayland-0")
+		seal.sys.bwrap.SetEnv[waylandDisplay] = w
+
+		if seal.directWayland {
 			// hardlink wayland socket
-			wp := path.Join(seal.RuntimePath, wd)
 			wpi := path.Join(seal.shareLocal, "wayland")
-			w := path.Join(seal.sys.runtime, "wayland-0")
 			seal.sys.Link(wp, wpi)
-			seal.sys.bwrap.SetEnv[waylandDisplay] = w
 			seal.sys.bwrap.Bind(wpi, w)
 
 			// ensure Wayland socket ACL (e.g. `/run/user/%d/wayland-%d`)
 			seal.sys.UpdatePermType(system.EWayland, wp, acl.Read, acl.Write, acl.Execute)
 		} else {
-			// set wayland socket path for mediation (e.g. `/run/user/%d/wayland-%d`)
-			seal.wl.Path = path.Join(seal.RuntimePath, wd)
+			wc := path.Join(seal.SharePath, "wayland")
+			wt := path.Join(wc, seal.id)
+			seal.sys.Ensure(wc, 0711)
+			appID := seal.fid
+			if appID == "" {
+				// use instance ID in case app id is not set
+				appID = "moe.ophivana.fortify." + seal.id
+			}
+			seal.sys.Wayland(wt, wp, appID, seal.id)
+			seal.sys.bwrap.Bind(wt, w)
 		}
 	}
 
@@ -58,7 +71,7 @@ func (seal *appSeal) shareDisplay(os internal.System) error {
 			return fmsg.WrapError(ErrXDisplay,
 				"DISPLAY is not set")
 		} else {
-			seal.sys.ChangeHosts(seal.sys.user.Username)
+			seal.sys.ChangeHosts("#" + seal.sys.user.us)
 			seal.sys.bwrap.SetEnv[display] = d
 			seal.sys.bwrap.Bind("/tmp/.X11-unix", "/tmp/.X11-unix")
 		}

internal/app/share.pulse.go

@@ -6,9 +6,9 @@ import (
 	"io/fs"
 	"path"
 
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 const (
@@ -25,7 +25,7 @@ var (
 	ErrPulseMode   = errors.New("unexpected pulse socket mode")
 )
 
-func (seal *appSeal) sharePulse(os internal.System) error {
+func (seal *appSeal) sharePulse(os linux.System) error {
 	if !seal.et.Has(system.EPulse) {
 		return nil
 	}
@@ -78,7 +78,7 @@ func (seal *appSeal) sharePulse(os internal.System) error {
 }
 
 // discoverPulseCookie attempts various standard methods to discover the current user's PulseAudio authentication cookie
-func discoverPulseCookie(os internal.System) (string, error) {
+func discoverPulseCookie(os linux.System) (string, error) {
 	if p, ok := os.LookupEnv(pulseCookie); ok {
 		return p, nil
 	}

internal/app/share.runtime.go

@@ -3,8 +3,8 @@ package app
 import (
 	"path"
 
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 const (

internal/app/share.system.go

@@ -3,9 +3,9 @@ package app
 import (
 	"path"
 
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 const (
@@ -16,12 +16,12 @@ const (
 func (seal *appSeal) shareSystem() {
 	// ensure Share (e.g. `/tmp/fortify.%d`)
 	// acl is unnecessary as this directory is world executable
-	seal.sys.Ensure(seal.SharePath, 0701)
+	seal.sys.Ensure(seal.SharePath, 0711)
 
 	// ensure process-specific share (e.g. `/tmp/fortify.%d/%s`)
 	// acl is unnecessary as this directory is world executable
 	seal.share = path.Join(seal.SharePath, seal.id)
-	seal.sys.Ephemeral(system.Process, seal.share, 0701)
+	seal.sys.Ephemeral(system.Process, seal.share, 0711)
 
 	// ensure child tmpdir parent directory (e.g. `/tmp/fortify.%d/tmpdir`)
 	targetTmpdirParent := path.Join(seal.SharePath, "tmpdir")
@@ -29,7 +29,7 @@ func (seal *appSeal) shareSystem() {
 	seal.sys.UpdatePermType(system.User, targetTmpdirParent, acl.Execute)
 
 	// ensure child tmpdir (e.g. `/tmp/fortify.%d/tmpdir/%d`)
-	targetTmpdir := path.Join(targetTmpdirParent, seal.sys.user.Uid)
+	targetTmpdir := path.Join(targetTmpdirParent, seal.sys.user.as)
 	seal.sys.Ensure(targetTmpdir, 01700)
 	seal.sys.UpdatePermType(system.User, targetTmpdir, acl.Read, acl.Write, acl.Execute)
 	seal.sys.bwrap.Bind(targetTmpdir, "/tmp", false, true)
@@ -38,7 +38,7 @@ func (seal *appSeal) shareSystem() {
 	seal.sys.bwrap.Tmpfs(seal.SharePath, 1*1024*1024)
 }
 
-func (seal *appSeal) sharePasswd(os internal.System) {
+func (seal *appSeal) sharePasswd(os linux.System) {
 	// look up shell
 	sh := "/bin/sh"
 	if s, ok := os.LookupEnv(shell); ok {
@@ -49,21 +49,27 @@ func (seal *appSeal) sharePasswd(os internal.System) {
 	// generate /etc/passwd
 	passwdPath := path.Join(seal.share, "passwd")
 	username := "chronos"
-	if seal.sys.user.Username != "" {
-		username = seal.sys.user.Username
-		seal.sys.bwrap.SetEnv["USER"] = seal.sys.user.Username
+	if seal.sys.user.username != "" {
+		username = seal.sys.user.username
 	}
 	homeDir := "/var/empty"
-	if seal.sys.user.HomeDir != "" {
-		homeDir = seal.sys.user.HomeDir
-		seal.sys.bwrap.SetEnv["HOME"] = seal.sys.user.HomeDir
+	if seal.sys.user.home != "" {
+		homeDir = seal.sys.user.home
 	}
-	passwd := username + ":x:65534:65534:Fortify:" + homeDir + ":" + sh + "\n"
+
+	// bind home directory
+	seal.sys.bwrap.Bind(seal.sys.user.data, homeDir, false, true)
+	seal.sys.bwrap.Chdir = homeDir
+
+	seal.sys.bwrap.SetEnv["USER"] = username
+	seal.sys.bwrap.SetEnv["HOME"] = homeDir
+
+	passwd := username + ":x:" + seal.sys.mappedIDString + ":" + seal.sys.mappedIDString + ":Fortify:" + homeDir + ":" + sh + "\n"
 	seal.sys.Write(passwdPath, passwd)
 
 	// write /etc/group
 	groupPath := path.Join(seal.share, "group")
-	seal.sys.Write(groupPath, "fortify:x:65534:\n")
+	seal.sys.Write(groupPath, "fortify:x:"+seal.sys.mappedIDString+":\n")
 
 	// bind /etc/passwd and /etc/group
 	seal.sys.bwrap.Bind(passwdPath, "/etc/passwd")

internal/app/start.go

@@ -4,15 +4,15 @@ import (
 	"errors"
 	"fmt"
 	"os/exec"
-	"path"
 	"path/filepath"
 	"strings"
 
-	"git.ophivana.moe/security/fortify/helper"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/shim"
-	"git.ophivana.moe/security/fortify/internal/state"
-	"git.ophivana.moe/security/fortify/internal/system"
+	shim0 "git.gensokyo.uk/security/fortify/cmd/fshim/ipc"
+	"git.gensokyo.uk/security/fortify/cmd/fshim/ipc/shim"
+	"git.gensokyo.uk/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/state"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 // Start selects a user switcher and starts shim.
@@ -22,9 +22,9 @@ func (a *app) Start() error {
 	defer a.lock.Unlock()
 
 	// resolve exec paths
-	shimExec := [3]string{a.seal.sys.executable, helper.BubblewrapName}
+	shimExec := [2]string{helper.BubblewrapName}
 	if len(a.seal.command) > 0 {
-		shimExec[2] = a.seal.command[0]
+		shimExec[1] = a.seal.command[0]
 	}
 	for i, n := range shimExec {
 		if len(n) == 0 {
@@ -40,30 +40,18 @@ func (a *app) Start() error {
 		}
 	}
 
-	// select command builder
-	var commandBuilder shim.CommandBuilder
-	switch a.seal.launchOption {
-	case LaunchMethodSudo:
-		commandBuilder = a.commandBuilderSudo
-	case LaunchMethodMachineCtl:
-		commandBuilder = a.commandBuilderMachineCtl
-	default:
-		panic("unreachable")
-	}
-
 	// construct shim manager
-	a.shim = shim.New(a.seal.toolPath, uint32(a.seal.sys.UID()), path.Join(a.seal.share, "shim"), a.seal.wl,
-		&shim.Payload{
+	a.shim = shim.New(
+		uint32(a.seal.sys.UID()),
+		a.seal.sys.user.as,
+		a.seal.sys.user.supp,
+		&shim0.Payload{
 			Argv:  a.seal.command,
 			Exec:  shimExec,
 			Bwrap: a.seal.sys.bwrap,
-			WL:    a.seal.wl != nil,
 
 			Verbose: fmsg.Verbose(),
 		},
-		// checkPid is impossible at the moment since there is no reliable way to obtain shim's pid
-		// this feature is disabled here until sudo is replaced by fortify suid wrapper
-		false,
 	)
 
 	// startup will go ahead, commit system setup
@@ -72,23 +60,24 @@ func (a *app) Start() error {
 	}
 	a.seal.sys.needRevert = true
 
-	if startTime, err := a.shim.Start(commandBuilder); err != nil {
+	// export sync pipe from sys
+	a.seal.sys.bwrap.SetSync(a.seal.sys.Sync())
+
+	if startTime, err := a.shim.Start(); err != nil {
 		return err
 	} else {
 		// shim start and setup success, create process state
 		sd := state.State{
-			PID:        a.shim.Unwrap().Process.Pid,
-			Command:    a.seal.command,
-			Capability: a.seal.et,
-			Method:     method[a.seal.launchOption],
-			Argv:       a.shim.Unwrap().Args,
-			Time:       *startTime,
+			ID:     *a.id,
+			PID:    a.shim.Unwrap().Process.Pid,
+			Config: a.ct.Unwrap(),
+			Time:   *startTime,
 		}
 
 		// register process state
 		var err0 = new(StateStoreError)
-		err0.Inner, err0.DoErr = a.seal.store.Do(func(b state.Backend) {
-			err0.InnerErr = b.Save(&sd)
+		err0.Inner, err0.DoErr = a.seal.store.Do(a.seal.sys.user.aid, func(c state.Cursor) {
+			err0.InnerErr = c.Save(&sd)
 		})
 		a.seal.sys.saveState = true
 		return err0.equiv("cannot save process state:")
@@ -165,39 +154,56 @@ func (a *app) Wait() (int, error) {
 		// failure prior to process start
 		r = 255
 	} else {
-		// wait for process and resolve exit code
-		if err := cmd.Wait(); err != nil {
-			var exitError *exec.ExitError
-			if !errors.As(err, &exitError) {
-				// should be unreachable
-				a.waitErr = err
-			}
+		wait := make(chan error, 1)
+		go func() { wait <- cmd.Wait() }()
 
-			// store non-zero return code
-			r = exitError.ExitCode()
-		} else {
-			r = cmd.ProcessState.ExitCode()
+		select {
+		// wait for process and resolve exit code
+		case err := <-wait:
+			if err != nil {
+				var exitError *exec.ExitError
+				if !errors.As(err, &exitError) {
+					// should be unreachable
+					a.waitErr = err
+				}
+
+				// store non-zero return code
+				r = exitError.ExitCode()
+			} else {
+				r = cmd.ProcessState.ExitCode()
+			}
+			fmsg.VPrintf("process %d exited with exit code %d", cmd.Process.Pid, r)
+
+		// alternative exit path when kill was unsuccessful
+		case err := <-a.shim.WaitFallback():
+			r = 255
+			if err != nil {
+				fmsg.Printf("cannot terminate shim on faulted setup: %v", err)
+			} else {
+				fmsg.VPrintln("alternative exit path selected")
+			}
 		}
-		fmsg.VPrintf("process %d exited with exit code %d", cmd.Process.Pid, r)
 	}
 
 	// child process exited, resume output
 	fmsg.Resume()
 
-	// close wayland connection
-	if a.seal.wl != nil {
-		if err := a.seal.wl.Close(); err != nil {
-			fmsg.Println("cannot close wayland connection:", err)
-		}
+	// print queued up dbus messages
+	if a.seal.dbusMsg != nil {
+		a.seal.dbusMsg(func(msgbuf []string) {
+			for _, msg := range msgbuf {
+				fmsg.Println(msg)
+			}
+		})
 	}
 
 	// update store and revert app setup transaction
 	e := new(StateStoreError)
-	e.Inner, e.DoErr = a.seal.store.Do(func(b state.Backend) {
+	e.Inner, e.DoErr = a.seal.store.Do(a.seal.sys.user.aid, func(b state.Cursor) {
 		e.InnerErr = func() error {
 			// destroy defunct state entry
 			if cmd := a.shim.Unwrap(); cmd != nil && a.seal.sys.saveState {
-				if err := b.Destroy(cmd.Process.Pid); err != nil {
+				if err := b.Destroy(*a.id); err != nil {
 					return err
 				}
 			}
@@ -218,8 +224,12 @@ func (a *app) Wait() (int, error) {
 				}
 
 				// accumulate capabilities of other launchers
-				for _, s := range states {
-					*rt |= s.Capability
+				for i, s := range states {
+					if s.Config != nil {
+						*rt |= s.Config.Confinement.Enablements
+					} else {
+						fmsg.Printf("state entry %d does not contain config", i)
+					}
 				}
 			}
 			// invert accumulated enablements for cleanup
@@ -240,9 +250,10 @@ func (a *app) Wait() (int, error) {
 				}
 			}
 
-			a.shim.AbortWait(errors.New("shim exited"))
-			if err := a.seal.sys.Revert(ec); err != nil {
-				return err.(RevertCompoundError)
+			if a.seal.sys.needRevert {
+				if err := a.seal.sys.Revert(ec); err != nil {
+					return err.(RevertCompoundError)
+				}
 			}
 
 			return nil

internal/app/system.go

@@ -1,12 +1,10 @@
 package app
 
 import (
-	"os/user"
-
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/internal/linux"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 // appSealSys encapsulates app seal behaviour with OS interactions
@@ -17,10 +15,13 @@ type appSealSys struct {
 
 	// default formatted XDG_RUNTIME_DIR of User
 	runtime string
-	// sealed path to fortify executable, used by shim
-	executable string
 	// target user sealed from config
-	user *user.User
+	user appUser
+
+	// mapped uid and gid in user namespace
+	mappedID int
+	// string representation of mappedID
+	mappedIDString string
 
 	needRevert bool
 	saveState  bool
@@ -29,8 +30,30 @@ type appSealSys struct {
 	// protected by upstream mutex
 }
 
+type appUser struct {
+	// full uid resolved by fsu
+	uid int
+	// string representation of uid
+	us string
+
+	// supplementary group ids
+	supp []string
+
+	// application id
+	aid int
+	// string representation of aid
+	as string
+
+	// home directory host path
+	data string
+	// app user home directory
+	home string
+	// passwd database username
+	username string
+}
+
 // shareAll calls all share methods in sequence
-func (seal *appSeal) shareAll(bus [2]*dbus.Config, os internal.System) error {
+func (seal *appSeal) shareAll(bus [2]*dbus.Config, os linux.System) error {
 	if seal.shared {
 		panic("seal shared twice")
 	}

internal/comp.go

@@ -0,0 +1,12 @@
+package internal
+
+const compPoison = "INVALIDINVALIDINVALIDINVALIDINVALID"
+
+var (
+	Version = compPoison
+)
+
+// Check validates string value set at compile time.
+func Check(s string) (string, bool) {
+	return s, s != compPoison && s != ""
+}

internal/fmsg/defer.go

@@ -8,6 +8,7 @@ import (
 
 var (
 	wstate   atomic.Bool
+	dropped  atomic.Uint64
 	withhold = make(chan struct{}, 1)
 	msgbuf   = make(chan dOp, 64) // these ops are tiny so a large buffer is allocated for withholding output
 
@@ -29,6 +30,26 @@ func dequeue() {
 	}()
 }
 
+// queue submits ops to msgbuf but drops messages
+// when the buffer is full and dequeue is withholding
+func queue(op dOp) {
+	queueSync.Add(1)
+
+	select {
+	case msgbuf <- op:
+	default:
+		// send the op anyway if not withholding
+		// as dequeue will get to it eventually
+		if !wstate.Load() {
+			msgbuf <- op
+		} else {
+			queueSync.Done()
+			// increment dropped message count
+			dropped.Add(1)
+		}
+	}
+}
+
 type dOp interface{ Do() }
 
 func Exit(code int) {
@@ -36,9 +57,10 @@ func Exit(code int) {
 	os.Exit(code)
 }
 
-func Withhold() {
+func Suspend() {
 	dequeueOnce.Do(dequeue)
 	if wstate.CompareAndSwap(false, true) {
+		queueSync.Wait()
 		withhold <- struct{}{}
 	}
 }
@@ -47,6 +69,9 @@ func Resume() {
 	dequeueOnce.Do(dequeue)
 	if wstate.CompareAndSwap(true, false) {
 		withhold <- struct{}{}
+		if d := dropped.Swap(0); d != 0 {
+			Printf("dropped %d messages during withhold", d)
+		}
 	}
 }
 

internal/fmsg/fmsg.go

@@ -16,20 +16,17 @@ func SetPrefix(prefix string) {
 
 func Print(v ...any) {
 	dequeueOnce.Do(dequeue)
-	queueSync.Add(1)
-	msgbuf <- dPrint(v)
+	queue(dPrint(v))
 }
 
 func Printf(format string, v ...any) {
 	dequeueOnce.Do(dequeue)
-	queueSync.Add(1)
-	msgbuf <- &dPrintf{format, v}
+	queue(&dPrintf{format, v})
 }
 
 func Println(v ...any) {
 	dequeueOnce.Do(dequeue)
-	queueSync.Add(1)
-	msgbuf <- dPrintln(v)
+	queue(dPrintln(v))
 }
 
 func Fatal(v ...any) {

internal/linux/interface.go

@@ -0,0 +1,70 @@
+package linux
+
+import (
+	"io"
+	"io/fs"
+	"os/user"
+	"path"
+	"strconv"
+
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+)
+
+// System provides safe access to operating system resources.
+type System interface {
+	// Geteuid provides [os.Geteuid].
+	Geteuid() int
+	// LookupEnv provides [os.LookupEnv].
+	LookupEnv(key string) (string, bool)
+	// TempDir provides [os.TempDir].
+	TempDir() string
+	// LookPath provides [exec.LookPath].
+	LookPath(file string) (string, error)
+	// Executable provides [os.Executable].
+	Executable() (string, error)
+	// LookupGroup provides [user.LookupGroup].
+	LookupGroup(name string) (*user.Group, error)
+	// ReadDir provides [os.ReadDir].
+	ReadDir(name string) ([]fs.DirEntry, error)
+	// Stat provides [os.Stat].
+	Stat(name string) (fs.FileInfo, error)
+	// Open provides [os.Open]
+	Open(name string) (fs.File, error)
+	// Exit provides [os.Exit].
+	Exit(code int)
+	// Stdout provides [os.Stdout].
+	Stdout() io.Writer
+
+	// Paths returns a populated [Paths] struct.
+	Paths() Paths
+	// Uid invokes fsu and returns target uid.
+	Uid(aid int) (int, error)
+}
+
+// Paths contains environment dependent paths used by fortify.
+type Paths struct {
+	// path to shared directory e.g. /tmp/fortify.%d
+	SharePath string `json:"share_path"`
+	// XDG_RUNTIME_DIR value e.g. /run/user/%d
+	RuntimePath string `json:"runtime_path"`
+	// application runtime directory e.g. /run/user/%d/fortify
+	RunDirPath string `json:"run_dir_path"`
+}
+
+// CopyPaths is a generic implementation of [System.Paths].
+func CopyPaths(os System, v *Paths) {
+	v.SharePath = path.Join(os.TempDir(), "fortify."+strconv.Itoa(os.Geteuid()))
+
+	fmsg.VPrintf("process share directory at %q", v.SharePath)
+
+	if r, ok := os.LookupEnv(xdgRuntimeDir); !ok || r == "" || !path.IsAbs(r) {
+		// fall back to path in share since fortify has no hard XDG dependency
+		v.RunDirPath = path.Join(v.SharePath, "run")
+		v.RuntimePath = path.Join(v.RunDirPath, "compat")
+	} else {
+		v.RuntimePath = r
+		v.RunDirPath = path.Join(v.RuntimePath, "fortify")
+	}
+
+	fmsg.VPrintf("runtime directory at %q", v.RunDirPath)
+}

internal/linux/std.go

@@ -0,0 +1,88 @@
+package linux
+
+import (
+	"io"
+	"io/fs"
+	"os"
+	"os/exec"
+	"os/user"
+	"strconv"
+	"sync"
+
+	"git.gensokyo.uk/security/fortify/internal"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+)
+
+// Std implements System using the standard library.
+type Std struct {
+	paths     Paths
+	pathsOnce sync.Once
+
+	uidOnce sync.Once
+	uidCopy map[int]struct {
+		uid int
+		err error
+	}
+	uidMu sync.RWMutex
+}
+
+func (s *Std) Geteuid() int                                 { return os.Geteuid() }
+func (s *Std) LookupEnv(key string) (string, bool)          { return os.LookupEnv(key) }
+func (s *Std) TempDir() string                              { return os.TempDir() }
+func (s *Std) LookPath(file string) (string, error)         { return exec.LookPath(file) }
+func (s *Std) Executable() (string, error)                  { return os.Executable() }
+func (s *Std) LookupGroup(name string) (*user.Group, error) { return user.LookupGroup(name) }
+func (s *Std) ReadDir(name string) ([]os.DirEntry, error)   { return os.ReadDir(name) }
+func (s *Std) Stat(name string) (fs.FileInfo, error)        { return os.Stat(name) }
+func (s *Std) Open(name string) (fs.File, error)            { return os.Open(name) }
+func (s *Std) Exit(code int)                                { fmsg.Exit(code) }
+func (s *Std) Stdout() io.Writer                            { return os.Stdout }
+
+const xdgRuntimeDir = "XDG_RUNTIME_DIR"
+
+func (s *Std) Paths() Paths {
+	s.pathsOnce.Do(func() { CopyPaths(s, &s.paths) })
+	return s.paths
+}
+
+func (s *Std) Uid(aid int) (int, error) {
+	s.uidOnce.Do(func() {
+		s.uidCopy = make(map[int]struct {
+			uid int
+			err error
+		})
+	})
+
+	s.uidMu.RLock()
+	if u, ok := s.uidCopy[aid]; ok {
+		s.uidMu.RUnlock()
+		return u.uid, u.err
+	}
+
+	s.uidMu.RUnlock()
+	s.uidMu.Lock()
+	defer s.uidMu.Unlock()
+
+	u := struct {
+		uid int
+		err error
+	}{}
+	defer func() { s.uidCopy[aid] = u }()
+
+	u.uid = -1
+	if fsu, ok := internal.Check(internal.Fsu); !ok {
+		fmsg.Fatal("invalid fsu path, this copy of fshim is not compiled correctly")
+		panic("unreachable")
+	} else {
+		cmd := exec.Command(fsu)
+		cmd.Path = fsu
+		cmd.Stderr = os.Stderr // pass through fatal messages
+		cmd.Env = []string{"FORTIFY_APP_ID=" + strconv.Itoa(aid)}
+		cmd.Dir = "/"
+		var p []byte
+		if p, u.err = cmd.Output(); u.err == nil {
+			u.uid, u.err = strconv.Atoi(string(p))
+		}
+		return u.uid, u.err
+	}
+}

internal/path.go

@@ -0,0 +1,12 @@
+package internal
+
+import "path"
+
+var (
+	Fsu   = compPoison
+	Finit = compPoison
+)
+
+func Path(p string) (string, bool) {
+	return p, p != compPoison && p != "" && path.IsAbs(p)
+}

internal/prctl.go

@@ -0,0 +1,20 @@
+package internal
+
+import "syscall"
+
+func PR_SET_DUMPABLE__SUID_DUMP_DISABLE() error {
+	// linux/sched/coredump.h
+	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_DUMPABLE, 0, 0); errno != 0 {
+		return errno
+	}
+
+	return nil
+}
+
+func PR_SET_PDEATHSIG__SIGKILL() error {
+	if _, _, errno := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, uintptr(syscall.SIGKILL), 0); errno != 0 {
+		return errno
+	}
+
+	return nil
+}

internal/proc/fd.go

@@ -0,0 +1,42 @@
+package proc
+
+import (
+	"encoding/gob"
+	"errors"
+	"os"
+	"strconv"
+)
+
+var (
+	ErrNotSet  = errors.New("environment variable not set")
+	ErrInvalid = errors.New("bad file descriptor")
+)
+
+func Setup(extraFiles *[]*os.File) (int, *gob.Encoder, error) {
+	if r, w, err := os.Pipe(); err != nil {
+		return -1, nil, err
+	} else {
+		fd := 3 + len(*extraFiles)
+		*extraFiles = append(*extraFiles, r)
+		return fd, gob.NewEncoder(w), nil
+	}
+}
+
+func Receive(key string, e any) (func() error, error) {
+	var setup *os.File
+
+	if s, ok := os.LookupEnv(key); !ok {
+		return nil, ErrNotSet
+	} else {
+		if fd, err := strconv.Atoi(s); err != nil {
+			return nil, err
+		} else {
+			setup = os.NewFile(uintptr(fd), "setup")
+			if setup == nil {
+				return nil, ErrInvalid
+			}
+		}
+	}
+
+	return func() error { return setup.Close() }, gob.NewDecoder(setup).Decode(e)
+}

internal/proc/files.go

@@ -0,0 +1,13 @@
+package proc
+
+import (
+	"os"
+	"os/exec"
+)
+
+func ExtraFile(cmd *exec.Cmd, f *os.File) (fd uintptr) {
+	// ExtraFiles: If non-nil, entry i becomes file descriptor 3+i.
+	fd = uintptr(3 + len(cmd.ExtraFiles))
+	cmd.ExtraFiles = append(cmd.ExtraFiles, f)
+	return
+}

internal/shim/main.go

@@ -1,179 +0,0 @@
-package shim
-
-import (
-	"encoding/gob"
-	"errors"
-	"flag"
-	"net"
-	"os"
-	"path"
-	"strconv"
-	"syscall"
-
-	"git.ophivana.moe/security/fortify/helper"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	init0 "git.ophivana.moe/security/fortify/internal/init"
-)
-
-// everything beyond this point runs as target user
-// proceed with caution!
-
-func doShim(socket string) {
-	fmsg.SetPrefix("shim")
-
-	// re-exec
-	if len(os.Args) > 0 && os.Args[0] != "fortify" && path.IsAbs(os.Args[0]) {
-		if err := syscall.Exec(os.Args[0], []string{"fortify", "shim"}, os.Environ()); err != nil {
-			fmsg.Println("cannot re-exec self:", err)
-			// continue anyway
-		}
-	}
-
-	// dial setup socket
-	var conn *net.UnixConn
-	if c, err := net.DialUnix("unix", nil, &net.UnixAddr{Name: socket, Net: "unix"}); err != nil {
-		fmsg.Fatal("cannot dial setup socket:", err)
-		panic("unreachable")
-	} else {
-		conn = c
-	}
-
-	// decode payload gob stream
-	var payload Payload
-	if err := gob.NewDecoder(conn).Decode(&payload); err != nil {
-		fmsg.Fatal("cannot decode shim payload:", err)
-	} else {
-		// sharing stdout with parent
-		// USE WITH CAUTION
-		fmsg.SetVerbose(payload.Verbose)
-	}
-
-	if payload.Bwrap == nil {
-		fmsg.Fatal("bwrap config not supplied")
-	}
-
-	// receive wayland fd over socket
-	wfd := -1
-	if payload.WL {
-		if fd, err := receiveWLfd(conn); err != nil {
-			fmsg.Fatal("cannot receive wayland fd:", err)
-		} else {
-			wfd = fd
-		}
-	}
-
-	// close setup socket
-	if err := conn.Close(); err != nil {
-		fmsg.Println("cannot close setup socket:", err)
-		// not fatal
-	}
-
-	var ic init0.Payload
-
-	// resolve argv0
-	ic.Argv = payload.Argv
-	if len(ic.Argv) > 0 {
-		// looked up from $PATH by parent
-		ic.Argv0 = payload.Exec[2]
-	} else {
-		// no argv, look up shell instead
-		var ok bool
-		if ic.Argv0, ok = os.LookupEnv("SHELL"); !ok {
-			fmsg.Fatal("no command was specified and $SHELL was unset")
-		}
-
-		ic.Argv = []string{ic.Argv0}
-	}
-
-	conf := payload.Bwrap
-
-	var extraFiles []*os.File
-
-	// pass wayland fd
-	if wfd != -1 {
-		if f := os.NewFile(uintptr(wfd), "wayland"); f != nil {
-			ic.WL = 3 + len(extraFiles)
-			extraFiles = append(extraFiles, f)
-		}
-	} else {
-		ic.WL = -1
-	}
-
-	// share config pipe
-	if r, w, err := os.Pipe(); err != nil {
-		fmsg.Fatal("cannot pipe:", err)
-	} else {
-		conf.SetEnv[init0.EnvInit] = strconv.Itoa(3 + len(extraFiles))
-		extraFiles = append(extraFiles, r)
-
-		fmsg.VPrintln("transmitting config to init")
-		go func() {
-			// stream config to pipe
-			if err = gob.NewEncoder(w).Encode(&ic); err != nil {
-				fmsg.Fatal("cannot transmit init config:", err)
-			}
-		}()
-	}
-
-	helper.BubblewrapName = payload.Exec[1] // resolved bwrap path by parent
-	if b, err := helper.NewBwrap(conf, nil, payload.Exec[0], func(int, int) []string { return []string{"init"} }); err != nil {
-		fmsg.Fatal("malformed sandbox config:", err)
-	} else {
-		cmd := b.Unwrap()
-		cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
-		cmd.ExtraFiles = extraFiles
-
-		if fmsg.Verbose() {
-			fmsg.VPrintln("bwrap args:", conf.Args())
-		}
-
-		// run and pass through exit code
-		if err = b.Start(); err != nil {
-			fmsg.Fatal("cannot start target process:", err)
-		} else if err = b.Wait(); err != nil {
-			fmsg.VPrintln("wait:", err)
-		}
-		if b.Unwrap().ProcessState != nil {
-			fmsg.Exit(b.Unwrap().ProcessState.ExitCode())
-		} else {
-			fmsg.Exit(127)
-		}
-	}
-}
-
-func receiveWLfd(conn *net.UnixConn) (int, error) {
-	oob := make([]byte, syscall.CmsgSpace(4)) // single fd
-
-	if _, oobn, _, _, err := conn.ReadMsgUnix(nil, oob); err != nil {
-		return -1, err
-	} else if len(oob) != oobn {
-		return -1, errors.New("invalid message length")
-	}
-
-	var msg syscall.SocketControlMessage
-	if messages, err := syscall.ParseSocketControlMessage(oob); err != nil {
-		return -1, err
-	} else if len(messages) != 1 {
-		return -1, errors.New("unexpected message count")
-	} else {
-		msg = messages[0]
-	}
-
-	if fds, err := syscall.ParseUnixRights(&msg); err != nil {
-		return -1, err
-	} else if len(fds) != 1 {
-		return -1, errors.New("unexpected fd count")
-	} else {
-		return fds[0], nil
-	}
-}
-
-// Try runs shim and stops execution if FORTIFY_SHIM is set.
-func Try() {
-	if args := flag.Args(); len(args) == 1 && args[0] == "shim" {
-		if s, ok := os.LookupEnv(EnvShim); ok {
-			doShim(s)
-			panic("unreachable")
-		}
-	}
-}

internal/shim/parent.go

@@ -1,200 +0,0 @@
-package shim
-
-import (
-	"errors"
-	"net"
-	"os"
-	"os/exec"
-	"sync"
-	"sync/atomic"
-	"syscall"
-	"time"
-
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-)
-
-// used by the parent process
-
-type Shim struct {
-	// user switcher process
-	cmd *exec.Cmd
-	// uid of shim target user
-	uid uint32
-	// whether to check shim pid
-	checkPid bool
-	// user switcher executable path
-	executable string
-	// path to setup socket
-	socket string
-	// shim setup abort reason and completion
-	abort     chan error
-	abortErr  atomic.Pointer[error]
-	abortOnce sync.Once
-	// wayland mediation, nil if disabled
-	wl *Wayland
-	// shim setup payload
-	payload *Payload
-}
-
-func New(executable string, uid uint32, socket string, wl *Wayland, payload *Payload, checkPid bool) *Shim {
-	return &Shim{uid: uid, executable: executable, socket: socket, wl: wl, payload: payload, checkPid: checkPid}
-}
-
-func (s *Shim) String() string {
-	if s.cmd == nil {
-		return "(unused shim manager)"
-	}
-	return s.cmd.String()
-}
-
-func (s *Shim) Unwrap() *exec.Cmd {
-	return s.cmd
-}
-
-func (s *Shim) Abort(err error) {
-	s.abortOnce.Do(func() {
-		s.abortErr.Store(&err)
-		// s.abort is buffered so this will never block
-		s.abort <- err
-	})
-}
-
-func (s *Shim) AbortWait(err error) {
-	s.Abort(err)
-	<-s.abort
-}
-
-type CommandBuilder func(shimEnv string) (args []string)
-
-func (s *Shim) Start(f CommandBuilder) (*time.Time, error) {
-	var (
-		cf     chan *net.UnixConn
-		accept func()
-	)
-
-	// listen on setup socket
-	if c, a, err := s.serve(); err != nil {
-		return nil, fmsg.WrapErrorSuffix(err,
-			"cannot listen on shim setup socket:")
-	} else {
-		// accepts a connection after each call to accept
-		// connections are sent to the channel cf
-		cf, accept = c, a
-	}
-
-	// start user switcher process and save time
-	s.cmd = exec.Command(s.executable, f(EnvShim+"="+s.socket)...)
-	s.cmd.Env = []string{}
-	s.cmd.Stdin, s.cmd.Stdout, s.cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
-	s.cmd.Dir = "/"
-	fmsg.VPrintln("starting shim via user switcher:", s.cmd)
-	fmsg.Withhold() // withhold messages to stderr
-	if err := s.cmd.Start(); err != nil {
-		return nil, fmsg.WrapErrorSuffix(err,
-			"cannot start user switcher:")
-	}
-	startTime := time.Now().UTC()
-
-	// kill shim if something goes wrong and an error is returned
-	killShim := func() {
-		if err := s.cmd.Process.Signal(os.Interrupt); err != nil {
-			fmsg.Println("cannot terminate shim on faulted setup:", err)
-		}
-	}
-	defer func() { killShim() }()
-
-	accept()
-	conn := <-cf
-	if conn == nil {
-		return &startTime, fmsg.WrapErrorSuffix(*s.abortErr.Load(), "cannot accept call on setup socket:")
-	}
-
-	// authenticate against called provided uid and shim pid
-	if cred, err := peerCred(conn); err != nil {
-		return &startTime, fmsg.WrapErrorSuffix(*s.abortErr.Load(), "cannot retrieve shim credentials:")
-	} else if cred.Uid != s.uid {
-		fmsg.Printf("process %d owned by user %d tried to connect, expecting %d",
-			cred.Pid, cred.Uid, s.uid)
-		err = errors.New("compromised fortify build")
-		s.Abort(err)
-		return &startTime, err
-	} else if s.checkPid && cred.Pid != int32(s.cmd.Process.Pid) {
-		fmsg.Printf("process %d tried to connect to shim setup socket, expecting shim %d",
-			cred.Pid, s.cmd.Process.Pid)
-		err = errors.New("compromised target user")
-		s.Abort(err)
-		return &startTime, err
-	}
-
-	// serve payload and wayland fd if enabled
-	// this also closes the connection
-	err := s.payload.serve(conn, s.wl)
-	if err == nil {
-		killShim = func() {}
-	}
-	s.Abort(err) // aborting with nil indicates success
-	return &startTime, err
-}
-
-func (s *Shim) serve() (chan *net.UnixConn, func(), error) {
-	if s.abort != nil {
-		panic("attempted to serve shim setup twice")
-	}
-	s.abort = make(chan error, 1)
-
-	cf := make(chan *net.UnixConn)
-	accept := make(chan struct{}, 1)
-
-	if l, err := net.ListenUnix("unix", &net.UnixAddr{Name: s.socket, Net: "unix"}); err != nil {
-		return nil, nil, err
-	} else {
-		l.SetUnlinkOnClose(true)
-
-		fmsg.VPrintf("listening on shim setup socket %q", s.socket)
-		if err = acl.UpdatePerm(s.socket, int(s.uid), acl.Read, acl.Write, acl.Execute); err != nil {
-			fmsg.Println("cannot append ACL entry to shim setup socket:", err)
-			s.Abort(err) // ensures setup socket cleanup
-		}
-
-		go func() {
-			for {
-				select {
-				case err = <-s.abort:
-					if err != nil {
-						fmsg.VPrintln("aborting shim setup, reason:", err)
-					}
-					if err = l.Close(); err != nil {
-						fmsg.Println("cannot close setup socket:", err)
-					}
-					close(s.abort)
-					close(cf)
-					return
-				case <-accept:
-					if conn, err0 := l.AcceptUnix(); err0 != nil {
-						s.Abort(err0) // does not block, breaks loop
-						cf <- nil     // receiver sees nil value and loads err0 stored during abort
-					} else {
-						cf <- conn
-					}
-				}
-			}
-		}()
-	}
-
-	return cf, func() { accept <- struct{}{} }, nil
-}
-
-// peerCred fetches peer credentials of conn
-func peerCred(conn *net.UnixConn) (ucred *syscall.Ucred, err error) {
-	var raw syscall.RawConn
-	if raw, err = conn.SyscallConn(); err != nil {
-		return
-	}
-
-	err0 := raw.Control(func(fd uintptr) {
-		ucred, err = syscall.GetsockoptUcred(int(fd), syscall.SOL_SOCKET, syscall.SO_PEERCRED)
-	})
-	err = errors.Join(err, err0)
-	return
-}

internal/shim/payload.go

@@ -1,42 +0,0 @@
-package shim
-
-import (
-	"encoding/gob"
-	"errors"
-	"net"
-
-	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-)
-
-const EnvShim = "FORTIFY_SHIM"
-
-type Payload struct {
-	// child full argv
-	Argv []string
-	// fortify, bwrap, target full exec path
-	Exec [3]string
-	// bwrap config
-	Bwrap *bwrap.Config
-	// whether to pass wayland fd
-	WL bool
-
-	// verbosity pass through
-	Verbose bool
-}
-
-func (p *Payload) serve(conn *net.UnixConn, wl *Wayland) error {
-	if err := gob.NewEncoder(conn).Encode(*p); err != nil {
-		return fmsg.WrapErrorSuffix(err,
-			"cannot stream shim payload:")
-	}
-
-	if wl != nil {
-		if err := wl.WriteUnix(conn); err != nil {
-			return errors.Join(err, conn.Close())
-		}
-	}
-
-	return fmsg.WrapErrorSuffix(conn.Close(),
-		"cannot close setup connection:")
-}

internal/shim/wayland.go

@@ -1,75 +0,0 @@
-package shim
-
-import (
-	"fmt"
-	"net"
-	"sync"
-	"syscall"
-
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-)
-
-// Wayland implements wayland mediation.
-type Wayland struct {
-	// wayland socket path
-	Path string
-
-	// wayland connection
-	conn *net.UnixConn
-
-	connErr error
-	sync.Once
-	// wait for wayland client to exit
-	done chan struct{}
-}
-
-func (wl *Wayland) WriteUnix(conn *net.UnixConn) error {
-	// connect to host wayland socket
-	if f, err := net.DialUnix("unix", nil, &net.UnixAddr{Name: wl.Path, Net: "unix"}); err != nil {
-		return fmsg.WrapErrorSuffix(err,
-			fmt.Sprintf("cannot connect to wayland at %q:", wl.Path))
-	} else {
-		fmsg.VPrintf("connected to wayland at %q", wl.Path)
-		wl.conn = f
-	}
-
-	// set up for passing wayland socket
-	if rc, err := wl.conn.SyscallConn(); err != nil {
-		return fmsg.WrapErrorSuffix(err, "cannot obtain raw wayland connection:")
-	} else {
-		ec := make(chan error)
-		go func() {
-			// pass wayland connection fd
-			if err = rc.Control(func(fd uintptr) {
-				if _, _, err = conn.WriteMsgUnix(nil, syscall.UnixRights(int(fd)), nil); err != nil {
-					ec <- fmsg.WrapErrorSuffix(err, "cannot pass wayland connection to shim:")
-					return
-				}
-				ec <- nil
-
-				// block until shim exits
-				<-wl.done
-				fmsg.VPrintln("releasing wayland connection")
-			}); err != nil {
-				ec <- fmsg.WrapErrorSuffix(err, "cannot obtain wayland connection fd:")
-				return
-			}
-		}()
-		return <-ec
-	}
-}
-
-func (wl *Wayland) Close() error {
-	wl.Do(func() {
-		close(wl.done)
-		wl.connErr = wl.conn.Close()
-	})
-
-	return wl.connErr
-}
-
-func NewWayland() *Wayland {
-	wl := new(Wayland)
-	wl.done = make(chan struct{})
-	return wl
-}

internal/state/multi.go

@@ -0,0 +1,292 @@
+package state
+
+import (
+	"encoding/gob"
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"path"
+	"strconv"
+	"sync"
+	"syscall"
+
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+)
+
+// fine-grained locking and access
+type multiStore struct {
+	base string
+
+	// initialised backends
+	backends *sync.Map
+
+	lock sync.RWMutex
+}
+
+func (s *multiStore) Do(aid int, f func(c Cursor)) (bool, error) {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+
+	// load or initialise new backend
+	b := new(multiBackend)
+	if v, ok := s.backends.LoadOrStore(aid, b); ok {
+		b = v.(*multiBackend)
+	} else {
+		b.lock.Lock()
+		b.path = path.Join(s.base, strconv.Itoa(aid))
+
+		// ensure directory
+		if err := os.MkdirAll(b.path, 0700); err != nil && !errors.Is(err, fs.ErrExist) {
+			s.backends.CompareAndDelete(aid, b)
+			return false, err
+		}
+
+		// open locker file
+		if l, err := os.OpenFile(b.path+".lock", os.O_RDWR|os.O_CREATE, 0600); err != nil {
+			s.backends.CompareAndDelete(aid, b)
+			return false, err
+		} else {
+			b.lockfile = l
+		}
+		b.lock.Unlock()
+	}
+
+	// lock backend
+	if err := b.lockFile(); err != nil {
+		return false, err
+	}
+
+	// expose backend methods without exporting the pointer
+	c := new(struct{ *multiBackend })
+	c.multiBackend = b
+	f(b)
+	// disable access to the backend on a best-effort basis
+	c.multiBackend = nil
+
+	// unlock backend
+	return true, b.unlockFile()
+}
+
+func (s *multiStore) List() ([]int, error) {
+	var entries []os.DirEntry
+
+	// read base directory to get all aids
+	if v, err := os.ReadDir(s.base); err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	} else {
+		entries = v
+	}
+
+	aidsBuf := make([]int, 0, len(entries))
+	for _, e := range entries {
+		// skip non-directories
+		if !e.IsDir() {
+			fmsg.VPrintf("skipped non-directory entry %q", e.Name())
+			continue
+		}
+
+		// skip non-numerical names
+		if v, err := strconv.Atoi(e.Name()); err != nil {
+			fmsg.VPrintf("skipped non-aid entry %q", e.Name())
+			continue
+		} else {
+			if v < 0 || v > 9999 {
+				fmsg.VPrintf("skipped out of bounds entry %q", e.Name())
+				continue
+			}
+
+			aidsBuf = append(aidsBuf, v)
+		}
+	}
+
+	return append([]int(nil), aidsBuf...), nil
+}
+
+func (s *multiStore) Close() error {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	var errs []error
+	s.backends.Range(func(_, value any) bool {
+		b := value.(*multiBackend)
+		errs = append(errs, b.close())
+		return true
+	})
+
+	return errors.Join(errs...)
+}
+
+type multiBackend struct {
+	path string
+
+	// created/opened by prepare
+	lockfile *os.File
+
+	lock sync.RWMutex
+}
+
+func (b *multiBackend) filename(id *fst.ID) string {
+	return path.Join(b.path, id.String())
+}
+
+func (b *multiBackend) lockFileAct(lt int) (err error) {
+	op := "LockAct"
+	switch lt {
+	case syscall.LOCK_EX:
+		op = "Lock"
+	case syscall.LOCK_UN:
+		op = "Unlock"
+	}
+
+	for {
+		err = syscall.Flock(int(b.lockfile.Fd()), lt)
+		if !errors.Is(err, syscall.EINTR) {
+			break
+		}
+	}
+	if err != nil {
+		return &fs.PathError{
+			Op:   op,
+			Path: b.lockfile.Name(),
+			Err:  err,
+		}
+	}
+	return nil
+}
+
+func (b *multiBackend) lockFile() error {
+	return b.lockFileAct(syscall.LOCK_EX)
+}
+
+func (b *multiBackend) unlockFile() error {
+	return b.lockFileAct(syscall.LOCK_UN)
+}
+
+// reads all launchers in simpleBackend
+// file contents are ignored if decode is false
+func (b *multiBackend) load(decode bool) (Entries, error) {
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	// read directory contents, should only contain files named after ids
+	var entries []os.DirEntry
+	if pl, err := os.ReadDir(b.path); err != nil {
+		return nil, err
+	} else {
+		entries = pl
+	}
+
+	// allocate as if every entry is valid
+	// since that should be the case assuming no external interference happens
+	r := make(Entries, len(entries))
+
+	for _, e := range entries {
+		if e.IsDir() {
+			return nil, fmt.Errorf("unexpected directory %q in store", e.Name())
+		}
+
+		id := new(fst.ID)
+		if err := fst.ParseAppID(id, e.Name()); err != nil {
+			return nil, err
+		}
+
+		// run in a function to better handle file closing
+		if err := func() error {
+			// open state file for reading
+			if f, err := os.Open(path.Join(b.path, e.Name())); err != nil {
+				return err
+			} else {
+				defer func() {
+					if f.Close() != nil {
+						// unreachable
+						panic("foreign state file closed prematurely")
+					}
+				}()
+
+				s := new(State)
+				r[*id] = s
+
+				// append regardless, but only parse if required, used to implement Len
+				if decode {
+					if err = gob.NewDecoder(f).Decode(s); err != nil {
+						return err
+					}
+
+					if s.ID != *id {
+						return fmt.Errorf("state entry %s has unexpected id %s", id, &s.ID)
+					}
+				}
+
+				return nil
+			}
+		}(); err != nil {
+			return nil, err
+		}
+	}
+
+	return r, nil
+}
+
+// Save writes process state to filesystem
+func (b *multiBackend) Save(state *State) error {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	if state.Config == nil {
+		return errors.New("state does not contain config")
+	}
+
+	statePath := b.filename(&state.ID)
+
+	// create and open state data file
+	if f, err := os.OpenFile(statePath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600); err != nil {
+		return err
+	} else {
+		defer func() {
+			if f.Close() != nil {
+				// unreachable
+				panic("state file closed prematurely")
+			}
+		}()
+		// encode into state file
+		return gob.NewEncoder(f).Encode(state)
+	}
+}
+
+func (b *multiBackend) Destroy(id fst.ID) error {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	return os.Remove(b.filename(&id))
+}
+
+func (b *multiBackend) Load() (Entries, error) {
+	return b.load(true)
+}
+
+func (b *multiBackend) Len() (int, error) {
+	// rn consists of only nil entries but has the correct length
+	rn, err := b.load(false)
+	return len(rn), err
+}
+
+func (b *multiBackend) close() error {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	err := b.lockfile.Close()
+	if err == nil || errors.Is(err, os.ErrInvalid) || errors.Is(err, os.ErrClosed) {
+		return nil
+	}
+	return err
+}
+
+// NewMulti returns an instance of the multi-file store.
+func NewMulti(runDir string) Store {
+	b := new(multiStore)
+	b.base = path.Join(runDir, "state")
+	b.backends = new(sync.Map)
+	return b
+}

internal/state/multi_test.go

@@ -0,0 +1,11 @@
+package state_test
+
+import (
+	"testing"
+
+	"git.gensokyo.uk/security/fortify/internal/state"
+)
+
+func TestMulti(t *testing.T) {
+	testStore(t, state.NewMulti(t.TempDir()))
+}

internal/state/print.go

@@ -1,62 +1,45 @@
 package state
 
 import (
-	"errors"
 	"fmt"
 	"os"
-	"path"
-	"strconv"
 	"strings"
 	"text/tabwriter"
 	"time"
 
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 // MustPrintLauncherStateSimpleGlobal prints active launcher states of all simple stores
 // in an implementation-specific way.
 func MustPrintLauncherStateSimpleGlobal(w **tabwriter.Writer, runDir string) {
 	now := time.Now().UTC()
+	s := NewMulti(runDir)
 
 	// read runtime directory to get all UIDs
-	if dirs, err := os.ReadDir(path.Join(runDir, "state")); err != nil && !errors.Is(err, os.ErrNotExist) {
-		fmsg.Fatal("cannot read runtime directory:", err)
+	if aids, err := s.List(); err != nil {
+		fmsg.Fatal("cannot list store:", err)
 	} else {
-		for _, e := range dirs {
-			// skip non-directories
-			if !e.IsDir() {
-				fmsg.VPrintf("skipped non-directory entry %q", e.Name())
-				continue
-			}
-
-			// skip non-numerical names
-			if _, err = strconv.Atoi(e.Name()); err != nil {
-				fmsg.VPrintf("skipped non-uid entry %q", e.Name())
-				continue
-			}
-
-			// obtain temporary store
-			s := NewSimple(runDir, e.Name()).(*simpleStore)
-
+		for _, aid := range aids {
 			// print states belonging to this store
-			s.mustPrintLauncherState(w, now)
-
-			// mustPrintLauncherState causes store activity so store needs to be closed
-			if err = s.Close(); err != nil {
-				fmsg.Printf("cannot close store for user %q: %s", e.Name(), err)
-			}
+			s.(*multiStore).mustPrintLauncherState(aid, w, now)
 		}
 	}
+
+	// mustPrintLauncherState causes store activity so store needs to be closed
+	if err := s.Close(); err != nil {
+		fmsg.Printf("cannot close store: %v", err)
+	}
 }
 
-func (s *simpleStore) mustPrintLauncherState(w **tabwriter.Writer, now time.Time) {
+func (s *multiStore) mustPrintLauncherState(aid int, w **tabwriter.Writer, now time.Time) {
 	var innerErr error
 
-	if ok, err := s.Do(func(b Backend) {
+	if ok, err := s.Do(aid, func(c Cursor) {
 		innerErr = func() error {
 			// read launcher states
-			states, err := b.Load()
+			states, err := c.Load()
 			if err != nil {
 				return err
 			}
@@ -67,10 +50,10 @@ func (s *simpleStore) mustPrintLauncherState(w **tabwriter.Writer, now time.Time
 
 				// write header when initialising
 				if !fmsg.Verbose() {
-					_, _ = fmt.Fprintln(*w, "\tUID\tPID\tUptime\tEnablements\tMethod\tCommand")
+					_, _ = fmt.Fprintln(*w, "\tPID\tApp\tUptime\tEnablements\tCommand")
 				} else {
 					// argv is emitted in body when verbose
-					_, _ = fmt.Fprintln(*w, "\tUID\tPID\tArgv")
+					_, _ = fmt.Fprintln(*w, "\tPID\tApp\tArgv")
 				}
 			}
 
@@ -82,40 +65,54 @@ func (s *simpleStore) mustPrintLauncherState(w **tabwriter.Writer, now time.Time
 					continue
 				}
 
-				// build enablements string
-				ets := strings.Builder{}
-				// append enablement strings in order
-				for i := system.Enablement(0); i < system.Enablement(system.ELen); i++ {
-					if state.Capability.Has(i) {
-						ets.WriteString(", " + i.String())
+				// build enablements and command string
+				var (
+					ets *strings.Builder
+					cs  = "(No command information)"
+				)
+
+				// check if enablements are provided
+				if state.Config != nil {
+					ets = new(strings.Builder)
+					// append enablement strings in order
+					for i := system.Enablement(0); i < system.Enablement(system.ELen); i++ {
+						if state.Config.Confinement.Enablements.Has(i) {
+							ets.WriteString(", " + i.String())
+						}
 					}
+
+					cs = fmt.Sprintf("%q", state.Config.Command)
 				}
-				// prevent an empty string when
-				if ets.Len() == 0 {
-					ets.WriteString("(No enablements)")
+				if ets != nil {
+					// prevent an empty string
+					if ets.Len() == 0 {
+						ets.WriteString("(No enablements)")
+					}
+				} else {
+					ets = new(strings.Builder)
+					ets.WriteString("(No confinement information)")
 				}
 
 				if !fmsg.Verbose() {
-					_, _ = fmt.Fprintf(*w, "\t%s\t%d\t%s\t%s\t%s\t%s\n",
-						s.path[len(s.path)-1], state.PID, now.Sub(state.Time).Round(time.Second).String(), strings.TrimPrefix(ets.String(), ", "), state.Method,
-						state.Command)
+					_, _ = fmt.Fprintf(*w, "\t%d\t%d\t%s\t%s\t%s\n",
+						state.PID, aid, now.Sub(state.Time).Round(time.Second).String(), strings.TrimPrefix(ets.String(), ", "), cs)
 				} else {
 					// emit argv instead when verbose
-					_, _ = fmt.Fprintf(*w, "\t%s\t%d\t%s\n",
-						s.path[len(s.path)-1], state.PID, state.Argv)
+					_, _ = fmt.Fprintf(*w, "\t%d\t%d\t%s\n",
+						state.PID, aid, state.ID)
 				}
 			}
 
 			return nil
 		}()
 	}); err != nil {
-		fmsg.Printf("cannot perform action on store %q: %s", path.Join(s.path...), err)
+		fmsg.Printf("cannot perform action on app %d: %v", aid, err)
 		if !ok {
 			fmsg.Fatal("store faulted before printing")
 		}
 	}
 
 	if innerErr != nil {
-		fmsg.Fatalf("cannot print launcher state for store %q: %s", path.Join(s.path...), innerErr)
+		fmsg.Fatalf("cannot print launcher state of app %d: %s", aid, innerErr)
 	}
 }

internal/state/simple.go

@@ -1,218 +0,0 @@
-package state
-
-import (
-	"encoding/gob"
-	"errors"
-	"io/fs"
-	"os"
-	"path"
-	"strconv"
-	"sync"
-	"syscall"
-)
-
-// file-based locking
-type simpleStore struct {
-	path []string
-
-	// created/opened by prepare
-	lockfile *os.File
-	// enforce prepare method
-	init sync.Once
-	// error returned by prepare
-	initErr error
-
-	lock sync.Mutex
-}
-
-func (s *simpleStore) Do(f func(b Backend)) (bool, error) {
-	s.init.Do(s.prepare)
-	if s.initErr != nil {
-		return false, s.initErr
-	}
-
-	s.lock.Lock()
-	defer s.lock.Unlock()
-
-	// lock store
-	if err := s.lockFile(); err != nil {
-		return false, err
-	}
-
-	// initialise new backend for caller
-	b := new(simpleBackend)
-	b.path = path.Join(s.path...)
-	f(b)
-	// disable backend
-	b.lock.Lock()
-
-	// unlock store
-	return true, s.unlockFile()
-}
-
-func (s *simpleStore) lockFileAct(lt int) (err error) {
-	op := "LockAct"
-	switch lt {
-	case syscall.LOCK_EX:
-		op = "Lock"
-	case syscall.LOCK_UN:
-		op = "Unlock"
-	}
-
-	for {
-		err = syscall.Flock(int(s.lockfile.Fd()), lt)
-		if !errors.Is(err, syscall.EINTR) {
-			break
-		}
-	}
-	if err != nil {
-		return &fs.PathError{
-			Op:   op,
-			Path: s.lockfile.Name(),
-			Err:  err,
-		}
-	}
-	return nil
-}
-
-func (s *simpleStore) lockFile() error {
-	return s.lockFileAct(syscall.LOCK_EX)
-}
-
-func (s *simpleStore) unlockFile() error {
-	return s.lockFileAct(syscall.LOCK_UN)
-}
-
-func (s *simpleStore) prepare() {
-	s.initErr = func() error {
-		prefix := path.Join(s.path...)
-		// ensure directory
-		if err := os.MkdirAll(prefix, 0700); err != nil && !errors.Is(err, fs.ErrExist) {
-			return err
-		}
-
-		// open locker file
-		if f, err := os.OpenFile(prefix+".lock", os.O_RDWR|os.O_CREATE, 0600); err != nil {
-			return err
-		} else {
-			s.lockfile = f
-		}
-
-		return nil
-	}()
-}
-
-func (s *simpleStore) Close() error {
-	s.lock.Lock()
-	defer s.lock.Unlock()
-
-	err := s.lockfile.Close()
-	if err == nil || errors.Is(err, os.ErrInvalid) || errors.Is(err, os.ErrClosed) {
-		return nil
-	}
-	return err
-}
-
-type simpleBackend struct {
-	path string
-
-	lock sync.RWMutex
-}
-
-func (b *simpleBackend) filename(pid int) string {
-	return path.Join(b.path, strconv.Itoa(pid))
-}
-
-// reads all launchers in simpleBackend
-// file contents are ignored if decode is false
-func (b *simpleBackend) load(decode bool) ([]*State, error) {
-	b.lock.RLock()
-	defer b.lock.RUnlock()
-
-	var (
-		r []*State
-		f *os.File
-	)
-
-	// read directory contents, should only contain files named after PIDs
-	if pl, err := os.ReadDir(b.path); err != nil {
-		return nil, err
-	} else {
-		for _, e := range pl {
-			// run in a function to better handle file closing
-			if err = func() error {
-				// open state file for reading
-				if f, err = os.Open(path.Join(b.path, e.Name())); err != nil {
-					return err
-				} else {
-					defer func() {
-						if f.Close() != nil {
-							// unreachable
-							panic("foreign state file closed prematurely")
-						}
-					}()
-
-					var s State
-					r = append(r, &s)
-
-					// append regardless, but only parse if required, used to implement Len
-					if decode {
-						return gob.NewDecoder(f).Decode(&s)
-					} else {
-						return nil
-					}
-				}
-			}(); err != nil {
-				return nil, err
-			}
-		}
-	}
-
-	return r, nil
-}
-
-// Save writes process state to filesystem
-func (b *simpleBackend) Save(state *State) error {
-	b.lock.Lock()
-	defer b.lock.Unlock()
-
-	statePath := b.filename(state.PID)
-
-	// create and open state data file
-	if f, err := os.OpenFile(statePath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600); err != nil {
-		return err
-	} else {
-		defer func() {
-			if f.Close() != nil {
-				// unreachable
-				panic("state file closed prematurely")
-			}
-		}()
-		// encode into state file
-		return gob.NewEncoder(f).Encode(state)
-	}
-}
-
-func (b *simpleBackend) Destroy(pid int) error {
-	b.lock.Lock()
-	defer b.lock.Unlock()
-
-	return os.Remove(b.filename(pid))
-}
-
-func (b *simpleBackend) Load() ([]*State, error) {
-	return b.load(true)
-}
-
-func (b *simpleBackend) Len() (int, error) {
-	// rn consists of only nil entries but has the correct length
-	rn, err := b.load(false)
-	return len(rn), err
-}
-
-// NewSimple returns an instance of a file-based store.
-func NewSimple(runDir string, prefix ...string) Store {
-	b := new(simpleStore)
-	b.path = append([]string{runDir, "state"}, prefix...)
-	return b
-}

internal/state/state.go

@@ -3,40 +3,42 @@ package state
 import (
 	"time"
 
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/fst"
 )
 
+type Entries map[fst.ID]*State
+
 type Store interface {
 	// Do calls f exactly once and ensures store exclusivity until f returns.
 	// Returns whether f is called and any errors during the locking process.
-	// Backend provided to f becomes invalid as soon as f returns.
-	Do(f func(b Backend)) (bool, error)
+	// Cursor provided to f becomes invalid as soon as f returns.
+	Do(aid int, f func(c Cursor)) (ok bool, err error)
+
+	// List queries the store and returns a list of aids known to the store.
+	// Note that some or all returned aids might not have any active apps.
+	List() (aids []int, err error)
 
 	// Close releases any resources held by Store.
 	Close() error
 }
 
-// Backend provides access to the store
-type Backend interface {
+// Cursor provides access to the store
+type Cursor interface {
 	Save(state *State) error
-	Destroy(pid int) error
-	Load() ([]*State, error)
+	Destroy(id fst.ID) error
+	Load() (Entries, error)
 	Len() (int, error)
 }
 
 // State is the on-disk format for a fortified process's state information
 type State struct {
+	// fortify instance id
+	ID fst.ID `json:"instance"`
 	// child process PID value
-	PID int
-	// command used to seal the app
-	Command []string
-	// capability enablements applied to child
-	Capability system.Enablements
+	PID int `json:"pid"`
+	// sealed app configuration
+	Config *fst.Config `json:"config"`
 
-	// user switch method
-	Method string
-	// full argv whe launching
-	Argv []string
 	// process start time
 	Time time.Time
 }

internal/state/state_test.go

@@ -0,0 +1,126 @@
+package state_test
+
+import (
+	"math/rand/v2"
+	"reflect"
+	"slices"
+	"testing"
+	"time"
+
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/state"
+)
+
+func testStore(t *testing.T, s state.Store) {
+	t.Run("list empty store", func(t *testing.T) {
+		if aids, err := s.List(); err != nil {
+			t.Fatalf("List: error = %v", err)
+		} else if len(aids) != 0 {
+			t.Fatalf("List: aids = %#v", aids)
+		}
+	})
+
+	const (
+		insertEntryChecked = iota
+		insertEntryNoCheck
+		insertEntryOtherApp
+
+		tl
+	)
+
+	var tc [tl]state.State
+	for i := 0; i < tl; i++ {
+		makeState(t, &tc[i])
+	}
+
+	do := func(aid int, f func(c state.Cursor)) {
+		if ok, err := s.Do(aid, f); err != nil {
+			t.Fatalf("Do: ok = %v, error = %v", ok, err)
+		}
+	}
+
+	insert := func(i, aid int) {
+		do(aid, func(c state.Cursor) {
+			if err := c.Save(&tc[i]); err != nil {
+				t.Fatalf("Save(&tc[%v]): error = %v", i, err)
+			}
+		})
+	}
+
+	check := func(i, aid int) {
+		do(aid, func(c state.Cursor) {
+			if entries, err := c.Load(); err != nil {
+				t.Fatalf("Load: error = %v", err)
+			} else if got, ok := entries[tc[i].ID]; !ok {
+				t.Fatalf("Load: entry %s missing",
+					&tc[i].ID)
+			} else {
+				got.Time = tc[i].Time
+				if !reflect.DeepEqual(got, &tc[i]) {
+					t.Fatalf("Load: entry %s got %#v, want %#v",
+						&tc[i].ID, got, &tc[i])
+				}
+			}
+		})
+	}
+
+	t.Run("insert entry checked", func(t *testing.T) {
+		insert(insertEntryChecked, 0)
+		check(insertEntryChecked, 0)
+	})
+
+	t.Run("insert entry unchecked", func(t *testing.T) {
+		insert(insertEntryNoCheck, 0)
+	})
+
+	t.Run("insert entry different aid", func(t *testing.T) {
+		insert(insertEntryOtherApp, 1)
+		check(insertEntryOtherApp, 1)
+	})
+
+	t.Run("check previous insertion", func(t *testing.T) {
+		check(insertEntryNoCheck, 0)
+	})
+
+	t.Run("list aids", func(t *testing.T) {
+		if aids, err := s.List(); err != nil {
+			t.Fatalf("List: error = %v", err)
+		} else {
+			slices.Sort(aids)
+			want := []int{0, 1}
+			if slices.Compare(aids, want) != 0 {
+				t.Fatalf("List() = %#v, want %#v", aids, want)
+			}
+		}
+	})
+
+	t.Run("clear aid 1", func(t *testing.T) {
+		do(1, func(c state.Cursor) {
+			if err := c.Destroy(tc[insertEntryOtherApp].ID); err != nil {
+				t.Fatalf("Destroy: error = %v", err)
+			}
+		})
+		do(1, func(c state.Cursor) {
+			if l, err := c.Len(); err != nil {
+				t.Fatalf("Len: error = %v", err)
+			} else if l != 0 {
+				t.Fatalf("Len() = %d, want 0", l)
+			}
+		})
+	})
+
+	t.Run("close store", func(t *testing.T) {
+		if err := s.Close(); err != nil {
+			t.Fatalf("Close: error = %v", err)
+		}
+	})
+}
+
+func makeState(t *testing.T, s *state.State) {
+	if err := fst.NewAppID(&s.ID); err != nil {
+		t.Fatalf("cannot create dummy state: %v", err)
+	}
+	s.Config = fst.Template()
+	s.PID = rand.Int()
+	s.Time = time.Now()
+}

internal/system.go

@@ -1,126 +0,0 @@
-package internal
-
-import (
-	"errors"
-	"io/fs"
-	"os"
-	"os/exec"
-	"os/user"
-	"path"
-	"strconv"
-	"sync"
-
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-)
-
-// System provides safe access to operating system resources.
-type System interface {
-	// Geteuid provides [os.Geteuid].
-	Geteuid() int
-	// LookupEnv provides [os.LookupEnv].
-	LookupEnv(key string) (string, bool)
-	// TempDir provides [os.TempDir].
-	TempDir() string
-	// LookPath provides [exec.LookPath].
-	LookPath(file string) (string, error)
-	// Executable provides [os.Executable].
-	Executable() (string, error)
-	// Lookup provides [user.Lookup].
-	Lookup(username string) (*user.User, error)
-	// ReadDir provides [os.ReadDir].
-	ReadDir(name string) ([]fs.DirEntry, error)
-	// Stat provides [os.Stat].
-	Stat(name string) (fs.FileInfo, error)
-	// Open provides [os.Open]
-	Open(name string) (fs.File, error)
-	// Exit provides [os.Exit].
-	Exit(code int)
-
-	// Paths returns a populated [Paths] struct.
-	Paths() Paths
-	// SdBooted implements https://www.freedesktop.org/software/systemd/man/sd_booted.html
-	SdBooted() bool
-}
-
-// Paths contains environment dependent paths used by fortify.
-type Paths struct {
-	// path to shared directory e.g. /tmp/fortify.%d
-	SharePath string `json:"share_path"`
-	// XDG_RUNTIME_DIR value e.g. /run/user/%d
-	RuntimePath string `json:"runtime_path"`
-	// application runtime directory e.g. /run/user/%d/fortify
-	RunDirPath string `json:"run_dir_path"`
-}
-
-// CopyPaths is a generic implementation of [System.Paths].
-func CopyPaths(os System, v *Paths) {
-	v.SharePath = path.Join(os.TempDir(), "fortify."+strconv.Itoa(os.Geteuid()))
-
-	fmsg.VPrintf("process share directory at %q", v.SharePath)
-
-	if r, ok := os.LookupEnv(xdgRuntimeDir); !ok || r == "" || !path.IsAbs(r) {
-		// fall back to path in share since fortify has no hard XDG dependency
-		v.RunDirPath = path.Join(v.SharePath, "run")
-		v.RuntimePath = path.Join(v.RunDirPath, "compat")
-	} else {
-		v.RuntimePath = r
-		v.RunDirPath = path.Join(v.RuntimePath, "fortify")
-	}
-
-	fmsg.VPrintf("runtime directory at %q", v.RunDirPath)
-}
-
-// Std implements System using the standard library.
-type Std struct {
-	paths     Paths
-	pathsOnce sync.Once
-
-	sdBooted     bool
-	sdBootedOnce sync.Once
-}
-
-func (s *Std) Geteuid() int                               { return os.Geteuid() }
-func (s *Std) LookupEnv(key string) (string, bool)        { return os.LookupEnv(key) }
-func (s *Std) TempDir() string                            { return os.TempDir() }
-func (s *Std) LookPath(file string) (string, error)       { return exec.LookPath(file) }
-func (s *Std) Executable() (string, error)                { return os.Executable() }
-func (s *Std) Lookup(username string) (*user.User, error) { return user.Lookup(username) }
-func (s *Std) ReadDir(name string) ([]os.DirEntry, error) { return os.ReadDir(name) }
-func (s *Std) Stat(name string) (fs.FileInfo, error)      { return os.Stat(name) }
-func (s *Std) Open(name string) (fs.File, error)          { return os.Open(name) }
-func (s *Std) Exit(code int)                              { fmsg.Exit(code) }
-
-const xdgRuntimeDir = "XDG_RUNTIME_DIR"
-
-func (s *Std) Paths() Paths {
-	s.pathsOnce.Do(func() { CopyPaths(s, &s.paths) })
-	return s.paths
-}
-
-func (s *Std) SdBooted() bool {
-	s.sdBootedOnce.Do(func() { s.sdBooted = copySdBooted() })
-	return s.sdBooted
-}
-
-const systemdCheckPath = "/run/systemd/system"
-
-func copySdBooted() bool {
-	if v, err := sdBooted(); err != nil {
-		fmsg.Println("cannot read systemd marker:", err)
-		return false
-	} else {
-		return v
-	}
-}
-
-func sdBooted() (bool, error) {
-	_, err := os.Stat(systemdCheckPath)
-	if err != nil {
-		if errors.Is(err, fs.ErrNotExist) {
-			err = nil
-		}
-		return false, err
-	}
-
-	return true, nil
-}

internal/system/acl.go

@@ -4,8 +4,8 @@ import (
 	"fmt"
 	"slices"
 
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 // UpdatePerm appends an ephemeral acl update Op.

internal/system/acl_test.go

@@ -3,7 +3,7 @@ package system
 import (
 	"testing"
 
-	"git.ophivana.moe/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/acl"
 )
 
 func TestUpdatePerm(t *testing.T) {

internal/system/dbus.go

@@ -1,11 +1,14 @@
 package system
 
 import (
+	"bytes"
 	"errors"
 	"os"
+	"strings"
+	"sync"
 
-	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 var (
@@ -13,14 +16,14 @@ var (
 )
 
 func (sys *I) MustProxyDBus(sessionPath string, session *dbus.Config, systemPath string, system *dbus.Config) *I {
-	if err := sys.ProxyDBus(session, system, sessionPath, systemPath); err != nil {
+	if _, err := sys.ProxyDBus(session, system, sessionPath, systemPath); err != nil {
 		panic(err.Error())
 	} else {
 		return sys
 	}
 }
 
-func (sys *I) ProxyDBus(session, system *dbus.Config, sessionPath, systemPath string) error {
+func (sys *I) ProxyDBus(session, system *dbus.Config, sessionPath, systemPath string) (func(f func(msgbuf []string)), error) {
 	d := new(DBus)
 
 	// used by waiting goroutine to notify process exit
@@ -28,7 +31,7 @@ func (sys *I) ProxyDBus(session, system *dbus.Config, sessionPath, systemPath st
 
 	// session bus is mandatory
 	if session == nil {
-		return fmsg.WrapError(ErrDBusConfig,
+		return nil, fmsg.WrapError(ErrDBusConfig,
 			"attempted to seal message bus proxy without session bus config")
 	}
 
@@ -61,13 +64,15 @@ func (sys *I) ProxyDBus(session, system *dbus.Config, sessionPath, systemPath st
 	sys.ops = append(sys.ops, d)
 
 	// seal dbus proxy
-	return fmsg.WrapErrorSuffix(d.proxy.Seal(session, system),
+	d.out = &scanToFmsg{msg: new(strings.Builder)}
+	return d.out.F, fmsg.WrapErrorSuffix(d.proxy.Seal(session, system),
 		"cannot seal message bus proxy:")
 }
 
 type DBus struct {
 	proxy *dbus.Proxy
 
+	out *scanToFmsg
 	// whether system bus proxy is enabled
 	system bool
 	// notification from goroutine waiting for dbus.Proxy
@@ -88,7 +93,7 @@ func (d *DBus) apply(_ *I) error {
 	ready := make(chan error, 1)
 
 	// background dbus proxy start
-	if err := d.proxy.Start(ready, os.Stderr, true); err != nil {
+	if err := d.proxy.Start(ready, d.out, true); err != nil {
 		return fmsg.WrapErrorSuffix(err,
 			"cannot start message bus proxy:")
 	}
@@ -164,3 +169,34 @@ func (d *DBus) Path() string {
 func (d *DBus) String() string {
 	return d.proxy.String()
 }
+
+type scanToFmsg struct {
+	msg    *strings.Builder
+	msgbuf []string
+
+	mu sync.RWMutex
+}
+
+func (s *scanToFmsg) Write(p []byte) (n int, err error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.write(p, 0)
+}
+
+func (s *scanToFmsg) write(p []byte, a int) (int, error) {
+	if i := bytes.IndexByte(p, '\n'); i == -1 {
+		n, _ := s.msg.Write(p)
+		return a + n, nil
+	} else {
+		n, _ := s.msg.Write(p[:i])
+		s.msgbuf = append(s.msgbuf, s.msg.String())
+		s.msg.Reset()
+		return s.write(p[i+1:], a+n+1)
+	}
+}
+
+func (s *scanToFmsg) F(f func(msgbuf []string)) {
+	s.mu.RLock()
+	f(s.msgbuf)
+	s.mu.RUnlock()
+}

internal/system/mkdir.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"os"
 
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 // Ensure the existence and mode of a directory.

internal/system/op.go

@@ -2,9 +2,10 @@ package system
 
 import (
 	"errors"
+	"os"
 	"sync"
 
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 const (
@@ -56,6 +57,7 @@ func TypeString(e Enablement) string {
 type I struct {
 	uid int
 	ops []Op
+	sp  *os.File
 
 	state [2]bool
 	lock  sync.Mutex
@@ -65,6 +67,10 @@ func (sys *I) UID() int {
 	return sys.uid
 }
 
+func (sys *I) Sync() *os.File {
+	return sys.sp
+}
+
 func (sys *I) Equal(v *I) bool {
 	if v == nil || sys.uid != v.uid || len(sys.ops) != len(v.ops) {
 		return false

internal/system/op_test.go

@@ -4,7 +4,7 @@ import (
 	"strconv"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/internal/system"
+	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
 func TestNew(t *testing.T) {

internal/system/tmpfiles.go

@@ -7,8 +7,8 @@ import (
 	"os"
 	"strconv"
 
-	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 // CopyFile registers an Op that copies path dst from src.

internal/system/tmpfiles_test.go

@@ -4,7 +4,7 @@ import (
 	"strconv"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/acl"
 )
 
 func TestCopyFile(t *testing.T) {

internal/system/wayland.go

@@ -0,0 +1,85 @@
+package system
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/wl"
+)
+
+// Wayland sets up a wayland socket with a security context attached.
+func (sys *I) Wayland(dst, src, appID, instanceID string) *I {
+	sys.lock.Lock()
+	defer sys.lock.Unlock()
+
+	sys.ops = append(sys.ops, Wayland{[2]string{dst, src}, new(wl.Conn), appID, instanceID})
+
+	return sys
+}
+
+type Wayland struct {
+	pair [2]string
+	conn *wl.Conn
+
+	appID, instanceID string
+}
+
+func (w Wayland) Type() Enablement {
+	return Process
+}
+
+func (w Wayland) apply(sys *I) error {
+	// the Wayland op is not repeatable
+	if sys.sp != nil {
+		return errors.New("attempted to attach multiple wayland sockets")
+	}
+
+	if err := w.conn.Attach(w.pair[1]); err != nil {
+		return fmsg.WrapErrorSuffix(err,
+			fmt.Sprintf("cannot attach to wayland on %q:", w.pair[1]))
+	} else {
+		fmsg.VPrintf("wayland attached on %q", w.pair[1])
+	}
+
+	if sp, err := w.conn.Bind(w.pair[0], w.appID, w.instanceID); err != nil {
+		return fmsg.WrapErrorSuffix(err,
+			fmt.Sprintf("cannot bind to socket on %q:", w.pair[0]))
+	} else {
+		sys.sp = sp
+		fmsg.VPrintf("wayland listening on %q", w.pair[0])
+		return fmsg.WrapErrorSuffix(errors.Join(os.Chmod(w.pair[0], 0), acl.UpdatePerm(w.pair[0], sys.uid, acl.Read, acl.Write, acl.Execute)),
+			fmt.Sprintf("cannot chmod socket on %q:", w.pair[0]))
+	}
+}
+
+func (w Wayland) revert(_ *I, ec *Criteria) error {
+	if ec.hasType(w) {
+		fmsg.VPrintf("removing wayland socket on %q", w.pair[0])
+		if err := os.Remove(w.pair[0]); err != nil && !errors.Is(err, os.ErrNotExist) {
+			return err
+		}
+
+		fmsg.VPrintf("detaching from wayland on %q", w.pair[1])
+		return fmsg.WrapErrorSuffix(w.conn.Close(),
+			fmt.Sprintf("cannot detach from wayland on %q:", w.pair[1]))
+	} else {
+		fmsg.VPrintf("skipping wayland cleanup on %q", w.pair[0])
+		return nil
+	}
+}
+
+func (w Wayland) Is(o Op) bool {
+	w0, ok := o.(Wayland)
+	return ok && w.pair == w0.pair
+}
+
+func (w Wayland) Path() string {
+	return w.pair[0]
+}
+
+func (w Wayland) String() string {
+	return fmt.Sprintf("wayland socket at %q", w.pair[0])
+}

internal/system/xhost.go

@@ -3,8 +3,8 @@ package system
 import (
 	"fmt"
 
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/xcb"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/xcb"
 )
 
 // ChangeHosts appends an X11 ChangeHosts command Op.

ldd/exec.go

@@ -6,8 +6,8 @@ import (
 	"os/exec"
 	"strings"
 
-	"git.ophivana.moe/security/fortify/helper"
-	"git.ophivana.moe/security/fortify/helper/bwrap"
+	"git.gensokyo.uk/security/fortify/helper"
+	"git.gensokyo.uk/security/fortify/helper/bwrap"
 )
 
 func Exec(p string) ([]*Entry, error) {

ldd/ldd.go

@@ -1,3 +1,4 @@
+// Package ldd retrieves linker information by invoking ldd from glibc or musl and parsing its output.
 package ldd
 
 import (

ldd/ldd_test.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"testing"
 
-	"git.ophivana.moe/security/fortify/ldd"
+	"git.gensokyo.uk/security/fortify/ldd"
 )
 
 func TestParseError(t *testing.T) {