app: test app permissive defaults sealing behaviour

This test seals App against a deterministic os stub and checks the resulting sys and bwrap values against known correct ones. The effects of sys and bwrap on the OS and sandbox is deterministic and tested in their own respective packages.

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

1 files changed, 379 insertions, 0 deletions

diff --git a/internal/app/app_test.go b/internal/app/app_test.go
new file mode 100644
index 00000000..ed98a6bd
--- /dev/null
+++ b/internal/app/app_test.go
@@ -0,0 +1,379 @@
+package app_test
+
+import (
+	"fmt"
+	"io/fs"
+	"os/user"
+	"reflect"
+	"strconv"
+	"testing"
+
+	"git.ophivana.moe/security/fortify/acl"
+	"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"
+)
+
+func TestApp(t *testing.T) {
+	testCases := []struct {
+		name      string
+		config    *app.Config
+		id        app.ID
+		wantSys   *system.I
+		wantBwrap *bwrap.Config
+	}{
+		{
+			"permissive defaults no enablements",
+			&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),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			a := app.NewWithID(tc.id, new(stub))
+
+			if !t.Run("seal", func(t *testing.T) {
+				if err := a.Seal(tc.config); err != nil {
+					t.Errorf("Seal: error = %v", err)
+				}
+			}) {
+				return
+			}
+
+			gotSys, gotBwrap := app.AppSystemBwrap(a)
+
+			t.Run("compare sys", func(t *testing.T) {
+				if !gotSys.Equal(tc.wantSys) {
+					t.Errorf("Seal: sys = %#v, want %#v",
+						gotSys, tc.wantSys)
+				}
+			})
+
+			t.Run("compare bwrap", func(t *testing.T) {
+				if !reflect.DeepEqual(gotBwrap, tc.wantBwrap) {
+					t.Errorf("seal: bwrap = %#v, want %#v",
+						gotBwrap, tc.wantBwrap)
+				}
+			})
+		})
+	}
+}
+
+// fs methods are not implemented using a real FS
+// to help better understand filesystem access behaviour
+type stub struct {
+	lookPathErr map[string]error
+	usernameErr map[string]error
+}
+
+func (s *stub) Geteuid() int {
+	return 1971
+}
+
+func (s *stub) LookupEnv(key string) (string, bool) {
+	switch key {
+	case "SHELL":
+		return "/run/current-system/sw/bin/zsh", true
+	case "TERM":
+		return "xterm-256color", true
+	default:
+		panic(fmt.Sprintf("attempted to access unexpected environment variable %q", key))
+	}
+}
+
+func (s *stub) TempDir() string {
+	return "/tmp"
+}
+
+func (s *stub) 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
+	default:
+		panic(fmt.Sprintf("attempted to look up unexpected executable %q", file))
+	}
+}
+
+func (s *stub) Executable() (string, error) {
+	return "/home/ophestra/.nix-profile/bin/fortify", nil
+}
+
+func (s *stub) 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 *stub) 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 *stub) Stat(name string) (fs.FileInfo, error) {
+	switch name {
+	case "/var/run/nscd":
+		return nil, nil
+	default:
+		panic(fmt.Sprintf("attempted to stat unexpected path %q", name))
+	}
+}
+
+func (s *stub) Open(name string) (fs.File, error) {
+	switch name {
+	default:
+		panic(fmt.Sprintf("attempted to open unexpected file %q", name))
+	}
+}
+
+func (s *stub) Exit(code int) {
+	panic("called exit on stub with code " + strconv.Itoa(code))
+}
+
+func (s *stub) Paths() internal.Paths {
+	return internal.Paths{
+		SharePath:   "/tmp/fortify.1971",
+		RuntimePath: "/run/user/1971",
+		RunDirPath:  "/run/user/1971/fortify",
+	}
+}
+
+func stubDirEntries(names ...string) (e []fs.DirEntry, err error) {
+	e = make([]fs.DirEntry, len(names))
+	for i, name := range names {
+		e[i] = stubDirEntryPath(name)
+	}
+	return
+}
+
+type stubDirEntryPath string
+
+func (p stubDirEntryPath) Name() string {
+	return string(p)
+}
+
+func (p stubDirEntryPath) IsDir() bool {
+	panic("attempted to call IsDir")
+}
+
+func (p stubDirEntryPath) Type() fs.FileMode {
+	panic("attempted to call Type")
+}
+
+func (p stubDirEntryPath) Info() (fs.FileInfo, error) {
+	panic("attempted to call Info")
+}