1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
package app
import (
"errors"
"git.ophivana.moe/security/fortify/dbus"
"git.ophivana.moe/security/fortify/helper/bwrap"
"git.ophivana.moe/security/fortify/internal/linux"
"git.ophivana.moe/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"`
// value passed through to the child process as its argv
Command []string `json:"command"`
// child confinement configuration
Confinement ConfinementConfig `json:"confinement"`
}
// 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
Home string `json:"home"`
// bwrap sandbox confinement configuration
Sandbox *SandboxConfig `json:"sandbox"`
// reference to a system D-Bus proxy configuration,
// nil value disables system bus proxy
SystemBus *dbus.Config `json:"system_bus,omitempty"`
// reference to a session D-Bus proxy configuration,
// nil value makes session bus proxy assume built-in defaults
SessionBus *dbus.Config `json:"session_bus,omitempty"`
// child capability enablements
Enablements system.Enablements `json:"enablements"`
}
// SandboxConfig describes resources made available to the sandbox.
type SandboxConfig struct {
// unix hostname within sandbox
Hostname string `json:"hostname,omitempty"`
// userns availability within sandbox
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"`
// map target user uid to privileged user uid in the user namespace
MapRealUID bool `json:"map_real_uid"`
// mediated access to wayland socket
Wayland bool `json:"wayland,omitempty"`
// final environment variables
Env map[string]string `json:"env"`
// sandbox host filesystem access
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"`
}
type FilesystemConfig struct {
// mount point in sandbox, same as src if empty
Dst string `json:"dst,omitempty"`
// host filesystem path to make available to sandbox
Src string `json:"src"`
// write access
Write bool `json:"write,omitempty"`
// device access
Device bool `json:"dev,omitempty"`
// exit if unable to share
Must bool `json:"require,omitempty"`
}
// 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(os linux.System) (*bwrap.Config, error) {
if s == nil {
return nil, errors.New("nil sandbox config")
}
var uid int
if !s.MapRealUID {
uid = 65534
} else {
uid = os.Geteuid()
}
conf := (&bwrap.Config{
Net: s.Net,
UserNS: s.UserNS,
Hostname: s.Hostname,
Clearenv: true,
SetEnv: s.Env,
NewSession: !s.NoNewSession,
DieWithParent: true,
AsInit: true,
// initialise map
Chmod: make(bwrap.ChmodConfig),
}).
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 {
continue
}
src := c.Src
dest := c.Dst
if c.Dst == "" {
dest = c.Src
}
conf.Bind(src, dest, !c.Must, c.Write, c.Device)
}
for _, l := range s.Link {
conf.Symlink(l[0], l[1])
}
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",
Command: []string{
"chromium",
"--ignore-gpu-blocklist",
"--disable-smooth-scrolling",
"--enable-features=UseOzonePlatform",
"--ozone-platform=wayland",
},
Confinement: ConfinementConfig{
AppID: 9,
Groups: []string{"video"},
Username: "chronos",
Home: "/var/lib/persist/home/org.chromium.Chromium",
Sandbox: &SandboxConfig{
Hostname: "localhost",
UserNS: true,
Net: true,
NoNewSession: true,
MapRealUID: true,
Dev: true,
Wayland: false,
// example API credentials pulled from Google Chrome
// DO NOT USE THESE IN A REAL BROWSER
Env: map[string]string{
"GOOGLE_API_KEY": "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
"GOOGLE_DEFAULT_CLIENT_ID": "77185425430.apps.googleusercontent.com",
"GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT",
},
Filesystem: []*FilesystemConfig{
{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{{"/run/user/65534", "/run/user/150"}},
AutoEtc: true,
Override: []string{"/var/run/nscd"},
},
SystemBus: &dbus.Config{
See: nil,
Talk: []string{"org.bluez", "org.freedesktop.Avahi", "org.freedesktop.UPower"},
Own: nil,
Call: nil,
Broadcast: nil,
Log: false,
Filter: true,
},
SessionBus: &dbus.Config{
See: nil,
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/*"},
Log: false,
Filter: true,
},
Enablements: system.EWayland.Mask() | system.EDBus.Mask() | system.EPulse.Mask(),
},
}
}
|
