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
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
|
/*
* Copyright © 2014-2024 The Android Password Store Authors. All Rights Reserved.
* SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
*/
package com.github.androidpasswordstore.autofillparser
import android.content.Context
import android.content.Intent
import android.content.pm.PackageManager
import android.content.pm.PackageManager.ResolveInfoFlags
import android.os.Build
import android.provider.Settings
import android.service.autofill.SaveInfo
import androidx.annotation.RequiresApi
import androidx.core.net.toUri
/**
* In order to add a new browser, do the following:
* 1. Obtain the .apk from a trusted source. For example, download it from the Play Store on your
* phone and use adb pull to get it onto your computer. We will assume that it is called
* browser.apk.
* 2. Run
*
* aapt dump badging browser.apk | grep package: | grep -Eo " name='[a-zA-Z0-9_\.]*" | cut -c8-
*
* to obtain the package name (actually, the application ID) of the app in the .apk.
* 3. Run
*
* apksigner verify --print-certs browser.apk | grep "#1 certificate SHA-256" | grep -Eo
* "[a-f0-9]{64}" | tr -d '\n' | xxd -r -p | base64
*
* to calculate the hash of browser.apk's first signing certificate. Note: This will only work if
* the apk has a single signing certificate. Apps with multiple signers are very rare, so there is
* probably no need to add them. Refer to computeCertificatesHash to learn how the hash would be
* computed in this case.
* 4. Verify the package name and the hash, for example by asking other people to repeat the steps
* above.
* 5. Add an entry with the browser apps's package name and the hash to
* TRUSTED_BROWSER_CERTIFICATE_HASH.
* 6. Optionally, try adding the browser's package name to BROWSERS_WITH_SAVE_SUPPORT and check
* whether a save request to Password Store is triggered when you submit a registration form.
* 7. Optionally, try adding the browser's package name to BROWSERS_WITH_MULTI_ORIGIN_SUPPORT and
* check whether it correctly distinguishes web origins even if iframes are present on the page.
* You can use https://fabianhenneke.github.io/Android-Password-Store/ as a test form.
*
* **Security assumption**: Browsers on this list correctly report the web origin of the top-level
* window as part of their AssistStructure.
*
* Note: Browsers can be on this list even if they don't report the correct web origins of all
* fields on the page, e.g. of those in iframes.
*/
private val TRUSTED_BROWSER_CERTIFICATE_HASH =
mapOf(
"com.android.chrome" to arrayOf("8P1sW0EPJcslw7UzRsiXL64w+O50Ed+RBICtay1g24M="),
"com.brave.browser" to arrayOf("nC23BRNRX9v7vFhbPt89cSPU3GfJT/0wY2HB15u/GKw="),
"com.chrome.beta" to arrayOf("2mM9NLaeY64hA7SdU84FL8X388U6q5T9wqIIvf0UJJw="),
"com.chrome.canary" to arrayOf("IBnfofsj779wxbzRRDxb6rBPPy/0Nm6aweNFdjmiTPw="),
"com.chrome.dev" to arrayOf("kETuX+5LvF4h3URmVDHE6x8fcaMnFqC8knvLs5Izyr8="),
"com.duckduckgo.mobile.android" to
arrayOf(
"u3uzHFc8RqHaf8XFKKas9DIQhFb+7FCBDH8zaU6z0tQ=",
"8HB9AhwL8+b43MEbo/VwBCXVl9yjAaMeIQVWk067Gwo=",
),
"com.jamal2367.styx" to arrayOf("Lph3oaG1C8WLhLiK5PVxOp5+6wTU9ipJSBYlD2bA3VI="),
"com.microsoft.emmx" to arrayOf("AeGZlxCoLCdJtNUMRF3IXWcLYTYInQp2anOCfIKh6sk="),
"com.opera.mini.native" to arrayOf("V6y8Ul8bLr0ZGWzW8BQ5fMkQ/RiEHgroUP68Ph5ZP/I="),
"com.opera.mini.native.beta" to arrayOf("V6y8Ul8bLr0ZGWzW8BQ5fMkQ/RiEHgroUP68Ph5ZP/I="),
"com.opera.touch" to arrayOf("qtjiBNJNF3k0yc0MY8xqo4779CxKaVcJfiIQ9X+qZ6o="),
"org.bromite.bromite" to arrayOf("4e5c0HbXsNyEyytF+3i4bfLrOaO2xWuj3CkqXgw7lQQ="),
"org.cromite.cromite" to arrayOf("Yz+kHYIR1tCRaoGbiWaMbekuZCMtpn+dFv2Bw7fpI/8="),
"org.gnu.icecat" to arrayOf("wi2iuVvK/WYZUzd2g0Qzn9ef3kAisQURZ8U1WSMTkcM="),
"org.mozilla.fenix" to arrayOf("UAR3kIjn+YjVvFzF+HmP6/T4zQhKGypG79TI7krq8hE="),
"org.mozilla.fenix.nightly" to arrayOf("d+rEzu02r++6dheZMd1MwZWrDNVLrzVdIV57vdKOQCo="),
"org.mozilla.fennec_aurora" to arrayOf("vASIg40G9Mpr8yOG2qsN2OvPPncweHRZ9i+zzRShuqo="),
"org.mozilla.fennec_fdroid" to arrayOf("BmZTWO/YugW+I2pHoSywlY19dd2TnXfCsx9TmFN+vcU="),
"org.mozilla.firefox" to arrayOf("p4tipRZbRJSy/q2edqKA0i2Tf+5iUa7OWZRGsuoxmwQ="),
"org.mozilla.firefox_beta" to arrayOf("p4tipRZbRJSy/q2edqKA0i2Tf+5iUa7OWZRGsuoxmwQ="),
"org.mozilla.focus" to arrayOf("YgOkc7421k7jf4f6UA7bx56rkwYQq5ufpMp9XB8bT/w="),
"org.mozilla.klar" to arrayOf("YgOkc7421k7jf4f6UA7bx56rkwYQq5ufpMp9XB8bT/w="),
"org.torproject.torbrowser" to arrayOf("IAYfBF5zfGc3XBd5TP7bQ2oDzsa6y3y5+WZCIFyizsg="),
"org.ungoogled.chromium.stable" to arrayOf("29UOO5cXoxO/e/hH3hOu6bbtg1My4tK6Eik2Ym5Krtk="),
"org.ungoogled.chromium.extensions.stable" to
arrayOf("29UOO5cXoxO/e/hH3hOu6bbtg1My4tK6Eik2Ym5Krtk="),
"com.kiwibrowser.browser" to arrayOf("wGnqlmMy6R4KDDzFd+b1Cf49ndr3AVrQxcXvj9o/hig="),
"us.spotco.fennec_dos" to
arrayOf(
"Jg4KSWeMeLcMAtZTet07bcChcXG73oznX9QCaoo+GNI=",
"/4H1vlY5ZZTu5w/vKDIlbhUhQSLiupzt0mAF/9S8qqg=",
),
"com.vivaldi.browser" to arrayOf("6KeFRGVbqMCYF/cydo9WibFmLsSyvFoLwOwTjTPKPR4="),
"app.vanadium.browser" to arrayOf("xq24uDxtTBfSkq/eVv1IilHTFv+PLBHFQQIjv/in27M="),
)
private fun isTrustedBrowser(context: Context, appPackage: String): Boolean {
val expectedCertificateHashes = TRUSTED_BROWSER_CERTIFICATE_HASH[appPackage] ?: return false
val certificateHash = computeCertificatesHash(context, appPackage)
return certificateHash in expectedCertificateHashes
}
internal enum class BrowserMultiOriginMethod {
None,
WebView,
Field,
}
/**
* **Security assumption**: Browsers on this list correctly distinguish the web origins of form
* fields, e.g. on a page which contains both a first-party login form and an iframe with a
* (potentially malicious) third-party login form.
*
* There are two methods used by browsers:
* - Browsers based on Android's WebView report web domains on each WebView view node, which then
* needs to be propagated to the child nodes ( [BrowserMultiOriginMethod.WebView]).
* - Browsers with custom Autofill implementations report web domains on each input field (
* [BrowserMultiOriginMethod.Field]).
*/
private val BROWSER_MULTI_ORIGIN_METHOD =
mapOf(
"com.duckduckgo.mobile.android" to BrowserMultiOriginMethod.WebView,
"com.opera.mini.native" to BrowserMultiOriginMethod.WebView,
"com.opera.mini.native.beta" to BrowserMultiOriginMethod.WebView,
"com.opera.touch" to BrowserMultiOriginMethod.WebView,
"org.gnu.icecat" to BrowserMultiOriginMethod.WebView,
"org.mozilla.fenix" to BrowserMultiOriginMethod.Field,
"org.mozilla.fenix.nightly" to BrowserMultiOriginMethod.Field,
"org.mozilla.fennec_aurora" to BrowserMultiOriginMethod.Field,
"org.mozilla.fennec_fdroid" to BrowserMultiOriginMethod.Field,
"org.mozilla.firefox" to BrowserMultiOriginMethod.WebView,
"org.mozilla.firefox_beta" to BrowserMultiOriginMethod.WebView,
"org.mozilla.focus" to BrowserMultiOriginMethod.Field,
"org.mozilla.klar" to BrowserMultiOriginMethod.Field,
"org.torproject.torbrowser" to BrowserMultiOriginMethod.WebView,
"us.spotco.fennec_dos" to BrowserMultiOriginMethod.Field,
)
private fun getBrowserMultiOriginMethod(appPackage: String): BrowserMultiOriginMethod =
BROWSER_MULTI_ORIGIN_METHOD[appPackage] ?: BrowserMultiOriginMethod.None
/**
* Browsers on this list issue Autofill save requests and provide unmasked passwords as
* `autofillValue`.
*
* Some browsers may not issue save requests automatically and thus need
* `FLAG_SAVE_ON_ALL_VIEW_INVISIBLE` to be set.
*/
@RequiresApi(Build.VERSION_CODES.O)
private val BROWSER_SAVE_FLAG =
mapOf(
"com.duckduckgo.mobile.android" to 0,
"org.mozilla.klar" to 0,
"org.mozilla.focus" to 0,
"org.mozilla.fenix" to 0,
"org.mozilla.fenix.nightly" to 0,
"org.mozilla.fennec_aurora" to 0,
"com.opera.mini.native" to 0,
"com.opera.mini.native.beta" to 0,
"com.opera.touch" to 0,
)
@RequiresApi(Build.VERSION_CODES.O)
private val BROWSER_SAVE_FLAG_IF_NO_ACCESSIBILITY =
mapOf(
"com.android.chrome" to SaveInfo.FLAG_SAVE_ON_ALL_VIEWS_INVISIBLE,
"com.chrome.beta" to SaveInfo.FLAG_SAVE_ON_ALL_VIEWS_INVISIBLE,
"com.chrome.canary" to SaveInfo.FLAG_SAVE_ON_ALL_VIEWS_INVISIBLE,
"com.chrome.dev" to SaveInfo.FLAG_SAVE_ON_ALL_VIEWS_INVISIBLE,
"org.bromite.bromite" to SaveInfo.FLAG_SAVE_ON_ALL_VIEWS_INVISIBLE,
"org.cromite.cromite" to SaveInfo.FLAG_SAVE_ON_ALL_VIEWS_INVISIBLE,
"org.ungoogled.chromium.stable" to SaveInfo.FLAG_SAVE_ON_ALL_VIEWS_INVISIBLE,
)
private fun isNoAccessibilityServiceEnabled(context: Context): Boolean {
// See https://chromium.googlesource.com/chromium/src/+/447a31e977a65e2eb78804e4a09633699b4ede33
return Settings.Secure.getString(
context.contentResolver,
Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES,
)
.isNullOrEmpty()
}
@RequiresApi(Build.VERSION_CODES.O)
private fun getBrowserSaveFlag(context: Context, appPackage: String): Int? =
BROWSER_SAVE_FLAG[appPackage]
?: BROWSER_SAVE_FLAG_IF_NO_ACCESSIBILITY[appPackage]?.takeIf {
isNoAccessibilityServiceEnabled(context)
}
internal data class BrowserAutofillSupportInfo(
val multiOriginMethod: BrowserMultiOriginMethod,
val saveFlags: Int?,
)
@RequiresApi(Build.VERSION_CODES.O)
internal fun getBrowserAutofillSupportInfoIfTrusted(
context: Context,
appPackage: String,
): BrowserAutofillSupportInfo? {
if (!isTrustedBrowser(context, appPackage)) return null
return BrowserAutofillSupportInfo(
multiOriginMethod = getBrowserMultiOriginMethod(appPackage),
saveFlags = getBrowserSaveFlag(context, appPackage),
)
}
private val FLAKY_BROWSERS = listOf("com.kiwibrowser.browser")
public enum class BrowserAutofillSupportLevel {
None,
FlakyFill,
PasswordFill,
PasswordFillAndSaveIfNoAccessibility,
GeneralFill,
GeneralFillAndSave,
}
@RequiresApi(Build.VERSION_CODES.O)
private fun getBrowserAutofillSupportLevel(
context: Context,
appPackage: String,
): BrowserAutofillSupportLevel {
val browserInfo = getBrowserAutofillSupportInfoIfTrusted(context, appPackage)
return when {
browserInfo == null -> BrowserAutofillSupportLevel.None
appPackage in FLAKY_BROWSERS -> BrowserAutofillSupportLevel.FlakyFill
appPackage in BROWSER_SAVE_FLAG_IF_NO_ACCESSIBILITY ->
BrowserAutofillSupportLevel.PasswordFillAndSaveIfNoAccessibility
browserInfo.multiOriginMethod == BrowserMultiOriginMethod.None ->
BrowserAutofillSupportLevel.PasswordFill
browserInfo.saveFlags == null -> BrowserAutofillSupportLevel.GeneralFill
else -> BrowserAutofillSupportLevel.GeneralFillAndSave
}.takeUnless { supportLevel ->
// On Android Oreo, only browsers with native Autofill support can be used with Password
// Store
// (compatibility mode is only available on Android Pie and higher). Since all known
// browsers
// with native Autofill support offer full save support as well, we reuse the list of those
// browsers here.
supportLevel != BrowserAutofillSupportLevel.GeneralFillAndSave &&
Build.VERSION.SDK_INT < Build.VERSION_CODES.P
} ?: BrowserAutofillSupportLevel.None
}
@RequiresApi(Build.VERSION_CODES.O)
public fun getInstalledBrowsersWithAutofillSupportLevel(
context: Context
): List<Pair<String, BrowserAutofillSupportLevel>> {
val testWebIntent = Intent(Intent.ACTION_VIEW).apply { data = "https://example.org".toUri() }
val installedBrowsers =
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
context.packageManager.queryIntentActivities(
testWebIntent,
ResolveInfoFlags.of(PackageManager.MATCH_ALL.toLong()),
)
} else {
context.packageManager.queryIntentActivities(testWebIntent, PackageManager.MATCH_ALL)
}
return installedBrowsers
.map { it to getBrowserAutofillSupportLevel(context, it.activityInfo.packageName) }
.filter { it.first.isDefault || it.second != BrowserAutofillSupportLevel.None }
.map {
context.packageManager
.getApplicationLabel(it.first.activityInfo.applicationInfo)
.toString() to it.second
}
}
|
