@recaptime-dev's working patches + fork for Phorge, a community fork of Phabricator. (Upstream dev and stable branches are at upstream/main and upstream/stable respectively.)
hq.recaptime.dev/wiki/Phorge
phorge
phabricator
Upgrade sessions digests to HMAC256, retaining compatibility with old digests
Summary:
Ref T13222. Ref T13225. We store a digest of the session key in the session table (not the session key itself) so that users with access to this table can't easily steal sessions by just setting their cookies to values from the table.
Users with access to the database can //probably// do plenty of other bad stuff (e.g., T13134 mentions digesting Conduit tokens) but there's very little cost to storing digests instead of live tokens.
We currently digest session keys with HMAC-SHA1. This is fine, but HMAC-SHA256 is better. Upgrade:
- Always write new digests.
- We still match sessions with either digest.
- When we read a session with an old digest, upgrade it to a new digest.
In a few months we can throw away the old code. When we do, installs that skip upgrades for a long time may suffer a one-time logout, but I'll note this in the changelog.
We could avoid this by storing `hmac256(hmac1(key))` instead and re-hashing in a migration, but I think the cost of a one-time logout for some tiny subset of users is very low, and worth keeping things simpler in the long run.
Test Plan:
- Hit a page with an old session, got a session upgrade.
- Reviewed sessions in Settings.
- Reviewed user logs.
- Logged out.
- Logged in.
- Terminated other sessions individually.
- Terminated all other sessions.
- Spot checked session table for general sanity.
Reviewers: amckinley
Reviewed By: amckinley
Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam
Maniphest Tasks: T13225, T13222
Differential Revision: https://secure.phabricator.com/D19883
+84
-42
+2
resources/sql/autopatches/20181213.auth.04.longerhashes.sql
+2
resources/sql/autopatches/20181213.auth.04.longerhashes.sql
+2
resources/sql/autopatches/20181213.auth.05.longerloghashes.sql
+2
resources/sql/autopatches/20181213.auth.05.longerloghashes.sql
+5
-20
resources/sql/patches/20130530.sessionhash.php
+5
-20
resources/sql/patches/20130530.sessionhash.php
···
1
1
<?php
2
2
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-
$table = new PhabricatorUser();
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-
$table->openTransaction();
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-
$conn = $table->establishConnection('w');
6
-
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-
$sessions = queryfx_all(
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-
$conn,
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-
'SELECT userPHID, type, sessionKey FROM %T FOR UPDATE',
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-
PhabricatorUser::SESSION_TABLE);
11
-
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-
foreach ($sessions as $session) {
13
-
queryfx(
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-
$conn,
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-
'UPDATE %T SET sessionKey = %s WHERE userPHID = %s AND type = %s',
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-
PhabricatorUser::SESSION_TABLE,
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-
PhabricatorHash::weakDigest($session['sessionKey']),
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-
$session['userPHID'],
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-
$session['type']);
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-
}
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-
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$table->saveTransaction();
3
+
// See T13225. Long ago, this upgraded session key storage from unhashed to
4
+
// HMAC-SHA1 here. We later upgraded storage to HMAC-SHA256, so this is initial
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+
// upgrade is now fairly pointless. Dropping this migration entirely only logs
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+
// users out of installs that waited more than 5 years to upgrade, which seems
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+
// like a reasonable behavior.
+3
-2
src/applications/auth/controller/PhabricatorAuthTerminateSessionController.php
+3
-2
src/applications/auth/controller/PhabricatorAuthTerminateSessionController.php
···
16
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$query->withIDs(array($id));
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}
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-
$current_key = PhabricatorHash::weakDigest(
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-
$request->getCookie(PhabricatorCookies::COOKIE_SESSION));
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+
$current_key = PhabricatorAuthSession::newSessionDigest(
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+
new PhutilOpaqueEnvelope(
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+
$request->getCookie(PhabricatorCookies::COOKIE_SESSION)));
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$sessions = $query->execute();
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foreach ($sessions as $key => $session) {
+2
-1
src/applications/auth/controller/PhabricatorAuthUnlinkController.php
+2
-1
src/applications/auth/controller/PhabricatorAuthUnlinkController.php
···
56
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id(new PhabricatorAuthSessionEngine())->terminateLoginSessions(
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$viewer,
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-
$request->getCookie(PhabricatorCookies::COOKIE_SESSION));
59
+
new PhutilOpaqueEnvelope(
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$request->getCookie(PhabricatorCookies::COOKIE_SESSION)));
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return id(new AphrontRedirectResponse())->setURI($this->getDoneURI());
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}
+38
-11
src/applications/auth/engine/PhabricatorAuthSessionEngine.php
+38
-11
src/applications/auth/engine/PhabricatorAuthSessionEngine.php
···
109
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$session_table = new PhabricatorAuthSession();
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$user_table = new PhabricatorUser();
112
-
$conn_r = $session_table->establishConnection('r');
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-
$session_key = PhabricatorHash::weakDigest($session_token);
112
+
$conn = $session_table->establishConnection('r');
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+
114
+
// TODO: See T13225. We're moving sessions to a more modern digest
115
+
// algorithm, but still accept older cookies for compatibility.
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+
$session_key = PhabricatorAuthSession::newSessionDigest(
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+
new PhutilOpaqueEnvelope($session_token));
118
+
$weak_key = PhabricatorHash::weakDigest($session_token);
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-
$cache_parts = $this->getUserCacheQueryParts($conn_r);
120
+
$cache_parts = $this->getUserCacheQueryParts($conn);
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list($cache_selects, $cache_joins, $cache_map, $types_map) = $cache_parts;
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$info = queryfx_one(
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-
$conn_r,
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+
$conn,
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'SELECT
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s.id AS s_id,
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s.phid AS s_phid,
···
125
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s.highSecurityUntil AS s_highSecurityUntil,
126
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s.isPartial AS s_isPartial,
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132
s.signedLegalpadDocuments as s_signedLegalpadDocuments,
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+
IF(s.sessionKey = %P, 1, 0) as s_weak,
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u.*
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%Q
130
-
FROM %T u JOIN %T s ON u.phid = s.userPHID
131
-
AND s.type = %s AND s.sessionKey = %P %Q',
136
+
FROM %R u JOIN %R s ON u.phid = s.userPHID
137
+
AND s.type = %s AND s.sessionKey IN (%P, %P) %Q',
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+
new PhutilOpaqueEnvelope($weak_key),
132
139
$cache_selects,
133
-
$user_table->getTableName(),
134
-
$session_table->getTableName(),
140
+
$user_table,
141
+
$session_table,
135
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$session_type,
136
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new PhutilOpaqueEnvelope($session_key),
144
+
new PhutilOpaqueEnvelope($weak_key),
137
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$cache_joins);
138
146
139
147
if (!$info) {
140
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return null;
141
149
}
142
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151
+
// TODO: Remove this, see T13225.
152
+
$is_weak = (bool)$info['s_weak'];
153
+
unset($info['s_weak']);
154
+
143
155
$session_dict = array(
144
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'userPHID' => $info['phid'],
145
157
'sessionKey' => $session_key,
···
202
214
unset($unguarded);
203
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}
204
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217
+
// TODO: Remove this, see T13225.
218
+
if ($is_weak) {
219
+
$unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
220
+
$conn_w = $session_table->establishConnection('w');
221
+
queryfx(
222
+
$conn_w,
223
+
'UPDATE %T SET sessionKey = %P WHERE id = %d',
224
+
$session->getTableName(),
225
+
new PhutilOpaqueEnvelope($session_key),
226
+
$session->getID());
227
+
unset($unguarded);
228
+
}
229
+
205
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$user->attachSession($session);
206
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return $user;
207
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}
···
241
266
// This has a side effect of validating the session type.
242
267
$session_ttl = PhabricatorAuthSession::getSessionTypeTTL($session_type);
243
268
244
-
$digest_key = PhabricatorHash::weakDigest($session_key);
269
+
$digest_key = PhabricatorAuthSession::newSessionDigest(
270
+
new PhutilOpaqueEnvelope($session_key));
245
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246
272
// Logging-in users don't have CSRF stuff yet, so we have to unguard this
247
273
// write.
···
299
325
*/
300
326
public function terminateLoginSessions(
301
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PhabricatorUser $user,
302
-
$except_session = null) {
328
+
PhutilOpaqueEnvelope $except_session = null) {
303
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$sessions = id(new PhabricatorAuthSessionQuery())
305
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->setViewer($user)
···
307
333
->execute();
308
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if ($except_session !== null) {
310
-
$except_session = PhabricatorHash::weakDigest($except_session);
336
+
$except_session = PhabricatorAuthSession::newSessionDigest(
337
+
$except_session);
311
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}
312
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foreach ($sessions as $key => $session) {
+2
-1
src/applications/auth/query/PhabricatorAuthSessionQuery.php
+2
-1
src/applications/auth/query/PhabricatorAuthSessionQuery.php
···
91
91
if ($this->sessionKeys !== null) {
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$hashes = array();
93
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foreach ($this->sessionKeys as $session_key) {
94
-
$hashes[] = PhabricatorHash::weakDigest($session_key);
94
+
$hashes[] = PhabricatorAuthSession::newSessionDigest(
95
+
new PhutilOpaqueEnvelope($session_key));
95
96
}
96
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$where[] = qsprintf(
97
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$conn,
+9
-1
src/applications/auth/storage/PhabricatorAuthSession.php
+9
-1
src/applications/auth/storage/PhabricatorAuthSession.php
···
6
6
const TYPE_WEB = 'web';
7
7
const TYPE_CONDUIT = 'conduit';
8
8
9
+
const SESSION_DIGEST_KEY = 'session.digest';
10
+
9
11
protected $userPHID;
10
12
protected $type;
11
13
protected $sessionKey;
···
17
19
18
20
private $identityObject = self::ATTACHABLE;
19
21
22
+
public static function newSessionDigest(PhutilOpaqueEnvelope $session_token) {
23
+
return PhabricatorHash::digestWithNamedKey(
24
+
$session_token->openEnvelope(),
25
+
self::SESSION_DIGEST_KEY);
26
+
}
27
+
20
28
protected function getConfiguration() {
21
29
return array(
22
30
self::CONFIG_TIMESTAMPS => false,
23
31
self::CONFIG_AUX_PHID => true,
24
32
self::CONFIG_COLUMN_SCHEMA => array(
25
33
'type' => 'text32',
26
-
'sessionKey' => 'bytes40',
34
+
'sessionKey' => 'text64',
27
35
'sessionStart' => 'epoch',
28
36
'sessionExpires' => 'epoch',
29
37
'highSecurityUntil' => 'epoch?',
+1
-1
src/applications/people/storage/PhabricatorUserLog.php
+1
-1
src/applications/people/storage/PhabricatorUserLog.php
+2
-1
src/applications/settings/panel/PhabricatorMultiFactorSettingsPanel.php
+2
-1
src/applications/settings/panel/PhabricatorMultiFactorSettingsPanel.php
···
193
193
194
194
id(new PhabricatorAuthSessionEngine())->terminateLoginSessions(
195
195
$user,
196
-
$request->getCookie(PhabricatorCookies::COOKIE_SESSION));
196
+
new PhutilOpaqueEnvelope(
197
+
$request->getCookie(PhabricatorCookies::COOKIE_SESSION)));
197
198
198
199
return id(new AphrontRedirectResponse())
199
200
->setURI($this->getPanelURI('?id='.$config->getID()));
+2
-1
src/applications/settings/panel/PhabricatorPasswordSettingsPanel.php
+2
-1
src/applications/settings/panel/PhabricatorPasswordSettingsPanel.php
···
121
121
122
122
id(new PhabricatorAuthSessionEngine())->terminateLoginSessions(
123
123
$user,
124
-
$request->getCookie(PhabricatorCookies::COOKIE_SESSION));
124
+
new PhutilOpaqueEnvelope(
125
+
$request->getCookie(PhabricatorCookies::COOKIE_SESSION)));
125
126
126
127
return id(new AphrontRedirectResponse())->setURI($next);
127
128
}
+3
-2
src/applications/settings/panel/PhabricatorSessionsSettingsPanel.php
+3
-2
src/applications/settings/panel/PhabricatorSessionsSettingsPanel.php
···
44
44
->withPHIDs($identity_phids)
45
45
->execute();
46
46
47
-
$current_key = PhabricatorHash::weakDigest(
48
-
$request->getCookie(PhabricatorCookies::COOKIE_SESSION));
47
+
$current_key = PhabricatorAuthSession::newSessionDigest(
48
+
new PhutilOpaqueEnvelope(
49
+
$request->getCookie(PhabricatorCookies::COOKIE_SESSION)));
49
50
50
51
$rows = array();
51
52
$rowc = array();
+13
-1
src/infrastructure/util/PhabricatorHash.php
+13
-1
src/infrastructure/util/PhabricatorHash.php
···
187
187
}
188
188
189
189
public static function digestHMACSHA256($message, $key) {
190
+
if (!is_string($message)) {
191
+
throw new Exception(
192
+
pht('HMAC-SHA256 can only digest strings.'));
193
+
}
194
+
195
+
if (!is_string($key)) {
196
+
throw new Exception(
197
+
pht('HMAC-SHA256 keys must be strings.'));
198
+
}
199
+
190
200
if (!strlen($key)) {
191
201
throw new Exception(
192
202
pht('HMAC-SHA256 requires a nonempty key.'));
···
194
204
195
205
$result = hash_hmac('sha256', $message, $key, $raw_output = false);
196
206
197
-
if ($result === false) {
207
+
// Although "hash_hmac()" is documented as returning `false` when it fails,
208
+
// it can also return `null` if you pass an object as the "$message".
209
+
if ($result === false || $result === null) {
198
210
throw new Exception(
199
211
pht('Unable to compute HMAC-SHA256 digest of message.'));
200
212
}