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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703
// Copyright 2020 The Matrix.org Foundation C.I.C.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::{
collections::{BTreeMap, HashMap},
fmt,
ops::{Deref, Not as _},
sync::Arc,
time::Duration,
};
use js_option::JsOption;
use ruma::{
api::client::{
dehydrated_device::{DehydratedDeviceData, DehydratedDeviceV1},
keys::{
upload_keys,
upload_signatures::v3::{Request as SignatureUploadRequest, SignedKeys},
},
},
events::AnyToDeviceEvent,
serde::Raw,
DeviceId, DeviceKeyAlgorithm, DeviceKeyId, MilliSecondsSinceUnixEpoch, OneTimeKeyAlgorithm,
OneTimeKeyId, OwnedDeviceId, OwnedDeviceKeyId, OwnedOneTimeKeyId, OwnedUserId, RoomId,
SecondsSinceUnixEpoch, UInt, UserId,
};
use serde::{de::Error, Deserialize, Serialize};
use serde_json::{
value::{to_raw_value, RawValue as RawJsonValue},
Value,
};
use sha2::{Digest, Sha256};
use tokio::sync::Mutex;
use tracing::{debug, field::debug, info, instrument, trace, warn, Span};
use vodozemac::{
base64_encode,
olm::{
Account as InnerAccount, AccountPickle, IdentityKeys, OlmMessage,
OneTimeKeyGenerationResult, PreKeyMessage, SessionConfig,
},
Curve25519PublicKey, Ed25519Signature, KeyId, PickleError,
};
use super::{
utility::SignJson, EncryptionSettings, InboundGroupSession, OutboundGroupSession,
PrivateCrossSigningIdentity, Session, SessionCreationError as MegolmSessionCreationError,
};
#[cfg(feature = "experimental-algorithms")]
use crate::types::events::room::encrypted::OlmV2Curve25519AesSha2Content;
use crate::{
dehydrated_devices::DehydrationError,
error::{EventError, OlmResult, SessionCreationError},
identities::DeviceData,
olm::SenderData,
requests::UploadSigningKeysRequest,
store::{Changes, DeviceChanges, Store},
types::{
events::{
olm_v1::AnyDecryptedOlmEvent,
room::encrypted::{
EncryptedToDeviceEvent, OlmV1Curve25519AesSha2Content,
ToDeviceEncryptedEventContent,
},
},
CrossSigningKey, DeviceKeys, EventEncryptionAlgorithm, MasterPubkey, OneTimeKey, SignedKey,
},
OlmError, SignatureError,
};
#[derive(Debug)]
enum PrekeyBundle {
Olm3DH { key: SignedKey },
}
#[derive(Debug, Clone)]
pub(crate) enum SessionType {
New(Session),
Existing(Session),
}
#[derive(Debug)]
pub struct InboundCreationResult {
pub session: Session,
pub plaintext: String,
}
impl SessionType {
#[cfg(test)]
pub fn session(self) -> Session {
match self {
SessionType::New(s) => s,
SessionType::Existing(s) => s,
}
}
}
/// A struct witnessing a successful decryption of an Olm-encrypted to-device
/// event.
///
/// Contains the decrypted event plaintext along with some associated metadata,
/// such as the identity (Curve25519) key of the to-device event sender.
#[derive(Debug)]
pub(crate) struct OlmDecryptionInfo {
pub session: SessionType,
pub message_hash: OlmMessageHash,
pub inbound_group_session: Option<InboundGroupSession>,
pub result: DecryptionResult,
}
#[derive(Debug)]
pub(crate) struct DecryptionResult {
// AnyDecryptedOlmEvent is pretty big at 512 bytes, box it to reduce stack size
pub event: Box<AnyDecryptedOlmEvent>,
pub raw_event: Raw<AnyToDeviceEvent>,
pub sender_key: Curve25519PublicKey,
}
/// A hash of a successfully decrypted Olm message.
///
/// Can be used to check if a message has been replayed to us.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct OlmMessageHash {
/// The curve25519 key of the sender that sent us the Olm message.
pub sender_key: String,
/// The hash of the message.
pub hash: String,
}
impl OlmMessageHash {
fn new(sender_key: Curve25519PublicKey, ciphertext: &OlmMessage) -> Self {
let (message_type, ciphertext) = ciphertext.clone().to_parts();
let sender_key = sender_key.to_base64();
let sha = Sha256::new()
.chain_update(sender_key.as_bytes())
.chain_update([message_type as u8])
.chain_update(ciphertext)
.finalize();
Self { sender_key, hash: base64_encode(sha.as_slice()) }
}
}
/// Account data that's static for the lifetime of a Client.
///
/// This data never changes once it's set, so it can be freely passed and cloned
/// everywhere.
#[derive(Clone)]
#[cfg_attr(not(tarpaulin_include), derive(Debug))]
pub struct StaticAccountData {
/// The user_id this account belongs to.
pub user_id: OwnedUserId,
/// The device_id of this entry.
pub device_id: OwnedDeviceId,
/// The associated identity keys.
pub identity_keys: Arc<IdentityKeys>,
/// Whether the account is for a dehydrated device.
pub dehydrated: bool,
// The creation time of the account in milliseconds since epoch.
creation_local_time: MilliSecondsSinceUnixEpoch,
}
impl StaticAccountData {
const ALGORITHMS: &'static [&'static EventEncryptionAlgorithm] = &[
&EventEncryptionAlgorithm::OlmV1Curve25519AesSha2,
#[cfg(feature = "experimental-algorithms")]
&EventEncryptionAlgorithm::OlmV2Curve25519AesSha2,
&EventEncryptionAlgorithm::MegolmV1AesSha2,
#[cfg(feature = "experimental-algorithms")]
&EventEncryptionAlgorithm::MegolmV2AesSha2,
];
/// Create a group session pair.
///
/// This session pair can be used to encrypt and decrypt messages meant for
/// a large group of participants.
///
/// The outbound session is used to encrypt messages while the inbound one
/// is used to decrypt messages encrypted by the outbound one.
///
/// # Arguments
///
/// * `room_id` - The ID of the room where the group session will be used.
///
/// * `settings` - Settings determining the algorithm and rotation period of
/// the outbound group session.
pub async fn create_group_session_pair(
&self,
room_id: &RoomId,
settings: EncryptionSettings,
own_sender_data: SenderData,
) -> Result<(OutboundGroupSession, InboundGroupSession), MegolmSessionCreationError> {
trace!(?room_id, algorithm = settings.algorithm.as_str(), "Creating a new room key");
let visibility = settings.history_visibility.clone();
let algorithm = settings.algorithm.to_owned();
let outbound = OutboundGroupSession::new(
self.device_id.clone(),
self.identity_keys.clone(),
room_id,
settings,
)?;
let identity_keys = &self.identity_keys;
let sender_key = identity_keys.curve25519;
let signing_key = identity_keys.ed25519;
let inbound = InboundGroupSession::new(
sender_key,
signing_key,
room_id,
&outbound.session_key().await,
own_sender_data,
algorithm,
Some(visibility),
)?;
Ok((outbound, inbound))
}
#[cfg(any(test, feature = "testing"))]
#[allow(dead_code)]
/// Testing only facility to create a group session pair with default
/// settings.
pub async fn create_group_session_pair_with_defaults(
&self,
room_id: &RoomId,
) -> (OutboundGroupSession, InboundGroupSession) {
self.create_group_session_pair(
room_id,
EncryptionSettings::default(),
SenderData::unknown(),
)
.await
.expect("Can't create default group session pair")
}
/// Get the key ID of our Ed25519 signing key.
pub fn signing_key_id(&self) -> OwnedDeviceKeyId {
DeviceKeyId::from_parts(DeviceKeyAlgorithm::Ed25519, self.device_id())
}
/// Check if the given JSON is signed by this Account key.
///
/// This method should only be used if an object's signature needs to be
/// checked multiple times, and you'd like to avoid performing the
/// canonicalization step each time.
///
/// **Note**: Use this method with caution, the `canonical_json` needs to be
/// correctly canonicalized and make sure that the object you are checking
/// the signature for is allowed to be signed by our own device.
pub fn has_signed_raw(
&self,
signatures: &crate::types::Signatures,
canonical_json: &str,
) -> Result<(), SignatureError> {
use crate::olm::utility::VerifyJson;
let signing_key = self.identity_keys.ed25519;
signing_key.verify_canonicalized_json(
&self.user_id,
&DeviceKeyId::from_parts(DeviceKeyAlgorithm::Ed25519, self.device_id()),
signatures,
canonical_json,
)
}
/// Generate the unsigned `DeviceKeys` from this `StaticAccountData`.
pub fn unsigned_device_keys(&self) -> DeviceKeys {
let identity_keys = self.identity_keys();
let keys = BTreeMap::from([
(
DeviceKeyId::from_parts(DeviceKeyAlgorithm::Curve25519, &self.device_id),
identity_keys.curve25519.into(),
),
(
DeviceKeyId::from_parts(DeviceKeyAlgorithm::Ed25519, &self.device_id),
identity_keys.ed25519.into(),
),
]);
let mut ret = DeviceKeys::new(
(*self.user_id).to_owned(),
(*self.device_id).to_owned(),
Self::ALGORITHMS.iter().map(|a| (**a).clone()).collect(),
keys,
Default::default(),
);
if self.dehydrated {
ret.dehydrated = JsOption::Some(true);
}
ret
}
/// Get the user id of the owner of the account.
pub fn user_id(&self) -> &UserId {
&self.user_id
}
/// Get the device ID that owns this account.
pub fn device_id(&self) -> &DeviceId {
&self.device_id
}
/// Get the public parts of the identity keys for the account.
pub fn identity_keys(&self) -> IdentityKeys {
*self.identity_keys
}
/// Get the local timestamp creation of the account in secs since epoch.
pub fn creation_local_time(&self) -> MilliSecondsSinceUnixEpoch {
self.creation_local_time
}
}
/// Account holding identity keys for which sessions can be created.
///
/// An account is the central identity for encrypted communication between two
/// devices.
pub struct Account {
pub(crate) static_data: StaticAccountData,
/// `vodozemac` account.
inner: Box<InnerAccount>,
/// Is this account ready to encrypt messages? (i.e. has it shared keys with
/// a homeserver)
shared: bool,
/// The number of signed one-time keys we have uploaded to the server. If
/// this is None, no action will be taken. After a sync request the client
/// needs to set this for us, depending on the count we will suggest the
/// client to upload new keys.
uploaded_signed_key_count: u64,
/// The timestamp of the last time we generated a fallback key. Fallback
/// keys are rotated in a time-based manner. This field records when we
/// either generated our first fallback key or rotated one.
///
/// Will be `None` if we never created a fallback key, or if we're migrating
/// from a `AccountPickle` that didn't use time-based fallback key
/// rotation.
fallback_creation_timestamp: Option<MilliSecondsSinceUnixEpoch>,
}
impl Deref for Account {
type Target = StaticAccountData;
fn deref(&self) -> &Self::Target {
&self.static_data
}
}
/// A pickled version of an `Account`.
///
/// Holds all the information that needs to be stored in a database to restore
/// an account.
#[derive(Serialize, Deserialize)]
#[allow(missing_debug_implementations)]
pub struct PickledAccount {
/// The user id of the account owner.
pub user_id: OwnedUserId,
/// The device ID of the account owner.
pub device_id: OwnedDeviceId,
/// The pickled version of the Olm account.
pub pickle: AccountPickle,
/// Was the account shared.
pub shared: bool,
/// Whether this is for a dehydrated device
#[serde(default)]
pub dehydrated: bool,
/// The number of uploaded one-time keys we have on the server.
pub uploaded_signed_key_count: u64,
/// The local time creation of this account (milliseconds since epoch), used
/// as creation time of own device
#[serde(default = "default_account_creation_time")]
pub creation_local_time: MilliSecondsSinceUnixEpoch,
/// The timestamp of the last time we generated a fallback key.
#[serde(default)]
pub fallback_key_creation_timestamp: Option<MilliSecondsSinceUnixEpoch>,
}
fn default_account_creation_time() -> MilliSecondsSinceUnixEpoch {
MilliSecondsSinceUnixEpoch(UInt::default())
}
#[cfg(not(tarpaulin_include))]
impl fmt::Debug for Account {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("Account")
.field("identity_keys", &self.identity_keys())
.field("shared", &self.shared())
.finish()
}
}
pub type OneTimeKeys = BTreeMap<OwnedOneTimeKeyId, Raw<ruma::encryption::OneTimeKey>>;
pub type FallbackKeys = OneTimeKeys;
impl Account {
pub(crate) fn new_helper(
mut account: InnerAccount,
user_id: &UserId,
device_id: &DeviceId,
) -> Self {
let identity_keys = account.identity_keys();
// Let's generate some initial one-time keys while we're here. Since we know
// that this is a completely new [`Account`] we're certain that the
// server does not yet have any one-time keys of ours.
//
// This ensures we upload one-time keys along with our device keys right
// away, rather than waiting for the key counts to be echoed back to us
// from the server.
//
// It would be nice to do this for the fallback key as well but we can't assume
// that the server supports fallback keys. Maybe one of these days we
// will be able to do so.
account.generate_one_time_keys(account.max_number_of_one_time_keys());
Self {
static_data: StaticAccountData {
user_id: user_id.into(),
device_id: device_id.into(),
identity_keys: Arc::new(identity_keys),
dehydrated: false,
creation_local_time: MilliSecondsSinceUnixEpoch::now(),
},
inner: Box::new(account),
shared: false,
uploaded_signed_key_count: 0,
fallback_creation_timestamp: None,
}
}
/// Create a fresh new account, this will generate the identity key-pair.
pub fn with_device_id(user_id: &UserId, device_id: &DeviceId) -> Self {
let account = InnerAccount::new();
Self::new_helper(account, user_id, device_id)
}
/// Create a new random Olm Account, the long-term Curve25519 identity key
/// encoded as base64 will be used for the device ID.
pub fn new(user_id: &UserId) -> Self {
let account = InnerAccount::new();
let device_id: OwnedDeviceId =
base64_encode(account.identity_keys().curve25519.as_bytes()).into();
Self::new_helper(account, user_id, &device_id)
}
/// Create a new random Olm Account for a dehydrated device
pub fn new_dehydrated(user_id: &UserId) -> Self {
let account = InnerAccount::new();
let device_id: OwnedDeviceId =
base64_encode(account.identity_keys().curve25519.as_bytes()).into();
let mut ret = Self::new_helper(account, user_id, &device_id);
ret.static_data.dehydrated = true;
ret
}
/// Get the immutable data for this account.
pub fn static_data(&self) -> &StaticAccountData {
&self.static_data
}
/// Update the uploaded key count.
///
/// # Arguments
///
/// * `new_count` - The new count that was reported by the server.
pub fn update_uploaded_key_count(&mut self, new_count: u64) {
self.uploaded_signed_key_count = new_count;
}
/// Get the currently known uploaded key count.
pub fn uploaded_key_count(&self) -> u64 {
self.uploaded_signed_key_count
}
/// Has the account been shared with the server.
pub fn shared(&self) -> bool {
self.shared
}
/// Mark the account as shared.
///
/// Messages shouldn't be encrypted with the session before it has been
/// shared.
pub fn mark_as_shared(&mut self) {
self.shared = true;
}
/// Get the one-time keys of the account.
///
/// This can be empty, keys need to be generated first.
pub fn one_time_keys(&self) -> HashMap<KeyId, Curve25519PublicKey> {
self.inner.one_time_keys()
}
/// Generate count number of one-time keys.
pub fn generate_one_time_keys(&mut self, count: usize) -> OneTimeKeyGenerationResult {
self.inner.generate_one_time_keys(count)
}
/// Get the maximum number of one-time keys the account can hold.
pub fn max_one_time_keys(&self) -> usize {
self.inner.max_number_of_one_time_keys()
}
pub(crate) fn update_key_counts(
&mut self,
one_time_key_counts: &BTreeMap<OneTimeKeyAlgorithm, UInt>,
unused_fallback_keys: Option<&[OneTimeKeyAlgorithm]>,
) {
if let Some(count) = one_time_key_counts.get(&OneTimeKeyAlgorithm::SignedCurve25519) {
let count: u64 = (*count).into();
let old_count = self.uploaded_key_count();
// Some servers might always return the key counts in the sync
// response, we don't want to the logs with noop changes if they do
// so.
if count != old_count {
debug!(
"Updated uploaded one-time key count {} -> {count}.",
self.uploaded_key_count(),
);
}
self.update_uploaded_key_count(count);
self.generate_one_time_keys_if_needed();
}
// If the server supports fallback keys or if it did so in the past, shown by
// the existence of a fallback creation timestamp, generate a new one if
// we don't have one, or if the current fallback key expired.
if unused_fallback_keys.is_some() || self.fallback_creation_timestamp.is_some() {
self.generate_fallback_key_if_needed();
}
}
/// Generate new one-time keys that need to be uploaded to the server.
///
/// Returns None if no keys need to be uploaded, otherwise the number of
/// newly generated one-time keys. May return 0 if some one-time keys are
/// already generated but weren't uploaded.
///
/// Generally `Some` means that keys should be uploaded, while `None` means
/// that keys should not be uploaded.
#[instrument(skip_all)]
pub fn generate_one_time_keys_if_needed(&mut self) -> Option<u64> {
// Only generate one-time keys if there aren't any, otherwise the caller
// might have failed to upload them the last time this method was
// called.
if !self.one_time_keys().is_empty() {
return Some(0);
}
let count = self.uploaded_key_count();
let max_keys = self.max_one_time_keys();
if count >= max_keys as u64 {
return None;
}
let key_count = (max_keys as u64) - count;
let key_count: usize = key_count.try_into().unwrap_or(max_keys);
let result = self.generate_one_time_keys(key_count);
debug!(
count = key_count,
discarded_keys = ?result.removed,
created_keys = ?result.created,
"Generated new one-time keys"
);
Some(key_count as u64)
}
/// Generate a new fallback key iff a unpublished one isn't already inside
/// of vodozemac and if the currently active one expired.
///
/// The former is checked using [`Account::fallback_key().is_empty()`],
/// which is a hashmap that gets cleared by the
/// [`Account::mark_keys_as_published()`] call.
pub(crate) fn generate_fallback_key_if_needed(&mut self) {
if self.inner.fallback_key().is_empty() && self.fallback_key_expired() {
let removed_fallback_key = self.inner.generate_fallback_key();
self.fallback_creation_timestamp = Some(MilliSecondsSinceUnixEpoch::now());
debug!(
?removed_fallback_key,
"The fallback key either expired or we didn't have one: generated a new fallback key.",
);
}
}
/// Check if our most recent fallback key has expired.
///
/// We consider the fallback key to be expired if it's older than a week.
/// This is the lower bound for the recommended signed pre-key bundle
/// rotation interval in the X3DH spec[1].
///
/// [1]: https://signal.org/docs/specifications/x3dh/#publishing-keys
fn fallback_key_expired(&self) -> bool {
const FALLBACK_KEY_MAX_AGE: Duration = Duration::from_secs(3600 * 24 * 7);
if let Some(time) = self.fallback_creation_timestamp {
// `to_system_time()` returns `None` if the the UNIX_EPOCH + `time` doesn't fit
// into a i64. This will likely never happen, but let's rotate the
// key in case the values are messed up for some other reason.
let Some(system_time) = time.to_system_time() else {
return true;
};
// `elapsed()` errors if the `system_time` is in the future, this should mean
// that our clock has changed to the past, let's rotate just in case
// and then we'll get to a normal time.
let Ok(elapsed) = system_time.elapsed() else {
return true;
};
// Alright, our times are normal and we know how much time elapsed since the
// last time we created/rotated a fallback key.
//
// If the key is older than a week, then we rotate it.
elapsed > FALLBACK_KEY_MAX_AGE
} else {
// We never created a fallback key, or we're migrating to the time-based
// fallback key rotation, so let's generate a new fallback key.
true
}
}
fn fallback_key(&self) -> HashMap<KeyId, Curve25519PublicKey> {
self.inner.fallback_key()
}
/// Get a tuple of device, one-time, and fallback keys that need to be
/// uploaded.
///
/// If no keys need to be uploaded the `DeviceKeys` will be `None` and the
/// one-time and fallback keys maps will be empty.
pub fn keys_for_upload(&self) -> (Option<DeviceKeys>, OneTimeKeys, FallbackKeys) {
let device_keys = self.shared().not().then(|| self.device_keys());
let one_time_keys = self.signed_one_time_keys();
let fallback_keys = self.signed_fallback_keys();
(device_keys, one_time_keys, fallback_keys)
}
/// Mark the current set of one-time keys as being published.
pub fn mark_keys_as_published(&mut self) {
self.inner.mark_keys_as_published();
}
/// Sign the given string using the accounts signing key.
///
/// Returns the signature as a base64 encoded string.
pub fn sign(&self, string: &str) -> Ed25519Signature {
self.inner.sign(string)
}
/// Get a serializable version of the `Account` so it can be persisted.
pub fn pickle(&self) -> PickledAccount {
let pickle = self.inner.pickle();
PickledAccount {
user_id: self.user_id().to_owned(),
device_id: self.device_id().to_owned(),
pickle,
shared: self.shared(),
dehydrated: self.static_data.dehydrated,
uploaded_signed_key_count: self.uploaded_key_count(),
creation_local_time: self.static_data.creation_local_time,
fallback_key_creation_timestamp: self.fallback_creation_timestamp,
}
}
pub(crate) fn dehydrate(&self, pickle_key: &[u8; 32]) -> Raw<DehydratedDeviceData> {
let device_pickle = self
.inner
.to_libolm_pickle(pickle_key)
.expect("We should be able to convert a freshly created Account into a libolm pickle");
let data = DehydratedDeviceData::V1(DehydratedDeviceV1::new(device_pickle));
Raw::from_json(to_raw_value(&data).expect("Couldn't serialize our dehydrated device data"))
}
pub(crate) fn rehydrate(
pickle_key: &[u8; 32],
user_id: &UserId,
device_id: &DeviceId,
device_data: Raw<DehydratedDeviceData>,
) -> Result<Self, DehydrationError> {
let data = device_data.deserialize()?;
match data {
DehydratedDeviceData::V1(d) => {
let account = InnerAccount::from_libolm_pickle(&d.device_pickle, pickle_key)?;
Ok(Self::new_helper(account, user_id, device_id))
}
_ => Err(DehydrationError::Json(serde_json::Error::custom(format!(
"Unsupported dehydrated device algorithm {:?}",
data.algorithm()
)))),
}
}
/// Restore an account from a previously pickled one.
///
/// # Arguments
///
/// * `pickle` - The pickled version of the Account.
///
/// * `pickle_mode` - The mode that was used to pickle the account, either
/// an unencrypted mode or an encrypted using passphrase.
pub fn from_pickle(pickle: PickledAccount) -> Result<Self, PickleError> {
let account: vodozemac::olm::Account = pickle.pickle.into();
let identity_keys = account.identity_keys();
Ok(Self {
static_data: StaticAccountData {
user_id: (*pickle.user_id).into(),
device_id: (*pickle.device_id).into(),
identity_keys: Arc::new(identity_keys),
dehydrated: pickle.dehydrated,
creation_local_time: pickle.creation_local_time,
},
inner: Box::new(account),
shared: pickle.shared,
uploaded_signed_key_count: pickle.uploaded_signed_key_count,
fallback_creation_timestamp: pickle.fallback_key_creation_timestamp,
})
}
/// Sign the device keys of the account and return them so they can be
/// uploaded.
pub fn device_keys(&self) -> DeviceKeys {
let mut device_keys = self.unsigned_device_keys();
// Create a copy of the device keys containing only fields that will
// get signed.
let json_device_keys =
serde_json::to_value(&device_keys).expect("device key is always safe to serialize");
let signature = self
.sign_json(json_device_keys)
.expect("Newly created device keys can always be signed");
device_keys.signatures.add_signature(
self.user_id().to_owned(),
DeviceKeyId::from_parts(DeviceKeyAlgorithm::Ed25519, &self.static_data.device_id),
signature,
);
device_keys
}
/// Bootstrap Cross-Signing
pub async fn bootstrap_cross_signing(
&self,
) -> (PrivateCrossSigningIdentity, UploadSigningKeysRequest, SignatureUploadRequest) {
PrivateCrossSigningIdentity::with_account(self).await
}
/// Sign the given CrossSigning Key in place
pub fn sign_cross_signing_key(
&self,
cross_signing_key: &mut CrossSigningKey,
) -> Result<(), SignatureError> {
#[allow(clippy::needless_borrows_for_generic_args)]
// XXX: false positive, see https://github.com/rust-lang/rust-clippy/issues/12856
let signature = self.sign_json(serde_json::to_value(&cross_signing_key)?)?;
cross_signing_key.signatures.add_signature(
self.user_id().to_owned(),
DeviceKeyId::from_parts(DeviceKeyAlgorithm::Ed25519, self.device_id()),
signature,
);
Ok(())
}
/// Sign the given Master Key
pub fn sign_master_key(
&self,
master_key: &MasterPubkey,
) -> Result<SignatureUploadRequest, SignatureError> {
let public_key =
master_key.get_first_key().ok_or(SignatureError::MissingSigningKey)?.to_base64().into();
let mut cross_signing_key: CrossSigningKey = master_key.as_ref().clone();
cross_signing_key.signatures.clear();
self.sign_cross_signing_key(&mut cross_signing_key)?;
let mut user_signed_keys = SignedKeys::new();
user_signed_keys.add_cross_signing_keys(public_key, cross_signing_key.to_raw());
let signed_keys = [(self.user_id().to_owned(), user_signed_keys)].into();
Ok(SignatureUploadRequest::new(signed_keys))
}
/// Convert a JSON value to the canonical representation and sign the JSON
/// string.
///
/// # Arguments
///
/// * `json` - The value that should be converted into a canonical JSON
/// string.
pub fn sign_json(&self, json: Value) -> Result<Ed25519Signature, SignatureError> {
self.inner.sign_json(json)
}
/// Sign and prepare one-time keys to be uploaded.
///
/// If no one-time keys need to be uploaded, returns an empty `BTreeMap`.
pub fn signed_one_time_keys(&self) -> OneTimeKeys {
let one_time_keys = self.one_time_keys();
if one_time_keys.is_empty() {
BTreeMap::new()
} else {
self.signed_keys(one_time_keys, false)
}
}
/// Sign and prepare fallback keys to be uploaded.
///
/// If no fallback keys need to be uploaded returns an empty BTreeMap.
pub fn signed_fallback_keys(&self) -> FallbackKeys {
let fallback_key = self.fallback_key();
if fallback_key.is_empty() {
BTreeMap::new()
} else {
self.signed_keys(fallback_key, true)
}
}
fn signed_keys(
&self,
keys: HashMap<KeyId, Curve25519PublicKey>,
fallback: bool,
) -> OneTimeKeys {
let mut keys_map = BTreeMap::new();
for (key_id, key) in keys {
let signed_key = self.sign_key(key, fallback);
keys_map.insert(
OneTimeKeyId::from_parts(
OneTimeKeyAlgorithm::SignedCurve25519,
key_id.to_base64().as_str().into(),
),
signed_key.into_raw(),
);
}
keys_map
}
fn sign_key(&self, key: Curve25519PublicKey, fallback: bool) -> SignedKey {
let mut key = if fallback {
SignedKey::new_fallback(key.to_owned())
} else {
SignedKey::new(key.to_owned())
};
let signature = self
.sign_json(serde_json::to_value(&key).expect("Can't serialize a signed key"))
.expect("Newly created one-time keys can always be signed");
key.signatures_mut().add_signature(
self.user_id().to_owned(),
DeviceKeyId::from_parts(DeviceKeyAlgorithm::Ed25519, self.device_id()),
signature,
);
key
}
/// Create a new session with another account given a one-time key.
///
/// Returns the newly created session or a `OlmSessionError` if creating a
/// session failed.
///
/// # Arguments
///
/// * `config` - The session config that should be used when creating the
/// Session.
///
/// * `identity_key` - The other account's identity/curve25519 key.
///
/// * `one_time_key` - A signed one-time key that the other account created
/// and shared with us.
///
/// * `fallback_used` - Was the one-time key a fallback key.
///
/// * `our_device_keys` - Our own `DeviceKeys`, including cross-signing
/// signatures if applicable, for embedding in encrypted messages.
pub fn create_outbound_session_helper(
&self,
config: SessionConfig,
identity_key: Curve25519PublicKey,
one_time_key: Curve25519PublicKey,
fallback_used: bool,
our_device_keys: DeviceKeys,
) -> Session {
let session = self.inner.create_outbound_session(config, identity_key, one_time_key);
let now = SecondsSinceUnixEpoch::now();
let session_id = session.session_id();
Session {
inner: Arc::new(Mutex::new(session)),
session_id: session_id.into(),
sender_key: identity_key,
our_device_keys,
created_using_fallback_key: fallback_used,
creation_time: now,
last_use_time: now,
}
}
#[instrument(
skip_all,
fields(
user_id = ?device.user_id(),
device_id = ?device.device_id(),
algorithms = ?device.algorithms()
)
)]
fn find_pre_key_bundle(
device: &DeviceData,
key_map: &OneTimeKeys,
) -> Result<PrekeyBundle, SessionCreationError> {
let mut keys = key_map.iter();
let first_key = keys.next().ok_or_else(|| {
SessionCreationError::OneTimeKeyMissing(
device.user_id().to_owned(),
device.device_id().into(),
)
})?;
let first_key_id = first_key.0.to_owned();
let first_key = OneTimeKey::deserialize(first_key_id.algorithm(), first_key.1)?;
let result = match first_key {
OneTimeKey::SignedKey(key) => Ok(PrekeyBundle::Olm3DH { key }),
};
trace!(?result, "Finished searching for a valid pre-key bundle");
result
}
/// Create a new session with another account given a one-time key and a
/// device.
///
/// Returns the newly created session or a `OlmSessionError` if creating a
/// session failed.
///
/// # Arguments
/// * `device` - The other account's device.
///
/// * `key_map` - A map from the algorithm and device ID to the one-time key
/// that the other account created and shared with us.
///
/// * `our_device_keys` - Our own `DeviceKeys`, including cross-signing
/// signatures if applicable, for embedding in encrypted messages.
#[allow(clippy::result_large_err)]
pub fn create_outbound_session(
&self,
device: &DeviceData,
key_map: &OneTimeKeys,
our_device_keys: DeviceKeys,
) -> Result<Session, SessionCreationError> {
let pre_key_bundle = Self::find_pre_key_bundle(device, key_map)?;
match pre_key_bundle {
PrekeyBundle::Olm3DH { key } => {
device.verify_one_time_key(&key).map_err(|error| {
SessionCreationError::InvalidSignature {
signing_key: device.ed25519_key().map(Box::new),
one_time_key: key.clone().into(),
error: error.into(),
}
})?;
let identity_key = device.curve25519_key().ok_or_else(|| {
SessionCreationError::DeviceMissingCurveKey(
device.user_id().to_owned(),
device.device_id().into(),
)
})?;
let is_fallback = key.fallback();
let one_time_key = key.key();
let config = device.olm_session_config();
Ok(self.create_outbound_session_helper(
config,
identity_key,
one_time_key,
is_fallback,
our_device_keys,
))
}
}
}
/// Create a new session with another account given a pre-key Olm message.
///
/// Returns the newly created session or a `OlmSessionError` if creating a
/// session failed.
///
/// # Arguments
///
/// * `their_identity_key` - The other account's identity/curve25519 key.
///
/// * `our_device_keys` - Our own `DeviceKeys`, including cross-signing
/// signatures if applicable, for embedding in encrypted messages.
///
/// * `message` - A pre-key Olm message that was sent to us by the other
/// account.
pub fn create_inbound_session(
&mut self,
their_identity_key: Curve25519PublicKey,
our_device_keys: DeviceKeys,
message: &PreKeyMessage,
) -> Result<InboundCreationResult, SessionCreationError> {
Span::current().record("session_id", debug(message.session_id()));
trace!("Creating a new Olm session from a pre-key message");
let result = self.inner.create_inbound_session(their_identity_key, message)?;
let now = SecondsSinceUnixEpoch::now();
let session_id = result.session.session_id();
debug!(session=?result.session, "Decrypted an Olm message from a new Olm session");
let session = Session {
inner: Arc::new(Mutex::new(result.session)),
session_id: session_id.into(),
sender_key: their_identity_key,
our_device_keys,
created_using_fallback_key: false,
creation_time: now,
last_use_time: now,
};
let plaintext = String::from_utf8_lossy(&result.plaintext).to_string();
Ok(InboundCreationResult { session, plaintext })
}
#[cfg(any(test, feature = "testing"))]
#[allow(dead_code)]
/// Testing only helper to create a session for the given Account
pub async fn create_session_for_test_helper(
&mut self,
other: &mut Account,
) -> (Session, Session) {
use ruma::events::dummy::ToDeviceDummyEventContent;
other.generate_one_time_keys(1);
let one_time_map = other.signed_one_time_keys();
let device = DeviceData::from_account(other);
let mut our_session =
self.create_outbound_session(&device, &one_time_map, self.device_keys()).unwrap();
other.mark_keys_as_published();
let message = our_session
.encrypt(&device, "m.dummy", ToDeviceDummyEventContent::new(), None)
.await
.unwrap()
.deserialize()
.unwrap();
#[cfg(feature = "experimental-algorithms")]
let content = if let ToDeviceEncryptedEventContent::OlmV2Curve25519AesSha2(c) = message {
c
} else {
panic!("Invalid encrypted event algorithm {}", message.algorithm());
};
#[cfg(not(feature = "experimental-algorithms"))]
let content = if let ToDeviceEncryptedEventContent::OlmV1Curve25519AesSha2(c) = message {
c
} else {
panic!("Invalid encrypted event algorithm {}", message.algorithm());
};
let prekey = if let OlmMessage::PreKey(m) = content.ciphertext {
m
} else {
panic!("Wrong Olm message type");
};
let our_device = DeviceData::from_account(self);
let other_session = other
.create_inbound_session(
our_device.curve25519_key().unwrap(),
other.device_keys(),
&prekey,
)
.unwrap();
(our_session, other_session.session)
}
async fn decrypt_olm_helper(
&mut self,
store: &Store,
sender: &UserId,
sender_key: Curve25519PublicKey,
ciphertext: &OlmMessage,
) -> OlmResult<OlmDecryptionInfo> {
let message_hash = OlmMessageHash::new(sender_key, ciphertext);
match self.decrypt_and_parse_olm_message(store, sender, sender_key, ciphertext).await {
Ok((session, result)) => {
Ok(OlmDecryptionInfo { session, message_hash, result, inbound_group_session: None })
}
Err(OlmError::SessionWedged(user_id, sender_key)) => {
if store.is_message_known(&message_hash).await? {
info!(?sender_key, "An Olm message got replayed, decryption failed");
Err(OlmError::ReplayedMessage(user_id, sender_key))
} else {
Err(OlmError::SessionWedged(user_id, sender_key))
}
}
Err(e) => Err(e),
}
}
#[cfg(feature = "experimental-algorithms")]
async fn decrypt_olm_v2(
&mut self,
store: &Store,
sender: &UserId,
content: &OlmV2Curve25519AesSha2Content,
) -> OlmResult<OlmDecryptionInfo> {
self.decrypt_olm_helper(store, sender, content.sender_key, &content.ciphertext).await
}
#[instrument(skip_all, fields(sender, sender_key = ?content.sender_key))]
async fn decrypt_olm_v1(
&mut self,
store: &Store,
sender: &UserId,
content: &OlmV1Curve25519AesSha2Content,
) -> OlmResult<OlmDecryptionInfo> {
if content.recipient_key != self.static_data.identity_keys.curve25519 {
warn!("Olm event doesn't contain a ciphertext for our key");
Err(EventError::MissingCiphertext.into())
} else {
Box::pin(self.decrypt_olm_helper(
store,
sender,
content.sender_key,
&content.ciphertext,
))
.await
}
}
#[instrument(skip_all, fields(algorithm = ?event.content.algorithm()))]
pub(crate) async fn decrypt_to_device_event(
&mut self,
store: &Store,
event: &EncryptedToDeviceEvent,
) -> OlmResult<OlmDecryptionInfo> {
trace!("Decrypting a to-device event");
match &event.content {
ToDeviceEncryptedEventContent::OlmV1Curve25519AesSha2(c) => {
self.decrypt_olm_v1(store, &event.sender, c).await
}
#[cfg(feature = "experimental-algorithms")]
ToDeviceEncryptedEventContent::OlmV2Curve25519AesSha2(c) => {
self.decrypt_olm_v2(store, &event.sender, c).await
}
ToDeviceEncryptedEventContent::Unknown(_) => {
warn!(
"Error decrypting an to-device event, unsupported \
encryption algorithm"
);
Err(EventError::UnsupportedAlgorithm.into())
}
}
}
/// Handles a response to a /keys/upload request.
pub fn receive_keys_upload_response(
&mut self,
response: &upload_keys::v3::Response,
) -> OlmResult<()> {
if !self.shared() {
debug!("Marking account as shared");
}
self.mark_as_shared();
debug!("Marking one-time keys as published");
// First mark the current keys as published, as updating the key counts might
// generate some new keys if we're still below the limit.
self.mark_keys_as_published();
self.update_key_counts(&response.one_time_key_counts, None);
Ok(())
}
/// Try to decrypt an olm message, creating a new session if necessary.
async fn decrypt_olm_message(
&mut self,
store: &Store,
sender: &UserId,
sender_key: Curve25519PublicKey,
message: &OlmMessage,
) -> Result<(SessionType, String), OlmError> {
let existing_sessions = store.get_sessions(&sender_key.to_base64()).await?;
match message {
OlmMessage::Normal(_) => {
let mut errors_by_olm_session = Vec::new();
if let Some(sessions) = existing_sessions {
// Try to decrypt the message using each Session we share with the
// given curve25519 sender key.
for session in sessions.lock().await.iter_mut() {
match session.decrypt(message).await {
Ok(p) => {
// success!
return Ok((SessionType::Existing(session.clone()), p));
}
Err(e) => {
// An error here is completely normal, after all we don't know
// which session was used to encrypt a message.
// We keep hold of the error, so that if *all* sessions fail to
// decrypt, we can log something useful.
errors_by_olm_session.push((session.session_id().to_owned(), e));
}
}
}
}
warn!(
?errors_by_olm_session,
"Failed to decrypt a non-pre-key message with all available sessions"
);
Err(OlmError::SessionWedged(sender.to_owned(), sender_key))
}
OlmMessage::PreKey(prekey_message) => {
// First try to decrypt using an existing session.
if let Some(sessions) = existing_sessions {
for session in sessions.lock().await.iter_mut() {
if prekey_message.session_id() != session.session_id() {
// wrong session
continue;
}
if let Ok(p) = session.decrypt(message).await {
// success!
return Ok((SessionType::Existing(session.clone()), p));
}
// The message was intended for this session, but we weren't able to
// decrypt it.
//
// There's no point trying any other sessions, nor should we try to
// create a new one since we have already previously created a `Session`
// with the same keys.
//
// (Attempts to create a new session would likely fail anyway since the
// corresponding one-time key would've been already used up in the
// previous session creation operation. The one exception where this
// would not be so is if the fallback key was used for creating the
// session in lieu of an OTK.)
warn!(
session_id = session.session_id(),
"Failed to decrypt a pre-key message with the corresponding session"
);
return Err(OlmError::SessionWedged(
session.our_device_keys.user_id.to_owned(),
session.sender_key(),
));
}
}
let device_keys = store.get_own_device().await?.as_device_keys().clone();
let result =
match self.create_inbound_session(sender_key, device_keys, prekey_message) {
Ok(r) => r,
Err(e) => {
warn!(
"Failed to create a new Olm session from a pre-key message: {e:?}"
);
return Err(OlmError::SessionWedged(sender.to_owned(), sender_key));
}
};
// We need to add the new session to the session cache, otherwise
// we might try to create the same session again.
// TODO: separate the session cache from the storage so we only add
// it to the cache but don't store it.
let mut changes =
Changes { sessions: vec![result.session.clone()], ..Default::default() };
// Any new Olm session will bump the Olm wedging index for the
// sender's device, if we have their device, which will cause us
// to re-send existing Megolm sessions to them the next time we
// use the session. If we don't have their device, this means
// that we haven't tried to send them any Megolm sessions yet,
// so we don't need to worry about it.
if let Some(device) = store.get_device_from_curve_key(sender, sender_key).await? {
let mut device_data = device.inner;
device_data.olm_wedging_index.increment();
changes.devices =
DeviceChanges { changed: vec![device_data], ..Default::default() };
}
store.save_changes(changes).await?;
Ok((SessionType::New(result.session), result.plaintext))
}
}
}
/// Decrypt an Olm message, creating a new Olm session if necessary, and
/// parse the result.
#[instrument(skip(self, store), fields(session, session_id))]
async fn decrypt_and_parse_olm_message(
&mut self,
store: &Store,
sender: &UserId,
sender_key: Curve25519PublicKey,
message: &OlmMessage,
) -> OlmResult<(SessionType, DecryptionResult)> {
let (session, plaintext) =
self.decrypt_olm_message(store, sender, sender_key, message).await?;
trace!("Successfully decrypted an Olm message");
match self.parse_decrypted_to_device_event(store, sender, sender_key, plaintext).await {
Ok(result) => Ok((session, result)),
Err(e) => {
// We might have created a new session but decryption might still
// have failed, store it for the error case here, this is fine
// since we don't expect this to happen often or at all.
match session {
SessionType::New(s) | SessionType::Existing(s) => {
store.save_sessions(&[s]).await?;
}
}
warn!(
error = ?e,
"A to-device message was successfully decrypted but \
parsing and checking the event fields failed"
);
Err(e)
}
}
}
/// Parse the decrypted plaintext as JSON and verify that it wasn't
/// forwarded by a third party.
///
/// These checks are mandated by the spec[1]:
///
/// > Other properties are included in order to prevent an attacker from
/// > publishing someone else's Curve25519 keys as their own and
/// > subsequently claiming to have sent messages which they didn't.
/// > sender must correspond to the user who sent the event, recipient to
/// > the local user, and recipient_keys to the local Ed25519 key.
///
/// # Arguments
///
/// * `sender` - The `sender` field from the top level of the received
/// event.
/// * `sender_key` - The `sender_key` from the cleartext `content` of the
/// received event (which should also have been used to find or establish
/// the Olm session that was used to decrypt the event -- so it is
/// guaranteed to be correct).
/// * `plaintext` - The decrypted content of the event.
async fn parse_decrypted_to_device_event(
&self,
store: &Store,
sender: &UserId,
sender_key: Curve25519PublicKey,
plaintext: String,
) -> OlmResult<DecryptionResult> {
let event: Box<AnyDecryptedOlmEvent> = serde_json::from_str(&plaintext)?;
let identity_keys = &self.static_data.identity_keys;
if event.recipient() != self.static_data.user_id {
Err(EventError::MismatchedSender(
event.recipient().to_owned(),
self.static_data.user_id.clone(),
)
.into())
}
// Check that the `sender` in the decrypted to-device event matches that at the
// top level of the encrypted event.
else if event.sender() != sender {
Err(EventError::MismatchedSender(event.sender().to_owned(), sender.to_owned()).into())
} else if identity_keys.ed25519 != event.recipient_keys().ed25519 {
Err(EventError::MismatchedKeys(
identity_keys.ed25519.into(),
event.recipient_keys().ed25519.into(),
)
.into())
} else {
// If this event is an `m.room_key` event, defer the check for the
// Ed25519 key of the sender until we decrypt room events. This
// ensures that we receive the room key even if we don't have access
// to the device.
if !matches!(*event, AnyDecryptedOlmEvent::RoomKey(_)) {
let Some(device) =
store.get_device_from_curve_key(event.sender(), sender_key).await?
else {
return Err(EventError::MissingSigningKey.into());
};
let Some(key) = device.ed25519_key() else {
return Err(EventError::MissingSigningKey.into());
};
if key != event.keys().ed25519 {
return Err(EventError::MismatchedKeys(
key.into(),
event.keys().ed25519.into(),
)
.into());
}
}
Ok(DecryptionResult {
event,
raw_event: Raw::from_json(RawJsonValue::from_string(plaintext)?),
sender_key,
})
}
}
/// Internal use only.
///
/// Cloning should only be done for testing purposes or when we are certain
/// that we don't want the inner state to be shared.
#[doc(hidden)]
pub fn deep_clone(&self) -> Self {
// `vodozemac::Account` isn't really cloneable, but... Don't tell anyone.
Self::from_pickle(self.pickle()).unwrap()
}
}
impl PartialEq for Account {
fn eq(&self, other: &Self) -> bool {
self.identity_keys() == other.identity_keys() && self.shared() == other.shared()
}
}
#[cfg(test)]
mod tests {
use std::{
collections::{BTreeMap, BTreeSet},
ops::Deref,
time::Duration,
};
use anyhow::Result;
use matrix_sdk_test::async_test;
use ruma::{
device_id, user_id, DeviceId, MilliSecondsSinceUnixEpoch, OneTimeKeyAlgorithm,
OneTimeKeyId, UserId,
};
use serde_json::json;
use super::Account;
use crate::{
olm::SignedJsonObject,
types::{DeviceKeys, SignedKey},
DeviceData,
};
fn user_id() -> &'static UserId {
user_id!("@alice:localhost")
}
fn device_id() -> &'static DeviceId {
device_id!("DEVICEID")
}
#[test]
fn test_one_time_key_creation() -> Result<()> {
let mut account = Account::with_device_id(user_id(), device_id());
let (_, one_time_keys, _) = account.keys_for_upload();
assert!(!one_time_keys.is_empty());
let (_, second_one_time_keys, _) = account.keys_for_upload();
assert!(!second_one_time_keys.is_empty());
let one_time_key_ids: BTreeSet<&OneTimeKeyId> =
one_time_keys.keys().map(Deref::deref).collect();
let second_one_time_key_ids: BTreeSet<&OneTimeKeyId> =
second_one_time_keys.keys().map(Deref::deref).collect();
assert_eq!(one_time_key_ids, second_one_time_key_ids);
account.mark_keys_as_published();
account.update_uploaded_key_count(50);
account.generate_one_time_keys_if_needed();
let (_, third_one_time_keys, _) = account.keys_for_upload();
assert!(third_one_time_keys.is_empty());
account.update_uploaded_key_count(0);
account.generate_one_time_keys_if_needed();
let (_, fourth_one_time_keys, _) = account.keys_for_upload();
assert!(!fourth_one_time_keys.is_empty());
let fourth_one_time_key_ids: BTreeSet<&OneTimeKeyId> =
fourth_one_time_keys.keys().map(Deref::deref).collect();
assert_ne!(one_time_key_ids, fourth_one_time_key_ids);
Ok(())
}
#[test]
fn test_fallback_key_creation() -> Result<()> {
let mut account = Account::with_device_id(user_id(), device_id());
let (_, _, fallback_keys) = account.keys_for_upload();
// We don't create fallback keys since we don't know if the server
// supports them, we need to receive a sync response to decide if we're
// going to create them or not.
assert!(
fallback_keys.is_empty(),
"We should not upload fallback keys until we know if the server supports them."
);
let one_time_keys = BTreeMap::from([(OneTimeKeyAlgorithm::SignedCurve25519, 50u8.into())]);
// A `None` here means that the server doesn't support fallback keys, no
// fallback key gets uploaded.
account.update_key_counts(&one_time_keys, None);
let (_, _, fallback_keys) = account.keys_for_upload();
assert!(
fallback_keys.is_empty(),
"We should not upload a fallback key if we're certain that the server doesn't support \
them."
);
// The empty array means that the server supports fallback keys but
// there isn't a unused fallback key on the server. This time we upload
// a fallback key.
let unused_fallback_keys = &[];
account.update_key_counts(&one_time_keys, Some(unused_fallback_keys.as_ref()));
let (_, _, fallback_keys) = account.keys_for_upload();
assert!(
!fallback_keys.is_empty(),
"We should upload the initial fallback key if the server supports them."
);
account.mark_keys_as_published();
// There's no unused fallback key on the server, but our initial fallback key
// did not yet expire.
let unused_fallback_keys = &[];
account.update_key_counts(&one_time_keys, Some(unused_fallback_keys.as_ref()));
let (_, _, fallback_keys) = account.keys_for_upload();
assert!(
fallback_keys.is_empty(),
"We should not upload new fallback keys unless our current fallback key expires."
);
let fallback_key_timestamp =
account.fallback_creation_timestamp.unwrap().to_system_time().unwrap()
- Duration::from_secs(3600 * 24 * 30);
account.fallback_creation_timestamp =
Some(MilliSecondsSinceUnixEpoch::from_system_time(fallback_key_timestamp).unwrap());
account.update_key_counts(&one_time_keys, None);
let (_, _, fallback_keys) = account.keys_for_upload();
assert!(
!fallback_keys.is_empty(),
"Now that our fallback key has expired, we should try to upload a new one, even if the \
server supposedly doesn't support fallback keys anymore"
);
Ok(())
}
#[test]
fn test_fallback_key_signing() -> Result<()> {
let key = vodozemac::Curve25519PublicKey::from_base64(
"7PUPP6Ijt5R8qLwK2c8uK5hqCNF9tOzWYgGaAay5JBs",
)?;
let account = Account::with_device_id(user_id(), device_id());
let key = account.sign_key(key, true);
let canonical_key = key.to_canonical_json()?;
assert_eq!(
canonical_key,
"{\"fallback\":true,\"key\":\"7PUPP6Ijt5R8qLwK2c8uK5hqCNF9tOzWYgGaAay5JBs\"}"
);
account
.has_signed_raw(key.signatures(), &canonical_key)
.expect("Couldn't verify signature");
let device = DeviceData::from_account(&account);
device.verify_one_time_key(&key).expect("The device can verify its own signature");
Ok(())
}
#[test]
fn test_account_and_device_creation_timestamp() -> Result<()> {
let now = MilliSecondsSinceUnixEpoch::now();
let account = Account::with_device_id(user_id(), device_id());
let then = MilliSecondsSinceUnixEpoch::now();
assert!(account.creation_local_time() >= now);
assert!(account.creation_local_time() <= then);
let device = DeviceData::from_account(&account);
assert_eq!(account.creation_local_time(), device.first_time_seen_ts());
Ok(())
}
#[async_test]
async fn test_fallback_key_signature_verification() -> Result<()> {
let fallback_key = json!({
"fallback": true,
"key": "XPFqtLvBepBmW6jSAbBuJbhEpprBhQOX1IjUu+cnMF4",
"signatures": {
"@dkasak_c:matrix.org": {
"ed25519:EXPDYDPWZH": "RJCBMJPL5hvjxgq8rmLmqkNOuPsaan7JeL1wsE+gW6R39G894lb2sBmzapHeKCn/KFjmkonPLkICApRDS+zyDw"
}
}
});
let device_keys = json!({
"algorithms": [
"m.olm.v1.curve25519-aes-sha2",
"m.megolm.v1.aes-sha2"
],
"device_id": "EXPDYDPWZH",
"keys": {
"curve25519:EXPDYDPWZH": "k7f3igo0Vrdm88JSSA5d3OCuUfHYELChB2b57aOROB8",
"ed25519:EXPDYDPWZH": "GdjYI8fxs175gSpYRJkyN6FRfvcyTsNOhJ2OR/Ggp+E"
},
"signatures": {
"@dkasak_c:matrix.org": {
"ed25519:EXPDYDPWZH": "kzrtfQMbJXWXQ1uzhybtwFnGk0JJBS4Mg8VPMusMu6U8MPJccwoHVZKo5+owuHTzIodI+GZYqLmMSzvfvsChAA"
}
},
"user_id": "@dkasak_c:matrix.org",
"unsigned": {}
});
let device_keys: DeviceKeys = serde_json::from_value(device_keys).unwrap();
let device = DeviceData::try_from(&device_keys).unwrap();
let fallback_key: SignedKey = serde_json::from_value(fallback_key).unwrap();
device
.verify_one_time_key(&fallback_key)
.expect("The fallback key should pass the signature verification");
Ok(())
}
}