matrix_sdk_crypto/store/
types.rs

1// Copyright 2020, 2026 The Matrix.org Foundation C.I.C.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15//! Data types for persistent storage.
16//!
17//! This module defines the data structures used by the crypto store to
18//! represent objects that are persisted in the database.
19
20use std::{
21    collections::{BTreeMap, HashMap, HashSet},
22    time::Duration,
23};
24
25use rand::Rng;
26use ruma::{
27    MilliSecondsSinceUnixEpoch, OwnedDeviceId, OwnedRoomId, OwnedUserId,
28    events::secret::request::SecretName,
29};
30use serde::{Deserialize, Serialize};
31use vodozemac::{Curve25519PublicKey, base64_encode};
32use zeroize::{Zeroize, ZeroizeOnDrop, Zeroizing};
33
34use super::{DehydrationError, GossipRequest};
35#[cfg(feature = "experimental-push-secrets")]
36use crate::types::events::secret_push::SecretPushContent;
37use crate::{
38    Account, Device, DeviceData, GossippedSecret, Session, UserIdentity, UserIdentityData,
39    olm::{
40        InboundGroupSession, OlmMessageHash, OutboundGroupSession, PrivateCrossSigningIdentity,
41        SenderData,
42    },
43    types::{
44        EventEncryptionAlgorithm,
45        events::{
46            room_key_bundle::RoomKeyBundleContent,
47            room_key_withheld::{RoomKeyWithheldContent, RoomKeyWithheldEvent},
48        },
49    },
50};
51
52/// Aggregated changes to be saved in the database.
53///
54/// This is an update version of `Changes` that will replace it as #2624
55/// progresses.
56// If you ever add a field here, make sure to update `Changes::is_empty` too.
57#[derive(Default, Debug)]
58#[allow(missing_docs)]
59pub struct PendingChanges {
60    pub account: Option<Account>,
61}
62
63impl PendingChanges {
64    /// Are there any changes stored or is this an empty `Changes` struct?
65    pub fn is_empty(&self) -> bool {
66        self.account.is_none()
67    }
68}
69
70/// Aggregated changes to be saved in the database.
71// If you ever add a field here, make sure to update `Changes::is_empty` too.
72#[derive(Default, Debug)]
73#[allow(missing_docs)]
74pub struct Changes {
75    pub private_identity: Option<PrivateCrossSigningIdentity>,
76    pub backup_version: Option<String>,
77    pub backup_decryption_key: Option<BackupDecryptionKey>,
78    pub dehydrated_device_pickle_key: Option<DehydratedDeviceKey>,
79    pub sessions: Vec<Session>,
80    pub message_hashes: Vec<OlmMessageHash>,
81    pub inbound_group_sessions: Vec<InboundGroupSession>,
82    pub outbound_group_sessions: Vec<OutboundGroupSession>,
83    pub key_requests: Vec<GossipRequest>,
84    pub identities: IdentityChanges,
85    pub devices: DeviceChanges,
86    /// Stores when a `m.room_key.withheld` is received
87    pub withheld_session_info: BTreeMap<OwnedRoomId, BTreeMap<String, RoomKeyWithheldEntry>>,
88    pub room_settings: HashMap<OwnedRoomId, RoomSettings>,
89    pub secrets: Vec<SecretsInboxItem>,
90    pub next_batch_token: Option<String>,
91
92    /// Historical room key history bundles that we have received and should
93    /// store.
94    pub received_room_key_bundles: Vec<StoredRoomKeyBundleData>,
95
96    /// The set of rooms for which we have requested all room keys from the
97    /// backup in advance of constructing a room key bundle.
98    pub room_key_backups_fully_downloaded: HashSet<OwnedRoomId>,
99
100    /// Updates to the list of rooms where we have recently accepted invites
101    /// (and should now accept a key bundle, if one arrives soon).
102    pub rooms_pending_key_bundle: HashMap<OwnedRoomId, Option<RoomPendingKeyBundleDetails>>,
103}
104
105/// A secret that was received via an `m.secret.send` or
106/// `io.element.msc4385.secret.push` event.
107#[derive(Clone)]
108pub struct SecretsInboxItem {
109    /// The name of the secret.
110    pub secret_name: SecretName,
111    /// The contents of the secret.
112    pub secret: Zeroizing<String>,
113}
114
115#[cfg(not(tarpaulin_include))]
116impl std::fmt::Debug for SecretsInboxItem {
117    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
118        f.debug_tuple("SecretsInboxItem").field(&self.secret_name).finish()
119    }
120}
121
122impl From<GossippedSecret> for SecretsInboxItem {
123    fn from(secret: GossippedSecret) -> Self {
124        Self { secret_name: secret.secret_name, secret: secret.event.content.secret.clone().into() }
125    }
126}
127
128#[cfg(feature = "experimental-push-secrets")]
129impl From<SecretPushContent> for SecretsInboxItem {
130    fn from(secret: SecretPushContent) -> Self {
131        Self { secret_name: secret.name.clone(), secret: secret.secret.clone().into() }
132    }
133}
134
135/// Information about an [MSC4268] room key bundle.
136///
137/// [MSC4268]: https://github.com/matrix-org/matrix-spec-proposals/pull/4268
138#[derive(Clone, Debug, Serialize, Deserialize)]
139pub struct StoredRoomKeyBundleData {
140    /// The user that sent us this data.
141    pub sender_user: OwnedUserId,
142
143    /// The [`Curve25519PublicKey`] of the device that sent us this data.
144    pub sender_key: Curve25519PublicKey,
145
146    /// Information about the sender of this data and how much we trust that
147    /// information.
148    pub sender_data: SenderData,
149
150    /// The room key bundle data itself.
151    pub bundle_data: RoomKeyBundleContent,
152}
153
154/// A user for which we are tracking the list of devices.
155#[derive(Clone, Debug, Serialize, Deserialize)]
156pub struct TrackedUser {
157    /// The user ID of the user.
158    pub user_id: OwnedUserId,
159    /// The outdate/dirty flag of the user, remembers if the list of devices for
160    /// the user is considered to be out of date. If the list of devices is out
161    /// of date, a `/keys/query` request should be sent out for this user.
162    pub dirty: bool,
163}
164
165impl Changes {
166    /// Are there any changes stored or is this an empty `Changes` struct?
167    pub fn is_empty(&self) -> bool {
168        self.private_identity.is_none()
169            && self.backup_version.is_none()
170            && self.backup_decryption_key.is_none()
171            && self.dehydrated_device_pickle_key.is_none()
172            && self.sessions.is_empty()
173            && self.message_hashes.is_empty()
174            && self.inbound_group_sessions.is_empty()
175            && self.outbound_group_sessions.is_empty()
176            && self.key_requests.is_empty()
177            && self.identities.is_empty()
178            && self.devices.is_empty()
179            && self.withheld_session_info.is_empty()
180            && self.room_settings.is_empty()
181            && self.secrets.is_empty()
182            && self.next_batch_token.is_none()
183            && self.received_room_key_bundles.is_empty()
184    }
185}
186
187/// This struct is used to remember whether an identity has undergone a change
188/// or remains the same as the one we already know about.
189///
190/// When the homeserver informs us of a potential change in a user's identity or
191/// device during a `/sync` response, it triggers a `/keys/query` request from
192/// our side. In response to this query, the server provides a comprehensive
193/// snapshot of all the user's devices and identities.
194///
195/// Our responsibility is to discern whether a device or identity is new,
196/// changed, or unchanged.
197#[derive(Debug, Clone, Default)]
198#[allow(missing_docs)]
199pub struct IdentityChanges {
200    pub new: Vec<UserIdentityData>,
201    pub changed: Vec<UserIdentityData>,
202    pub unchanged: Vec<UserIdentityData>,
203}
204
205impl IdentityChanges {
206    pub(super) fn is_empty(&self) -> bool {
207        self.new.is_empty() && self.changed.is_empty()
208    }
209
210    /// Convert the vectors contained in the [`IdentityChanges`] into three maps
211    /// from user id to user identity (new, updated, unchanged).
212    pub(super) fn into_maps(
213        self,
214    ) -> (
215        BTreeMap<OwnedUserId, UserIdentityData>,
216        BTreeMap<OwnedUserId, UserIdentityData>,
217        BTreeMap<OwnedUserId, UserIdentityData>,
218    ) {
219        let new: BTreeMap<_, _> = self
220            .new
221            .into_iter()
222            .map(|identity| (identity.user_id().to_owned(), identity))
223            .collect();
224
225        let changed: BTreeMap<_, _> = self
226            .changed
227            .into_iter()
228            .map(|identity| (identity.user_id().to_owned(), identity))
229            .collect();
230
231        let unchanged: BTreeMap<_, _> = self
232            .unchanged
233            .into_iter()
234            .map(|identity| (identity.user_id().to_owned(), identity))
235            .collect();
236
237        (new, changed, unchanged)
238    }
239}
240
241#[derive(Debug, Clone, Default)]
242#[allow(missing_docs)]
243pub struct DeviceChanges {
244    pub new: Vec<DeviceData>,
245    pub changed: Vec<DeviceData>,
246    pub deleted: Vec<DeviceData>,
247}
248
249/// Updates about [`Device`]s which got received over the `/keys/query`
250/// endpoint.
251#[derive(Clone, Debug, Default)]
252pub struct DeviceUpdates {
253    /// The list of newly discovered devices.
254    ///
255    /// A device being in this list does not necessarily mean that the device
256    /// was just created, it just means that it's the first time we're seeing
257    /// this device.
258    pub new: BTreeMap<OwnedUserId, BTreeMap<OwnedDeviceId, Device>>,
259    /// The list of changed devices.
260    pub changed: BTreeMap<OwnedUserId, BTreeMap<OwnedDeviceId, Device>>,
261}
262
263/// Updates about [`UserIdentity`]s which got received over the `/keys/query`
264/// endpoint.
265#[derive(Clone, Debug, Default)]
266pub struct IdentityUpdates {
267    /// The list of newly discovered user identities .
268    ///
269    /// A identity being in this list does not necessarily mean that the
270    /// identity was just created, it just means that it's the first time we're
271    /// seeing this identity.
272    pub new: BTreeMap<OwnedUserId, UserIdentity>,
273    /// The list of changed identities.
274    pub changed: BTreeMap<OwnedUserId, UserIdentity>,
275    /// The list of unchanged identities.
276    pub unchanged: BTreeMap<OwnedUserId, UserIdentity>,
277}
278
279/// The private part of a backup key.
280///
281/// The private part of the key is not used on a regular basis. Rather, it is
282/// used only when we need to _recover_ the backup.
283///
284/// Typically, this private key is itself encrypted and stored in server-side
285/// secret storage (SSSS), whence it can be retrieved when it is needed for a
286/// recovery operation. Alternatively, the key can be "gossiped" between devices
287/// via "secret sharing".
288#[derive(Clone, Zeroize, ZeroizeOnDrop, Deserialize, Serialize)]
289#[serde(transparent)]
290pub struct BackupDecryptionKey {
291    pub(crate) inner: Box<[u8; BackupDecryptionKey::KEY_SIZE]>,
292}
293
294impl BackupDecryptionKey {
295    /// The number of bytes the decryption key will hold.
296    pub const KEY_SIZE: usize = 32;
297
298    /// Create a new random decryption key.
299    #[allow(clippy::new_without_default)]
300    pub fn new() -> Self {
301        let mut rng = rand::rng();
302
303        let mut key = Box::new([0u8; Self::KEY_SIZE]);
304        rng.fill_bytes(key.as_mut_slice());
305
306        Self { inner: key }
307    }
308
309    /// Export the [`BackupDecryptionKey`] as a base64 encoded string.
310    pub fn to_base64(&self) -> String {
311        base64_encode(self.inner.as_slice())
312    }
313}
314
315#[cfg(not(tarpaulin_include))]
316impl std::fmt::Debug for BackupDecryptionKey {
317    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
318        f.debug_tuple("BackupDecryptionKey").field(&"...").finish()
319    }
320}
321
322/// The pickle key used to safely store the dehydrated device pickle.
323///
324/// This input key material will be expanded using HKDF into an AES key, MAC
325/// key, and an initialization vector (IV).
326#[derive(Clone, Zeroize, ZeroizeOnDrop, Deserialize, Serialize)]
327#[serde(transparent)]
328pub struct DehydratedDeviceKey {
329    pub(crate) inner: Box<[u8; DehydratedDeviceKey::KEY_SIZE]>,
330}
331
332impl DehydratedDeviceKey {
333    /// The number of bytes the encryption key will hold.
334    pub const KEY_SIZE: usize = 32;
335
336    /// Generates a new random pickle key.
337    #[allow(clippy::new_without_default)]
338    pub fn new() -> Self {
339        let mut rng = rand::rng();
340
341        let mut key = Box::new([0u8; Self::KEY_SIZE]);
342        rng.fill_bytes(key.as_mut_slice());
343
344        Self { inner: key }
345    }
346
347    /// Creates a new dehydration pickle key from the given slice.
348    ///
349    /// Fail if the slice length is not 32.
350    pub fn from_slice(slice: &[u8]) -> Result<Self, DehydrationError> {
351        if slice.len() == 32 {
352            let mut key = Box::new([0u8; 32]);
353            key.copy_from_slice(slice);
354            Ok(DehydratedDeviceKey { inner: key })
355        } else {
356            Err(DehydrationError::PickleKeyLength(slice.len()))
357        }
358    }
359
360    /// Creates a dehydration pickle key from the given bytes.
361    pub fn from_bytes(raw_key: &[u8; 32]) -> Self {
362        let mut inner = Box::new([0u8; Self::KEY_SIZE]);
363        inner.copy_from_slice(raw_key);
364
365        Self { inner }
366    }
367
368    /// Export the [`DehydratedDeviceKey`] as a base64 encoded string.
369    pub fn to_base64(&self) -> String {
370        base64_encode(self.inner.as_slice())
371    }
372}
373
374impl From<&[u8; 32]> for DehydratedDeviceKey {
375    fn from(value: &[u8; 32]) -> Self {
376        DehydratedDeviceKey { inner: Box::new(*value) }
377    }
378}
379
380impl From<DehydratedDeviceKey> for Vec<u8> {
381    fn from(key: DehydratedDeviceKey) -> Self {
382        key.inner.to_vec()
383    }
384}
385
386#[cfg(not(tarpaulin_include))]
387impl std::fmt::Debug for DehydratedDeviceKey {
388    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
389        f.debug_tuple("DehydratedDeviceKey").field(&"...").finish()
390    }
391}
392
393impl DeviceChanges {
394    /// Merge the given `DeviceChanges` into this instance of `DeviceChanges`.
395    pub fn extend(&mut self, other: DeviceChanges) {
396        self.new.extend(other.new);
397        self.changed.extend(other.changed);
398        self.deleted.extend(other.deleted);
399    }
400
401    /// Are there any changes is this an empty [`DeviceChanges`] struct?
402    pub fn is_empty(&self) -> bool {
403        self.new.is_empty() && self.changed.is_empty() && self.deleted.is_empty()
404    }
405}
406
407/// Struct holding info about how many room keys the store has.
408#[derive(Debug, Clone, Default)]
409pub struct RoomKeyCounts {
410    /// The total number of room keys the store has.
411    pub total: usize,
412    /// The number of backed up room keys the store has.
413    pub backed_up: usize,
414}
415
416/// Stored versions of the backup keys.
417#[derive(Default, Clone, Debug)]
418pub struct BackupKeys {
419    /// The key used to decrypt backed up room keys.
420    pub decryption_key: Option<BackupDecryptionKey>,
421    /// The version that we are using for backups.
422    pub backup_version: Option<String>,
423}
424
425/// A struct containing private cross signing keys that can be backed up or
426/// uploaded to the secret store.
427#[derive(Default, Zeroize, ZeroizeOnDrop)]
428pub struct CrossSigningKeyExport {
429    /// The seed of the master key encoded as unpadded base64.
430    pub master_key: Option<String>,
431    /// The seed of the self signing key encoded as unpadded base64.
432    pub self_signing_key: Option<String>,
433    /// The seed of the user signing key encoded as unpadded base64.
434    pub user_signing_key: Option<String>,
435}
436
437#[cfg(not(tarpaulin_include))]
438impl std::fmt::Debug for CrossSigningKeyExport {
439    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
440        f.debug_struct("CrossSigningKeyExport")
441            .field("master_key", &self.master_key.is_some())
442            .field("self_signing_key", &self.self_signing_key.is_some())
443            .field("user_signing_key", &self.user_signing_key.is_some())
444            .finish_non_exhaustive()
445    }
446}
447
448/// Result type telling us if a `/keys/query` response was expected for a given
449/// user.
450#[derive(Clone, Copy, Debug, PartialEq, Eq)]
451pub(crate) enum UserKeyQueryResult {
452    WasPending,
453    WasNotPending,
454
455    /// A query was pending, but we gave up waiting
456    TimeoutExpired,
457}
458
459/// Room encryption settings which are modified by state events or user options
460#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq)]
461pub struct RoomSettings {
462    /// The encryption algorithm that should be used in the room.
463    pub algorithm: EventEncryptionAlgorithm,
464
465    /// Whether state event encryption is enabled.
466    #[cfg(feature = "experimental-encrypted-state-events")]
467    #[serde(default)]
468    pub encrypt_state_events: bool,
469
470    /// Should untrusted devices receive the room key, or should they be
471    /// excluded from the conversation.
472    pub only_allow_trusted_devices: bool,
473
474    /// The maximum time an encryption session should be used for, before it is
475    /// rotated.
476    pub session_rotation_period: Option<Duration>,
477
478    /// The maximum number of messages an encryption session should be used for,
479    /// before it is rotated.
480    pub session_rotation_period_messages: Option<usize>,
481}
482
483impl Default for RoomSettings {
484    fn default() -> Self {
485        Self {
486            algorithm: EventEncryptionAlgorithm::MegolmV1AesSha2,
487            #[cfg(feature = "experimental-encrypted-state-events")]
488            encrypt_state_events: false,
489            only_allow_trusted_devices: false,
490            session_rotation_period: None,
491            session_rotation_period_messages: None,
492        }
493    }
494}
495
496/// Information on a room key that has been received or imported.
497#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq)]
498pub struct RoomKeyInfo {
499    /// The [messaging algorithm] that this key is used for. Will be one of the
500    /// `m.megolm.*` algorithms.
501    ///
502    /// [messaging algorithm]: https://spec.matrix.org/v1.6/client-server-api/#messaging-algorithms
503    pub algorithm: EventEncryptionAlgorithm,
504
505    /// The room where the key is used.
506    pub room_id: OwnedRoomId,
507
508    /// The Curve25519 key of the device which initiated the session originally.
509    pub sender_key: Curve25519PublicKey,
510
511    /// The ID of the session that the key is for.
512    pub session_id: String,
513}
514
515impl From<&InboundGroupSession> for RoomKeyInfo {
516    fn from(group_session: &InboundGroupSession) -> Self {
517        RoomKeyInfo {
518            algorithm: group_session.algorithm().clone(),
519            room_id: group_session.room_id().to_owned(),
520            sender_key: group_session.sender_key(),
521            session_id: group_session.session_id().to_owned(),
522        }
523    }
524}
525
526/// Information on a room key that has been withheld
527#[derive(Clone, Debug, Deserialize, Serialize)]
528pub struct RoomKeyWithheldInfo {
529    /// The room where the key is used.
530    pub room_id: OwnedRoomId,
531
532    /// The ID of the session that the key is for.
533    pub session_id: String,
534
535    /// The withheld entry from a `m.room_key.withheld` event or [MSC4268] room
536    /// key bundle.
537    ///
538    /// [MSC4268]: https://github.com/matrix-org/matrix-spec-proposals/pull/4268
539    pub withheld_event: RoomKeyWithheldEntry,
540}
541
542/// Represents an entry for a withheld room key event, which can be either a
543/// to-device event or a bundle entry.
544#[derive(Clone, Debug, Serialize, Deserialize)]
545pub struct RoomKeyWithheldEntry {
546    /// The user ID responsible for this entry, either from a
547    /// `m.room_key.withheld` to-device event or an [MSC4268] room key bundle.
548    ///
549    /// [MSC4268]: https://github.com/matrix-org/matrix-spec-proposals/pull/4268
550    pub sender: OwnedUserId,
551    /// The content of the entry, which provides details about the reason the
552    /// key was withheld.
553    pub content: RoomKeyWithheldContent,
554}
555
556impl From<RoomKeyWithheldEvent> for RoomKeyWithheldEntry {
557    fn from(value: RoomKeyWithheldEvent) -> Self {
558        Self { sender: value.sender, content: value.content }
559    }
560}
561
562/// Information about a received historic room key bundle.
563///
564/// This struct contains information needed to uniquely identify a room key
565/// bundle. Only a single bundle per sender for a given room is persisted at a
566/// time.
567///
568/// It is used to notify listeners about received room key bundles.
569#[derive(Debug, Clone)]
570pub struct RoomKeyBundleInfo {
571    /// The user ID of the person that sent us the historic room key bundle.
572    pub sender: OwnedUserId,
573
574    /// The [`Curve25519PublicKey`] of the device that sent us this data.
575    pub sender_key: Curve25519PublicKey,
576
577    /// The ID of the room the bundle should be used in.
578    pub room_id: OwnedRoomId,
579}
580
581impl From<&StoredRoomKeyBundleData> for RoomKeyBundleInfo {
582    fn from(value: &StoredRoomKeyBundleData) -> Self {
583        let StoredRoomKeyBundleData { sender_user, sender_data: _, bundle_data, sender_key } =
584            value;
585        let sender_key = *sender_key;
586
587        Self { sender: sender_user.clone(), room_id: bundle_data.room_id.clone(), sender_key }
588    }
589}
590
591/// A struct remembering details of a room that we recently joined following an
592/// invite (and so should accept a room key bundle if we receive one).
593#[derive(Debug, Clone, Serialize, Deserialize)]
594pub struct RoomPendingKeyBundleDetails {
595    /// The ID of the room associated with this entry, used to track and
596    /// enumerate all such rooms during the startup process. This enables the
597    /// client to resume importing after a crash.
598    pub room_id: OwnedRoomId,
599
600    /// A timestamp remembering when we observed the user accepting an invite
601    /// using this client.
602    pub invite_accepted_at: MilliSecondsSinceUnixEpoch,
603
604    /// The user ID of the person that invited us.
605    pub inviter: OwnedUserId,
606}
matrix_sdk_crypto/store/types.rs

matrix_sdk_crypto/store/
types.rs
