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Merge branch 'crypto-improvements'

master
Damir Jelić 2020-12-01 15:10:58 +01:00
parent 4800e80492 5d0ff961b2
commit e65915e159
13 changed files with 279 additions and 98 deletions
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5
matrix_sdk_crypto/Cargo.toml
View File

@ -46,11 +46,10 @@ base64 = "0.13.0"
byteorder = "1.3.4"
[target.'cfg(not(target_arch = "wasm32"))'.dependencies.sqlx]
git = "https://github.com/launchbadge/sqlx/"
rev = "fd25a7530cf087e1529553ff854f192738db3461"
version = "0.4.1"
optional = true
default-features = false
features = ["runtime-tokio", "sqlite", "macros"]
features = ["runtime-tokio-native-tls", "sqlite", "macros"]
[dev-dependencies]
tokio = { version = "0.2.22", default-features = false, features = ["rt-threaded", "macros"] }

9
matrix_sdk_crypto/src/error.rs
View File

@ -47,9 +47,16 @@ pub enum OlmError {
Store(#[from] CryptoStoreError),
/// The session with a device has become corrupted.
#[error("decryption failed likely because an Olm from {0} with sender key {1} was wedged")]
#[error(
"decryption failed likely because an Olm session from {0} with sender key {1} was wedged"
)]
SessionWedged(UserId, String),
/// An Olm message got replayed while the Olm ratchet has already moved
/// forward.
#[error("decryption failed because an Olm message from {0} with sender key {1} was replayed")]
ReplayedMessage(UserId, String),
/// Encryption failed because the device does not have a valid Olm session
/// with us.
#[error(

4
matrix_sdk_crypto/src/file_encryption/mod.rs
View File

@ -14,10 +14,10 @@ fn decode_url_safe(input: impl AsRef<[u8]>) -> Result<Vec<u8>, DecodeError> {
decode_config(input, URL_SAFE_NO_PAD)
}
fn encode(input: impl AsRef<[u8]>) -> String {
pub fn encode(input: impl AsRef<[u8]>) -> String {
encode_config(input, STANDARD_NO_PAD)
}
fn encode_url_safe(input: impl AsRef<[u8]>) -> String {
pub fn encode_url_safe(input: impl AsRef<[u8]>) -> String {
encode_config(input, URL_SAFE_NO_PAD)
}

26
matrix_sdk_crypto/src/key_request.rs
View File

@ -1137,12 +1137,11 @@ mod test {
.unwrap()
.is_none());
let (_, decrypted, sender_key, _) =
alice_account.decrypt_to_device_event(&event).await.unwrap();
let decrypted = alice_account.decrypt_to_device_event(&event).await.unwrap();
if let AnyToDeviceEvent::ForwardedRoomKey(mut e) = decrypted.deserialize().unwrap() {
if let AnyToDeviceEvent::ForwardedRoomKey(mut e) = decrypted.event.deserialize().unwrap() {
let (_, session) = alice_machine
.receive_forwarded_room_key(&sender_key, &mut e)
.receive_forwarded_room_key(&decrypted.sender_key, &mut e)
.await
.unwrap();
alice_machine
@ -1157,7 +1156,11 @@ mod test {
// Check that alice now does have the session.
let session = alice_machine
.store
.get_inbound_group_session(&room_id(), &sender_key, group_session.session_id())
.get_inbound_group_session(
&room_id(),
&decrypted.sender_key,
group_session.session_id(),
)
.await
.unwrap()
.unwrap();
@ -1325,12 +1328,11 @@ mod test {
.unwrap()
.is_none());
let (_, decrypted, sender_key, _) =
alice_account.decrypt_to_device_event(&event).await.unwrap();
let decrypted = alice_account.decrypt_to_device_event(&event).await.unwrap();
if let AnyToDeviceEvent::ForwardedRoomKey(mut e) = decrypted.deserialize().unwrap() {
if let AnyToDeviceEvent::ForwardedRoomKey(mut e) = decrypted.event.deserialize().unwrap() {
let (_, session) = alice_machine
.receive_forwarded_room_key(&sender_key, &mut e)
.receive_forwarded_room_key(&decrypted.sender_key, &mut e)
.await
.unwrap();
alice_machine
@ -1345,7 +1347,11 @@ mod test {
// Check that alice now does have the session.
let session = alice_machine
.store
.get_inbound_group_session(&room_id(), &sender_key, group_session.session_id())
.get_inbound_group_session(
&room_id(),
&decrypted.sender_key,
group_session.session_id(),
)
.await
.unwrap()
.unwrap();

73
matrix_sdk_crypto/src/machine.rs
View File

@ -52,7 +52,7 @@ use crate::{
key_request::KeyRequestMachine,
olm::{
Account, EncryptionSettings, ExportedRoomKey, GroupSessionKey, IdentityKeys,
InboundGroupSession, PrivateCrossSigningIdentity, ReadOnlyAccount, Session,
InboundGroupSession, OlmDecryptionInfo, PrivateCrossSigningIdentity, ReadOnlyAccount,
},
requests::{IncomingResponse, OutgoingRequest, UploadSigningKeysRequest},
session_manager::{GroupSessionManager, SessionManager},
@ -555,24 +555,23 @@ impl OlmMachine {
async fn decrypt_to_device_event(
&self,
event: &ToDeviceEvent<EncryptedEventContent>,
) -> OlmResult<(Session, Raw<AnyToDeviceEvent>, Option<InboundGroupSession>)> {
let (session, decrypted_event, sender_key, signing_key) =
self.account.decrypt_to_device_event(event).await?;
) -> OlmResult<OlmDecryptionInfo> {
let mut decrypted = self.account.decrypt_to_device_event(event).await?;
// Handle the decrypted event, e.g. fetch out Megolm sessions out of
// the event.
if let (Some(event), group_session) = self
.handle_decrypted_to_device_event(&sender_key, &signing_key, &decrypted_event)
.await?
if let (Some(event), group_session) =
self.handle_decrypted_to_device_event(&decrypted).await?
{
// Some events may have sensitive data e.g. private keys, while we
// want to notify our users that a private key was received we
// don't want them to be able to do silly things with it. Handling
// events modifies them and returns a modified one, so replace it
// here if we get one.
Ok((session, event, group_session))
} else {
Ok((session, decrypted_event, None))
decrypted.event = event;
decrypted.inbound_group_session = group_session;
}
Ok(decrypted)
}
/// Create a group session from a room key and add it to our crypto store.
@ -704,27 +703,29 @@ impl OlmMachine {
/// * `event` - The decrypted to-device event.
async fn handle_decrypted_to_device_event(
&self,
sender_key: &str,
signing_key: &str,
event: &Raw<AnyToDeviceEvent>,
decrypted: &OlmDecryptionInfo,
) -> OlmResult<(Option<Raw<AnyToDeviceEvent>>, Option<InboundGroupSession>)> {
let event = if let Ok(e) = event.deserialize() {
let event = match decrypted.event.deserialize() {
Ok(e) => e,
Err(e) => {
warn!(
"Decrypted to-device event failed to be parsed correctly {:?}",
e
} else {
warn!("Decrypted to-device event failed to be parsed correctly");
);
return Ok((None, None));
}
};
match event {
AnyToDeviceEvent::RoomKey(mut e) => {
Ok(self.add_room_key(sender_key, signing_key, &mut e).await?)
}
AnyToDeviceEvent::RoomKey(mut e) => Ok(self
.add_room_key(&decrypted.sender_key, &decrypted.signing_key, &mut e)
.await?),
AnyToDeviceEvent::ForwardedRoomKey(mut e) => Ok(self
.key_request_machine
.receive_forwarded_room_key(sender_key, &mut e)
.receive_forwarded_room_key(&decrypted.sender_key, &mut e)
.await?),
_ => {
warn!("Received a unexpected encrypted to-device event");
warn!("Received an unexpected encrypted to-device event");
Ok((None, None))
}
}
@ -808,8 +809,7 @@ impl OlmMachine {
match &mut event {
AnyToDeviceEvent::RoomEncrypted(e) => {
let (session, decrypted_event, group_session) =
match self.decrypt_to_device_event(e).await {
let decrypted = match self.decrypt_to_device_event(e).await {
Ok(e) => e,
Err(err) => {
warn!(
@ -833,13 +833,14 @@ impl OlmMachine {
}
};
changes.sessions.push(session);
changes.sessions.push(decrypted.session);
changes.message_hashes.push(decrypted.message_hash);
if let Some(group_session) = group_session {
if let Some(group_session) = decrypted.inbound_group_session {
changes.inbound_group_sessions.push(group_session);
}
*event_result = decrypted_event;
*event_result = decrypted.event;
}
AnyToDeviceEvent::RoomKeyRequest(e) => {
self.key_request_machine.receive_incoming_key_request(e)
@ -1283,8 +1284,8 @@ pub(crate) mod test {
content,
};
let (session, _, _) = bob.decrypt_to_device_event(&event).await.unwrap();
bob.store.save_sessions(&[session]).await.unwrap();
let decrypted = bob.decrypt_to_device_event(&event).await.unwrap();
bob.store.save_sessions(&[decrypted.session]).await.unwrap();
(alice, bob)
}
@ -1578,7 +1579,7 @@ pub(crate) mod test {
.decrypt_to_device_event(&event)
.await
.unwrap()
.1
.event
.deserialize()
.unwrap();
@ -1614,14 +1615,14 @@ pub(crate) mod test {
.get_outbound_group_session(&room_id)
.unwrap();
let (session, event, group_session) = bob.decrypt_to_device_event(&event).await.unwrap();
let decrypted = bob.decrypt_to_device_event(&event).await.unwrap();
bob.store.save_sessions(&[session]).await.unwrap();
bob.store.save_sessions(&[decrypted.session]).await.unwrap();
bob.store
.save_inbound_group_sessions(&[group_session.unwrap()])
.save_inbound_group_sessions(&[decrypted.inbound_group_session.unwrap()])
.await
.unwrap();
let event = event.deserialize().unwrap();
let event = decrypted.event.deserialize().unwrap();
if let AnyToDeviceEvent::RoomKey(event) = event {
assert_eq!(&event.sender, alice.user_id());
@ -1661,7 +1662,11 @@ pub(crate) mod test {
content: to_device_requests_to_content(to_device_requests),
};
let (_, _, group_session) = bob.decrypt_to_device_event(&event).await.unwrap();
let group_session = bob
.decrypt_to_device_event(&event)
.await
.unwrap()
.inbound_group_session;
bob.store
.save_inbound_group_sessions(&[group_session.unwrap()])
.await

63
matrix_sdk_crypto/src/olm/account.rs
View File

@ -15,6 +15,7 @@
use matrix_sdk_common::events::ToDeviceEvent;
use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use sha2::{Digest, Sha256};
use std::{
collections::BTreeMap,
convert::{TryFrom, TryInto},
@ -53,6 +54,7 @@ use olm_rs::{
use crate::{
error::{EventError, OlmResult, SessionCreationError},
file_encryption::encode,
identities::ReadOnlyDevice,
requests::UploadSigningKeysRequest,
store::Store,
@ -70,6 +72,27 @@ pub struct Account {
pub(crate) store: Store,
}
#[derive(Debug, Clone)]
pub struct OlmDecryptionInfo {
pub session: Session,
pub message_hash: OlmMessageHash,
pub event: Raw<AnyToDeviceEvent>,
pub signing_key: String,
pub sender_key: String,
pub inbound_group_session: Option<InboundGroupSession>,
}
/// A hash of a succesfully decrypted Olm message.
///
/// Can be used to check if a message has been replayed to us.
#[derive(Debug, Clone)]
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 Deref for Account {
type Target = ReadOnlyAccount;
@ -82,7 +105,7 @@ impl Account {
pub async fn decrypt_to_device_event(
&self,
event: &ToDeviceEvent<EncryptedEventContent>,
) -> OlmResult<(Session, Raw<AnyToDeviceEvent>, String, String)> {
) -> OlmResult<OlmDecryptionInfo> {
debug!("Decrypting to-device event");
let content = if let EncryptedEventContent::OlmV1Curve25519AesSha2(c) = &event.content {
@ -103,23 +126,47 @@ impl Account {
.try_into()
.map_err(|_| EventError::UnsupportedOlmType)?;
let sha = Sha256::new()
.chain(&content.sender_key)
.chain(&[message_type])
.chain(&ciphertext.body);
let message_hash = OlmMessageHash {
sender_key: content.sender_key.clone(),
hash: encode(sha.finalize().as_slice()),
};
// Create a OlmMessage from the ciphertext and the type.
let message =
OlmMessage::from_type_and_ciphertext(message_type.into(), ciphertext.body.clone())
.map_err(|_| EventError::UnsupportedOlmType)?;
// Decrypt the OlmMessage and get a Ruma event out of it.
let (session, decrypted_event, signing_key) = self
let (session, event, signing_key) = match self
.decrypt_olm_message(&event.sender, &content.sender_key, message)
.await?;
.await
{
Ok(d) => d,
Err(OlmError::SessionWedged(user_id, sender_key)) => {
if self.store.is_message_known(&message_hash).await? {
return Err(OlmError::ReplayedMessage(user_id, sender_key));
} else {
return Err(OlmError::SessionWedged(user_id, sender_key));
}
}
Err(e) => return Err(e.into()),
};
debug!("Decrypted a to-device event {:?}", decrypted_event);
Ok((
debug!("Decrypted a to-device event {:?}", event);
Ok(OlmDecryptionInfo {
session,
decrypted_event,
content.sender_key.clone(),
message_hash,
event,
signing_key,
))
sender_key: content.sender_key.clone(),
inbound_group_session: None,
})
} else {
warn!("Olm event doesn't contain a ciphertext for our key");
Err(EventError::MissingCiphertext.into())

4
matrix_sdk_crypto/src/olm/mod.rs
View File

@ -23,8 +23,8 @@ mod session;
mod signing;
mod utility;
pub(crate) use account::Account;
pub use account::{AccountPickle, PickledAccount, ReadOnlyAccount};
pub(crate) use account::{Account, OlmDecryptionInfo};
pub use account::{AccountPickle, OlmMessageHash, PickledAccount, ReadOnlyAccount};
pub use group_sessions::{
EncryptionSettings, ExportedRoomKey, InboundGroupSession, InboundGroupSessionPickle,
PickledInboundGroupSession,

4
matrix_sdk_crypto/src/olm/session.rs
View File

@ -126,9 +126,7 @@ impl Session {
"content": content,
});
let plaintext = serde_json::to_string(&payload)
.unwrap_or_else(|_| panic!(format!("Can't serialize {} to canonical JSON", payload)));
let plaintext = serde_json::to_string(&payload)?;
let ciphertext = self.encrypt_helper(&plaintext).await.to_tuple();
let message_type = ciphertext.0;

1
matrix_sdk_crypto/src/olm/signing/pk_signing.rs
View File

@ -170,7 +170,6 @@ impl MasterSigning {
}
pub async fn sign_subkey<'a>(&self, subkey: &mut CrossSigningKey) {
// TODO create a borrowed version of a cross singing key.
let subkey_wihtout_signatures = json!({
"user_id": subkey.user_id.clone(),
"keys": subkey.keys.clone(),

38
matrix_sdk_crypto/src/store/memorystore.rs
View File

@ -40,6 +40,7 @@ pub struct MemoryStore {
inbound_group_sessions: GroupSessionStore,
tracked_users: Arc<DashSet<UserId>>,
users_for_key_query: Arc<DashSet<UserId>>,
olm_hashes: Arc<DashMap<String, DashSet<String>>>,
devices: DeviceStore,
identities: Arc<DashMap<UserId, UserIdentities>>,
values: Arc<DashMap<String, String>>,
@ -52,6 +53,7 @@ impl Default for MemoryStore {
inbound_group_sessions: GroupSessionStore::new(),
tracked_users: Arc::new(DashSet::new()),
users_for_key_query: Arc::new(DashSet::new()),
olm_hashes: Arc::new(DashMap::new()),
devices: DeviceStore::new(),
identities: Arc::new(DashMap::new()),
values: Arc::new(DashMap::new()),
@ -120,6 +122,13 @@ impl CryptoStore for MemoryStore {
.insert(identity.user_id().to_owned(), identity.clone());
}
for hash in changes.message_hashes {
self.olm_hashes
.entry(hash.sender_key.to_owned())
.or_insert_with(DashSet::new)
.insert(hash.hash.clone());
}
Ok(())
}
@ -218,14 +227,22 @@ impl CryptoStore for MemoryStore {
async fn load_identity(&self) -> Result<Option<PrivateCrossSigningIdentity>> {
Ok(None)
}
async fn is_message_known(&self, message_hash: &crate::olm::OlmMessageHash) -> Result<bool> {
Ok(self
.olm_hashes
.entry(message_hash.sender_key.to_owned())
.or_insert_with(DashSet::new)
.contains(&message_hash.hash))
}
}
#[cfg(test)]
mod test {
use crate::{
identities::device::test::get_device,
olm::{test::get_account_and_session, InboundGroupSession},
store::{memorystore::MemoryStore, CryptoStore},
olm::{test::get_account_and_session, InboundGroupSession, OlmMessageHash},
store::{memorystore::MemoryStore, Changes, CryptoStore},
};
use matrix_sdk_common::identifiers::room_id;
@ -329,4 +346,21 @@ mod test {
assert!(store.is_user_tracked(device.user_id()));
}
#[tokio::test]
async fn test_message_hash() {
let store = MemoryStore::new();
let hash = OlmMessageHash {
sender_key: "test_sender".to_owned(),
hash: "test_hash".to_owned(),
};
let mut changes = Changes::default();
changes.message_hashes.push(hash.clone());
assert!(!store.is_message_known(&hash).await.unwrap());
store.save_changes(changes).await.unwrap();
assert!(store.is_message_known(&hash).await.unwrap());
}
}

23
matrix_sdk_crypto/src/store/mod.rs
View File

@ -82,7 +82,9 @@ use matrix_sdk_common_macros::send_sync;
use crate::{
error::SessionUnpicklingError,
identities::{Device, ReadOnlyDevice, UserDevices, UserIdentities},
olm::{InboundGroupSession, PrivateCrossSigningIdentity, ReadOnlyAccount, Session},
olm::{
InboundGroupSession, OlmMessageHash, PrivateCrossSigningIdentity, ReadOnlyAccount, Session,
},
verification::VerificationMachine,
};
@ -108,6 +110,7 @@ pub(crate) struct Store {
pub struct Changes {
pub account: Option<ReadOnlyAccount>,
pub sessions: Vec<Session>,
pub message_hashes: Vec<OlmMessageHash>,
pub inbound_group_sessions: Vec<InboundGroupSession>,
pub identities: IdentityChanges,
pub devices: DeviceChanges,
@ -342,13 +345,22 @@ pub trait CryptoStore: Debug {
/// * `account` - The account that should be stored.
async fn save_account(&self, account: ReadOnlyAccount) -> Result<()>;
/// TODO
/// Save the given privat identity in the store.
///
/// # Arguments
///
/// * `identity` - The private cross signing identity that should be saved
/// in the store.
async fn save_identity(&self, identity: PrivateCrossSigningIdentity) -> Result<()>;
/// TODO
/// Try to load a private cross signing identity, if one is stored.
async fn load_identity(&self) -> Result<Option<PrivateCrossSigningIdentity>>;
/// TODO
/// Save the set of changes to the store.
///
/// # Arguments
///
/// * `changes` - The set of changes that should be stored.
async fn save_changes(&self, changes: Changes) -> Result<()>;
/// Get all the sessions that belong to the given sender key.
@ -435,4 +447,7 @@ pub trait CryptoStore: Debug {
/// Load a serializeable object from the store.
async fn get_value(&self, key: &str) -> Result<Option<String>>;
/// Check if a hash for an Olm message stored in the database.
async fn is_message_known(&self, message_hash: &OlmMessageHash) -> Result<bool>;
}

82
matrix_sdk_crypto/src/store/sqlite.rs
View File

@ -42,8 +42,9 @@ use crate::{
identities::{LocalTrust, OwnUserIdentity, ReadOnlyDevice, UserIdentities, UserIdentity},
olm::{
AccountPickle, IdentityKeys, InboundGroupSession, InboundGroupSessionPickle,
PickledAccount, PickledCrossSigningIdentity, PickledInboundGroupSession, PickledSession,
PicklingMode, PrivateCrossSigningIdentity, ReadOnlyAccount, Session, SessionPickle,
OlmMessageHash, PickledAccount, PickledCrossSigningIdentity, PickledInboundGroupSession,
PickledSession, PicklingMode, PrivateCrossSigningIdentity, ReadOnlyAccount, Session,
SessionPickle,
},
};
@ -491,6 +492,24 @@ impl SqliteStore {
)
.await?;
connection
.execute(
r#"
CREATE TABLE IF NOT EXISTS olm_hashes (
"id" INTEGER NOT NULL PRIMARY KEY,
"account_id" INTEGER NOT NULL,
"sender_key" TEXT NOT NULL,
"hash" TEXT NOT NULL,
FOREIGN KEY ("account_id") REFERENCES "accounts" ("id")
ON DELETE CASCADE
UNIQUE(account_id,sender_key,hash)
);
CREATE INDEX IF NOT EXISTS "olm_hashes_index" ON "olm_hashes" ("account_id");
"#,
)
.await?;
Ok(())
}
@ -1466,6 +1485,25 @@ impl SqliteStore {
Ok(())
}
async fn save_olm_hashses(
&self,
connection: &mut SqliteConnection,
hashes: &[OlmMessageHash],
) -> Result<()> {
let account_id = self.account_id().ok_or(CryptoStoreError::AccountUnset)?;
for hash in hashes {
query("REPLACE INTO olm_hashes (account_id, sender_key, hash) VALUES (?1, ?2, ?3)")
.bind(account_id)
.bind(&hash.sender_key)
.bind(&hash.hash)
.execute(&mut *connection)
.await?;
}
Ok(())
}
async fn save_user_helper(
&self,
mut connection: &mut SqliteConnection,
@ -1681,6 +1719,9 @@ impl CryptoStore for SqliteStore {
self.save_user_identities(&mut transaction, &changes.identities.changed)
.await?;
self.save_olm_hashses(&mut transaction, &changes.message_hashes)
.await?;
transaction.commit().await?;
Ok(())
@ -1796,6 +1837,22 @@ impl CryptoStore for SqliteStore {
Ok(row.map(|r| r.0))
}
async fn is_message_known(&self, message_hash: &OlmMessageHash) -> Result<bool> {
let account_id = self.account_id().ok_or(CryptoStoreError::AccountUnset)?;
let mut connection = self.connection.lock().await;
let row: Option<(String,)> = query_as(
"SELECT hash FROM olm_hashes WHERE account_id = ? and sender_key = ? and hash = ?",
)
.bind(account_id)
.bind(&message_hash.sender_key)
.bind(&message_hash.hash)
.fetch_optional(&mut *connection)
.await?;
Ok(row.is_some())
}
}
#[cfg(not(tarpaulin_include))]
@ -1817,8 +1874,8 @@ mod test {
user::test::{get_other_identity, get_own_identity},
},
olm::{
GroupSessionKey, InboundGroupSession, PrivateCrossSigningIdentity, ReadOnlyAccount,
Session,
GroupSessionKey, InboundGroupSession, OlmMessageHash, PrivateCrossSigningIdentity,
ReadOnlyAccount, Session,
},
store::{Changes, DeviceChanges, IdentityChanges},
};
@ -2371,4 +2428,21 @@ mod test {
store.remove_value(&key).await.unwrap();
assert!(store.get_value(&key).await.unwrap().is_none());
}
#[tokio::test(threaded_scheduler)]
async fn olm_hash_saving() {
let (_, store, _dir) = get_loaded_store().await;
let hash = OlmMessageHash {
sender_key: "test_sender".to_owned(),
hash: "test_hash".to_owned(),
};
let mut changes = Changes::default();
changes.message_hashes.push(hash.clone());
assert!(!store.is_message_known(&hash).await.unwrap());
store.save_changes(changes).await.unwrap();
assert!(store.is_message_known(&hash).await.unwrap());
}
}

3
matrix_sdk_crypto/src/verification/sas/sas_state.rs
View File

@ -117,9 +117,6 @@ impl Default for AcceptedProtocols {
}
}
// TODO implement expiration of the verification flow using the timeouts defined
// in the spec.
/// A type level state machine modeling the Sas flow.
///
/// This is the generic struc holding common data between the different states