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crypto: Split out the olm module into separate files.

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This commit is contained in:
Damir Jelić 2020-07-21 10:38:14 +02:00
parent 037d62b165
commit b22324b305
5 changed files with 1313 additions and 1225 deletions
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matrix_sdk_crypto/src/olm.rs
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matrix_sdk_crypto/src/olm/account.rs Normal file
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// 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 matrix_sdk_common::instant::Instant;
use std::convert::TryFrom;
use std::convert::TryInto;
use std::fmt;
use std::sync::atomic::{AtomicBool, AtomicI64, Ordering};
use std::sync::Arc;
use matrix_sdk_common::locks::Mutex;
use serde_json::{json, Value};
use std::collections::BTreeMap;
pub use olm_rs::account::IdentityKeys;
use olm_rs::account::{OlmAccount, OneTimeKeys};
use olm_rs::errors::{OlmAccountError, OlmSessionError};
use olm_rs::PicklingMode;
use crate::device::Device;
use crate::error::SessionCreationError;
pub use olm_rs::{
session::{OlmMessage, PreKeyMessage},
utility::OlmUtility,
};
use matrix_sdk_common::{
api::r0::keys::{AlgorithmAndDeviceId, DeviceKeys, KeyAlgorithm, OneTimeKey, SignedKey},
events::Algorithm,
identifiers::{DeviceId, RoomId, UserId},
};
use super::{InboundGroupSession, OutboundGroupSession, Session};
/// Account holding identity keys for which sessions can be created.
///
/// An account is the central identity for encrypted communication between two
/// devices.
#[derive(Clone)]
pub struct Account {
user_id: Arc<UserId>,
device_id: Arc<Box<DeviceId>>,
inner: Arc<Mutex<OlmAccount>>,
identity_keys: Arc<IdentityKeys>,
shared: Arc<AtomicBool>,
/// 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: Arc<AtomicI64>,
}
// #[cfg_attr(tarpaulin, skip)]
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()
}
}
impl Account {
const ALGORITHMS: &'static [&'static Algorithm] = &[
&Algorithm::OlmV1Curve25519AesSha2,
&Algorithm::MegolmV1AesSha2,
];
/// Create a fresh new account, this will generate the identity key-pair.
#[allow(clippy::ptr_arg)]
pub fn new(user_id: &UserId, device_id: &DeviceId) -> Self {
let account = OlmAccount::new();
let identity_keys = account.parsed_identity_keys();
Account {
user_id: Arc::new(user_id.to_owned()),
device_id: Arc::new(device_id.into()),
inner: Arc::new(Mutex::new(account)),
identity_keys: Arc::new(identity_keys),
shared: Arc::new(AtomicBool::new(false)),
uploaded_signed_key_count: Arc::new(AtomicI64::new(0)),
}
}
/// Get the public parts of the identity keys for the account.
pub fn identity_keys(&self) -> &IdentityKeys {
&self.identity_keys
}
/// Update the uploaded key count.
///
/// # Arguments
///
/// * `new_count` - The new count that was reported by the server.
pub(crate) fn update_uploaded_key_count(&self, new_count: u64) {
let key_count = i64::try_from(new_count).unwrap_or(i64::MAX);
self.uploaded_signed_key_count
.store(key_count, Ordering::Relaxed);
}
/// Get the currently known uploaded key count.
pub fn uploaded_key_count(&self) -> i64 {
self.uploaded_signed_key_count.load(Ordering::Relaxed)
}
/// Has the account been shared with the server.
pub fn shared(&self) -> bool {
self.shared.load(Ordering::Relaxed)
}
/// Mark the account as shared.
///
/// Messages shouldn't be encrypted with the session before it has been
/// shared.
pub(crate) fn mark_as_shared(&self) {
self.shared.store(true, Ordering::Relaxed);
}
/// Get the one-time keys of the account.
///
/// This can be empty, keys need to be generated first.
pub(crate) async fn one_time_keys(&self) -> OneTimeKeys {
self.inner.lock().await.parsed_one_time_keys()
}
/// Generate count number of one-time keys.
pub(crate) async fn generate_one_time_keys_helper(&self, count: usize) {
self.inner.lock().await.generate_one_time_keys(count);
}
/// Get the maximum number of one-time keys the account can hold.
pub(crate) async fn max_one_time_keys(&self) -> usize {
self.inner.lock().await.max_number_of_one_time_keys()
}
/// Get a tuple of device and one-time keys that need to be uploaded.
///
/// Returns an empty error if no keys need to be uploaded.
pub(crate) async fn generate_one_time_keys(&self) -> Result<u64, ()> {
let count = self.uploaded_key_count() as u64;
let max_keys = self.max_one_time_keys().await;
let max_on_server = (max_keys as u64) / 2;
if count >= (max_on_server) {
return Err(());
}
let key_count = (max_on_server) - count;
let key_count: usize = key_count.try_into().unwrap_or(max_keys);
self.generate_one_time_keys_helper(key_count).await;
Ok(key_count as u64)
}
/// Should account or one-time keys be uploaded to the server.
pub(crate) async fn should_upload_keys(&self) -> bool {
if !self.shared() {
return true;
}
let count = self.uploaded_key_count() as u64;
// If we have a known key count, check that we have more than
// max_one_time_Keys() / 2, otherwise tell the client to upload more.
let max_keys = self.max_one_time_keys().await as u64;
// If there are more keys already uploaded than max_key / 2
// bail out returning false, this also avoids overflow.
if count > (max_keys / 2) {
return false;
}
let key_count = (max_keys / 2) - count;
key_count > 0
}
/// Get a tuple of device and one-time keys that need to be uploaded.
///
/// Returns an empty error if no keys need to be uploaded.
pub(crate) async fn keys_for_upload(
&self,
) -> Result<
(
Option<DeviceKeys>,
Option<BTreeMap<AlgorithmAndDeviceId, OneTimeKey>>,
),
(),
> {
if !self.should_upload_keys().await {
return Err(());
}
let device_keys = if !self.shared() {
Some(self.device_keys().await)
} else {
None
};
let one_time_keys = self.signed_one_time_keys().await.ok();
Ok((device_keys, one_time_keys))
}
/// Mark the current set of one-time keys as being published.
pub(crate) async fn mark_keys_as_published(&self) {
self.inner.lock().await.mark_keys_as_published();
}
/// Sign the given string using the accounts signing key.
///
/// Returns the signature as a base64 encoded string.
pub async fn sign(&self, string: &str) -> String {
self.inner.lock().await.sign(string)
}
/// Store the account as a base64 encoded string.
///
/// # Arguments
///
/// * `pickle_mode` - The mode that was used to pickle the account, either an
/// unencrypted mode or an encrypted using passphrase.
pub async fn pickle(&self, pickle_mode: PicklingMode) -> String {
self.inner.lock().await.pickle(pickle_mode)
}
/// Restore an account from a previously pickled string.
///
/// # Arguments
///
/// * `pickle` - The pickled string of the account.
///
/// * `pickle_mode` - The mode that was used to pickle the account, either an
/// unencrypted mode or an encrypted using passphrase.
///
/// * `shared` - Boolean determining if the account was uploaded to the
/// server.
#[allow(clippy::ptr_arg)]
pub fn from_pickle(
pickle: String,
pickle_mode: PicklingMode,
shared: bool,
uploaded_signed_key_count: i64,
user_id: &UserId,
device_id: &DeviceId,
) -> Result<Self, OlmAccountError> {
let account = OlmAccount::unpickle(pickle, pickle_mode)?;
let identity_keys = account.parsed_identity_keys();
Ok(Account {
user_id: Arc::new(user_id.to_owned()),
device_id: Arc::new(device_id.into()),
inner: Arc::new(Mutex::new(account)),
identity_keys: Arc::new(identity_keys),
shared: Arc::new(AtomicBool::from(shared)),
uploaded_signed_key_count: Arc::new(AtomicI64::new(uploaded_signed_key_count)),
})
}
/// Sign the device keys of the account and return them so they can be
/// uploaded.
pub(crate) async fn device_keys(&self) -> DeviceKeys {
let identity_keys = self.identity_keys();
let mut keys = BTreeMap::new();
keys.insert(
AlgorithmAndDeviceId(KeyAlgorithm::Curve25519, (*self.device_id).clone()),
identity_keys.curve25519().to_owned(),
);
keys.insert(
AlgorithmAndDeviceId(KeyAlgorithm::Ed25519, (*self.device_id).clone()),
identity_keys.ed25519().to_owned(),
);
let device_keys = json!({
"user_id": (*self.user_id).clone(),
"device_id": (*self.device_id).clone(),
"algorithms": Account::ALGORITHMS,
"keys": keys,
});
let mut signatures = BTreeMap::new();
let mut signature = BTreeMap::new();
signature.insert(
AlgorithmAndDeviceId(KeyAlgorithm::Ed25519, (*self.device_id).clone()),
self.sign_json(&device_keys).await,
);
signatures.insert((*self.user_id).clone(), signature);
DeviceKeys {
user_id: (*self.user_id).clone(),
device_id: (*self.device_id).clone(),
algorithms: vec![
Algorithm::OlmV1Curve25519AesSha2,
Algorithm::MegolmV1AesSha2,
],
keys,
signatures,
unsigned: None,
}
}
/// 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.
///
/// # Panic
///
/// Panics if the json value can't be serialized.
pub async fn sign_json(&self, json: &Value) -> String {
let canonical_json = cjson::to_string(json)
.unwrap_or_else(|_| panic!(format!("Can't serialize {} to canonical JSON", json)));
self.sign(&canonical_json).await
}
/// Generate, sign and prepare one-time keys to be uploaded.
///
/// If no one-time keys need to be uploaded returns an empty error.
pub(crate) async fn signed_one_time_keys(
&self,
) -> Result<BTreeMap<AlgorithmAndDeviceId, OneTimeKey>, ()> {
let _ = self.generate_one_time_keys().await?;
let one_time_keys = self.one_time_keys().await;
let mut one_time_key_map = BTreeMap::new();
for (key_id, key) in one_time_keys.curve25519().iter() {
let key_json = json!({
"key": key,
});
let signature = self.sign_json(&key_json).await;
let mut signature_map = BTreeMap::new();
signature_map.insert(
AlgorithmAndDeviceId(KeyAlgorithm::Ed25519, (*self.device_id).clone()),
signature,
);
let mut signatures = BTreeMap::new();
signatures.insert((*self.user_id).clone(), signature_map);
let signed_key = SignedKey {
key: key.to_owned(),
signatures,
};
one_time_key_map.insert(
AlgorithmAndDeviceId(KeyAlgorithm::SignedCurve25519, key_id.as_str().into()),
OneTimeKey::SignedKey(signed_key),
);
}
Ok(one_time_key_map)
}
/// 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
/// * `their_identity_key` - The other account's identity/curve25519 key.
///
/// * `their_one_time_key` - A signed one-time key that the other account
/// created and shared with us.
pub(crate) async fn create_outbound_session_helper(
&self,
their_identity_key: &str,
their_one_time_key: &SignedKey,
) -> Result<Session, OlmSessionError> {
let session = self
.inner
.lock()
.await
.create_outbound_session(their_identity_key, &their_one_time_key.key)?;
let now = Instant::now();
let session_id = session.session_id();
Ok(Session {
inner: Arc::new(Mutex::new(session)),
session_id: Arc::new(session_id),
sender_key: Arc::new(their_identity_key.to_owned()),
creation_time: Arc::new(now),
last_use_time: Arc::new(now),
})
}
/// 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.
pub(crate) async fn create_outbound_session(
&self,
device: Device,
key_map: &BTreeMap<AlgorithmAndDeviceId, OneTimeKey>,
) -> Result<Session, SessionCreationError> {
let one_time_key = key_map.values().next().ok_or_else(|| {
SessionCreationError::OneTimeKeyMissing(
device.user_id().to_owned(),
device.device_id().into(),
)
})?;
let one_time_key = match one_time_key {
OneTimeKey::SignedKey(k) => k,
OneTimeKey::Key(_) => {
return Err(SessionCreationError::OneTimeKeyNotSigned(
device.user_id().to_owned(),
device.device_id().into(),
));
}
};
device.verify_one_time_key(&one_time_key).map_err(|e| {
SessionCreationError::InvalidSignature(
device.user_id().to_owned(),
device.device_id().into(),
e,
)
})?;
let curve_key = device.get_key(KeyAlgorithm::Curve25519).ok_or_else(|| {
SessionCreationError::DeviceMissingCurveKey(
device.user_id().to_owned(),
device.device_id().into(),
)
})?;
self.create_outbound_session_helper(curve_key, &one_time_key)
.await
.map_err(|e| {
SessionCreationError::OlmError(
device.user_id().to_owned(),
device.device_id().into(),
e,
)
})
}
/// 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 identitiy/curve25519 key.
///
/// * `message` - A pre-key Olm message that was sent to us by the other
/// account.
pub(crate) async fn create_inbound_session(
&self,
their_identity_key: &str,
message: PreKeyMessage,
) -> Result<Session, OlmSessionError> {
let session = self
.inner
.lock()
.await
.create_inbound_session_from(their_identity_key, message)?;
self.inner
.lock()
.await
.remove_one_time_keys(&session)
.expect(
"Session was successfully created but the account doesn't hold a matching one-time key",
);
let now = Instant::now();
let session_id = session.session_id();
Ok(Session {
inner: Arc::new(Mutex::new(session)),
session_id: Arc::new(session_id),
sender_key: Arc::new(their_identity_key.to_owned()),
creation_time: Arc::new(now),
last_use_time: Arc::new(now),
})
}
/// 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.
pub(crate) async fn create_group_session_pair(
&self,
room_id: &RoomId,
) -> (OutboundGroupSession, InboundGroupSession) {
let outbound =
OutboundGroupSession::new(self.device_id.clone(), self.identity_keys.clone(), room_id);
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,
)
.expect("Can't create inbound group session from a newly created outbound group session");
(outbound, inbound)
}
}
impl PartialEq for Account {
fn eq(&self, other: &Self) -> bool {
self.identity_keys() == other.identity_keys() && self.shared() == other.shared()
}
}

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// 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 matrix_sdk_common::instant::Instant;
use std::convert::TryInto;
use std::fmt;
use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
use std::sync::Arc;
use matrix_sdk_common::locks::Mutex;
use serde::Serialize;
use serde_json::{json, Value};
use zeroize::Zeroize;
pub use olm_rs::account::IdentityKeys;
use olm_rs::errors::OlmGroupSessionError;
use olm_rs::inbound_group_session::OlmInboundGroupSession;
use olm_rs::outbound_group_session::OlmOutboundGroupSession;
use olm_rs::PicklingMode;
use crate::error::{EventError, MegolmResult};
pub use olm_rs::{
session::{OlmMessage, PreKeyMessage},
utility::OlmUtility,
};
use matrix_sdk_common::{
events::{
room::{
encrypted::{EncryptedEventContent, MegolmV1AesSha2Content},
message::MessageEventContent,
},
AnySyncRoomEvent, EventJson, EventType, SyncMessageEvent,
},
identifiers::{DeviceId, RoomId},
};
/// The private session key of a group session.
/// Can be used to create a new inbound group session.
#[derive(Clone, Debug, Serialize, Zeroize)]
#[zeroize(drop)]
pub struct GroupSessionKey(pub String);
/// Inbound group session.
///
/// Inbound group sessions are used to exchange room messages between a group of
/// participants. Inbound group sessions are used to decrypt the room messages.
#[derive(Clone)]
pub struct InboundGroupSession {
inner: Arc<Mutex<OlmInboundGroupSession>>,
session_id: Arc<String>,
pub(crate) sender_key: Arc<String>,
pub(crate) signing_key: Arc<String>,
pub(crate) room_id: Arc<RoomId>,
forwarding_chains: Arc<Mutex<Option<Vec<String>>>>,
}
impl InboundGroupSession {
/// Create a new inbound group session for the given room.
///
/// These sessions are used to decrypt room messages.
///
/// # Arguments
///
/// * `sender_key` - The public curve25519 key of the account that
/// sent us the session
///
/// * `signing_key` - The public ed25519 key of the account that
/// sent us the session.
///
/// * `room_id` - The id of the room that the session is used in.
///
/// * `session_key` - The private session key that is used to decrypt
/// messages.
pub fn new(
sender_key: &str,
signing_key: &str,
room_id: &RoomId,
session_key: GroupSessionKey,
) -> Result<Self, OlmGroupSessionError> {
let session = OlmInboundGroupSession::new(&session_key.0)?;
let session_id = session.session_id();
Ok(InboundGroupSession {
inner: Arc::new(Mutex::new(session)),
session_id: Arc::new(session_id),
sender_key: Arc::new(sender_key.to_owned()),
signing_key: Arc::new(signing_key.to_owned()),
room_id: Arc::new(room_id.clone()),
forwarding_chains: Arc::new(Mutex::new(None)),
})
}
/// Store the group session as a base64 encoded string.
///
/// # Arguments
///
/// * `pickle_mode` - The mode that was used to pickle the group session,
/// either an unencrypted mode or an encrypted using passphrase.
pub async fn pickle(&self, pickle_mode: PicklingMode) -> String {
self.inner.lock().await.pickle(pickle_mode)
}
/// Restore a Session from a previously pickled string.
///
/// Returns the restored group session or a `OlmGroupSessionError` if there
/// was an error.
///
/// # Arguments
///
/// * `pickle` - The pickled string of the group session session.
///
/// * `pickle_mode` - The mode that was used to pickle the session, either
/// an unencrypted mode or an encrypted using passphrase.
///
/// * `sender_key` - The public curve25519 key of the account that
/// sent us the session
///
/// * `signing_key` - The public ed25519 key of the account that
/// sent us the session.
///
/// * `room_id` - The id of the room that the session is used in.
pub fn from_pickle(
pickle: String,
pickle_mode: PicklingMode,
sender_key: String,
signing_key: String,
room_id: RoomId,
) -> Result<Self, OlmGroupSessionError> {
let session = OlmInboundGroupSession::unpickle(pickle, pickle_mode)?;
let session_id = session.session_id();
Ok(InboundGroupSession {
inner: Arc::new(Mutex::new(session)),
session_id: Arc::new(session_id),
sender_key: Arc::new(sender_key),
signing_key: Arc::new(signing_key),
room_id: Arc::new(room_id),
forwarding_chains: Arc::new(Mutex::new(None)),
})
}
/// Returns the unique identifier for this session.
pub fn session_id(&self) -> &str {
&self.session_id
}
/// Get the first message index we know how to decrypt.
pub async fn first_known_index(&self) -> u32 {
self.inner.lock().await.first_known_index()
}
/// Decrypt the given ciphertext.
///
/// Returns the decrypted plaintext or an `OlmGroupSessionError` if
/// decryption failed.
///
/// # Arguments
///
/// * `message` - The message that should be decrypted.
pub async fn decrypt_helper(
&self,
message: String,
) -> Result<(String, u32), OlmGroupSessionError> {
self.inner.lock().await.decrypt(message)
}
/// Decrypt an event from a room timeline.
///
/// # Arguments
///
/// * `event` - The event that should be decrypted.
pub async fn decrypt(
&self,
event: &SyncMessageEvent<EncryptedEventContent>,
) -> MegolmResult<(EventJson<AnySyncRoomEvent>, u32)> {
let content = match &event.content {
EncryptedEventContent::MegolmV1AesSha2(c) => c,
_ => return Err(EventError::UnsupportedAlgorithm.into()),
};
let (plaintext, message_index) = self.decrypt_helper(content.ciphertext.clone()).await?;
let mut decrypted_value = serde_json::from_str::<Value>(&plaintext)?;
let decrypted_object = decrypted_value
.as_object_mut()
.ok_or(EventError::NotAnObject)?;
// TODO better number conversion here.
let server_ts = event
.origin_server_ts
.duration_since(std::time::SystemTime::UNIX_EPOCH)
.unwrap_or_default()
.as_millis();
let server_ts: i64 = server_ts.try_into().unwrap_or_default();
decrypted_object.insert("sender".to_owned(), event.sender.to_string().into());
decrypted_object.insert("event_id".to_owned(), event.event_id.to_string().into());
decrypted_object.insert("origin_server_ts".to_owned(), server_ts.into());
decrypted_object.insert(
"unsigned".to_owned(),
serde_json::to_value(&event.unsigned).unwrap_or_default(),
);
Ok((
serde_json::from_value::<EventJson<AnySyncRoomEvent>>(decrypted_value)?,
message_index,
))
}
}
// #[cfg_attr(tarpaulin, skip)]
impl fmt::Debug for InboundGroupSession {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("InboundGroupSession")
.field("session_id", &self.session_id())
.finish()
}
}
impl PartialEq for InboundGroupSession {
fn eq(&self, other: &Self) -> bool {
self.session_id() == other.session_id()
}
}
/// Outbound group session.
///
/// Outbound group sessions are used to exchange room messages between a group
/// of participants. Outbound group sessions are used to encrypt the room
/// messages.
#[derive(Clone)]
pub struct OutboundGroupSession {
inner: Arc<Mutex<OlmOutboundGroupSession>>,
device_id: Arc<Box<DeviceId>>,
account_identity_keys: Arc<IdentityKeys>,
session_id: Arc<String>,
room_id: Arc<RoomId>,
creation_time: Arc<Instant>,
message_count: Arc<AtomicUsize>,
shared: Arc<AtomicBool>,
}
impl OutboundGroupSession {
/// Create a new outbound group session for the given room.
///
/// Outbound group sessions are used to encrypt room messages.
///
/// # Arguments
///
/// * `device_id` - The id of the device that created this session.
///
/// * `identity_keys` - The identity keys of the account that created this
/// session.
///
/// * `room_id` - The id of the room that the session is used in.
pub fn new(
device_id: Arc<Box<DeviceId>>,
identity_keys: Arc<IdentityKeys>,
room_id: &RoomId,
) -> Self {
let session = OlmOutboundGroupSession::new();
let session_id = session.session_id();
OutboundGroupSession {
inner: Arc::new(Mutex::new(session)),
room_id: Arc::new(room_id.to_owned()),
device_id,
account_identity_keys: identity_keys,
session_id: Arc::new(session_id),
creation_time: Arc::new(Instant::now()),
message_count: Arc::new(AtomicUsize::new(0)),
shared: Arc::new(AtomicBool::new(false)),
}
}
/// Encrypt the given plaintext using this session.
///
/// Returns the encrypted ciphertext.
///
/// # Arguments
///
/// * `plaintext` - The plaintext that should be encrypted.
pub(crate) async fn encrypt_helper(&self, plaintext: String) -> String {
let session = self.inner.lock().await;
session.encrypt(plaintext)
}
/// Encrypt a room message for the given room.
///
/// Beware that a group session needs to be shared before this method can be
/// called using the `share_group_session()` method.
///
/// Since group sessions can expire or become invalid if the room membership
/// changes client authors should check with the
/// `should_share_group_session()` method if a new group session needs to
/// be shared.
///
/// # Arguments
///
/// * `content` - The plaintext content of the message that should be
/// encrypted.
///
/// # Panics
///
/// Panics if the content can't be serialized.
pub async fn encrypt(&self, content: MessageEventContent) -> EncryptedEventContent {
let json_content = json!({
"content": content,
"room_id": &*self.room_id,
"type": EventType::RoomMessage,
});
let plaintext = cjson::to_string(&json_content).unwrap_or_else(|_| {
panic!(format!(
"Can't serialize {} to canonical JSON",
json_content
))
});
let ciphertext = self.encrypt_helper(plaintext).await;
EncryptedEventContent::MegolmV1AesSha2(MegolmV1AesSha2Content::new(
matrix_sdk_common::events::room::encrypted::MegolmV1AesSha2ContentInit {
ciphertext,
sender_key: self.account_identity_keys.curve25519().to_owned(),
session_id: self.session_id().to_owned(),
device_id: (&*self.device_id).to_owned(),
},
))
}
/// Check if the session has expired and if it should be rotated.
///
/// A session will expire after some time or if enough messages have been
/// encrypted using it.
pub fn expired(&self) -> bool {
// TODO implement this.
false
}
/// Mark the session as shared.
///
/// Messages shouldn't be encrypted with the session before it has been
/// shared.
pub fn mark_as_shared(&self) {
self.shared.store(true, Ordering::Relaxed);
}
/// Check if the session has been marked as shared.
pub fn shared(&self) -> bool {
self.shared.load(Ordering::Relaxed)
}
/// Get the session key of this session.
///
/// A session key can be used to to create an `InboundGroupSession`.
pub async fn session_key(&self) -> GroupSessionKey {
let session = self.inner.lock().await;
GroupSessionKey(session.session_key())
}
/// Returns the unique identifier for this session.
pub fn session_id(&self) -> &str {
&self.session_id
}
/// Get the current message index for this session.
///
/// Each message is sent with an increasing index. This returns the
/// message index that will be used for the next encrypted message.
pub async fn message_index(&self) -> u32 {
let session = self.inner.lock().await;
session.session_message_index()
}
}
// #[cfg_attr(tarpaulin, skip)]
impl std::fmt::Debug for OutboundGroupSession {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("OutboundGroupSession")
.field("session_id", &self.session_id)
.field("room_id", &self.room_id)
.field("creation_time", &self.creation_time)
.field("message_count", &self.message_count)
.finish()
}
}

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// 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.
mod account;
mod group_sessions;
mod session;
pub use account::{Account, IdentityKeys};
pub use group_sessions::{GroupSessionKey, InboundGroupSession, OutboundGroupSession};
pub use session::{OlmMessage, Session};
#[cfg(test)]
pub(crate) mod test {
use crate::olm::{Account, InboundGroupSession, Session};
use matrix_sdk_common::api::r0::keys::SignedKey;
use matrix_sdk_common::identifiers::{DeviceId, RoomId, UserId};
use olm_rs::session::OlmMessage;
use std::collections::BTreeMap;
use std::convert::TryFrom;
fn alice_id() -> UserId {
UserId::try_from("@alice:example.org").unwrap()
}
fn alice_device_id() -> Box<DeviceId> {
"ALICEDEVICE".into()
}
fn bob_id() -> UserId {
UserId::try_from("@bob:example.org").unwrap()
}
fn bob_device_id() -> Box<DeviceId> {
"BOBDEVICE".into()
}
pub(crate) async fn get_account_and_session() -> (Account, Session) {
let alice = Account::new(&alice_id(), &alice_device_id());
let bob = Account::new(&bob_id(), &bob_device_id());
bob.generate_one_time_keys_helper(1).await;
let one_time_key = bob
.one_time_keys()
.await
.curve25519()
.iter()
.next()
.unwrap()
.1
.to_owned();
let one_time_key = SignedKey {
key: one_time_key,
signatures: BTreeMap::new(),
};
let sender_key = bob.identity_keys().curve25519().to_owned();
let session = alice
.create_outbound_session_helper(&sender_key, &one_time_key)
.await
.unwrap();
(alice, session)
}
#[test]
fn account_creation() {
let account = Account::new(&alice_id(), &alice_device_id());
let identyty_keys = account.identity_keys();
assert!(!account.shared());
assert!(!identyty_keys.ed25519().is_empty());
assert_ne!(identyty_keys.values().len(), 0);
assert_ne!(identyty_keys.keys().len(), 0);
assert_ne!(identyty_keys.iter().len(), 0);
assert!(identyty_keys.contains_key("ed25519"));
assert_eq!(
identyty_keys.ed25519(),
identyty_keys.get("ed25519").unwrap()
);
assert!(!identyty_keys.curve25519().is_empty());
account.mark_as_shared();
assert!(account.shared());
}
#[tokio::test]
async fn one_time_keys_creation() {
let account = Account::new(&alice_id(), &alice_device_id());
let one_time_keys = account.one_time_keys().await;
assert!(one_time_keys.curve25519().is_empty());
assert_ne!(account.max_one_time_keys().await, 0);
account.generate_one_time_keys_helper(10).await;
let one_time_keys = account.one_time_keys().await;
assert!(!one_time_keys.curve25519().is_empty());
assert_ne!(one_time_keys.values().len(), 0);
assert_ne!(one_time_keys.keys().len(), 0);
assert_ne!(one_time_keys.iter().len(), 0);
assert!(one_time_keys.contains_key("curve25519"));
assert_eq!(one_time_keys.curve25519().keys().len(), 10);
assert_eq!(
one_time_keys.curve25519(),
one_time_keys.get("curve25519").unwrap()
);
account.mark_keys_as_published().await;
let one_time_keys = account.one_time_keys().await;
assert!(one_time_keys.curve25519().is_empty());
}
#[tokio::test]
async fn session_creation() {
let alice = Account::new(&alice_id(), &alice_device_id());
let bob = Account::new(&bob_id(), &bob_device_id());
let alice_keys = alice.identity_keys();
alice.generate_one_time_keys_helper(1).await;
let one_time_keys = alice.one_time_keys().await;
alice.mark_keys_as_published().await;
let one_time_key = one_time_keys
.curve25519()
.iter()
.next()
.unwrap()
.1
.to_owned();
let one_time_key = SignedKey {
key: one_time_key,
signatures: BTreeMap::new(),
};
let mut bob_session = bob
.create_outbound_session_helper(alice_keys.curve25519(), &one_time_key)
.await
.unwrap();
let plaintext = "Hello world";
let message = bob_session.encrypt(plaintext).await;
let prekey_message = match message.clone() {
OlmMessage::PreKey(m) => m,
OlmMessage::Message(_) => panic!("Incorrect message type"),
};
let bob_keys = bob.identity_keys();
let mut alice_session = alice
.create_inbound_session(bob_keys.curve25519(), prekey_message.clone())
.await
.unwrap();
assert!(alice_session
.matches(bob_keys.curve25519(), prekey_message)
.await
.unwrap());
assert_eq!(bob_session.session_id(), alice_session.session_id());
let decyrpted = alice_session.decrypt(message).await.unwrap();
assert_eq!(plaintext, decyrpted);
}
#[tokio::test]
async fn group_session_creation() {
let alice = Account::new(&alice_id(), &alice_device_id());
let room_id = RoomId::try_from("!test:localhost").unwrap();
let (outbound, _) = alice.create_group_session_pair(&room_id).await;
assert_eq!(0, outbound.message_index().await);
assert!(!outbound.shared());
outbound.mark_as_shared();
assert!(outbound.shared());
let inbound = InboundGroupSession::new(
"test_key",
"test_key",
&room_id,
outbound.session_key().await,
)
.unwrap();
assert_eq!(0, inbound.first_known_index().await);
assert_eq!(outbound.session_id(), inbound.session_id());
let plaintext = "This is a secret to everybody".to_owned();
let ciphertext = outbound.encrypt_helper(plaintext.clone()).await;
assert_eq!(
plaintext,
inbound.decrypt_helper(ciphertext).await.unwrap().0
);
}
}

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// 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 matrix_sdk_common::instant::Instant;
use std::fmt;
use std::sync::Arc;
use matrix_sdk_common::locks::Mutex;
pub use olm_rs::account::IdentityKeys;
use olm_rs::errors::OlmSessionError;
use olm_rs::session::OlmSession;
use olm_rs::PicklingMode;
pub use olm_rs::{
session::{OlmMessage, PreKeyMessage},
utility::OlmUtility,
};
/// Cryptographic session that enables secure communication between two
/// `Account`s
#[derive(Clone)]
pub struct Session {
pub(crate) inner: Arc<Mutex<OlmSession>>,
pub(crate) session_id: Arc<String>,
pub(crate) sender_key: Arc<String>,
pub(crate) creation_time: Arc<Instant>,
pub(crate) last_use_time: Arc<Instant>,
}
// #[cfg_attr(tarpaulin, skip)]
impl fmt::Debug for Session {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("Session")
.field("session_id", &self.session_id())
.field("sender_key", &self.sender_key)
.finish()
}
}
impl Session {
/// Decrypt the given Olm message.
///
/// Returns the decrypted plaintext or an `OlmSessionError` if decryption
/// failed.
///
/// # Arguments
///
/// * `message` - The Olm message that should be decrypted.
pub async fn decrypt(&mut self, message: OlmMessage) -> Result<String, OlmSessionError> {
let plaintext = self.inner.lock().await.decrypt(message)?;
self.last_use_time = Arc::new(Instant::now());
Ok(plaintext)
}
/// Encrypt the given plaintext as a OlmMessage.
///
/// Returns the encrypted Olm message.
///
/// # Arguments
///
/// * `plaintext` - The plaintext that should be encrypted.
pub async fn encrypt(&mut self, plaintext: &str) -> OlmMessage {
let message = self.inner.lock().await.encrypt(plaintext);
self.last_use_time = Arc::new(Instant::now());
message
}
/// Check if a pre-key Olm message was encrypted for this session.
///
/// Returns true if it matches, false if not and a OlmSessionError if there
/// was an error checking if it matches.
///
/// # Arguments
///
/// * `their_identity_key` - The identity/curve25519 key of the account
/// that encrypted this Olm message.
///
/// * `message` - The pre-key Olm message that should be checked.
pub async fn matches(
&self,
their_identity_key: &str,
message: PreKeyMessage,
) -> Result<bool, OlmSessionError> {
self.inner
.lock()
.await
.matches_inbound_session_from(their_identity_key, message)
}
/// Returns the unique identifier for this session.
pub fn session_id(&self) -> &str {
&self.session_id
}
/// Store the session as a base64 encoded string.
///
/// # Arguments
///
/// * `pickle_mode` - The mode that was used to pickle the session, either
/// an unencrypted mode or an encrypted using passphrase.
pub async fn pickle(&self, pickle_mode: PicklingMode) -> String {
self.inner.lock().await.pickle(pickle_mode)
}
/// Restore a Session from a previously pickled string.
///
/// Returns the restored Olm Session or a `OlmSessionError` if there was an
/// error.
///
/// # Arguments
///
/// * `pickle` - The pickled string of the session.
///
/// * `pickle_mode` - The mode that was used to pickle the session, either
/// an unencrypted mode or an encrypted using passphrase.
///
/// * `sender_key` - The public curve25519 key of the account that
/// established the session with us.
///
/// * `creation_time` - The timestamp that marks when the session was
/// created.
///
/// * `last_use_time` - The timestamp that marks when the session was
/// last used to encrypt or decrypt an Olm message.
pub fn from_pickle(
pickle: String,
pickle_mode: PicklingMode,
sender_key: String,
creation_time: Instant,
last_use_time: Instant,
) -> Result<Self, OlmSessionError> {
let session = OlmSession::unpickle(pickle, pickle_mode)?;
let session_id = session.session_id();
Ok(Session {
inner: Arc::new(Mutex::new(session)),
session_id: Arc::new(session_id),
sender_key: Arc::new(sender_key),
creation_time: Arc::new(creation_time),
last_use_time: Arc::new(last_use_time),
})
}
}
impl PartialEq for Session {
fn eq(&self, other: &Self) -> bool {
self.session_id() == other.session_id()
}
}