matrix-rust-sdk/matrix_sdk_crypto/src/machine.rs
2020-08-02 07:46:02 -04:00

1730 lines
58 KiB
Rust

// 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.
#[cfg(feature = "sqlite-cryptostore")]
use std::path::Path;
use std::{
collections::{BTreeMap, HashMap, HashSet},
convert::{TryFrom, TryInto},
mem,
result::Result as StdResult,
};
#[cfg(feature = "sqlite-cryptostore")]
use super::store::sqlite::SqliteStore;
use super::{
device::Device,
error::{EventError, MegolmError, MegolmResult, OlmError, OlmResult},
olm::{
Account, GroupSessionKey, IdentityKeys, InboundGroupSession, OlmMessage,
OutboundGroupSession,
},
store::{memorystore::MemoryStore, Result as StoreResult},
CryptoStore,
};
use matrix_sdk_common::{
api,
events::{
forwarded_room_key::ForwardedRoomKeyEventContent,
room::{encrypted::EncryptedEventContent, message::MessageEventContent},
room_key::RoomKeyEventContent,
room_key_request::RoomKeyRequestEventContent,
Algorithm, AnySyncRoomEvent, AnyToDeviceEvent, EventType, SyncMessageEvent, ToDeviceEvent,
},
identifiers::{DeviceId, RoomId, UserId},
uuid::Uuid,
Raw,
};
use api::r0::{
keys,
keys::{AlgorithmAndDeviceId, DeviceKeys, KeyAlgorithm, OneTimeKey},
sync::sync_events::Response as SyncResponse,
to_device::{send_event_to_device::Request as ToDeviceRequest, DeviceIdOrAllDevices},
};
use serde_json::Value;
use tracing::{debug, error, info, instrument, trace, warn};
/// A map from the algorithm and device id to a one-time key.
///
/// These keys need to be periodically uploaded to the server.
pub type OneTimeKeys = BTreeMap<AlgorithmAndDeviceId, OneTimeKey>;
/// State machine implementation of the Olm/Megolm encryption protocol used for
/// Matrix end to end encryption.
pub struct OlmMachine {
/// The unique user id that owns this account.
user_id: UserId,
/// The unique device id of the device that holds this account.
device_id: Box<DeviceId>,
/// Our underlying Olm Account holding our identity keys.
pub(crate) account: Account,
/// Store for the encryption keys.
/// Persists all the encryption keys so a client can resume the session
/// without the need to create new keys.
store: Box<dyn CryptoStore>,
/// The currently active outbound group sessions.
outbound_group_sessions: HashMap<RoomId, OutboundGroupSession>,
}
// #[cfg_attr(tarpaulin, skip)]
impl std::fmt::Debug for OlmMachine {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("OlmMachine")
.field("user_id", &self.user_id)
.field("device_id", &self.device_id)
.finish()
}
}
impl OlmMachine {
const MAX_TO_DEVICE_MESSAGES: usize = 20;
/// Create a new memory based OlmMachine.
///
/// The created machine will keep the encryption keys only in memory and
/// once the object is dropped the keys will be lost.
///
/// # Arguments
///
/// * `user_id` - The unique id of the user that owns this machine.
///
/// * `device_id` - The unique id of the device that owns this machine.
#[allow(clippy::ptr_arg)]
pub fn new(user_id: &UserId, device_id: &DeviceId) -> Self {
OlmMachine {
user_id: user_id.clone(),
device_id: device_id.into(),
account: Account::new(user_id, &device_id),
store: Box::new(MemoryStore::new()),
outbound_group_sessions: HashMap::new(),
}
}
/// Create a new OlmMachine with the given `CryptoStore`.
///
/// The created machine will keep the encryption keys only in memory and
/// once the object is dropped the keys will be lost.
///
/// If the store already contains encryption keys for the given user/device
/// pair those will be re-used. Otherwise new ones will be created and
/// stored.
///
/// # Arguments
///
/// * `user_id` - The unique id of the user that owns this machine.
///
/// * `device_id` - The unique id of the device that owns this machine.
///
/// * `store` - A `Cryptostore` implementation that will be used to store
/// the encryption keys.
pub async fn new_with_store(
user_id: UserId,
device_id: Box<DeviceId>,
mut store: Box<dyn CryptoStore>,
) -> StoreResult<Self> {
let account = match store.load_account().await? {
Some(a) => {
debug!("Restored account");
a
}
None => {
debug!("Creating a new account");
Account::new(&user_id, &device_id)
}
};
Ok(OlmMachine {
user_id,
device_id,
account,
store,
outbound_group_sessions: HashMap::new(),
})
}
#[cfg(feature = "sqlite-cryptostore")]
#[instrument(skip(path, passphrase))]
/// Create a new machine with the default crypto store.
///
/// The default store uses a SQLite database to store the encryption keys.
///
/// # Arguments
///
/// * `user_id` - The unique id of the user that owns this machine.
///
/// * `device_id` - The unique id of the device that owns this machine.
pub async fn new_with_default_store<P: AsRef<Path>>(
user_id: &UserId,
device_id: &DeviceId,
path: P,
passphrase: &str,
) -> StoreResult<Self> {
let store =
SqliteStore::open_with_passphrase(&user_id, device_id, path, passphrase).await?;
OlmMachine::new_with_store(user_id.to_owned(), device_id.into(), Box::new(store)).await
}
/// The unique user id that owns this identity.
pub fn user_id(&self) -> &UserId {
&self.user_id
}
/// The unique device id of the device that holds this identity.
pub fn device_id(&self) -> &DeviceId {
&self.device_id
}
/// Get the public parts of the identity keys.
pub fn identity_keys(&self) -> &IdentityKeys {
self.account.identity_keys()
}
/// Should account or one-time keys be uploaded to the server.
pub async fn should_upload_keys(&self) -> bool {
self.account.should_upload_keys().await
}
/// Update the count of one-time keys that are currently on the server.
fn update_key_count(&mut self, count: u64) {
self.account.update_uploaded_key_count(count);
}
/// Receive a successful keys upload response.
///
/// # Arguments
///
/// * `response` - The keys upload response of the request that the client
/// performed.
#[instrument]
pub async fn receive_keys_upload_response(
&mut self,
response: &keys::upload_keys::Response,
) -> OlmResult<()> {
if !self.account.shared() {
debug!("Marking account as shared");
}
self.account.mark_as_shared();
let one_time_key_count = response
.one_time_key_counts
.get(&keys::KeyAlgorithm::SignedCurve25519);
let count: u64 = one_time_key_count.map_or(0, |c| (*c).into());
debug!(
"Updated uploaded one-time key count {} -> {}, marking keys as published",
self.account.uploaded_key_count(),
count
);
self.update_key_count(count);
self.account.mark_keys_as_published().await;
self.store.save_account(self.account.clone()).await?;
Ok(())
}
/// Get the user/device pairs for which no Olm session exists.
///
/// Returns a map from the user id, to a map from the device id to a key
/// algorithm.
///
/// This can be used to make a key claiming request to the server.
///
/// Sessions need to be established between devices so group sessions for a
/// room can be shared with them.
///
/// This should be called every time a group session needs to be shared.
///
/// The response of a successful key claiming requests needs to be passed to
/// the `OlmMachine` with the `receive_keys_claim_response()`.
///
/// # Arguments
///
/// `users` - The list of users that we should check if we lack a session
/// with one of their devices.
pub async fn get_missing_sessions(
&mut self,
users: impl Iterator<Item = &UserId>,
) -> OlmResult<BTreeMap<UserId, BTreeMap<Box<DeviceId>, KeyAlgorithm>>> {
let mut missing = BTreeMap::new();
for user_id in users {
let user_devices = self.store.get_user_devices(user_id).await?;
for device in user_devices.devices() {
let sender_key = if let Some(k) = device.get_key(KeyAlgorithm::Curve25519) {
k
} else {
continue;
};
let sessions = self.store.get_sessions(sender_key).await?;
let is_missing = if let Some(sessions) = sessions {
sessions.lock().await.is_empty()
} else {
true
};
if is_missing {
if !missing.contains_key(user_id) {
let _ = missing.insert(user_id.clone(), BTreeMap::new());
}
let user_map = missing.get_mut(user_id).unwrap();
let _ =
user_map.insert(device.device_id().into(), KeyAlgorithm::SignedCurve25519);
}
}
}
Ok(missing)
}
/// Receive a successful key claim response and create new Olm sessions with
/// the claimed keys.
///
/// # Arguments
///
/// * `response` - The response containing the claimed one-time keys.
pub async fn receive_keys_claim_response(
&mut self,
response: &keys::claim_keys::Response,
) -> OlmResult<()> {
// TODO log the failures here
for (user_id, user_devices) in &response.one_time_keys {
for (device_id, key_map) in user_devices {
let device: Device = match self.store.get_device(&user_id, device_id).await {
Ok(Some(d)) => d,
Ok(None) => {
warn!(
"Tried to create an Olm session for {} {}, but the device is unknown",
user_id, device_id
);
continue;
}
Err(e) => {
warn!(
"Tried to create an Olm session for {} {}, but \
can't fetch the device from the store {:?}",
user_id, device_id, e
);
continue;
}
};
info!("Creating outbound Session for {} {}", user_id, device_id);
let session = match self.account.create_outbound_session(device, &key_map).await {
Ok(s) => s,
Err(e) => {
warn!("{:?}", e);
continue;
}
};
if let Err(e) = self.store.save_sessions(&[session]).await {
error!("Failed to store newly created Olm session {}", e);
continue;
}
// TODO if this session was created because a previous one was
// wedged queue up a dummy event to be sent out.
// TODO if this session was created because of a key request,
// mark the forwarding keys to be sent out
}
}
Ok(())
}
async fn handle_devices_from_key_query(
&mut self,
device_keys_map: &BTreeMap<UserId, BTreeMap<Box<DeviceId>, DeviceKeys>>,
) -> StoreResult<Vec<Device>> {
let mut changed_devices = Vec::new();
for (user_id, device_map) in device_keys_map {
self.store.update_tracked_user(user_id, false).await?;
for (device_id, device_keys) in device_map.iter() {
// We don't need our own device in the device store.
if user_id == &self.user_id && device_id == &self.device_id {
continue;
}
if user_id != &device_keys.user_id || device_id != &device_keys.device_id {
warn!(
"Mismatch in device keys payload of device {} from user {}",
device_keys.device_id, device_keys.user_id
);
continue;
}
let device = self.store.get_device(&user_id, device_id).await?;
let device = if let Some(mut device) = device {
if let Err(e) = device.update_device(device_keys) {
warn!(
"Failed to update the device keys for {} {}: {:?}",
user_id, device_id, e
);
continue;
}
device
} else {
let device = match Device::try_from(device_keys) {
Ok(d) => d,
Err(e) => {
warn!(
"Failed to create a new device for {} {}: {:?}",
user_id, device_id, e
);
continue;
}
};
info!("Adding a new device to the device store {:?}", device);
device
};
changed_devices.push(device);
}
let current_devices: HashSet<&DeviceId> =
device_map.keys().map(|id| id.as_ref()).collect();
let stored_devices = self.store.get_user_devices(&user_id).await.unwrap();
let stored_devices_set: HashSet<&DeviceId> = stored_devices.keys().collect();
let deleted_devices = stored_devices_set.difference(&current_devices);
for device_id in deleted_devices {
if let Some(device) = stored_devices.get(device_id) {
device.mark_as_deleted();
self.store.delete_device(device).await?;
}
}
}
Ok(changed_devices)
}
/// Receive a successful keys query response.
///
/// Returns a list of devices newly discovered devices and devices that
/// changed.
///
/// # Arguments
///
/// * `response` - The keys query response of the request that the client
/// performed.
pub async fn receive_keys_query_response(
&mut self,
response: &keys::get_keys::Response,
) -> OlmResult<Vec<Device>> {
let changed_devices = self
.handle_devices_from_key_query(&response.device_keys)
.await?;
self.store.save_devices(&changed_devices).await?;
Ok(changed_devices)
}
/// 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 async fn keys_for_upload(
&self,
) -> StdResult<(Option<DeviceKeys>, Option<OneTimeKeys>), ()> {
self.account.keys_for_upload().await
}
/// Try to decrypt an Olm message.
///
/// This try to decrypt an Olm message using all the sessions we share
/// have with the given sender.
async fn try_decrypt_olm_message(
&mut self,
sender: &UserId,
sender_key: &str,
message: &OlmMessage,
) -> OlmResult<Option<String>> {
let s = self.store.get_sessions(sender_key).await?;
// We don't have any existing sessions, return early.
let sessions = if let Some(s) = s {
s
} else {
return Ok(None);
};
let mut session_to_save = None;
let mut plaintext = None;
for session in &mut *sessions.lock().await {
let mut matches = false;
// If this is a pre-key message check if it was encrypted for our
// session, if it wasn't decryption will fail so no need to try.
if let OlmMessage::PreKey(m) = &message {
matches = session.matches(sender_key, m.clone()).await?;
if !matches {
continue;
}
}
let ret = session.decrypt(message.clone()).await;
if let Ok(p) = ret {
plaintext = Some(p);
session_to_save = Some(session.clone());
break;
} else {
// Decryption failed with a matching session, the session is
// likely wedged and needs to be rotated.
if matches {
warn!(
"Found a matching Olm session yet decryption failed
for sender {} and sender_key {}",
sender, sender_key
);
return Err(OlmError::SessionWedged);
}
}
}
if let Some(session) = session_to_save {
// Decryption was successful, save the new ratchet state of the
// session that was used to decrypt the message.
trace!("Saved the new session state for {}", sender);
self.store.save_sessions(&[session]).await?;
}
Ok(plaintext)
}
async fn decrypt_olm_message(
&mut self,
sender: &UserId,
sender_key: &str,
message: OlmMessage,
) -> OlmResult<(Raw<AnyToDeviceEvent>, String)> {
// First try to decrypt using an existing session.
let plaintext = if let Some(p) = self
.try_decrypt_olm_message(sender, sender_key, &message)
.await?
{
// Decryption succeeded, de-structure the plaintext out of the
// Option.
p
} else {
// Decryption failed with every known session, let's try to create a
// new session.
let mut session = match &message {
// A new session can only be created using a pre-key message,
// return with an error if it isn't one.
OlmMessage::Message(_) => {
warn!(
"Failed to decrypt a non-pre-key message with all
available sessions {} {}",
sender, sender_key
);
return Err(OlmError::SessionWedged);
}
OlmMessage::PreKey(m) => {
// Create the new session.
let session = match self
.account
.create_inbound_session(sender_key, m.clone())
.await
{
Ok(s) => s,
Err(e) => {
warn!(
"Failed to create a new Olm session for {} {}
from a prekey message: {}",
sender, sender_key, e
);
return Err(OlmError::SessionWedged);
}
};
// Save the account since we remove the one-time key that
// was used to create this session.
self.store.save_account(self.account.clone()).await?;
session
}
};
// Decrypt our message, this shouldn't fail since we're using a
// newly created Session.
let plaintext = session.decrypt(message).await?;
// Save the new ratcheted state of the session.
self.store.save_sessions(&[session]).await?;
plaintext
};
trace!("Successfully decrypted a Olm message: {}", plaintext);
Ok(self.parse_decrypted_to_device_event(sender, &plaintext)?)
}
/// Parse a decrypted Olm message, check that the plaintext and encrypted
/// senders match and that the message was meant for us.
fn parse_decrypted_to_device_event(
&self,
sender: &UserId,
plaintext: &str,
) -> OlmResult<(Raw<AnyToDeviceEvent>, String)> {
// TODO make the errors a bit more specific.
let decrypted_json: Value = serde_json::from_str(&plaintext)?;
let encrytped_sender = decrypted_json
.get("sender")
.cloned()
.ok_or_else(|| EventError::MissingField("sender".to_string()))?;
let encrytped_sender: UserId = serde_json::from_value(encrytped_sender)?;
let recipient = decrypted_json
.get("recipient")
.cloned()
.ok_or_else(|| EventError::MissingField("recipient".to_string()))?;
let recipient: UserId = serde_json::from_value(recipient)?;
let recipient_keys: BTreeMap<KeyAlgorithm, String> = serde_json::from_value(
decrypted_json
.get("recipient_keys")
.cloned()
.ok_or_else(|| EventError::MissingField("recipient_keys".to_string()))?,
)?;
let keys: BTreeMap<KeyAlgorithm, String> = serde_json::from_value(
decrypted_json
.get("keys")
.cloned()
.ok_or_else(|| EventError::MissingField("keys".to_string()))?,
)?;
if recipient != self.user_id || sender != &encrytped_sender {
return Err(EventError::MissmatchedSender.into());
}
if self.account.identity_keys().ed25519()
!= recipient_keys
.get(&KeyAlgorithm::Ed25519)
.ok_or(EventError::MissingSigningKey)?
{
return Err(EventError::MissmatchedKeys.into());
}
let signing_key = keys
.get(&KeyAlgorithm::Ed25519)
.ok_or(EventError::MissingSigningKey)?;
Ok((
Raw::from(serde_json::from_value::<AnyToDeviceEvent>(decrypted_json)?),
signing_key.to_owned(),
))
}
/// Decrypt a to-device event.
///
/// Returns a decrypted `ToDeviceEvent` if the decryption was successful,
/// an error indicating why decryption failed otherwise.
///
/// # Arguments
///
/// * `event` - The to-device event that should be decrypted.
async fn decrypt_to_device_event(
&mut self,
event: &ToDeviceEvent<EncryptedEventContent>,
) -> OlmResult<Raw<AnyToDeviceEvent>> {
info!("Decrypting to-device event");
let content = if let EncryptedEventContent::OlmV1Curve25519AesSha2(c) = &event.content {
c
} else {
warn!("Error, unsupported encryption algorithm");
return Err(EventError::UnsupportedAlgorithm.into());
};
let identity_keys = self.account.identity_keys();
let own_key = identity_keys.curve25519();
let own_ciphertext = content.ciphertext.get(own_key);
// Try to find a ciphertext that was meant for our device.
if let Some(ciphertext) = own_ciphertext {
let message_type: u8 = ciphertext
.message_type
.try_into()
.map_err(|_| EventError::UnsupportedOlmType)?;
// 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 (decrypted_event, signing_key) = self
.decrypt_olm_message(&event.sender, &content.sender_key, message)
.await?;
debug!("Decrypted a to-device event {:?}", decrypted_event);
// Handle the decrypted event, e.g. fetch out Megolm sessions out of
// the event.
if let Some(event) = self
.handle_decrypted_to_device_event(
&content.sender_key,
&signing_key,
&decrypted_event,
)
.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(event)
} else {
Ok(decrypted_event)
}
} else {
warn!("Olm event doesn't contain a ciphertext for our key");
Err(EventError::MissingCiphertext.into())
}
}
/// Create a group session from a room key and add it to our crypto store.
async fn add_room_key(
&mut self,
sender_key: &str,
signing_key: &str,
event: &mut ToDeviceEvent<RoomKeyEventContent>,
) -> OlmResult<Option<Raw<AnyToDeviceEvent>>> {
match event.content.algorithm {
Algorithm::MegolmV1AesSha2 => {
let session_key = GroupSessionKey(mem::take(&mut event.content.session_key));
let session = InboundGroupSession::new(
sender_key,
signing_key,
&event.content.room_id,
session_key,
)?;
let _ = self.store.save_inbound_group_session(session).await?;
let event = Raw::from(AnyToDeviceEvent::RoomKey(event.clone()));
Ok(Some(event))
}
_ => {
warn!(
"Received room key with unsupported key algorithm {}",
event.content.algorithm
);
Ok(None)
}
}
}
/// Create a new outbound group session.
///
/// This also creates a matching inbound group session and saves that one in
/// the store.
async fn create_outbound_group_session(&mut self, room_id: &RoomId) -> OlmResult<()> {
let (outbound, inbound) = self.account.create_group_session_pair(room_id).await;
let _ = self.store.save_inbound_group_session(inbound).await?;
let _ = self
.outbound_group_sessions
.insert(room_id.to_owned(), outbound);
Ok(())
}
/// 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
///
/// * `room_id` - The id of the room for which the message should be
/// encrypted.
///
/// * `content` - The plaintext content of the message that should be
/// encrypted.
///
/// # Panics
///
/// Panics if a group session for the given room wasn't shared beforehand.
pub async fn encrypt(
&self,
room_id: &RoomId,
content: MessageEventContent,
) -> MegolmResult<EncryptedEventContent> {
let session = self.outbound_group_sessions.get(room_id);
let session = if let Some(s) = session {
s
} else {
panic!("Session wasn't created nor shared");
};
if session.expired() {
panic!("Session is expired");
}
Ok(session.encrypt(content).await)
}
/// Encrypt the given event for the given Device
///
/// # Arguments
///
/// * `reciepient_device` - The device that the event should be encrypted
/// for.
///
/// * `event_type` - The type of the event.
///
/// * `content` - The content of the event that should be encrypted.
async fn olm_encrypt(
&mut self,
recipient_device: &Device,
event_type: EventType,
content: Value,
) -> OlmResult<EncryptedEventContent> {
let sender_key = if let Some(k) = recipient_device.get_key(KeyAlgorithm::Curve25519) {
k
} else {
warn!(
"Trying to encrypt a Megolm session for user {} on device {}, \
but the device doesn't have a curve25519 key",
recipient_device.user_id(),
recipient_device.device_id()
);
return Err(EventError::MissingSenderKey.into());
};
let mut session = if let Some(s) = self.store.get_sessions(sender_key).await? {
let session = &s.lock().await[0];
session.clone()
} else {
warn!(
"Trying to encrypt a Megolm session for user {} on device {}, \
but no Olm session is found",
recipient_device.user_id(),
recipient_device.device_id()
);
return Err(OlmError::MissingSession);
};
let message = session.encrypt(recipient_device, event_type, content).await;
self.store.save_sessions(&[session]).await?;
message
}
/// Should the client share a group session for the given room.
///
/// Returns true if a session needs to be shared before room messages can be
/// encrypted, false if one is already shared and ready to encrypt room
/// messages.
///
/// This should be called every time a new room message wants to be sent out
/// since group sessions can expire at any time.
pub fn should_share_group_session(&self, room_id: &RoomId) -> bool {
let session = self.outbound_group_sessions.get(room_id);
match session {
Some(s) => !s.shared() || s.expired(),
None => true,
}
}
/// Invalidate the currently active outbound group session for the given
/// room.
///
/// Returns true if a session was invalidated, false if there was no session
/// to invalidate.
pub fn invalidate_group_session(&mut self, room_id: &RoomId) -> bool {
self.outbound_group_sessions.remove(room_id).is_some()
}
// TODO accept an algorithm here
/// Get to-device requests to share a group session with users in a room.
///
/// # Arguments
///
/// `room_id` - The room id of the room where the group session will be
/// used.
///
/// `users` - The list of users that should receive the group session.
pub async fn share_group_session<'a, I>(
&mut self,
room_id: &RoomId,
users: I,
) -> OlmResult<Vec<ToDeviceRequest>>
where
I: IntoIterator<Item = &'a UserId>,
{
self.create_outbound_group_session(room_id).await?;
let session = self.outbound_group_sessions.get(room_id).unwrap();
if session.shared() {
panic!("Session is already shared");
}
// TODO don't mark the session as shared automatically only, when all
// the requests are done, failure to send these requests will likely end
// up in wedged sessions. We'll need to store the requests and let the
// caller mark them as sent using an UUID.
session.mark_as_shared();
let mut devices = Vec::new();
for user_id in users {
for device in self.store.get_user_devices(user_id).await?.devices() {
// TODO abort if the device isn't verified
devices.push(device.clone());
}
}
let mut requests = Vec::new();
let key_content = session.as_json().await;
for device_map_chunk in devices.chunks(OlmMachine::MAX_TO_DEVICE_MESSAGES) {
let mut messages = BTreeMap::new();
for device in device_map_chunk {
let encrypted = self
.olm_encrypt(&device, EventType::RoomKey, key_content.clone())
.await;
let encrypted = match encrypted {
Ok(c) => c,
Err(OlmError::MissingSession)
| Err(OlmError::EventError(EventError::MissingSenderKey)) => {
continue;
}
Err(e) => return Err(e),
};
if !messages.contains_key(device.user_id()) {
messages.insert(device.user_id().clone(), BTreeMap::new());
};
let user_messages = messages.get_mut(device.user_id()).unwrap();
user_messages.insert(
DeviceIdOrAllDevices::DeviceId(device.device_id().into()),
serde_json::value::to_raw_value(&encrypted)?,
);
}
requests.push(ToDeviceRequest {
event_type: EventType::RoomEncrypted,
txn_id: Uuid::new_v4().to_string(),
messages,
});
}
Ok(requests)
}
fn add_forwarded_room_key(
&self,
_sender_key: &str,
_signing_key: &str,
_event: &ToDeviceEvent<ForwardedRoomKeyEventContent>,
) -> OlmResult<()> {
Ok(())
// TODO
}
/// Receive and properly handle a decrypted to-device event.
///
/// # Arguments
///
/// * `sender_key` - The sender (curve25519) key of the event sender.
///
/// * `signing_key` - The signing (ed25519) key of the event sender.
///
/// * `event` - The decrypted to-device event.
async fn handle_decrypted_to_device_event(
&mut self,
sender_key: &str,
signing_key: &str,
event: &Raw<AnyToDeviceEvent>,
) -> OlmResult<Option<Raw<AnyToDeviceEvent>>> {
let event = if let Ok(e) = event.deserialize() {
e
} else {
warn!("Decrypted to-device event failed to be parsed correctly");
return Ok(None);
};
match event {
AnyToDeviceEvent::RoomKey(mut e) => {
Ok(self.add_room_key(sender_key, signing_key, &mut e).await?)
}
AnyToDeviceEvent::ForwardedRoomKey(e) => {
self.add_forwarded_room_key(sender_key, signing_key, &e)?;
Ok(None)
}
_ => {
warn!("Received a unexpected encrypted to-device event");
Ok(None)
}
}
}
fn handle_room_key_request(&self, _: &ToDeviceEvent<RoomKeyRequestEventContent>) {
// TODO handle room key requests here.
}
fn handle_verification_event(&self, _: &AnyToDeviceEvent) {
// TODO handle to-device verification events here.
}
/// Handle a sync response and update the internal state of the Olm machine.
///
/// This will decrypt to-device events but will not touch events in the room
/// timeline.
///
/// To decrypt an event from the room timeline call `decrypt_room_event()`.
///
/// # Arguments
///
/// * `response` - The sync latest sync response.
#[instrument(skip(response))]
pub async fn receive_sync_response(&mut self, response: &mut SyncResponse) {
let one_time_key_count = response
.device_one_time_keys_count
.get(&keys::KeyAlgorithm::SignedCurve25519);
let count: u64 = one_time_key_count.map_or(0, |c| (*c).into());
self.update_key_count(count);
for user_id in &response.device_lists.changed {
if let Err(e) = self.mark_user_as_changed(&user_id).await {
error!("Error marking a tracked user as changed {:?}", e);
}
}
for event_result in &mut response.to_device.events {
let event = if let Ok(e) = event_result.deserialize() {
e
} else {
// Skip invalid events.
warn!("Received an invalid to-device event {:?}", event_result);
continue;
};
info!("Received a to-device event {:?}", event);
match &event {
AnyToDeviceEvent::RoomEncrypted(e) => {
let decrypted_event = match self.decrypt_to_device_event(e).await {
Ok(e) => e,
Err(err) => {
warn!(
"Failed to decrypt to-device event from {} {}",
e.sender, err
);
// TODO if the session is wedged mark it for
// unwedging.
continue;
}
};
*event_result = decrypted_event;
}
AnyToDeviceEvent::RoomKeyRequest(e) => self.handle_room_key_request(e),
AnyToDeviceEvent::KeyVerificationAccept(..)
| AnyToDeviceEvent::KeyVerificationCancel(..)
| AnyToDeviceEvent::KeyVerificationKey(..)
| AnyToDeviceEvent::KeyVerificationMac(..)
| AnyToDeviceEvent::KeyVerificationRequest(..)
| AnyToDeviceEvent::KeyVerificationStart(..) => {
self.handle_verification_event(&event)
}
_ => continue,
}
}
}
/// Decrypt an event from a room timeline.
///
/// # Arguments
///
/// * `event` - The event that should be decrypted.
///
/// * `room_id` - The ID of the room where the event was sent to.
pub async fn decrypt_room_event(
&mut self,
event: &SyncMessageEvent<EncryptedEventContent>,
room_id: &RoomId,
) -> MegolmResult<Raw<AnySyncRoomEvent>> {
let content = match &event.content {
EncryptedEventContent::MegolmV1AesSha2(c) => c,
_ => return Err(EventError::UnsupportedAlgorithm.into()),
};
let session = self
.store
.get_inbound_group_session(room_id, &content.sender_key, &content.session_id)
.await?;
// TODO check if the Olm session is wedged and re-request the key.
let session = session.ok_or(MegolmError::MissingSession)?;
// TODO check the message index.
// TODO check if this is from a verified device.
let (decrypted_event, _) = session.decrypt(event).await?;
trace!("Successfully decrypted Megolm event {:?}", decrypted_event);
// TODO set the encryption info on the event (is it verified, was it
// decrypted, sender key...)
Ok(decrypted_event)
}
/// Mark that the given user has changed his devices.
///
/// This will queue up the given user for a key query.
///
/// Note: The user already needs to be tracked for it to be queued up for a
/// key query.
///
/// Returns true if the user was queued up for a key query, false otherwise.
pub async fn mark_user_as_changed(&mut self, user_id: &UserId) -> StoreResult<bool> {
if self.store.tracked_users().contains(user_id) {
self.store.update_tracked_user(user_id, true).await?;
Ok(true)
} else {
Ok(false)
}
}
/// Update the tracked users.
///
/// # Arguments
///
/// * `users` - An iterator over user ids that should be marked for
/// tracking.
///
/// This will mark users that weren't seen before for a key query and
/// tracking.
///
/// If the user is already known to the Olm machine it will not be
/// considered for a key query.
///
/// Use the `mark_user_as_changed()` if the user really needs a key query.
pub async fn update_tracked_users<'a, I>(&mut self, users: I)
where
I: IntoIterator<Item = &'a UserId>,
{
for user in users {
if self.store.tracked_users().contains(user) {
continue;
}
if let Err(e) = self.store.update_tracked_user(user, true).await {
warn!("Error storing users for tracking {}", e);
}
}
}
/// Should the client perform a key query request.
pub fn should_query_keys(&self) -> bool {
!self.store.users_for_key_query().is_empty()
}
/// Get the set of users that we need to query keys for.
///
/// Returns a hash set of users that need to be queried for keys.
pub fn users_for_key_query(&self) -> HashSet<UserId> {
self.store.users_for_key_query().clone()
}
}
#[cfg(test)]
mod test {
static USER_ID: &str = "@bob:example.org";
use matrix_sdk_common::js_int::uint;
use std::{
collections::BTreeMap,
convert::{TryFrom, TryInto},
time::SystemTime,
};
use http::Response;
use serde_json::json;
use crate::{
machine::{OlmMachine, OneTimeKeys},
verify_json, Device,
};
use matrix_sdk_common::{
api::r0::{keys, to_device::send_event_to_device::Request as ToDeviceRequest},
events::{
room::{
encrypted::EncryptedEventContent,
message::{MessageEventContent, TextMessageEventContent},
},
AnySyncMessageEvent, AnySyncRoomEvent, AnyToDeviceEvent, EventType, SyncMessageEvent,
ToDeviceEvent, Unsigned,
},
identifiers::{DeviceId, EventId, RoomId, UserId},
Raw,
};
use matrix_sdk_test::test_json;
fn alice_id() -> UserId {
UserId::try_from("@alice:example.org").unwrap()
}
fn alice_device_id() -> Box<DeviceId> {
"JLAFKJWSCS".into()
}
fn user_id() -> UserId {
UserId::try_from(USER_ID).unwrap()
}
fn response_from_file(json: &serde_json::Value) -> Response<Vec<u8>> {
Response::builder()
.status(200)
.body(json.to_string().as_bytes().to_vec())
.unwrap()
}
fn keys_upload_response() -> keys::upload_keys::Response {
let data = response_from_file(&test_json::KEYS_UPLOAD);
keys::upload_keys::Response::try_from(data).expect("Can't parse the keys upload response")
}
fn keys_query_response() -> keys::get_keys::Response {
let data = response_from_file(&test_json::KEYS_QUERY);
keys::get_keys::Response::try_from(data).expect("Can't parse the keys upload response")
}
fn to_device_requests_to_content(requests: Vec<ToDeviceRequest>) -> EncryptedEventContent {
let to_device_request = &requests[0];
let content: Raw<EncryptedEventContent> = serde_json::from_str(
to_device_request
.messages
.values()
.next()
.unwrap()
.values()
.next()
.unwrap()
.get(),
)
.unwrap();
content.deserialize().unwrap()
}
async fn get_prepared_machine() -> (OlmMachine, OneTimeKeys) {
let mut machine = OlmMachine::new(&user_id(), &alice_device_id());
machine.account.update_uploaded_key_count(0);
let (_, otk) = machine
.keys_for_upload()
.await
.expect("Can't prepare initial key upload");
let response = keys_upload_response();
machine
.receive_keys_upload_response(&response)
.await
.unwrap();
(machine, otk.unwrap())
}
async fn get_machine_after_query() -> (OlmMachine, OneTimeKeys) {
let (mut machine, otk) = get_prepared_machine().await;
let response = keys_query_response();
machine
.receive_keys_query_response(&response)
.await
.unwrap();
(machine, otk)
}
async fn get_machine_pair() -> (OlmMachine, OlmMachine, OneTimeKeys) {
let (bob, otk) = get_prepared_machine().await;
let alice_id = alice_id();
let alice_device = alice_device_id();
let alice = OlmMachine::new(&alice_id, &alice_device);
let alice_deivce = Device::from_machine(&alice).await;
let bob_device = Device::from_machine(&bob).await;
alice.store.save_devices(&[bob_device]).await.unwrap();
bob.store.save_devices(&[alice_deivce]).await.unwrap();
(alice, bob, otk)
}
async fn get_machine_pair_with_session() -> (OlmMachine, OlmMachine) {
let (mut alice, bob, one_time_keys) = get_machine_pair().await;
let mut bob_keys = BTreeMap::new();
let one_time_key = one_time_keys.iter().next().unwrap();
let mut keys = BTreeMap::new();
keys.insert(one_time_key.0.clone(), one_time_key.1.clone());
bob_keys.insert(bob.device_id.clone(), keys);
let mut one_time_keys = BTreeMap::new();
one_time_keys.insert(bob.user_id.clone(), bob_keys);
let response = keys::claim_keys::Response {
failures: BTreeMap::new(),
one_time_keys,
};
alice.receive_keys_claim_response(&response).await.unwrap();
(alice, bob)
}
async fn get_machine_pair_with_setup_sessions() -> (OlmMachine, OlmMachine) {
let (mut alice, mut bob) = get_machine_pair_with_session().await;
let bob_device = alice
.store
.get_device(&bob.user_id, &bob.device_id)
.await
.unwrap()
.unwrap();
let event = ToDeviceEvent {
sender: alice.user_id.clone(),
content: alice
.olm_encrypt(&bob_device, EventType::Dummy, json!({}))
.await
.unwrap(),
};
bob.decrypt_to_device_event(&event).await.unwrap();
(alice, bob)
}
#[tokio::test]
async fn create_olm_machine() {
let machine = OlmMachine::new(&user_id(), &alice_device_id());
assert!(machine.should_upload_keys().await);
}
#[tokio::test]
async fn receive_keys_upload_response() {
let mut machine = OlmMachine::new(&user_id(), &alice_device_id());
let mut response = keys_upload_response();
response
.one_time_key_counts
.remove(&keys::KeyAlgorithm::SignedCurve25519)
.unwrap();
assert!(machine.should_upload_keys().await);
machine
.receive_keys_upload_response(&response)
.await
.unwrap();
assert!(machine.should_upload_keys().await);
response
.one_time_key_counts
.insert(keys::KeyAlgorithm::SignedCurve25519, uint!(10));
machine
.receive_keys_upload_response(&response)
.await
.unwrap();
assert!(machine.should_upload_keys().await);
response
.one_time_key_counts
.insert(keys::KeyAlgorithm::SignedCurve25519, uint!(50));
machine
.receive_keys_upload_response(&response)
.await
.unwrap();
assert!(!machine.should_upload_keys().await);
}
#[tokio::test]
async fn generate_one_time_keys() {
let mut machine = OlmMachine::new(&user_id(), &alice_device_id());
let mut response = keys_upload_response();
assert!(machine.should_upload_keys().await);
machine
.receive_keys_upload_response(&response)
.await
.unwrap();
assert!(machine.should_upload_keys().await);
assert!(machine.account.generate_one_time_keys().await.is_ok());
response
.one_time_key_counts
.insert(keys::KeyAlgorithm::SignedCurve25519, uint!(50));
machine
.receive_keys_upload_response(&response)
.await
.unwrap();
assert!(machine.account.generate_one_time_keys().await.is_err());
}
#[tokio::test]
async fn test_device_key_signing() {
let machine = OlmMachine::new(&user_id(), &alice_device_id());
let mut device_keys = machine.account.device_keys().await;
let identity_keys = machine.account.identity_keys();
let ed25519_key = identity_keys.ed25519();
let ret = verify_json(
&machine.user_id,
machine.device_id.as_str(),
ed25519_key,
&mut json!(&mut device_keys),
);
assert!(ret.is_ok());
}
#[tokio::test]
async fn tests_session_invalidation() {
let mut machine = OlmMachine::new(&user_id(), &alice_device_id());
let room_id = RoomId::try_from("!test:example.org").unwrap();
machine
.create_outbound_group_session(&room_id)
.await
.unwrap();
assert!(machine.outbound_group_sessions.get(&room_id).is_some());
machine.invalidate_group_session(&room_id);
assert!(machine.outbound_group_sessions.get(&room_id).is_none());
}
#[tokio::test]
async fn test_invalid_signature() {
let machine = OlmMachine::new(&user_id(), &alice_device_id());
let mut device_keys = machine.account.device_keys().await;
let ret = verify_json(
&machine.user_id,
machine.device_id.as_str(),
"fake_key",
&mut json!(&mut device_keys),
);
assert!(ret.is_err());
}
#[tokio::test]
async fn test_one_time_key_signing() {
let machine = OlmMachine::new(&user_id(), &alice_device_id());
machine.account.update_uploaded_key_count(49);
let mut one_time_keys = machine.account.signed_one_time_keys().await.unwrap();
let identity_keys = machine.account.identity_keys();
let ed25519_key = identity_keys.ed25519();
let mut one_time_key = one_time_keys.values_mut().next().unwrap();
let ret = verify_json(
&machine.user_id,
machine.device_id.as_str(),
ed25519_key,
&mut json!(&mut one_time_key),
);
assert!(ret.is_ok());
}
#[tokio::test]
async fn test_keys_for_upload() {
let mut machine = OlmMachine::new(&user_id(), &alice_device_id());
machine.account.update_uploaded_key_count(0);
let identity_keys = machine.account.identity_keys();
let ed25519_key = identity_keys.ed25519();
let (device_keys, mut one_time_keys) = machine
.keys_for_upload()
.await
.expect("Can't prepare initial key upload");
let ret = verify_json(
&machine.user_id,
machine.device_id.as_str(),
ed25519_key,
&mut json!(&mut one_time_keys.as_mut().unwrap().values_mut().next()),
);
assert!(ret.is_ok());
let ret = verify_json(
&machine.user_id,
machine.device_id.as_str(),
ed25519_key,
&mut json!(&mut device_keys.unwrap()),
);
assert!(ret.is_ok());
let mut response = keys_upload_response();
response.one_time_key_counts.insert(
keys::KeyAlgorithm::SignedCurve25519,
(one_time_keys.unwrap().len() as u64).try_into().unwrap(),
);
machine
.receive_keys_upload_response(&response)
.await
.unwrap();
let ret = machine.keys_for_upload().await;
assert!(ret.is_err());
}
#[tokio::test]
async fn test_keys_query() {
let (mut machine, _) = get_prepared_machine().await;
let response = keys_query_response();
let alice_id = UserId::try_from("@alice:example.org").unwrap();
let alice_device_id: &DeviceId = "JLAFKJWSCS".into();
let alice_devices = machine.store.get_user_devices(&alice_id).await.unwrap();
assert!(alice_devices.devices().peekable().peek().is_none());
machine
.receive_keys_query_response(&response)
.await
.unwrap();
let device = machine
.store
.get_device(&alice_id, alice_device_id)
.await
.unwrap()
.unwrap();
assert_eq!(device.user_id(), &alice_id);
assert_eq!(device.device_id(), alice_device_id);
}
#[tokio::test]
async fn test_missing_sessions_calculation() {
let (mut machine, _) = get_machine_after_query().await;
let alice = alice_id();
let alice_device = alice_device_id();
let missing_sessions = machine
.get_missing_sessions([alice.clone()].iter())
.await
.unwrap();
assert!(missing_sessions.contains_key(&alice));
let user_sessions = missing_sessions.get(&alice).unwrap();
assert!(user_sessions.contains_key(&alice_device));
}
#[tokio::test]
async fn test_session_creation() {
let (mut alice_machine, bob_machine, one_time_keys) = get_machine_pair().await;
let mut bob_keys = BTreeMap::new();
let one_time_key = one_time_keys.iter().next().unwrap();
let mut keys = BTreeMap::new();
keys.insert(one_time_key.0.clone(), one_time_key.1.clone());
bob_keys.insert(bob_machine.device_id.clone(), keys);
let mut one_time_keys = BTreeMap::new();
one_time_keys.insert(bob_machine.user_id.clone(), bob_keys);
let response = keys::claim_keys::Response {
failures: BTreeMap::new(),
one_time_keys,
};
alice_machine
.receive_keys_claim_response(&response)
.await
.unwrap();
let session = alice_machine
.store
.get_sessions(bob_machine.account.identity_keys().curve25519())
.await
.unwrap()
.unwrap();
assert!(!session.lock().await.is_empty())
}
#[tokio::test]
async fn test_olm_encryption() {
let (mut alice, mut bob) = get_machine_pair_with_session().await;
let bob_device = alice
.store
.get_device(&bob.user_id, &bob.device_id)
.await
.unwrap()
.unwrap();
let event = ToDeviceEvent {
sender: alice.user_id.clone(),
content: alice
.olm_encrypt(&bob_device, EventType::Dummy, json!({}))
.await
.unwrap(),
};
let event = bob
.decrypt_to_device_event(&event)
.await
.unwrap()
.deserialize()
.unwrap();
if let AnyToDeviceEvent::Dummy(e) = event {
assert_eq!(e.sender, alice.user_id);
} else {
panic!("Wrong event type found {:?}", event);
}
}
#[tokio::test]
async fn test_room_key_sharing() {
let (mut alice, mut bob) = get_machine_pair_with_session().await;
let room_id = RoomId::try_from("!test:example.org").unwrap();
let to_device_requests = alice
.share_group_session(&room_id, [bob.user_id.clone()].iter())
.await
.unwrap();
let event = ToDeviceEvent {
sender: alice.user_id.clone(),
content: to_device_requests_to_content(to_device_requests),
};
let alice_session = alice.outbound_group_sessions.get(&room_id).unwrap();
let event = bob
.decrypt_to_device_event(&event)
.await
.unwrap()
.deserialize()
.unwrap();
if let AnyToDeviceEvent::RoomKey(event) = event {
assert_eq!(event.sender, alice.user_id);
assert!(event.content.session_key.is_empty());
} else {
panic!("expected RoomKeyEvent found {:?}", event);
}
let session = bob
.store
.get_inbound_group_session(
&room_id,
alice.account.identity_keys().curve25519(),
alice_session.session_id(),
)
.await;
assert!(session.unwrap().is_some());
}
#[tokio::test]
async fn test_megolm_encryption() {
let (mut alice, mut bob) = get_machine_pair_with_setup_sessions().await;
let room_id = RoomId::try_from("!test:example.org").unwrap();
let to_device_requests = alice
.share_group_session(&room_id, [bob.user_id().clone()].iter())
.await
.unwrap();
let event = ToDeviceEvent {
sender: alice.user_id.clone(),
content: to_device_requests_to_content(to_device_requests),
};
bob.decrypt_to_device_event(&event).await.unwrap();
let plaintext = "It is a secret to everybody";
let content = MessageEventContent::Text(TextMessageEventContent::plain(plaintext));
let encrypted_content = alice.encrypt(&room_id, content.clone()).await.unwrap();
let event = SyncMessageEvent {
event_id: EventId::try_from("$xxxxx:example.org").unwrap(),
origin_server_ts: SystemTime::now(),
sender: alice.user_id().clone(),
content: encrypted_content,
unsigned: Unsigned::default(),
};
let decrypted_event = bob
.decrypt_room_event(&event, &room_id)
.await
.unwrap()
.deserialize()
.unwrap();
match decrypted_event {
AnySyncRoomEvent::Message(AnySyncMessageEvent::RoomMessage(SyncMessageEvent {
sender,
content,
..
})) => {
assert_eq!(&sender, alice.user_id());
if let MessageEventContent::Text(c) = &content {
assert_eq!(&c.body, plaintext);
} else {
panic!("Decrypted event has a missmatched content");
}
}
_ => panic!("Decrypted room event has the wrong type"),
}
}
}