crypto: Notify our users that a verification timed out on our end

matrix_sdk_crypto/src/machine.rs

@@ -789,7 +789,7 @@ impl OlmMachine {
         one_time_keys_counts: &BTreeMap<DeviceKeyAlgorithm, UInt>,
     ) -> OlmResult<ToDevice> {
         // Remove verification objects that have expired or are done.
-        self.verification_machine.garbage_collect();
+        let mut events = self.verification_machine.garbage_collect();
 
         // Always save the account, a new session might get created which also
         // touches the account.
@@ -804,8 +804,6 @@ impl OlmMachine {
             }
         }
 
-        let mut events = Vec::new();
-
         for mut raw_event in to_device_events.events {
             let event = match raw_event.deserialize() {
                 Ok(e) => e,

matrix_sdk_crypto/src/verification/event_enums.rs

@@ -666,7 +666,8 @@ impl From<(RoomId, AnyMessageEventContent)> for OutgoingContent {
 }
 
 #[cfg(test)]
-use crate::{OutgoingRequest, OutgoingVerificationRequest, RoomMessageRequest, ToDeviceRequest};
+use crate::OutgoingVerificationRequest;
+use crate::{OutgoingRequest, RoomMessageRequest, ToDeviceRequest};
 
 #[cfg(test)]
 impl From<OutgoingVerificationRequest> for OutgoingContent {
@@ -678,14 +679,12 @@ impl From<OutgoingVerificationRequest> for OutgoingContent {
     }
 }
 
-#[cfg(test)]
 impl From<RoomMessageRequest> for OutgoingContent {
     fn from(value: RoomMessageRequest) -> Self {
         (value.room_id, value.content).into()
     }
 }
 
-#[cfg(test)]
 impl TryFrom<ToDeviceRequest> for OutgoingContent {
     type Error = String;
 
@@ -736,7 +735,6 @@ impl TryFrom<ToDeviceRequest> for OutgoingContent {
     }
 }
 
-#[cfg(test)]
 impl TryFrom<OutgoingRequest> for OutgoingContent {
     type Error = String;
 

matrix_sdk_crypto/src/verification/machine.rs

@@ -12,11 +12,18 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::{convert::TryFrom, sync::Arc};
+use std::{
+    convert::{TryFrom, TryInto},
+    sync::Arc,
+};
 
 use dashmap::DashMap;
 use matrix_sdk_common::{locks::Mutex, uuid::Uuid};
-use ruma::{DeviceId, MilliSecondsSinceUnixEpoch, UserId};
+use ruma::{
+    events::{AnyToDeviceEvent, AnyToDeviceEventContent, ToDeviceEvent},
+    serde::Raw,
+    DeviceId, MilliSecondsSinceUnixEpoch, UserId,
+};
 use tracing::{info, trace, warn};
 
 use super::{
@@ -165,15 +172,28 @@ impl VerificationMachine {
         self.verifications.outgoing_requests()
     }
 
-    pub fn garbage_collect(&self) {
+    pub fn garbage_collect(&self) -> Vec<Raw<AnyToDeviceEvent>> {
+        let mut events = vec![];
+
         for user_verification in self.requests.iter() {
             user_verification.retain(|_, v| !(v.is_done() || v.is_cancelled()));
         }
         self.requests.retain(|_, v| !v.is_empty());
 
         for request in self.verifications.garbage_collect() {
+            if let Ok(OutgoingContent::ToDevice(AnyToDeviceEventContent::KeyVerificationCancel(
+                content,
+            ))) = request.clone().try_into()
+            {
+                let event = ToDeviceEvent { content, sender: self.account.user_id().to_owned() };
+
+                events.push(AnyToDeviceEvent::KeyVerificationCancel(event).into());
+            }
+
             self.verifications.add_request(request)
         }
+
+        events
     }
 
     async fn mark_sas_as_done(