crypto: Add a verification machine.

matrix_sdk_crypto/src/store/mod.rs

@@ -180,7 +180,6 @@ pub trait CryptoStore: Debug {
     /// * `user_id` - The user that the device belongs to.
     ///
     /// * `device_id` - The unique id of the device.
-    #[allow(clippy::ptr_arg)]
     async fn get_device(&self, user_id: &UserId, device_id: &DeviceId) -> Result<Option<Device>>;
 
     /// Get all the devices of the given user.

matrix_sdk_crypto/src/verification/machine.rs

@@ -0,0 +1,277 @@
+// 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 std::collections::BTreeMap;
+use std::sync::Arc;
+
+use dashmap::DashMap;
+
+use matrix_sdk_common::{
+    api::r0::to_device::{send_event_to_device::Request as ToDeviceRequest, DeviceIdOrAllDevices},
+    events::{
+        key::verification::start::StartEventContent, AnyToDeviceEvent, AnyToDeviceEventContent,
+        EventType,
+    },
+    identifiers::{DeviceId, UserId},
+    uuid::Uuid,
+};
+
+use super::Sas;
+use crate::{Account, CryptoStore, CryptoStoreError};
+
+#[derive(Clone, Debug)]
+struct VerificationMachine {
+    account: Account,
+    store: Arc<Box<dyn CryptoStore>>,
+    verifications: Arc<DashMap<String, Sas>>,
+    outgoing_to_device_messages: Arc<DashMap<String, ToDeviceRequest>>,
+}
+
+impl VerificationMachine {
+    pub(crate) fn new(account: Account, store: Box<dyn CryptoStore>) -> Self {
+        Self {
+            account,
+            store: Arc::new(store),
+            verifications: Arc::new(DashMap::new()),
+            outgoing_to_device_messages: Arc::new(DashMap::new()),
+        }
+    }
+
+    fn get_sas(&self, transaction_id: &str) -> Option<Sas> {
+        self.verifications.get(transaction_id).map(|s| s.clone())
+    }
+
+    fn content_to_request(
+        &self,
+        recipient: &UserId,
+        recipient_device: &DeviceId,
+        content: AnyToDeviceEventContent,
+    ) -> ToDeviceRequest {
+        let mut messages = BTreeMap::new();
+        let mut user_messages = BTreeMap::new();
+
+        user_messages.insert(
+            DeviceIdOrAllDevices::DeviceId(recipient_device.into()),
+            serde_json::value::to_raw_value(&content).expect("Can't serialize to-device content"),
+        );
+        messages.insert(recipient.clone(), user_messages);
+
+        ToDeviceRequest {
+            txn_id: Uuid::new_v4().to_string(),
+            event_type: EventType::KeyVerificationAccept,
+            messages,
+        }
+    }
+
+    fn queue_up_content(
+        &self,
+        recipient: &UserId,
+        recipient_device: &DeviceId,
+        content: AnyToDeviceEventContent,
+    ) {
+        let request = self.content_to_request(recipient, recipient_device, content);
+
+        self.outgoing_to_device_messages
+            .insert(request.txn_id.clone(), request);
+    }
+
+    fn recieve_event_helper(&self, sas: &Sas, event: &mut AnyToDeviceEvent) {
+        if let Some(c) = sas.receive_event(event) {
+            self.queue_up_content(sas.other_user_id(), sas.other_device_id(), c);
+        }
+    }
+
+    pub fn mark_requests_as_sent(&self, uuid: &str) {
+        self.outgoing_to_device_messages.remove(uuid);
+    }
+
+    async fn receive_event(&self, event: &mut AnyToDeviceEvent) -> Result<(), CryptoStoreError> {
+        match event {
+            AnyToDeviceEvent::KeyVerificationStart(e) => match &e.content {
+                StartEventContent::MSasV1(content) => {
+                    if let Some(d) = self
+                        .store
+                        .get_device(&e.sender, &content.from_device)
+                        .await?
+                    {
+                        match Sas::from_start_event(self.account.clone(), d, e) {
+                            Ok(s) => {
+                                self.verifications.insert(content.transaction_id.clone(), s);
+                            }
+                            Err(c) => self.queue_up_content(&e.sender, &content.from_device, c),
+                        }
+                    };
+                }
+                _ => (),
+            },
+            AnyToDeviceEvent::KeyVerificationCancel(e) => {
+                self.verifications.remove(&e.content.transaction_id);
+            }
+            AnyToDeviceEvent::KeyVerificationAccept(e) => {
+                if let Some(s) = self.get_sas(&e.content.transaction_id) {
+                    self.recieve_event_helper(&s, event)
+                };
+            }
+            AnyToDeviceEvent::KeyVerificationKey(e) => {
+                if let Some(s) = self.get_sas(&e.content.transaction_id) {
+                    self.recieve_event_helper(&s, event)
+                };
+            }
+            AnyToDeviceEvent::KeyVerificationMac(e) => {
+                if let Some(s) = self.get_sas(&e.content.transaction_id) {
+                    self.recieve_event_helper(&s, event)
+                };
+            }
+            _ => (),
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+
+    use std::convert::TryFrom;
+
+    use matrix_sdk_common::{
+        events::AnyToDeviceEventContent,
+        identifiers::{DeviceId, UserId},
+    };
+
+    use super::{Sas, VerificationMachine};
+    use crate::verification::test::wrap_any_to_device_content;
+    use crate::{store::memorystore::MemoryStore, Account, CryptoStore, Device};
+
+    fn alice_id() -> UserId {
+        UserId::try_from("@alice:example.org").unwrap()
+    }
+
+    fn alice_device_id() -> Box<DeviceId> {
+        "JLAFKJWSCS".into()
+    }
+
+    fn bob_id() -> UserId {
+        UserId::try_from("@bob:example.org").unwrap()
+    }
+
+    fn bob_device_id() -> Box<DeviceId> {
+        "BOBDEVCIE".into()
+    }
+
+    async fn setup_verification_machine() -> (VerificationMachine, Sas) {
+        let alice = Account::new(&alice_id(), &alice_device_id());
+        let bob = Account::new(&bob_id(), &bob_device_id());
+        let store = MemoryStore::new();
+
+        let bob_device = Device::from_account(&bob).await;
+        let alice_device = Device::from_account(&alice).await;
+
+        store.save_devices(&[bob_device]).await.unwrap();
+
+        let machine = VerificationMachine::new(alice, Box::new(store));
+        let (bob_sas, start_content) = Sas::start(bob, alice_device);
+        machine
+            .receive_event(&mut wrap_any_to_device_content(
+                bob_sas.user_id(),
+                AnyToDeviceEventContent::KeyVerificationStart(start_content),
+            ))
+            .await
+            .unwrap();
+
+        (machine, bob_sas)
+    }
+
+    #[test]
+    fn create() {
+        let alice = Account::new(&alice_id(), &alice_device_id());
+        let store = MemoryStore::new();
+        let _ = VerificationMachine::new(alice, Box::new(store));
+    }
+
+    #[tokio::test]
+    async fn full_flow() {
+        let (alice_machine, bob) = setup_verification_machine().await;
+
+        let alice = alice_machine.verifications.get(bob.flow_id()).unwrap();
+
+        let mut event = alice
+            .accept()
+            .map(|c| {
+                wrap_any_to_device_content(
+                    alice.user_id(),
+                    AnyToDeviceEventContent::KeyVerificationAccept(c),
+                )
+            })
+            .unwrap();
+
+        let mut event = bob
+            .receive_event(&mut event)
+            .map(|c| wrap_any_to_device_content(bob.user_id(), c))
+            .unwrap();
+
+        assert!(alice_machine.outgoing_to_device_messages.is_empty());
+        alice_machine.receive_event(&mut event).await.unwrap();
+        assert!(!alice_machine.outgoing_to_device_messages.is_empty());
+
+        let request = alice_machine
+            .outgoing_to_device_messages
+            .iter()
+            .next()
+            .unwrap();
+
+        let txn_id = request.txn_id.clone();
+
+        let mut event = wrap_any_to_device_content(
+            alice.user_id(),
+            AnyToDeviceEventContent::KeyVerificationKey(
+                serde_json::from_str(
+                    request
+                        .messages
+                        .values()
+                        .next()
+                        .unwrap()
+                        .values()
+                        .next()
+                        .unwrap()
+                        .get(),
+                )
+                .unwrap(),
+            ),
+        );
+        drop(request);
+        alice_machine.mark_requests_as_sent(&txn_id);
+
+        assert!(bob.receive_event(&mut event).is_none());
+
+        assert!(alice.emoji().is_some());
+        assert!(bob.emoji().is_some());
+
+        assert_eq!(alice.emoji(), bob.emoji());
+
+        let mut event = wrap_any_to_device_content(
+            alice.user_id(),
+            AnyToDeviceEventContent::KeyVerificationMac(alice.confirm().unwrap()),
+        );
+        bob.receive_event(&mut event);
+
+        let mut event = wrap_any_to_device_content(
+            bob.user_id(),
+            AnyToDeviceEventContent::KeyVerificationMac(bob.confirm().unwrap()),
+        );
+        alice.receive_event(&mut event);
+
+        assert!(alice.is_done());
+        assert!(bob.is_done());
+    }
+}

matrix_sdk_crypto/src/verification/mod.rs

@@ -23,6 +23,8 @@ use matrix_sdk_common::identifiers::DeviceId;
 
 use crate::{Account, Device};
 
+#[allow(dead_code)]
+mod machine;
 #[allow(dead_code)]
 mod sas;
 
@@ -396,3 +398,43 @@ fn get_decimal(sas: &OlmSas, ids: &SasIds, flow_id: &str, we_started: bool) -> (
 
     (first + 1000, second + 1000, third + 1000)
 }
+
+#[cfg(test)]
+mod test {
+    use matrix_sdk_common::events::{AnyToDeviceEvent, AnyToDeviceEventContent, ToDeviceEvent};
+    use matrix_sdk_common::identifiers::UserId;
+
+    pub(crate) fn wrap_any_to_device_content(
+        sender: &UserId,
+        content: AnyToDeviceEventContent,
+    ) -> AnyToDeviceEvent {
+        match content {
+            AnyToDeviceEventContent::KeyVerificationKey(c) => {
+                AnyToDeviceEvent::KeyVerificationKey(ToDeviceEvent {
+                    sender: sender.clone(),
+                    content: c,
+                })
+            }
+            AnyToDeviceEventContent::KeyVerificationStart(c) => {
+                AnyToDeviceEvent::KeyVerificationStart(ToDeviceEvent {
+                    sender: sender.clone(),
+                    content: c,
+                })
+            }
+            AnyToDeviceEventContent::KeyVerificationAccept(c) => {
+                AnyToDeviceEvent::KeyVerificationAccept(ToDeviceEvent {
+                    sender: sender.clone(),
+                    content: c,
+                })
+            }
+            AnyToDeviceEventContent::KeyVerificationMac(c) => {
+                AnyToDeviceEvent::KeyVerificationMac(ToDeviceEvent {
+                    sender: sender.clone(),
+                    content: c,
+                })
+            }
+
+            _ => unreachable!(),
+        }
+    }
+}

matrix_sdk_crypto/src/verification/sas.rs

@@ -45,6 +45,7 @@ pub struct Sas {
     inner: Arc<Mutex<InnerSas>>,
     account: Account,
     other_device: Device,
+    flow_id: Arc<String>,
 }
 
 impl Sas {
@@ -67,6 +68,21 @@ impl Sas {
         self.account.device_id()
     }
 
+    /// Get the user id of the other side.
+    pub fn other_user_id(&self) -> &UserId {
+        self.other_device.user_id()
+    }
+
+    /// Get the device id of the other side.
+    pub fn other_device_id(&self) -> &DeviceId {
+        self.other_device.device_id()
+    }
+
+    /// Get the unique ID that identifies this SAS verification flow.
+    pub fn flow_id(&self) -> &str {
+        &self.flow_id
+    }
+
     /// Start a new SAS auth flow with the given device.
     ///
     /// # Arguments
@@ -77,13 +93,15 @@ impl Sas {
     ///
     /// Returns the new `Sas` object and a `StartEventContent` that needs to be
     /// sent out through the server to the other device.
-    fn start(account: Account, other_device: Device) -> (Sas, StartEventContent) {
+    pub(crate) fn start(account: Account, other_device: Device) -> (Sas, StartEventContent) {
         let (inner, content) = InnerSas::start(account.clone(), other_device.clone());
+        let flow_id = inner.verification_flow_id();
 
         let sas = Sas {
             inner: Arc::new(Mutex::new(inner)),
             account,
             other_device,
+            flow_id,
         };
 
         (sas, content)
@@ -99,16 +117,18 @@ impl Sas {
     ///
     /// * `event` - The m.key.verification.start event that was sent to us by
     /// the other side.
-    fn from_start_event(
+    pub(crate) fn from_start_event(
         account: Account,
         other_device: Device,
         event: &ToDeviceEvent<StartEventContent>,
     ) -> Result<Sas, AnyToDeviceEventContent> {
         let inner = InnerSas::from_start_event(account.clone(), other_device.clone(), event)?;
+        let flow_id = inner.verification_flow_id();
         Ok(Sas {
             inner: Arc::new(Mutex::new(inner)),
             account,
             other_device,
+            flow_id,
         })
     }
 
@@ -162,7 +182,10 @@ impl Sas {
         self.inner.lock().unwrap().decimals()
     }
 
-    fn receive_event(&self, event: &mut AnyToDeviceEvent) -> Option<AnyToDeviceEventContent> {
+    pub(crate) fn receive_event(
+        &self,
+        event: &mut AnyToDeviceEvent,
+    ) -> Option<AnyToDeviceEventContent> {
         let mut guard = self.inner.lock().unwrap();
         let sas: InnerSas = (*guard).clone();
         let (sas, content) = sas.receive_event(event);
@@ -171,7 +194,7 @@ impl Sas {
         content
     }
 
-    fn verified_devices(&self) -> Option<Arc<Vec<Box<DeviceId>>>> {
+    pub(crate) fn verified_devices(&self) -> Option<Arc<Vec<Box<DeviceId>>>> {
         self.inner.lock().unwrap().verified_devices()
     }
 }
@@ -314,6 +337,19 @@ impl InnerSas {
         }
     }
 
+    fn verification_flow_id(&self) -> Arc<String> {
+        match self {
+            InnerSas::Created(s) => s.verification_flow_id.clone(),
+            InnerSas::Started(s) => s.verification_flow_id.clone(),
+            InnerSas::Canceled(s) => s.verification_flow_id.clone(),
+            InnerSas::Accepted(s) => s.verification_flow_id.clone(),
+            InnerSas::KeyRecieved(s) => s.verification_flow_id.clone(),
+            InnerSas::Confirmed(s) => s.verification_flow_id.clone(),
+            InnerSas::MacReceived(s) => s.verification_flow_id.clone(),
+            InnerSas::Done(s) => s.verification_flow_id.clone(),
+        }
+    }
+
     fn emoji(&self) -> Option<Vec<(&'static str, &'static str)>> {
         match self {
             InnerSas::KeyRecieved(s) => Some(s.get_emoji()),
@@ -1017,10 +1053,9 @@ impl SasState<Canceled> {
 mod test {
     use std::convert::TryFrom;
 
+    use crate::verification::test::wrap_any_to_device_content;
     use crate::{Account, Device};
-    use matrix_sdk_common::events::{
-        AnyToDeviceEvent, AnyToDeviceEventContent, EventContent, ToDeviceEvent,
-    };
+    use matrix_sdk_common::events::{AnyToDeviceEvent, EventContent, ToDeviceEvent};
     use matrix_sdk_common::identifiers::{DeviceId, UserId};
 
     use super::{Accepted, Created, Sas, SasState, Started};
@@ -1048,21 +1083,6 @@ mod test {
         }
     }
 
-    fn wrap_any_to_device_content(
-        sender: &UserId,
-        content: AnyToDeviceEventContent,
-    ) -> AnyToDeviceEvent {
-        match content {
-            AnyToDeviceEventContent::KeyVerificationKey(c) => {
-                AnyToDeviceEvent::KeyVerificationKey(ToDeviceEvent {
-                    sender: sender.clone(),
-                    content: c,
-                })
-            }
-            _ => unreachable!(),
-        }
-    }
-
     async fn get_sas_pair() -> (SasState<Created>, SasState<Started>) {
         let alice = Account::new(&alice_id(), &alice_device_id());
         let alice_device = Device::from_account(&alice).await;