crypto: Initial support for device tracking.

src/crypto/device.rs

@@ -0,0 +1,71 @@
+// 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::HashMap;
+
+use ruma_client_api::r0::keys::{DeviceKeys, KeyAlgorithm};
+use ruma_events::Algorithm;
+
+#[derive(Debug)]
+pub struct Device {
+    user_id: String,
+    device_id: String,
+    algorithms: Vec<Algorithm>,
+    keys: HashMap<KeyAlgorithm, String>,
+    display_name: Option<String>,
+    deleted: bool,
+    trust_state: TrustState,
+}
+
+#[derive(Debug)]
+pub enum TrustState {
+    Verified,
+    BlackListed,
+    Ignored,
+    Unset,
+}
+
+impl Device {
+    pub fn id(&self) -> &str {
+        &self.device_id
+    }
+
+    pub fn user_id(&self) -> &str {
+        &self.user_id
+    }
+}
+
+impl From<&DeviceKeys> for Device {
+    fn from(device_keys: &DeviceKeys) -> Self {
+        let mut keys = HashMap::new();
+
+        for (key_id, key) in device_keys.keys.iter() {
+            let key_id = key_id.0;
+            keys.insert(key_id, key.clone());
+        }
+
+        Device {
+            user_id: device_keys.user_id.to_string(),
+            device_id: device_keys.device_id.clone(),
+            algorithms: device_keys.algorithms.clone(),
+            keys,
+            display_name: device_keys
+                .unsigned
+                .as_ref()
+                .map(|d| d.device_display_name.clone()),
+            deleted: false,
+            trust_state: TrustState::Unset,
+        }
+    }
+}

src/crypto/machine.rs

@@ -25,7 +25,7 @@ use super::olm::{Account, InboundGroupSession, Session};
 use super::store::memorystore::MemoryStore;
 #[cfg(feature = "sqlite-cryptostore")]
 use super::store::sqlite::SqliteStore;
-use super::CryptoStore;
+use super::{device::Device, CryptoStore};
 use crate::api;
 
 use api::r0::keys;
@@ -188,13 +188,71 @@ impl OlmMachine {
     ///
     /// * `response` - The keys query response of the request that the client
     /// performed.
-    // TODO this should return a
-    #[instrument]
+    // TODO this should return a list of changed devices.
     pub async fn receive_keys_query_response(
         &mut self,
         response: &keys::get_keys::Response,
     ) -> Result<()> {
+        for (user_id, device_map) in &response.device_keys {
+            let user_id_string = user_id.to_string();
+            self.users_for_key_query.remove(&user_id_string);
+
+            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 curve_key_id =
+                    AlgorithmAndDeviceId(KeyAlgorithm::Curve25519, device_id.to_owned());
+                let ed_key_id = AlgorithmAndDeviceId(KeyAlgorithm::Ed25519, device_id.to_owned());
+
+                let sender_key = if let Some(k) = device_keys.keys.get(&curve_key_id) {
+                    k
+                } else {
+                    continue;
+                };
+
+                let signing_key = if let Some(k) = device_keys.keys.get(&ed_key_id) {
+                    k
+                } else {
+                    continue;
+                };
+
+                if self
+                    .verify_json(user_id, device_id, signing_key, &mut json!(&device_keys))
+                    .is_err()
+                {
+                    warn!(
+                        "Failed to verify the device key signatures for {} {}",
+                        user_id, device_id
+                    );
+                    continue;
+                }
+
+                let device = self
+                    .store
+                    .get_user_device(&user_id_string, device_id)
+                    .await
+                    .expect("Can't load device");
+
+                if let Some(d) = device {
                     todo!()
+                } else {
+                    let device = Device::from(device_keys);
+                    info!("Found new device {:?}", device);
+                }
+            }
+        }
+        Ok(())
     }
 
     /// Generate new one-time keys.

src/crypto/mod.rs

@@ -14,6 +14,7 @@
 
 mod error;
 // TODO remove this.
+mod device;
 mod machine;
 mod memory_stores;
 #[allow(dead_code)]

src/crypto/store/memorystore.rs

@@ -19,6 +19,7 @@ use async_trait::async_trait;
 use tokio::sync::Mutex;
 
 use super::{Account, CryptoStore, CryptoStoreError, InboundGroupSession, Result, Session};
+use crate::crypto::device::Device;
 use crate::crypto::memory_stores::{GroupSessionStore, SessionStore};
 
 #[derive(Debug)]
@@ -86,4 +87,8 @@ impl CryptoStore for MemoryStore {
     async fn add_user_for_tracking(&mut self, user: &str) -> Result<bool> {
         Ok(self.tracked_users.insert(user.to_string()))
     }
+
+    async fn get_user_device(&self, user_id: &str, device_id: &str) -> Result<Option<Device>> {
+        Ok(None)
+    }
 }

src/crypto/store/mod.rs

@@ -24,6 +24,7 @@ use serde_json::Error as SerdeError;
 use thiserror::Error;
 use tokio::sync::Mutex;
 
+use super::device::Device;
 use super::olm::{Account, InboundGroupSession, Session};
 use olm_rs::errors::{OlmAccountError, OlmGroupSessionError, OlmSessionError};
 use olm_rs::PicklingMode;
@@ -81,4 +82,5 @@ pub trait CryptoStore: Debug + Send + Sync {
     ) -> Result<Option<Arc<Mutex<InboundGroupSession>>>>;
     fn tracked_users(&self) -> &HashSet<String>;
     async fn add_user_for_tracking(&mut self, user: &str) -> Result<bool>;
+    async fn get_user_device(&self, user_id: &str, device_id: &str) -> Result<Option<Device>>;
 }

src/crypto/store/sqlite.rs

@@ -27,6 +27,7 @@ use tokio::sync::Mutex;
 use zeroize::Zeroizing;
 
 use super::{Account, CryptoStore, CryptoStoreError, InboundGroupSession, Result, Session};
+use crate::crypto::device::Device;
 use crate::crypto::memory_stores::{GroupSessionStore, SessionStore};
 
 pub struct SqliteStore {
@@ -406,6 +407,10 @@ impl CryptoStore for SqliteStore {
     }
 
     async fn add_user_for_tracking(&mut self, user: &str) -> Result<bool> {
+        Ok(self.tracked_users.insert(user.to_string()))
+    }
+
+    async fn get_user_device(&self, user_id: &str, device_id: &str) -> Result<Option<Device>> {
         todo!()
     }
 }

src/models/room.rs

@@ -242,7 +242,8 @@ impl Room {
         }
     }
 
-    fn handle_encryption_event(&mut self, event: &EncryptionEvent) -> bool {
+    fn handle_encryption_event(&mut self, _: &EncryptionEvent) -> bool {
+        // TODO store the encryption settings.
         self.encrypted = true;
         true
     }