Add get_keys endpoint and changelog entry

ruma-federation-api/CHANGELOG.md

@@ -6,7 +6,10 @@ Improvements:
 
   ```
   device::get_devices::v1,
-  keys::claim_keys::v1,
+  keys::{
+      claim_keys::v1,
+      query_keys::v1,
+  },
   ```
 
 # 0.0.3

ruma-federation-api/src/keys.rs

@@ -1,3 +1,4 @@
 //! Endpoints for handling keys for end-to-end encryption
 
 pub mod claim_keys;
+pub mod get_keys;

ruma-federation-api/src/keys/get_keys/mod.rs

@@ -0,0 +1,3 @@
+//! Module for getting information about the current devices and identity keys for the given users
+
+pub mod v1;

ruma-federation-api/src/keys/get_keys/v1.rs

@@ -0,0 +1,43 @@
+//! [POST /_matrix/federation/v1/user/keys/query](https://matrix.org/docs/spec/server_server/r0.1.4#post-matrix-federation-v1-user-keys-claim)
+
+use std::collections::BTreeMap;
+
+use ruma_api::ruma_api;
+use ruma_common::encryption::DeviceKeys;
+use ruma_identifiers::{DeviceId, UserId};
+
+ruma_api! {
+    metadata: {
+        description: "Returns the current devices and identity keys for the given users.",
+        method: POST,
+        name: "get_keys",
+        path: "/_matrix/federation/v1/user/keys/query",
+        rate_limited: false,
+        requires_authentication: true,
+    }
+
+    request: {
+        /// The keys to be downloaded. Gives all keys for a given user if the list of device ids is
+        /// empty.
+        device_keys: BTreeMap<UserId, Vec<Box<DeviceId>>>,
+    }
+
+    response: {
+        /// Keys from the queried devices.
+        device_keys: BTreeMap<UserId, BTreeMap<Box<DeviceId>, DeviceKeys>>,
+    }
+}
+
+impl Request {
+    /// Creates a new `Request` asking for the given device keys.
+    pub fn new(device_keys: BTreeMap<UserId, Vec<Box<DeviceId>>>) -> Self {
+        Self { device_keys }
+    }
+}
+
+impl Response {
+    /// Creates a new `Response` with the given device keys.
+    pub fn new(device_keys: BTreeMap<UserId, BTreeMap<Box<DeviceId>, DeviceKeys>>) -> Self {
+        Self { device_keys }
+    }
+}