Add client API for uploading and querying keys for end to end encryption

1 files changed, 287 insertions, 0 deletions

diff --git a/synapse/rest/client/v2_alpha/keys.py b/synapse/rest/client/v2_alpha/keys.py
new file mode 100644
index 0000000000..3bb4ad64f3
--- /dev/null
+++ b/synapse/rest/client/v2_alpha/keys.py
@@ -0,0 +1,287 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015 OpenMarket Ltd
+#
+# 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.
+
+from twisted.internet import defer
+
+from synapse.api.errors import SynapseError
+from synapse.http.servlet import RestServlet
+from syutil.jsonutil import encode_canonical_json
+
+from ._base import client_v2_pattern
+
+import simplejson as json
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class KeyUploadServlet(RestServlet):
+    """
+    POST /keys/upload/<device_id> HTTP/1.1
+    Content-Type: application/json
+
+    {
+      "device_keys": {
+        "user_id": "<user_id>",
+        "device_id": "<device_id>",
+        "valid_until_ts": <millisecond_timestamp>,
+        "algorithms": [
+          "m.olm.curve25519-aes-sha256",
+        ]
+        "keys": {
+          "<algorithm>:<key_id>": "<key_base64>",
+        },
+        "signatures:" {
+          "<user_id>/<device_id>" {
+            "<algorithm>:<key_id>": "<signature_base64>"
+      } } },
+      "one_time_keys": {
+        "<algorithm>:<key_id>": "<key_base64>"
+      },
+      "one_time_keys_valid_for": <millisecond duration>,
+    }
+    """
+    PATTERN = client_v2_pattern("/keys/upload/(?P<device_id>[^/]*)")
+
+    def __init__(self, hs):
+        super(KeyUploadServlet, self).__init__()
+        self.store = hs.get_datastore()
+        self.clock = hs.get_clock()
+        self.auth = hs.get_auth()
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, device_id):
+        auth_user, client_info = yield self.auth.get_user_by_req(request)
+        user_id = auth_user.to_string()
+        # TODO: Check that the device_id matches that in the authentication
+        # or derive the device_id from the authentication instead.
+        try:
+            body = json.loads(request.content.read())
+        except:
+            raise SynapseError(400, "Invalid key JSON")
+        time_now = self.clock.time_msec()
+
+        # TODO: Validate the JSON to make sure it has the right keys.
+        device_keys = body.get("device_keys", None)
+        if device_keys:
+            logger.info(
+                "Updating device_keys for device %r for user %r at %d",
+                device_id, auth_user, time_now
+            )
+            # TODO: Sign the JSON with the server key
+            yield self.store.set_e2e_device_keys(
+                user_id, device_id, time_now,
+                encode_canonical_json(device_keys)
+            )
+
+        one_time_keys = body.get("one_time_keys", None)
+        one_time_keys_valid_for = body.get("one_time_keys_valid_for", None)
+        if one_time_keys:
+            valid_until = int(one_time_keys_valid_for) + time_now
+            logger.info(
+                "Adding %d one_time_keys for device %r for user %r at %d"
+                " valid_until %d",
+                len(one_time_keys), device_id, user_id, time_now, valid_until
+            )
+            key_list = []
+            for key_id, key_json in one_time_keys.items():
+                algorithm, key_id = key_id.split(":")
+                key_list.append((
+                    algorithm, key_id, encode_canonical_json(key_json)
+                ))
+
+            yield self.store.add_e2e_one_time_keys(
+                user_id, device_id, time_now, valid_until, key_list
+            )
+
+        result = yield self.store.count_e2e_one_time_keys(
+            user_id, device_id, time_now
+        )
+        defer.returnValue((200, {"one_time_key_counts": result}))
+
+    @defer.inlineCallbacks
+    def on_GET(self, request, device_id):
+        auth_user, client_info = yield self.auth.get_user_by_req(request)
+        user_id = auth_user.to_string()
+        time_now = self.clock.time_msec()
+
+        result = yield self.store.count_e2e_one_time_keys(
+            user_id, device_id, time_now
+        )
+        defer.returnValue((200, {"one_time_key_counts": result}))
+
+
+class KeyQueryServlet(RestServlet):
+    """
+    GET /keys/query/<user_id> HTTP/1.1
+
+    GET /keys/query/<user_id>/<device_id> HTTP/1.1
+
+    POST /keys/query HTTP/1.1
+    Content-Type: application/json
+    {
+      "device_keys": {
+        "<user_id>": ["<device_id>"]
+    } }
+
+    HTTP/1.1 200 OK
+    {
+      "device_keys": {
+        "<user_id>": {
+          "<device_id>": {
+            "user_id": "<user_id>", // Duplicated to be signed
+            "device_id": "<device_id>", // Duplicated to be signed
+            "valid_until_ts": <millisecond_timestamp>,
+            "algorithms": [ // List of supported algorithms
+              "m.olm.curve25519-aes-sha256",
+            ],
+            "keys": { // Must include a ed25519 signing key
+              "<algorithm>:<key_id>": "<key_base64>",
+            },
+            "signatures:" {
+              // Must be signed with device's ed25519 key
+              "<user_id>/<device_id>": {
+                "<algorithm>:<key_id>": "<signature_base64>"
+              }
+              // Must be signed by this server.
+              "<server_name>": {
+                "<algorithm>:<key_id>": "<signature_base64>"
+    } } } } } }
+    """
+
+    PATTERN = client_v2_pattern(
+        "/keys/query(?:"
+        "/(?P<user_id>[^/]*)(?:"
+        "/(?P<device_id>[^/]*)"
+        ")?"
+        ")?"
+    )
+
+    def __init__(self, hs):
+        super(KeyQueryServlet, self).__init__()
+        self.store = hs.get_datastore()
+        self.auth = hs.get_auth()
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, user_id, device_id):
+        logger.debug("onPOST")
+        yield self.auth.get_user_by_req(request)
+        try:
+            body = json.loads(request.content.read())
+        except:
+            raise SynapseError(400, "Invalid key JSON")
+        query = []
+        for user_id, device_ids in body.get("device_keys", {}).items():
+            if not device_ids:
+                query.append((user_id, None))
+            else:
+                for device_id in device_ids:
+                    query.append((user_id, device_id))
+        results = yield self.store.get_e2e_device_keys([(user_id, device_id)])
+        defer.returnValue(self.json_result(request, results))
+
+    @defer.inlineCallbacks
+    def on_GET(self, request, user_id, device_id):
+        auth_user, client_info = yield self.auth.get_user_by_req(request)
+        auth_user_id = auth_user.to_string()
+        if not user_id:
+            user_id = auth_user_id
+        if not device_id:
+            device_id = None
+        # Returns a map of user_id->device_id->json_bytes.
+        results = yield self.store.get_e2e_device_keys([(user_id, device_id)])
+        defer.returnValue(self.json_result(request, results))
+
+    def json_result(self, request, results):
+        json_result = {}
+        for user_id, device_keys in results.items():
+            for device_id, json_bytes in device_keys.items():
+                json_result.setdefault(user_id, {})[device_id] = json.loads(
+                    json_bytes
+                )
+        return (200, {"device_keys": json_result})
+
+
+class OneTimeKeyServlet(RestServlet):
+    """
+    GET /keys/take/<user-id>/<device-id>/<algorithm> HTTP/1.1
+
+    POST /keys/take HTTP/1.1
+    {
+      "one_time_keys": {
+        "<user_id>": {
+          "<device_id>": "<algorithm>"
+    } } }
+
+    HTTP/1.1 200 OK
+    {
+      "one_time_keys": {
+        "<user_id>": {
+          "<device_id>": {
+            "<algorithm>:<key_id>": "<key_base64>"
+    } } } }
+
+    """
+    PATTERN = client_v2_pattern(
+        "/keys/take(?:/?|(?:/"
+        "(?P<user_id>[^/]*)/(?P<device_id>[^/]*)/(?P<algorithm>[^/]*)"
+        ")?)"
+    )
+
+    def __init__(self, hs):
+        super(OneTimeKeyServlet, self).__init__()
+        self.store = hs.get_datastore()
+        self.auth = hs.get_auth()
+        self.clock = hs.get_clock()
+
+    @defer.inlineCallbacks
+    def on_GET(self, request, user_id, device_id, algorithm):
+        yield self.auth.get_user_by_req(request)
+        time_now = self.clock.time_msec()
+        results = yield self.store.take_e2e_one_time_keys(
+            [(user_id, device_id, algorithm)], time_now
+        )
+        defer.returnValue(self.json_result(request, results))
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, user_id, device_id, algorithm):
+        yield self.auth.get_user_by_req(request)
+        try:
+            body = json.loads(request.content.read())
+        except:
+            raise SynapseError(400, "Invalid key JSON")
+        query = []
+        for user_id, device_keys in body.get("one_time_keys", {}).items():
+            for device_id, algorithm in device_keys.items():
+                query.append((user_id, device_id, algorithm))
+        time_now = self.clock.time_msec()
+        results = yield self.store.take_e2e_one_time_keys(query, time_now)
+        defer.returnValue(self.json_result(request, results))
+
+    def json_result(self, request, results):
+        json_result = {}
+        for user_id, device_keys in results.items():
+            for device_id, keys in device_keys.items():
+                for key_id, json_bytes in keys.items():
+                    json_result.setdefault(user_id, {})[device_id] = {
+                        key_id: json.loads(json_bytes)
+                    }
+        return (200, {"one_time_keys": json_result})
+
+
+def register_servlets(hs, http_server):
+    KeyUploadServlet(hs).register(http_server)
+    KeyQueryServlet(hs).register(http_server)
+    OneTimeKeyServlet(hs).register(http_server)