forked from MirrorHub/synapse
Require sig from origin server on perspectives responses
This commit is contained in:
parent
ec24108cc2
commit
753b1270da
2 changed files with 91 additions and 23 deletions
|
@ -394,8 +394,7 @@ class BaseV2KeyFetcher(object):
|
|||
POST /_matrix/key/v2/query.
|
||||
|
||||
Checks that each signature in the response that claims to come from the origin
|
||||
server is valid. (Does not check that there actually is such a signature, for
|
||||
some reason.)
|
||||
server is valid, and that there is at least one such signature.
|
||||
|
||||
Stores the json in server_keys_json so that it can be used for future responses
|
||||
to /_matrix/key/v2/query.
|
||||
|
@ -430,16 +429,25 @@ class BaseV2KeyFetcher(object):
|
|||
verify_key=verify_key, valid_until_ts=ts_valid_until_ms
|
||||
)
|
||||
|
||||
# TODO: improve this signature checking
|
||||
server_name = response_json["server_name"]
|
||||
verified = False
|
||||
for key_id in response_json["signatures"].get(server_name, {}):
|
||||
if key_id not in verify_keys:
|
||||
# each of the keys used for the signature must be present in the response
|
||||
# json.
|
||||
key = verify_keys.get(key_id)
|
||||
if not key:
|
||||
raise KeyLookupError(
|
||||
"Key response must include verification keys for all signatures"
|
||||
"Key response is signed by key id %s:%s but that key is not "
|
||||
"present in the response" % (server_name, key_id)
|
||||
)
|
||||
|
||||
verify_signed_json(
|
||||
response_json, server_name, verify_keys[key_id].verify_key
|
||||
verify_signed_json(response_json, server_name, key.verify_key)
|
||||
verified = True
|
||||
|
||||
if not verified:
|
||||
raise KeyLookupError(
|
||||
"Key response for %s is not signed by the origin server"
|
||||
% (server_name,)
|
||||
)
|
||||
|
||||
for key_id, key_data in response_json["old_verify_keys"].items():
|
||||
|
@ -677,12 +685,6 @@ class ServerKeyFetcher(BaseV2KeyFetcher):
|
|||
except HttpResponseException as e:
|
||||
raise_from(KeyLookupError("Remote server returned an error"), e)
|
||||
|
||||
if (
|
||||
u"signatures" not in response
|
||||
or server_name not in response[u"signatures"]
|
||||
):
|
||||
raise KeyLookupError("Key response not signed by remote server")
|
||||
|
||||
if response["server_name"] != server_name:
|
||||
raise KeyLookupError(
|
||||
"Expected a response for server %r not %r"
|
||||
|
|
|
@ -55,12 +55,12 @@ class MockPerspectiveServer(object):
|
|||
key_id: {"key": signedjson.key.encode_verify_key_base64(verify_key)}
|
||||
},
|
||||
}
|
||||
return self.get_signed_response(res)
|
||||
|
||||
def get_signed_response(self, res):
|
||||
signedjson.sign.sign_json(res, self.server_name, self.key)
|
||||
self.sign_response(res)
|
||||
return res
|
||||
|
||||
def sign_response(self, res):
|
||||
signedjson.sign.sign_json(res, self.server_name, self.key)
|
||||
|
||||
|
||||
class KeyringTestCase(unittest.HomeserverTestCase):
|
||||
def make_homeserver(self, reactor, clock):
|
||||
|
@ -238,7 +238,7 @@ class ServerKeyFetcherTestCase(unittest.HomeserverTestCase):
|
|||
testkey = signedjson.key.generate_signing_key("ver1")
|
||||
testverifykey = signedjson.key.get_verify_key(testkey)
|
||||
testverifykey_id = "ed25519:ver1"
|
||||
VALID_UNTIL_TS = 1000
|
||||
VALID_UNTIL_TS = 200 * 1000
|
||||
|
||||
# valid response
|
||||
response = {
|
||||
|
@ -326,9 +326,10 @@ class PerspectivesKeyFetcherTestCase(unittest.HomeserverTestCase):
|
|||
},
|
||||
}
|
||||
|
||||
persp_resp = {
|
||||
"server_keys": [self.mock_perspective_server.get_signed_response(response)]
|
||||
}
|
||||
# the response must be signed by both the origin server and the perspectives
|
||||
# server.
|
||||
signedjson.sign.sign_json(response, SERVER_NAME, testkey)
|
||||
self.mock_perspective_server.sign_response(response)
|
||||
|
||||
def post_json(destination, path, data, **kwargs):
|
||||
self.assertEqual(destination, self.mock_perspective_server.server_name)
|
||||
|
@ -337,7 +338,7 @@ class PerspectivesKeyFetcherTestCase(unittest.HomeserverTestCase):
|
|||
# check that the request is for the expected key
|
||||
q = data["server_keys"]
|
||||
self.assertEqual(list(q[SERVER_NAME].keys()), ["key1"])
|
||||
return persp_resp
|
||||
return {"server_keys": [response]}
|
||||
|
||||
self.http_client.post_json.side_effect = post_json
|
||||
|
||||
|
@ -365,9 +366,74 @@ class PerspectivesKeyFetcherTestCase(unittest.HomeserverTestCase):
|
|||
|
||||
self.assertEqual(
|
||||
bytes(res["key_json"]),
|
||||
canonicaljson.encode_canonical_json(persp_resp["server_keys"][0]),
|
||||
canonicaljson.encode_canonical_json(response),
|
||||
)
|
||||
|
||||
def test_invalid_perspectives_responses(self):
|
||||
"""Check that invalid responses from the perspectives server are rejected"""
|
||||
# arbitrarily advance the clock a bit
|
||||
self.reactor.advance(100)
|
||||
|
||||
SERVER_NAME = "server2"
|
||||
testkey = signedjson.key.generate_signing_key("ver1")
|
||||
testverifykey = signedjson.key.get_verify_key(testkey)
|
||||
testverifykey_id = "ed25519:ver1"
|
||||
VALID_UNTIL_TS = 200 * 1000
|
||||
|
||||
def build_response():
|
||||
# valid response
|
||||
response = {
|
||||
"server_name": SERVER_NAME,
|
||||
"old_verify_keys": {},
|
||||
"valid_until_ts": VALID_UNTIL_TS,
|
||||
"verify_keys": {
|
||||
testverifykey_id: {
|
||||
"key": signedjson.key.encode_verify_key_base64(testverifykey)
|
||||
}
|
||||
},
|
||||
}
|
||||
|
||||
# the response must be signed by both the origin server and the perspectives
|
||||
# server.
|
||||
signedjson.sign.sign_json(response, SERVER_NAME, testkey)
|
||||
self.mock_perspective_server.sign_response(response)
|
||||
return response
|
||||
|
||||
def get_key_from_perspectives(response):
|
||||
fetcher = PerspectivesKeyFetcher(self.hs)
|
||||
server_name_and_key_ids = [(SERVER_NAME, ("key1",))]
|
||||
|
||||
def post_json(destination, path, data, **kwargs):
|
||||
self.assertEqual(destination, self.mock_perspective_server.server_name)
|
||||
self.assertEqual(path, "/_matrix/key/v2/query")
|
||||
return {"server_keys": [response]}
|
||||
|
||||
self.http_client.post_json.side_effect = post_json
|
||||
|
||||
return self.get_success(
|
||||
fetcher.get_keys(server_name_and_key_ids)
|
||||
)
|
||||
|
||||
# start with a valid response so we can check we are testing the right thing
|
||||
response = build_response()
|
||||
keys = get_key_from_perspectives(response)
|
||||
k = keys[SERVER_NAME][testverifykey_id]
|
||||
self.assertEqual(k.verify_key, testverifykey)
|
||||
|
||||
# remove the perspectives server's signature
|
||||
response = build_response()
|
||||
del response["signatures"][self.mock_perspective_server.server_name]
|
||||
self.http_client.post_json.return_value = {"server_keys": [response]}
|
||||
keys = get_key_from_perspectives(response)
|
||||
self.assertEqual(keys, {}, "Expected empty dict with missing persp server sig")
|
||||
|
||||
# remove the origin server's signature
|
||||
response = build_response()
|
||||
del response["signatures"][SERVER_NAME]
|
||||
self.http_client.post_json.return_value = {"server_keys": [response]}
|
||||
keys = get_key_from_perspectives(response)
|
||||
self.assertEqual(keys, {}, "Expected empty dict with missing origin server sig")
|
||||
|
||||
|
||||
@defer.inlineCallbacks
|
||||
def run_in_context(f, *args, **kwargs):
|
||||
|
|
Loading…
Reference in a new issue