diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index cca361b15b..352c8ee93b 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -19,6 +19,8 @@ import logging
from six import iteritems
+import attr
+
from canonicaljson import encode_canonical_json, json
from signedjson.key import decode_verify_key_bytes
from signedjson.sign import SignatureVerifyException, verify_signed_json
@@ -26,7 +28,7 @@ from unpaddedbase64 import decode_base64
from twisted.internet import defer
-from synapse.api.errors import CodeMessageException, Codes, SynapseError
+from synapse.api.errors import CodeMessageException, Codes, NotFoundError, SynapseError
from synapse.logging.context import make_deferred_yieldable, run_in_background
from synapse.logging.opentracing import log_kv, set_tag, tag_args, trace
from synapse.types import (
@@ -617,12 +619,18 @@ class E2eKeysHandler(object):
Args:
user_id (string): the user uploading the signatures
signatures (dict[string, dict[string, dict]]): map of users to
- devices to signed keys
+ devices to signed keys. This is the submission from the user; an
+ exception will be raised if it is malformed.
+ Returns:
+ dict: response to be sent back to the client. The response will have
+ a "failures" key, which will be a dict mapping users to devices
+ to errors for the signatures that failed.
+ Raises:
+ SynapseError: if the signatures dict is not valid.
"""
failures = {}
- # signatures to be stored. Each item will be a tuple of
- # (signing_key_id, target_user_id, target_device_id, signature)
+ # signatures to be stored. Each item will be a SignatureListItem
signature_list = []
# split between checking signatures for own user and signatures for
@@ -646,10 +654,10 @@ class E2eKeysHandler(object):
logger.debug("upload signature failures: %r", failures)
yield self.store.store_e2e_cross_signing_signatures(user_id, signature_list)
- self_device_ids = [device_id for (_, _, device_id, _) in self_signature_list]
+ self_device_ids = [item.target_device_id for item in self_signature_list]
if self_device_ids:
yield self.device_handler.notify_device_update(user_id, self_device_ids)
- signed_users = [user_id for (_, user_id, _, _) in other_signature_list]
+ signed_users = [item.target_user_id for item in other_signature_list]
if signed_users:
yield self.device_handler.notify_user_signature_update(
user_id, signed_users
@@ -661,48 +669,58 @@ class E2eKeysHandler(object):
def _process_self_signatures(self, user_id, signatures):
"""Process uploaded signatures of the user's own keys.
+ Signatures of the user's own keys from this API come in two forms:
+ - signatures of the user's devices by the user's self-signing key,
+ - signatures of the user's master key by the user's devices.
+
Args:
user_id (string): the user uploading the keys
signatures (dict[string, dict]): map of devices to signed keys
Returns:
- (list[(string, string, string, string)], dict[string, dict[string, dict]]):
- a list of signatures to upload, in the form (signing_key_id, target_user_id,
- target_device_id, signature), and a map of users to devices to failure
+ (list[SignatureListItem], dict[string, dict[string, dict]]):
+ a list of signatures to upload, and a map of users to devices to failure
reasons
+
+ Raises:
+ SynapseError: if the input is malformed
"""
signature_list = []
failures = {}
if not signatures:
return signature_list, failures
+ if not isinstance(signatures, dict):
+ raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
+
try:
# get our self-signing key to verify the signatures
- self_signing_key, self_signing_key_id, self_signing_verify_key = yield self._get_e2e_cross_signing_verify_key(
+ _, self_signing_key_id, self_signing_verify_key = yield self._get_e2e_cross_signing_verify_key(
user_id, "self_signing"
)
# get our master key, since it may be signed
- master_key, master_key_id, master_verify_key = yield self._get_e2e_cross_signing_verify_key(
+ master_key, _, master_verify_key = yield self._get_e2e_cross_signing_verify_key(
user_id, "master"
)
# fetch our stored devices. This is used to 1. verify
- # signatures on the master key, and 2. to can compare with what
+ # signatures on the master key, and 2. to compare with what
# was sent if the device was signed
devices = yield self.store.get_e2e_device_keys([(user_id, None)])
if user_id not in devices:
- raise SynapseError(404, "No device keys found", Codes.NOT_FOUND)
+ raise NotFoundError("No device keys found")
devices = devices[user_id]
except SynapseError as e:
- failures[user_id] = {
- device: _exception_to_failure(e) for device in signatures.keys()
- }
+ failure = _exception_to_failure(e)
+ failures[user_id] = {device: failure for device in signatures.keys()}
return signature_list, failures
for device_id, device in signatures.items():
+ if not isinstance(device, dict):
+ raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
try:
if "signatures" not in device or user_id not in device["signatures"]:
# no signature was sent
@@ -711,45 +729,9 @@ class E2eKeysHandler(object):
)
if device_id == master_verify_key.version:
- # we have master key signed by devices: for each
- # device that signed, check the signature. Since
- # the "failures" property in the response only has
- # granularity up to the signed device, either all
- # of the signatures on the master key succeed, or
- # all fail. So loop over the signatures and add
- # them to a separate signature list. If everything
- # works out, then add them all to the main
- # signature list. (In practice, we're likely to
- # only have only one signature anyways.)
- master_key_signature_list = []
- sigs = device["signatures"]
- for signing_key_id, signature in sigs[user_id].items():
- alg, signing_device_id = signing_key_id.split(":", 1)
- if (
- signing_device_id not in devices
- or signing_key_id
- not in devices[signing_device_id]["keys"]["keys"]
- ):
- # signed by an unknown device, or the
- # device does not have the key
- raise SynapseError(
- 400, "Invalid signature", Codes.INVALID_SIGNATURE
- )
-
- # get the key and check the signature
- pubkey = devices[signing_device_id]["keys"]["keys"][
- signing_key_id
- ]
- verify_key = decode_verify_key_bytes(
- signing_key_id, decode_base64(pubkey)
- )
- _check_device_signature(user_id, verify_key, device, master_key)
- device["signatures"] = sigs
-
- master_key_signature_list.append(
- (signing_key_id, user_id, device_id, signature)
- )
-
+ master_key_signature_list = self._check_master_key_signature(
+ user_id, device_id, device, master_key, devices
+ )
signature_list.extend(master_key_signature_list)
continue
@@ -765,7 +747,7 @@ class E2eKeysHandler(object):
try:
stored_device = devices[device_id]["keys"]
except KeyError:
- raise SynapseError(404, "Unknown device", Codes.NOT_FOUND)
+ raise NotFoundError("Unknown device")
if self_signing_key_id in stored_device.get("signatures", {}).get(
user_id, {}
):
@@ -779,26 +761,75 @@ class E2eKeysHandler(object):
signature = device["signatures"][user_id][self_signing_key_id]
signature_list.append(
- (self_signing_key_id, user_id, device_id, signature)
+ SignatureListItem(
+ self_signing_key_id, user_id, device_id, signature
+ )
)
except SynapseError as e:
failures.setdefault(user_id, {})[device_id] = _exception_to_failure(e)
return signature_list, failures
+ def _check_master_key_signature(
+ self, user_id, master_key_id, signed_master_key, stored_master_key, devices
+ ):
+ """Check signatures of the user's master key made by their devices.
+
+ Args:
+ user_id (string): the user uploading the keys
+ signatures (dict[string, dict]): map of users to devices to signed keys
+
+ Returns:
+ (list[SignatureListItem], dict[string, dict[string, dict]]):
+ a list of signatures to upload, and a map of users to devices to failure
+ reasons
+
+ Raises:
+ SynapseError: if the input is malformed
+ """
+ # for each device that signed the master key, check the signature.
+ master_key_signature_list = []
+ sigs = signed_master_key["signatures"]
+ for signing_key_id, signature in sigs[user_id].items():
+ _, signing_device_id = signing_key_id.split(":", 1)
+ if (
+ signing_device_id not in devices
+ or signing_key_id not in devices[signing_device_id]["keys"]["keys"]
+ ):
+ # signed by an unknown device, or the
+ # device does not have the key
+ raise SynapseError(400, "Invalid signature", Codes.INVALID_SIGNATURE)
+
+ # get the key and check the signature
+ pubkey = devices[signing_device_id]["keys"]["keys"][signing_key_id]
+ verify_key = decode_verify_key_bytes(signing_key_id, decode_base64(pubkey))
+ _check_device_signature(
+ user_id, verify_key, signed_master_key, stored_master_key
+ )
+
+ master_key_signature_list.append(
+ SignatureListItem(signing_key_id, user_id, master_key_id, signature)
+ )
+
+ return master_key_signature_list
+
@defer.inlineCallbacks
def _process_other_signatures(self, user_id, signatures):
- """Process uploaded signatures of other users' keys.
+ """Process uploaded signatures of other users' keys. These will be the
+ target user's master keys, signed by the uploading user's user-signing
+ key.
Args:
user_id (string): the user uploading the keys
signatures (dict[string, dict]): map of users to devices to signed keys
Returns:
- (list[(string, string, string, string)], dict[string, dict[string, dict]]):
- a list of signatures to upload, in the form (signing_key_id, target_user_id,
- target_device_id, signature), and a map of users to devices to failure
+ (list[SignatureListItem], dict[string, dict[string, dict]]):
+ a list of signatures to upload, and a map of users to devices to failure
reasons
+
+ Raises:
+ SynapseError: if the input is malformed
"""
signature_list = []
failures = {}
@@ -816,70 +847,89 @@ class E2eKeysHandler(object):
failures[user] = {device_id: failure for device_id in devicemap.keys()}
return signature_list, failures
- for user, devicemap in signatures.items():
+ for target_user, devicemap in signatures.items():
+ if not isinstance(devicemap, dict):
+ raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
+ for device in devicemap.values():
+ if not isinstance(device, dict):
+ raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
device_id = None
try:
- # get the user's master key, to make sure it matches
+ # get the target user's master key, to make sure it matches
# what was sent
- stored_key, stored_key_id, _ = yield self._get_e2e_cross_signing_verify_key(
- user, "master", user_id
+ master_key, master_key_id, _ = yield self._get_e2e_cross_signing_verify_key(
+ target_user, "master", user_id
)
- # make sure that the user's master key is the one that
+ # make sure that the target user's master key is the one that
# was signed (and no others)
- device_id = stored_key_id.split(":", 1)[1]
+ device_id = master_key_id.split(":", 1)[1]
if device_id not in devicemap:
- logger.error(
+ logger.debug(
"upload signature: could not find signature for device %s",
device_id,
)
# set device to None so that the failure gets
# marked on all the signatures
device_id = None
- raise SynapseError(404, "Unknown device", Codes.NOT_FOUND)
+ raise NotFoundError("Unknown device")
key = devicemap[device_id]
other_devices = [k for k in devicemap.keys() if k != device_id]
if other_devices:
# other devices were signed -- mark those as failures
- logger.error("upload signature: too many devices specified")
- failure = _exception_to_failure(
- SynapseError(404, "Unknown device", Codes.NOT_FOUND)
- )
- failures[user] = {device: failure for device in other_devices}
+ logger.debug("upload signature: too many devices specified")
+ failure = _exception_to_failure(NotFoundError("Unknown device"))
+ failures[target_user] = {
+ device: failure for device in other_devices
+ }
- if user_signing_key_id in stored_key.get("signatures", {}).get(
+ if user_signing_key_id in master_key.get("signatures", {}).get(
user_id, {}
):
# we already have the signature, so we can skip it
continue
_check_device_signature(
- user_id, user_signing_verify_key, key, stored_key
+ user_id, user_signing_verify_key, key, master_key
)
signature = key["signatures"][user_id][user_signing_key_id]
- signature_list.append((user_signing_key_id, user, device_id, signature))
+ signature_list.append(
+ SignatureListItem(
+ user_signing_key_id, target_user, device_id, signature
+ )
+ )
except SynapseError as e:
failure = _exception_to_failure(e)
if device_id is None:
- failures[user] = {
+ failures[target_user] = {
device_id: failure for device_id in devicemap.keys()
}
else:
- failures.setdefault(user, {})[device_id] = failure
+ failures.setdefault(target_user, {})[device_id] = failure
return signature_list, failures
@defer.inlineCallbacks
def _get_e2e_cross_signing_verify_key(self, user_id, key_type, from_user_id=None):
+ """Fetch the cross-signing public key from storage and interpret it.
+
+ Args:
+ user_id (str): the user whose key should be fetched
+ key_type (str): the type of key to fetch
+ from_user_id (str): the user that we are fetching the keys for.
+ This affects what signatures are fetched.
+
+ Returns:
+ dict, str, VerifyKey: the raw key data, the key ID, and the
+ signedjson verify key
+ """
key = yield self.store.get_e2e_cross_signing_key(
user_id, key_type, from_user_id
)
if key is None:
logger.error("no %s key found for %s", key_type, user_id)
- raise SynapseError(
- 404, "No %s key found for %s" % (key_type, user_id), Codes.NOT_FOUND
- )
+ raise NotFoundError("No %s key found for %s" % (key_type, user_id))
key_id, verify_key = get_verify_key_from_cross_signing_key(key)
return key, key_id, verify_key
@@ -912,36 +962,30 @@ def _check_cross_signing_key(key, user_id, key_type, signing_key=None):
def _check_device_signature(user_id, verify_key, signed_device, stored_device):
- """Check that a device signature is correct and matches the copy of the device
- that we have. Throws an exception if an error is detected.
+ """Check that a signature on a device or cross-signing key is correct and
+ matches the copy of the device/key that we have stored. Throws an
+ exception if an error is detected.
Args:
user_id (str): the user ID whose signature is being checked
verify_key (VerifyKey): the key to verify the device with
- signed_device (dict): the signed device data
- stored_device (dict): our previous copy of the device
- """
-
- key_id = "%s:%s" % (verify_key.alg, verify_key.version)
+ signed_device (dict): the uploaded signed device data
+ stored_device (dict): our previously stored copy of the device
- # make sure the device is signed
- if (
- "signatures" not in signed_device
- or user_id not in signed_device["signatures"]
- or key_id not in signed_device["signatures"][user_id]
- ):
- logger.error("upload signature: user not found in signatures")
- raise SynapseError(400, "Invalid signature", Codes.INVALID_SIGNATURE)
+ Raises:
+ SynapseError: if the signature was invalid or the sent device is not the
+ same as the stored device
- signature = signed_device["signatures"][user_id][key_id]
+ """
# make sure that the device submitted matches what we have stored
- del signed_device["signatures"]
- # use pop to avoid exception if key doesn't exist
- signed_device.pop("unsigned", None)
- stored_device.pop("signatures", None)
- stored_device.pop("unsigned", None)
- if signed_device != stored_device:
+ stripped_signed_device = {
+ k: v for k, v in signed_device.items() if k not in ["signatures", "unsigned"]
+ }
+ stripped_stored_device = {
+ k: v for k, v in stored_device.items() if k not in ["signatures", "unsigned"]
+ }
+ if stripped_signed_device != stripped_stored_device:
logger.error(
"upload signatures: key does not match %s vs %s",
signed_device,
@@ -949,9 +993,6 @@ def _check_device_signature(user_id, verify_key, signed_device, stored_device):
)
raise SynapseError(400, "Key does not match")
- # check the signature
- signed_device["signatures"] = {user_id: {key_id: signature}}
-
try:
verify_signed_json(signed_device, user_id, verify_key)
except SignatureVerifyException:
@@ -990,3 +1031,14 @@ def _one_time_keys_match(old_key_json, new_key):
new_key_copy.pop("signatures", None)
return old_key == new_key_copy
+
+
+@attr.s
+class SignatureListItem:
+ """An item in the signature list as used by upload_signatures_for_device_keys.
+ """
+
+ signing_key_id = attr.ib()
+ target_user_id = attr.ib()
+ target_device_id = attr.ib()
+ signature = attr.ib()
|
