11 files changed, 114 insertions, 24 deletions
diff --git a/changelog.d/6724.misc b/changelog.d/6724.misc
new file mode 100644
index 0000000000..5256be75fa
--- /dev/null
+++ b/changelog.d/6724.misc
@@ -0,0 +1 @@
+When processing a SAML response, log the assertions for easier configuration.
diff --git a/synapse/handlers/saml_handler.py b/synapse/handlers/saml_handler.py
index 90e69b49ee..7f411b53b9 100644
--- a/synapse/handlers/saml_handler.py
+++ b/synapse/handlers/saml_handler.py
@@ -32,6 +32,7 @@ from synapse.types import (
     mxid_localpart_allowed_characters,
 )
 from synapse.util.async_helpers import Linearizer
+from synapse.util.iterutils import chunk_seq
 
 logger = logging.getLogger(__name__)
 
@@ -132,7 +133,17 @@ class SamlHandler:
             logger.warning("SAML2 response was not signed")
             raise SynapseError(400, "SAML2 response was not signed")
 
-        logger.info("SAML2 response: %s", saml2_auth.origxml)
+        logger.debug("SAML2 response: %s", saml2_auth.origxml)
+        for assertion in saml2_auth.assertions:
+            # kibana limits the length of a log field, whereas this is all rather
+            # useful, so split it up.
+            count = 0
+            for part in chunk_seq(str(assertion), 10000):
+                logger.info(
+                    "SAML2 assertion: %s%s", "(%i)..." % (count,) if count else "", part
+                )
+                count += 1
+
         logger.info("SAML2 mapped attributes: %s", saml2_auth.ava)
 
         self._outstanding_requests_dict.pop(saml2_auth.in_response_to, None)
diff --git a/synapse/storage/data_stores/main/cache.py b/synapse/storage/data_stores/main/cache.py
index 54ed8574c4..bf91512daf 100644
--- a/synapse/storage/data_stores/main/cache.py
+++ b/synapse/storage/data_stores/main/cache.py
@@ -21,7 +21,7 @@ from twisted.internet import defer
 
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.engines import PostgresEngine
-from synapse.util import batch_iter
+from synapse.util.iterutils import batch_iter
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/storage/data_stores/main/devices.py b/synapse/storage/data_stores/main/devices.py
index 9a828231c4..f0a7962dd0 100644
--- a/synapse/storage/data_stores/main/devices.py
+++ b/synapse/storage/data_stores/main/devices.py
@@ -33,13 +33,13 @@ from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause
 from synapse.storage.database import Database
 from synapse.types import get_verify_key_from_cross_signing_key
-from synapse.util import batch_iter
 from synapse.util.caches.descriptors import (
     Cache,
     cached,
     cachedInlineCallbacks,
     cachedList,
 )
+from synapse.util.iterutils import batch_iter
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py
index e9fe63037b..bb69c20448 100644
--- a/synapse/storage/data_stores/main/events.py
+++ b/synapse/storage/data_stores/main/events.py
@@ -43,9 +43,9 @@ from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
 from synapse.storage.data_stores.main.state import StateGroupWorkerStore
 from synapse.storage.database import Database
 from synapse.types import RoomStreamToken, get_domain_from_id
-from synapse.util import batch_iter
 from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
 from synapse.util.frozenutils import frozendict_json_encoder
+from synapse.util.iterutils import batch_iter
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/storage/data_stores/main/events_worker.py b/synapse/storage/data_stores/main/events_worker.py
index 0cce5232f5..3b93e0597a 100644
--- a/synapse/storage/data_stores/main/events_worker.py
+++ b/synapse/storage/data_stores/main/events_worker.py
@@ -37,8 +37,8 @@ from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause
 from synapse.storage.database import Database
 from synapse.types import get_domain_from_id
-from synapse.util import batch_iter
 from synapse.util.caches.descriptors import Cache
+from synapse.util.iterutils import batch_iter
 from synapse.util.metrics import Measure
 
 logger = logging.getLogger(__name__)
diff --git a/synapse/storage/data_stores/main/keys.py b/synapse/storage/data_stores/main/keys.py
index 6b12f5a75f..ba89c68c9f 100644
--- a/synapse/storage/data_stores/main/keys.py
+++ b/synapse/storage/data_stores/main/keys.py
@@ -23,8 +23,8 @@ from signedjson.key import decode_verify_key_bytes
 
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.keys import FetchKeyResult
-from synapse.util import batch_iter
 from synapse.util.caches.descriptors import cached, cachedList
+from synapse.util.iterutils import batch_iter
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/storage/data_stores/main/presence.py b/synapse/storage/data_stores/main/presence.py
index a2c83e0867..604c8b7ddd 100644
--- a/synapse/storage/data_stores/main/presence.py
+++ b/synapse/storage/data_stores/main/presence.py
@@ -17,8 +17,8 @@ from twisted.internet import defer
 
 from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause
 from synapse.storage.presence import UserPresenceState
-from synapse.util import batch_iter
 from synapse.util.caches.descriptors import cached, cachedList
+from synapse.util.iterutils import batch_iter
 
 
 class PresenceStore(SQLBaseStore):
diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py
index 7856353002..60f0de70f7 100644
--- a/synapse/util/__init__.py
+++ b/synapse/util/__init__.py
@@ -15,7 +15,6 @@
 
 import logging
 import re
-from itertools import islice
 
 import attr
 
@@ -107,22 +106,6 @@ class Clock(object):
                 raise
 
 
-def batch_iter(iterable, size):
-    """batch an iterable up into tuples with a maximum size
-
-    Args:
-        iterable (iterable): the iterable to slice
-        size (int): the maximum batch size
-
-    Returns:
-        an iterator over the chunks
-    """
-    # make sure we can deal with iterables like lists too
-    sourceiter = iter(iterable)
-    # call islice until it returns an empty tuple
-    return iter(lambda: tuple(islice(sourceiter, size)), ())
-
-
 def log_failure(failure, msg, consumeErrors=True):
     """Creates a function suitable for passing to `Deferred.addErrback` that
     logs any failures that occur.
diff --git a/synapse/util/iterutils.py b/synapse/util/iterutils.py
new file mode 100644
index 0000000000..06faeebe7f
--- /dev/null
+++ b/synapse/util/iterutils.py
@@ -0,0 +1,48 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+# 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.
+from itertools import islice
+from typing import Iterable, Iterator, Sequence, Tuple, TypeVar
+
+T = TypeVar("T")
+
+
+def batch_iter(iterable: Iterable[T], size: int) -> Iterator[Tuple[T]]:
+    """batch an iterable up into tuples with a maximum size
+
+    Args:
+        iterable (iterable): the iterable to slice
+        size (int): the maximum batch size
+
+    Returns:
+        an iterator over the chunks
+    """
+    # make sure we can deal with iterables like lists too
+    sourceiter = iter(iterable)
+    # call islice until it returns an empty tuple
+    return iter(lambda: tuple(islice(sourceiter, size)), ())
+
+
+ISeq = TypeVar("ISeq", bound=Sequence, covariant=True)
+
+
+def chunk_seq(iseq: ISeq, maxlen: int) -> Iterable[ISeq]:
+    """Split the given sequence into chunks of the given size
+
+    The last chunk may be shorter than the given size.
+
+    If the input is empty, no chunks are returned.
+    """
+    return (iseq[i : i + maxlen] for i in range(0, len(iseq), maxlen))
diff --git a/tests/util/test_itertools.py b/tests/util/test_itertools.py
new file mode 100644
index 0000000000..0ab0a91483
--- /dev/null
+++ b/tests/util/test_itertools.py
@@ -0,0 +1,47 @@
+# -*- coding: utf-8 -*-
+# 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.
+from synapse.util.iterutils import chunk_seq
+
+from tests.unittest import TestCase
+
+
+class ChunkSeqTests(TestCase):
+    def test_short_seq(self):
+        parts = chunk_seq("123", 8)
+
+        self.assertEqual(
+            list(parts), ["123"],
+        )
+
+    def test_long_seq(self):
+        parts = chunk_seq("abcdefghijklmnop", 8)
+
+        self.assertEqual(
+            list(parts), ["abcdefgh", "ijklmnop"],
+        )
+
+    def test_uneven_parts(self):
+        parts = chunk_seq("abcdefghijklmnop", 5)
+
+        self.assertEqual(
+            list(parts), ["abcde", "fghij", "klmno", "p"],
+        )
+
+    def test_empty_input(self):
+        parts = chunk_seq([], 5)
+
+        self.assertEqual(
+            list(parts), [],
+        )