Export generate_random_key and get_default_params from ably.pubsub.server

UPDATING.md

@@ -49,6 +49,18 @@ Where 3.x left you reaching into submodules such as `ably.types.message` or
 the whole public API, and `ably.pubsub.server.sync` is its synchronous
 counterpart. The packages beneath them are internal and free to move.
 
+For example, the encryption helpers move from `ably.util.crypto`:
+
+Example 3.x code:
+```python
+from ably.util.crypto import generate_random_key, get_default_params
+```
+
+Example 4.0.0 code:
+```python
+from ably.pubsub.server import generate_random_key, get_default_params
+```
+
 ### Clients are built by factories
 
 `AblyRest` and `AblyRealtime` are internal in 4.0.0 and raise `TypeError` if

ably/pubsub/server/__init__.py

@@ -38,7 +38,7 @@
 from ably.pubsub.types.options import Options, VCDiffDecoder
 from ably.pubsub.types.tokendetails import TokenDetails
 from ably.pubsub.util.construction import factory_construction
-from ably.pubsub.util.crypto import CipherParams
+from ably.pubsub.util.crypto import CipherParams, generate_random_key, get_default_params
 from ably.pubsub.util.exceptions import AblyAuthException, AblyException, IncompatibleClientIdException
 from ably.pubsub.vcdiff.defaultvcdiffdecoder import AblyVCDiffDecoder
 from ably.pubsub.version import api_version, lib_version
@@ -275,5 +275,7 @@ def create_realtime_client(**kwargs) -> PubSubRealtimeClient:
     'api_version',
     'create_http_client',
     'create_realtime_client',
+    'generate_random_key',
+    'get_default_params',
     'lib_version',
 ]

ably/pubsub/server/sync.py

@@ -24,7 +24,7 @@
 from ably.pubsub.sync.types.options import Options, VCDiffDecoder
 from ably.pubsub.sync.types.tokendetails import TokenDetails
 from ably.pubsub.sync.util.construction import factory_construction
-from ably.pubsub.sync.util.crypto import CipherParams
+from ably.pubsub.sync.util.crypto import CipherParams, generate_random_key, get_default_params
 from ably.pubsub.sync.util.exceptions import AblyAuthException, AblyException, IncompatibleClientIdException
 from ably.pubsub.sync.vcdiff.defaultvcdiffdecoder import AblyVCDiffDecoder
 from ably.pubsub.version import api_version, lib_version
@@ -84,5 +84,7 @@ def create_http_client(**kwargs) -> PubSubHttpClient:
     'VCDiffDecoder',
     'api_version',
     'create_http_client',
+    'generate_random_key',
+    'get_default_params',
     'lib_version',
 ]

ably/pubsub/util/nocrypto.py

@@ -2,7 +2,7 @@
 class InstallPycrypto:
     def __getattr__(self, name):
         raise ImportError(
-            "This requires to install ably with crypto support: pip install 'ably[crypto]'"
+            "This requires ably-pubsub-server with crypto support: pip install 'ably-pubsub-server[crypto]'"
         )
 
 

test/unit/pubsub_server_test.py

@@ -161,3 +161,9 @@ class TestPublicTypes:
     def test_message_is_exported(self):
         assert 'Message' in server.__all__
         assert 'Message' in server_sync.__all__
+
+    # RSE2: channel encryption needs a public way to generate a key and build cipher params
+    @pytest.mark.parametrize('name', ['generate_random_key', 'get_default_params'])
+    def test_crypto_helpers_are_exported(self, name):
+        assert name in server.__all__
+        assert name in server_sync.__all__