Remove direct refeferences to PyNaCl (use signedjson instead). (#12902)

tests/crypto/test_event_signing.py

@@ -12,10 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
-import nacl.signing
-import signedjson.types
-from unpaddedbase64 import decode_base64
+from signedjson.key import decode_signing_key_base64
+from signedjson.types import SigningKey
 
 from synapse.api.room_versions import RoomVersions
 from synapse.crypto.event_signing import add_hashes_and_signatures
@@ -25,7 +23,7 @@ from tests import unittest
 
 # Perform these tests using given secret key so we get entirely deterministic
 # signatures output that we can test against.
-SIGNING_KEY_SEED = decode_base64("YJDBA9Xnr2sVqXD9Vj7XVUnmFZcZrlw8Md7kMW+3XA1")
+SIGNING_KEY_SEED = "YJDBA9Xnr2sVqXD9Vj7XVUnmFZcZrlw8Md7kMW+3XA1"
 
 KEY_ALG = "ed25519"
 KEY_VER = "1"
@@ -36,14 +34,9 @@ HOSTNAME = "domain"
 
 class EventSigningTestCase(unittest.TestCase):
     def setUp(self):
-        # NB: `signedjson` expects `nacl.signing.SigningKey` instances which have been
-        # monkeypatched to include new `alg` and `version` attributes. This is captured
-        # by the `signedjson.types.SigningKey` protocol.
-        self.signing_key: signedjson.types.SigningKey = nacl.signing.SigningKey(  # type: ignore[assignment]
-            SIGNING_KEY_SEED
+        self.signing_key: SigningKey = decode_signing_key_base64(
+            KEY_ALG, KEY_VER, SIGNING_KEY_SEED
         )
-        self.signing_key.alg = KEY_ALG
-        self.signing_key.version = KEY_VER
 
     def test_sign_minimal(self):
         event_dict = {

tests/crypto/test_keyring.py

@@ -19,8 +19,8 @@ import attr
 import canonicaljson
 import signedjson.key
 import signedjson.sign
-from nacl.signing import SigningKey
 from signedjson.key import encode_verify_key_base64, get_verify_key
+from signedjson.types import SigningKey
 
 from twisted.internet import defer
 from twisted.internet.defer import Deferred, ensureDeferred