Ensure JSON payloads are decoded from bytes when needed

Refs: #83

federation/protocols/diaspora/encrypted.py

@@ -20,9 +20,8 @@ class EncryptedPayload:
     def decrypt(payload, private_key):
         """Decrypt an encrypted JSON payload and return the Magic Envelope document inside."""
         cipher = PKCS1_v1_5.new(private_key)
-        aes_key = json.loads(
-            cipher.decrypt(b64decode(payload.get("aes_key")), sentinel=None)
-        )
+        aes_key_str = cipher.decrypt(b64decode(payload.get("aes_key")), sentinel=None)
+        aes_key = json.loads(aes_key_str.decode("utf-8"))
         key = b64decode(aes_key.get("key"))
         iv = b64decode(aes_key.get("iv"))
         encrypted_magic_envelope = b64decode(payload.get("encrypted_magic_envelope"))

federation/protocols/diaspora/protocol.py

@@ -14,6 +14,7 @@ from federation.exceptions import EncryptedMessageError, NoSenderKeyFoundError,
 from federation.protocols.base import BaseProtocol
 from federation.protocols.diaspora.encrypted import EncryptedPayload
 from federation.protocols.diaspora.magic_envelope import MagicEnvelope
+from federation.utils.text import decode_if_bytes
 
 logger = logging.getLogger("federation")
 
@@ -29,7 +30,7 @@ def identify_payload(payload):
     """
     # Private encrypted JSON payload
     try:
-        data = json.loads(payload)
+        data = json.loads(decode_if_bytes(payload))
         if "encrypted_magic_envelope" in data:
             return True
     except Exception:
@@ -67,7 +68,7 @@ class Protocol(BaseProtocol):
     def store_magic_envelope_doc(self, payload):
         """Get the Magic Envelope, trying JSON first."""
         try:
-            json_payload = json.loads(payload)
+            json_payload = json.loads(decode_if_bytes(payload))
         except ValueError:
             # XML payload
             xml = unquote_plus(payload)

federation/utils/text.py

@@ -0,0 +1,5 @@
+def decode_if_bytes(text):
+    try:
+        return text.decode("utf-8")
+    except AttributeError:
+        return text