Merge pull request #31 from Indicio-tech/refactor/flexible-services

refactor: make services more flexible

Author: frostyfrog

didcomm_messaging/__init__.py

@@ -46,24 +46,9 @@ class UnpackResult:
     sender_kid: Optional[str] = None
 
 
-class DIDCommMessaging(Generic[P, S]):
+class DIDCommMessagingService(Generic[P, S]):
     """Main entrypoint for DIDComm Messaging."""
 
-    def __init__(
-        self,
-        crypto: CryptoService[P, S],
-        secrets: SecretsManager[S],
-        resolver: DIDResolver,
-        packaging: PackagingService[P, S],
-        routing: RoutingService,
-    ):
-        """Initialize the DIDComm Messaging service."""
-        self.crypto = crypto
-        self.secrets = secrets
-        self.resolver = resolver
-        self.packaging = packaging
-        self.routing = routing
-
     def service_to_target(self, service: DIDCommV2Service) -> str:
         """Convert a service to a target uri.
 
@@ -76,20 +61,49 @@ def service_to_target(self, service: DIDCommV2Service) -> str:
 
         return service_endpoint.uri
 
-    async def pack(self, message: dict, to: str, frm: Optional[str] = None, **options):
+    async def pack(
+        self,
+        crypto: CryptoService[P, S],
+        resolver: DIDResolver,
+        secrets: SecretsManager[S],
+        packaging: PackagingService[P, S],
+        routing: RoutingService,
+        message: dict,
+        to: str,
+        frm: Optional[str] = None,
+        **options,
+    ):
         """Pack a message."""
         # TODO crypto layer permits packing to multiple recipients; should we as well?
 
-        encoded_message = await self.packaging.pack(
-            json.dumps(message).encode(), [to], frm, **options
+        encoded_message = await packaging.pack(
+            crypto,
+            resolver,
+            secrets,
+            json.dumps(message).encode(),
+            [to],
+            frm,
+            **options,
         )
 
-        forward, services = await self.routing.prepare_forward(to, encoded_message)
+        forward, services = await routing.prepare_forward(
+            crypto, packaging, resolver, secrets, to, encoded_message
+        )
         return PackResult(forward, services)
 
-    async def unpack(self, encoded_message: bytes, **options) -> UnpackResult:
+    async def unpack(
+        self,
+        crypto: CryptoService[P, S],
+        resolver: DIDResolver,
+        secrets: SecretsManager[S],
+        packaging: PackagingService[P, S],
+        encoded_message: bytes,
+        **options,
+    ) -> UnpackResult:
         """Unpack a message."""
-        unpacked, metadata = await self.packaging.unpack(encoded_message, **options)
+        unpacked, metadata = await packaging.unpack(
+            crypto, resolver, secrets, encoded_message, **options
+        )
         message = json.loads(unpacked.decode())
         return UnpackResult(
             message,
@@ -98,3 +112,58 @@ async def unpack(self, encoded_message: bytes, **options) -> UnpackResult:
             recipient_kid=metadata.recip_key.kid,
             sender_kid=metadata.sender_kid,
         )
+
+
+class DIDCommMessaging(Generic[P, S]):
+    """Main entrypoint for DIDComm Messaging."""
+
+    def __init__(
+        self,
+        crypto: CryptoService[P, S],
+        secrets: SecretsManager[S],
+        resolver: DIDResolver,
+        packaging: PackagingService[P, S],
+        routing: RoutingService,
+    ):
+        """Initialize the DIDComm Messaging service."""
+        self.crypto = crypto
+        self.secrets = secrets
+        self.resolver = resolver
+        self.packaging = packaging
+        self.routing = routing
+        self.dmp = DIDCommMessagingService()
+
+    async def pack(
+        self,
+        message: dict,
+        to: str,
+        frm: Optional[str] = None,
+        **options,
+    ) -> PackResult:
+        """Pack a message."""
+        return await self.dmp.pack(
+            self.crypto,
+            self.resolver,
+            self.secrets,
+            self.packaging,
+            self.routing,
+            message,
+            to,
+            frm,
+            **options,
+        )
+
+    async def unpack(
+        self,
+        encoded_message: bytes,
+        **options,
+    ) -> UnpackResult:
+        """Unpack a message."""
+        return await self.dmp.unpack(
+            self.crypto,
+            self.resolver,
+            self.secrets,
+            self.packaging,
+            encoded_message,
+            **options,
+        )

didcomm_messaging/packaging.py

@@ -28,19 +28,8 @@ class PackagingServiceError(Exception):
 class PackagingService(Generic[P, S]):
     """DIDComm Messaging interface."""
 
-    def __init__(
-        self,
-        resolver: DIDResolver,
-        crypto: CryptoService[P, S],
-        secrets: SecretsManager[S],
-    ):
-        """Initialize the KMS."""
-        self.resolver = resolver
-        self.crypto = crypto
-        self.secrets = secrets
-
     async def extract_packed_message_metadata(  # noqa: C901
-        self, enc_message: Union[str, bytes]
+        self, enc_message: Union[str, bytes], secrets: SecretsManager[S]
     ) -> PackedMessageMetadata:
         """Extract metadata from a packed DIDComm message."""
         try:
@@ -61,7 +50,7 @@ async def extract_packed_message_metadata(  # noqa: C901
         sender_kid = None
         recip_key = None
         for kid in wrapper.recipient_key_ids:
-            recip_key = await self.secrets.get_secret_by_kid(kid)
+            recip_key = await secrets.get_secret_by_kid(kid)
             if recip_key:
                 break
 
@@ -97,40 +86,42 @@ async def extract_packed_message_metadata(  # noqa: C901
         return PackedMessageMetadata(wrapper, method, recip_key, sender_kid)
 
     async def unpack(
-        self, enc_message: Union[str, bytes]
+        self,
+        crypto: CryptoService[P, S],
+        resolver: DIDResolver,
+        secrets: SecretsManager[S],
+        enc_message: Union[str, bytes],
     ) -> Tuple[bytes, PackedMessageMetadata]:
         """Unpack a DIDComm message."""
-        metadata = await self.extract_packed_message_metadata(enc_message)
+        metadata = await self.extract_packed_message_metadata(enc_message, secrets)
 
         if metadata.method == "ECDH-ES":
             return (
-                await self.crypto.ecdh_es_decrypt(enc_message, metadata.recip_key),
+                await crypto.ecdh_es_decrypt(enc_message, metadata.recip_key),
                 metadata,
             )
 
         if not metadata.sender_kid:
             raise PackagingServiceError("Missing sender key ID")
 
-        sender_vm = await self.resolver.resolve_and_dereference_verification_method(
+        sender_vm = await resolver.resolve_and_dereference_verification_method(
             metadata.sender_kid
         )
-        sender_key = self.crypto.verification_method_to_public_key(sender_vm)
+        sender_key = crypto.verification_method_to_public_key(sender_vm)
 
         return (
-            await self.crypto.ecdh_1pu_decrypt(
-                enc_message, metadata.recip_key, sender_key
-            ),
+            await crypto.ecdh_1pu_decrypt(enc_message, metadata.recip_key, sender_key),
             metadata,
         )
 
-    async def recip_for_kid_or_default_for_did(self, kid_or_did: str) -> P:
+    async def recip_for_kid_or_default_for_did(
+        self, crypto: CryptoService[P, S], resolver: DIDResolver, kid_or_did: str
+    ) -> P:
         """Resolve a verification method for a kid or return default recip."""
         if "#" in kid_or_did:
-            vm = await self.resolver.resolve_and_dereference_verification_method(
-                kid_or_did
-            )
+            vm = await resolver.resolve_and_dereference_verification_method(kid_or_did)
         else:
-            doc = await self.resolver.resolve_and_parse(kid_or_did)
+            doc = await resolver.resolve_and_parse(kid_or_did)
             if not doc.key_agreement:
                 raise PackagingServiceError(
                     "No key agreement methods found; cannot determine recipient"
@@ -146,14 +137,14 @@ async def recip_for_kid_or_default_for_did(self, kid_or_did: str) -> P:
             else:
                 vm = default
 
-        return self.crypto.verification_method_to_public_key(vm)
+        return crypto.verification_method_to_public_key(vm)
 
-    async def default_sender_kid_for_did(self, did: str) -> str:
+    async def default_sender_kid_for_did(self, resolver: DIDResolver, did: str) -> str:
         """Determine the kid of the default sender key for a DID."""
         if "#" in did:
             return did
 
-        doc = await self.resolver.resolve_and_parse(did)
+        doc = await resolver.resolve_and_parse(did)
         if not doc.key_agreement:
             raise PackagingServiceError(
                 "No key agreement methods found; cannot determine recipient"
@@ -175,21 +166,27 @@ async def default_sender_kid_for_did(self, did: str) -> str:
 
     async def pack(
         self,
+        crypto: CryptoService[P, S],
+        resolver: DIDResolver,
+        secrets: SecretsManager[S],
         message: bytes,
         to: Sequence[str],
         frm: Optional[str] = None,
         **options,
     ):
         """Pack a DIDComm message."""
-        recip_keys = [await self.recip_for_kid_or_default_for_did(kid) for kid in to]
-        sender_kid = await self.default_sender_kid_for_did(frm) if frm else None
-        sender_key = (
-            await self.secrets.get_secret_by_kid(sender_kid) if sender_kid else None
+        recip_keys = [
+            await self.recip_for_kid_or_default_for_did(crypto, resolver, kid)
+            for kid in to
+        ]
+        sender_kid = (
+            await self.default_sender_kid_for_did(resolver, frm) if frm else None
         )
+        sender_key = await secrets.get_secret_by_kid(sender_kid) if sender_kid else None
         if frm and not sender_key:
             raise PackagingServiceError("No sender key found")
 
         if sender_key:
-            return await self.crypto.ecdh_1pu_encrypt(recip_keys, sender_key, message)
+            return await crypto.ecdh_1pu_encrypt(recip_keys, sender_key, message)
         else:
-            return await self.crypto.ecdh_es_encrypt(recip_keys, message)
+            return await crypto.ecdh_es_encrypt(recip_keys, message)