Align AnonCreds implementation with draft spec + update DID events processing (#28)

Signed-off-by: Alexander Shenshin <[email protected]>
Signed-off-by: Alexander Shenshin <[email protected]>

Author: AlexanderShenshin

README.md

@@ -3,7 +3,7 @@
 [![Release](https://img.shields.io/github/v/release/hiero-ledger/hiero-did-sdk-python)](https://img.shields.io/github/v/release/hiero-ledger/hiero-did-sdk-python)
 [![Build status](https://img.shields.io/github/actions/workflow/status/hiero-ledger/hiero-did-sdk-python/main.yml?branch=main)](https://github.com/hiero-ledger/hiero-did-sdk-python/actions/workflows/main.yml?query=branch%3Amain)
 [![codecov](https://codecov.io/gh/hiero-ledger/hiero-did-sdk-python/branch/main/graph/badge.svg)](https://codecov.io/gh/hiero-ledger/hiero-did-sdk-python)
-[![Commit activity](https://img.shields.io/github/commit-activity/m/hiero-ledger/hiero-did-sdk-python)](https://img.shields.io/github/commit-activity/m/hiero-ledger/hiero-did-sdk-python)
+[![Commit activity](https://img.shields.io/github/commit-activity/m/hiero-ledger/hiero-did-sdk-python)](https://github.com/hiero-ledger/hiero-did-sdk-python/commits/main)
 [![License](https://img.shields.io/github/license/hiero-ledger/hiero-did-sdk-python)](https://github.com/hiero-ledger/hiero-did-sdk-python/blob/main/LICENSE)
 
 This repository contains the Python SDK that enables developers to manage Decentralized Identifiers (DIDs) and AnonCreds Verifiable Credentials on the Hedera network using the Hedera Consensus Service.

hiero_did_sdk_python/anoncreds/hedera_anoncreds_registry.py

@@ -336,7 +336,7 @@ async def register_rev_reg_def(
             entries_topic_id = await self._hcs_topic_service.create_topic(entries_topic_options, [issuer_key])
 
             rev_reg_def_with_metadata = RevRegDefWithHcsMetadata(
-                rev_reg_def=rev_reg_def, hcs_metadata={"entries_topic_id": entries_topic_id}
+                rev_reg_def=rev_reg_def, hcs_metadata={"entriesTopicId": entries_topic_id}
             )
 
             hcs_file_payload = rev_reg_def_with_metadata.to_json().encode()
@@ -391,7 +391,7 @@ async def get_rev_list(self, rev_reg_id: str, timestamp: int) -> GetRevListResul
                 )
 
             rev_reg_def = rev_reg_def_result.revocation_registry_definition
-            entries_topic_id = rev_reg_def_result.revocation_registry_definition_metadata.get("entries_topic_id")
+            entries_topic_id = rev_reg_def_result.revocation_registry_definition_metadata.get("entriesTopicId")
 
             if not entries_topic_id:
                 return GetRevListResult(
@@ -588,7 +588,7 @@ async def _submit_rev_list_entry(
                 revocation_list_metadata={},
             )
 
-        entries_topic_id = rev_reg_def_result.revocation_registry_definition_metadata.get("entries_topic_id")
+        entries_topic_id = rev_reg_def_result.revocation_registry_definition_metadata.get("entriesTopicId")
 
         if not entries_topic_id:
             return RegisterRevListResult(

hiero_did_sdk_python/anoncreds/models/revocation/revocation_registry_definition.py

@@ -85,7 +85,7 @@ def get_json_payload(self):
 
 
 class RevRegDefHcsMetadata(TypedDict):
-    entries_topic_id: str
+    entriesTopicId: str
 
 
 @dataclass(frozen=True)

hiero_did_sdk_python/anoncreds/utils.py

@@ -7,7 +7,7 @@
 ANONCREDS_IDENTIFIER_SEPARATOR = "/"
 
 ANONCREDS_OBJECT_FAMILY = "anoncreds"
-ANONCREDS_VERSION = "v0"
+ANONCREDS_VERSION = "v1"
 
 
 class AnonCredsObjectType(StrEnum):

hiero_did_sdk_python/did/did_document.py

@@ -1,6 +1,9 @@
 import logging
 from typing import cast
 
+from hiero_sdk_python import PublicKey
+
+from ..utils.encoding import b58_to_bytes, b64_to_bytes
 from ..utils.ipfs import download_ipfs_document_by_cid
 from ..utils.serializable import Serializable
 from .did_document_operation import DidDocumentOperation
@@ -15,7 +18,7 @@
 from .hcs.events.verification_relationship.hcs_did_update_verification_relationship_event import (
     HcsDidUpdateVerificationRelationshipEvent,
 )
-from .hcs.hcs_did_message import HcsDidMessage
+from .hcs.hcs_did_message import HcsDidMessage, HcsDidMessageEnvelope
 
 LOGGER = logging.getLogger(__name__)
 
@@ -56,21 +59,36 @@ def __init__(self, id_: str):
             DidDocumentJsonProperties.CAPABILITY_DELEGATION.value: [],
         }
 
-    async def process_messages(self, messages: list[HcsDidMessage]):
+        self._public_key: PublicKey | None = None
+
+    async def process_messages(self, envelopes: list[HcsDidMessageEnvelope]):
         """
         Process HCS DID messages - apply DID document state changes according to events.
 
         Args:
-            messages: HCS DID messages to process
+            envelopes: HCS DID message envelopes (message + signature) to process
 
         """
-        for message in messages:
-            if not self.controller and message.operation == DidDocumentOperation.CREATE:
+        for envelope in envelopes:
+            message = cast(HcsDidMessage, envelope.message)
+
+            if not self.controller:
                 event_target = message.event.event_target
                 if event_target != HcsDidEventTarget.DID_OWNER and event_target != HcsDidEventTarget.DID_DOCUMENT:
-                    LOGGER.warning("DID document is not registered, skipping DID update event...")
+                    LOGGER.warning("DID document is not registered, skipping DID event...")
                     continue
 
+            # TODO: Find a good way to support CID-based DID Document creation without workarounds and redundancy
+            # It's possible that we want to drop support for this case instead
+            is_signature_valid = (
+                message.event.event_target == HcsDidEventTarget.DID_DOCUMENT
+                or self._is_message_signature_valid(message, cast(str, envelope.signature))
+            )
+
+            if not is_signature_valid:
+                LOGGER.warning("HCS DID message signature is invalid, skipping event...")
+                continue
+
             match message.operation:
                 case DidDocumentOperation.CREATE:
                     await self._process_create_message(message)
@@ -154,6 +172,14 @@ async def _process_create_message(self, message: HcsDidMessage):  # noqa: C901
                     for verificationMethod in document.get(DidDocumentJsonProperties.VERIFICATION_METHOD, [])
                 }
 
+                root_verification_method = next(
+                    filter(
+                        lambda verification_method: "#did-root-key" in verification_method["id"],
+                        self.verification_methods.values(),
+                    )
+                )
+                self._public_key = PublicKey.from_bytes(b58_to_bytes(root_verification_method["publicKeyBase58"]))
+
                 self.verification_relationships[DidDocumentJsonProperties.ASSERTION_METHOD] = document.get(
                     DidDocumentJsonProperties.ASSERTION_METHOD, []
                 )
@@ -174,7 +200,10 @@ async def _process_create_message(self, message: HcsDidMessage):  # noqa: C901
                     LOGGER.warning(f"DID owner is already registered: {self.controller}, skipping event...")
                     return
 
-                self.controller = cast(HcsDidUpdateDidOwnerEvent, event).get_owner_def()
+                did_owner_event = cast(HcsDidUpdateDidOwnerEvent, event)
+
+                self.controller = did_owner_event.get_owner_def()
+                self._public_key = did_owner_event.public_key
                 self._on_activated(message.timestamp)
             case HcsDidEventTarget.SERVICE:
                 update_service_event = cast(HcsDidUpdateServiceEvent, event)
@@ -228,7 +257,10 @@ def _process_update_message(self, message: HcsDidMessage):
 
         match event.event_target:
             case HcsDidEventTarget.DID_OWNER:
-                self.controller = cast(HcsDidUpdateDidOwnerEvent, event).get_owner_def()
+                did_owner_event = cast(HcsDidUpdateDidOwnerEvent, event)
+
+                self.controller = did_owner_event.get_owner_def()
+                self._public_key = did_owner_event.public_key
                 self._on_updated(message.timestamp)
             case HcsDidEventTarget.SERVICE:
                 update_service_event = cast(HcsDidUpdateServiceEvent, event)
@@ -354,6 +386,32 @@ def _process_delete_message(self, message: HcsDidMessage):
             case _:
                 LOGGER.warning(f"Delete {event.event_target} operation is not supported, skipping event...")
 
+    def _is_message_signature_valid(self, message: HcsDidMessage, signature: str) -> bool:
+        is_create_or_update_event = (
+            message.operation == DidDocumentOperation.CREATE or message.operation == DidDocumentOperation.UPDATE
+        )
+        is_did_owner_change_event = (
+            is_create_or_update_event and message.event.event_target == HcsDidEventTarget.DID_OWNER
+        )
+
+        public_key = (
+            cast(HcsDidUpdateDidOwnerEvent, message.event).public_key if is_did_owner_change_event else self._public_key
+        )
+
+        if not public_key:
+            raise Exception("Cannot verify HCS DID Message signature - controller public key is not defined")
+
+        message_bytes = message.to_json().encode()
+        signature_bytes = b64_to_bytes(signature)
+
+        try:
+            public_key.verify(signature_bytes, message_bytes)
+        except Exception as error:
+            LOGGER.warning(f"HCS DID Message signature verification failed with error: {error!s}")
+            return False
+
+        return True
+
     def _on_activated(self, timestamp: float):
         self.created = timestamp
         self.updated = timestamp

hiero_did_sdk_python/did/hcs/hcs_did_message.py

@@ -91,7 +91,7 @@ def from_json_payload(cls, payload: dict):
         match payload:
             case {"timestamp": timestamp, "operation": operation, "did": did, "event": event_base64}:
                 parsed_event = _parse_hcs_did_event(event_base64, operation)
-                return cls(operation=operation, did=did, event=parsed_event, timestamp=timestamp)
+                return cls(operation=DidDocumentOperation(operation), did=did, event=parsed_event, timestamp=timestamp)
             case _:
                 raise Exception(f"{cls.__name__} JSON parsing failed: Invalid JSON structure")
 

hiero_did_sdk_python/did/hedera_did.py

@@ -62,7 +62,6 @@ def __init__(self, client: Client, identifier: str | None = None, private_key_de
         else:
             self.topic_id = None
 
-        self._messages: list[HcsDidMessage] = []
         self.document: DidDocument | None = None
 
     async def register(self):
@@ -349,9 +348,8 @@ async def _handle_resolution_result(self, result: list[HcsDidMessageEnvelope]):
         if not self.identifier:
             raise Exception("Cannot handle DID resolution result: DID identifier is not defined")
 
-        self._messages = [cast(HcsDidMessage, envelope.message) for envelope in result]
         self.document = DidDocument(self.identifier)
-        await self.document.process_messages(self._messages)
+        await self.document.process_messages(result)
 
     def _assert_can_submit_transaction(self):
         if not self.identifier:

hiero_did_sdk_python/did/hedera_did_resolver.py

@@ -10,7 +10,7 @@
 from ..utils.cache import Cache, MemoryCache, TimestampedRecord
 from .did_document import DidDocument
 from .did_error import DidErrorCode, DidException
-from .hcs.hcs_did_message import HcsDidMessage, HcsDidMessageEnvelope
+from .hcs.hcs_did_message import HcsDidMessageEnvelope
 from .hedera_did import HederaDid
 from .types import DIDDocument, DIDDocumentMetadata, DIDResolutionResult
 
@@ -102,11 +102,7 @@ async def resolve(self, did: str) -> DIDResolutionResult:
                         timestamp_from=Timestamp(int(last_updated_timestamp), 0),
                     ).execute(self._client)
 
-                    messages = [
-                        cast(HcsDidMessage, envelope.message) for envelope in cast(list[HcsDidMessageEnvelope], result)
-                    ]
-
-                    await did_document.process_messages(messages)
+                    await did_document.process_messages(cast(list[HcsDidMessageEnvelope], result))
 
                     self._cache.set(
                         topic_id,

hiero_did_sdk_python/hcs/hcs_message_envelope.py

@@ -22,7 +22,7 @@ def sign(self, signing_key: PrivateKey):
             raise Exception("Message is already signed")
 
         message_bytes = self.message.to_json().encode()
-        signature_bytes = bytes(signing_key.sign(message_bytes))
+        signature_bytes = signing_key.sign(message_bytes)
 
         self.signature = bytes_to_b64(signature_bytes)
 

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "hiero-did-sdk-python"
-version = "0.1.0"
+version = "0.1.1"
 description = "The repository contains the Python SDK for managing DID Documents and Anoncreds Verifiable Credentials registry using Hedera Consensus Service."
 authors = ["Alexander Shenshin <[email protected]>", "Paulo Caldas <[email protected]>"]
 repository = "https://github.com/hiero-ledger/hiero-did-sdk-python"