fix: add serialization/deserialization to bitstring-status-list, fix import statements

Signed-off-by: Athan Massouras <athan@indicio.tech>

Author: Athan Massouras

src/bitstring_status_list/issuer.py

@@ -1,11 +1,13 @@
-from issuer import *
-from bit_array import *
+from src.issuer import Issuer
+from src.bit_array import BitArray, IndexAllocator, N, LinearIndexAllocator, RandomIndexAllocator, Bits, dict_to_b64
 
 from typing import (
     List,
     Literal,
     Optional,
     Tuple,
+    Protocol,
+    Union,
 )
 
 MIN_LIST_LENGTH = 131072

src/bitstring_status_list/verifier.py

@@ -1,14 +1,13 @@
 from typing import (
-    Literal,
     Optional,
     Protocol,
 )
 
 from aiohttp import ClientSession
 import json
 
-from bit_array import BitArray, b64url_decode, b64url_encode, dict_to_b64
-from bitstring_status_list.issuer import MIN_LIST_LENGTH, StatusListLengthError
+from src.bit_array import BitArray, b64url_decode, b64url_encode, dict_to_b64
+from src.bitstring_status_list.issuer import MIN_LIST_LENGTH, StatusListLengthError
 
 class EnvelopingTokenVerifier(Protocol):
     """Protocol defining the verifying callable for enveloping signatures."""
@@ -207,4 +206,45 @@ def get_status(self, idx: Optional[int] = None):
             raise StatusVerificationError(f"statusMessage is malformed or not present: {k}")
 
         raise StatusVerificationError(f"Status {status} not found in message list: {self.credential_status["statusMessage"]}")
+
+    def serialize_verifier(self) -> dict:
+        """
+        Utility function: serialize a BitstringStatusListVerifier for storing.
+
+        Returns:
+            A dictionary with headers and payload, as well as relevant metadata.
+        """
+
+        return {
+            "credential_status": self.credential_status,
+            **({"headers": self.headers} if self.headers else {}),
+            "payload": self.payload,
+        }
+    
+
+    @classmethod
+    def deserialize_verifier(cls, seralized_verifier: dict) -> "BitstringStatusListVerifier":
+        """
+        Utility function: deserializes a seralized TokenStatusListVerifier, which must be in the
+        same format as the return type of seralize_verifier. Returns a TokenStatusListVerifier type
+        with fields populated and the status list stored as a BitArray.
+
+        Args:
+            serialized_verifier: REQUIRED. Serialized verifier type which must be in the same format 
+            as TokenStatusListVerifier.serialize_verifier.
+
+        Returns:
+            A TokenStatusListVerifier instance with relevant fields populated.
+        """
+
+        bits = seralized_verifier["credential_status"].get("statusSize")
+        return cls(
+            credential_status=seralized_verifier["credential_status"],
+            headers=seralized_verifier.get("headers"),
+            payload=seralized_verifier["payload"],
+            bit_array=BitArray.from_b64(
+                bits=1 if bits is None else bits,
+                value=seralized_verifier["payload"]["credentialSubject"]["encodedList"]
+            )
+        )
 

tests/test_bitstring_status_list.py

@@ -3,9 +3,9 @@
 from google.auth.crypt.es256 import ES256Signer, ES256Verifier
 from cryptography.hazmat.primitives.asymmetric import ec
 
-from bit_array import b64url_encode, b64url_decode
-from bitstring_status_list.issuer import BitstringStatusListIssuer, EmbeddingTokenSigner, EnvelopingTokenSigner, MIN_LIST_LENGTH
-from bitstring_status_list.verifier import BitstringStatusListVerifier, EmbeddingTokenVerifier, EnvelopingTokenVerifier
+from src.bit_array import b64url_encode, b64url_decode
+from src.bitstring_status_list.issuer import BitstringStatusListIssuer, EmbeddingTokenSigner, EnvelopingTokenSigner, MIN_LIST_LENGTH
+from src.bitstring_status_list.verifier import BitstringStatusListVerifier, EmbeddingTokenVerifier, EnvelopingTokenVerifier
 
 @pytest.fixture
 def status():
@@ -257,4 +257,38 @@ def test_verify_es256_embedding(
         assert verifier.get_status(i) == {
             "status": status[i],
             "valid": not bool(status[i])
-        }
+        }
+
+def test_serialization(status: BitstringStatusListIssuer):
+    encoded_jwt = status.sign_jwt_enveloping(
+        signer=trivial_enveloping_signer,
+        alg="ES256",
+        kid="12",
+        status_purpose="revocation",
+    )
+
+    credential_status = {
+        "id": "https://example.com/credentials/status/3#94567",
+        "type": "BitstringStatusListEntry",
+        "statusPurpose": "revocation",
+        "statusListIndex": "0",
+        "statusListCredential": "https://example.com/credentials/status/3"
+    }
+
+    verifier = BitstringStatusListVerifier.from_jwt(
+        token=encoded_jwt,
+        credential_status=credential_status,
+        verifier=trivial_embedding_verifier,
+    )
+
+    serialized_verifier = verifier.serialize_verifier()
+    unserialized_verifier = BitstringStatusListVerifier.deserialize_verifier(serialized_verifier)
+
+    assert verifier.credential_status == unserialized_verifier.credential_status
+
+    assert verifier.headers == unserialized_verifier.headers
+    assert verifier.payload == unserialized_verifier.payload
+
+    # Check that values match
+    for i in range(status.status_list.size):
+        assert verifier.get_status(i) == unserialized_verifier.get_status(i)

tests/test_token_status_list_issuer.py

@@ -2,8 +2,8 @@
 
 import json
 import pytest
-from bit_array import BitArray, b64url_decode
-from token_status_list.issuer import TokenStatusListIssuer
+from src.bit_array import BitArray, b64url_decode
+from src.token_status_list.issuer import TokenStatusListIssuer
 
 
 @pytest.fixture

tests/test_token_status_list_verifier.py

@@ -6,9 +6,9 @@
 from google.auth.crypt.es256 import ES256Signer, ES256Verifier
 from cryptography.hazmat.primitives.asymmetric import ec
 
-from bit_array import BitArray
-from token_status_list.issuer import TokenStatusListIssuer, ALG, KID, TYP, ISS, SUB, AUD, EXP, NBF, IAT, CTI, STATUS_LIST, TTL, KNOWN_ALGS_TO_CWT_ALG
-from token_status_list.verifier import TokenStatusListVerifier
+from src.bit_array import BitArray
+from src.token_status_list.issuer import TokenStatusListIssuer, ALG, KID, TYP, ISS, SUB, EXP, IAT, STATUS_LIST, KNOWN_ALGS_TO_CWT_ALG
+from src.token_status_list.verifier import TokenStatusListVerifier
 
 @pytest.fixture
 def status():

tests/test_token_status_list_webserver.py

@@ -7,10 +7,10 @@
 from cryptography.hazmat.primitives.asymmetric import ec
 import requests as r
 
-from token_status_list.verifier import TokenStatusListVerifier
-from token_status_list.issuer import TokenStatusListIssuer
-from token_status_list.issuer import ALG, KID, TYP, ISS, SUB, AUD, EXP, NBF, IAT, CTI, STATUS_LIST, TTL, KNOWN_ALGS_TO_CWT_ALG
-from bit_array import BitArray
+from src.token_status_list.verifier import TokenStatusListVerifier
+from src.token_status_list.issuer import TokenStatusListIssuer
+from src.token_status_list.issuer import ALG, KID, TYP, ISS, SUB, EXP, IAT, STATUS_LIST, KNOWN_ALGS_TO_CWT_ALG
+from src.bit_array import BitArray
 
 ISSUER = "http://localhost:3001"