Merge pull request #44 from Indicio-tech/feature/p256

feat: add did jwk resolver and support for p256 keys

Author: TheTechmage

didcomm_messaging/crypto/backend/askar.py

@@ -30,6 +30,7 @@ class AskarKey(PublicKey):
         "ed25519-pub": KeyAlg.ED25519,
         "x25519-pub": KeyAlg.X25519,
         "secp256k1-pub": KeyAlg.K256,
+        "p256-pub": KeyAlg.P256,
     }
     alg_to_codec = {v: k for k, v in codec_to_alg.items()}
 

didcomm_messaging/multiformats/multicodec.py

@@ -22,6 +22,7 @@ class SupportedCodecs(Enum):
     bls12381g2 = Multicodec("bls12_381-g2-pub", b"\xeb\x01")
     bls12381g1g2 = Multicodec("bls12_381-g1g2-pub", b"\xee\x01")
     secp256k1_pub = Multicodec("secp256k1-pub", b"\xe7\x01")
+    p256_pub = Multicodec("p256-pub", b"\x12\x00")
 
     @classmethod
     def by_name(cls, name: str) -> Multicodec:
@@ -49,6 +50,7 @@ def for_data(cls, data: bytes) -> Multicodec:
     "bls12_381-g2-pub",
     "bls12_381-g1g2-pub",
     "secp256k1-pub",
+    "p256-pub",
 ]
 
 

didcomm_messaging/resolver/jwk.py

@@ -0,0 +1,69 @@
+"""did:jwk Resolver."""
+
+import re
+import json
+
+from didcomm_messaging import DIDResolver
+from didcomm_messaging.resolver import DIDResolutionError
+from didcomm_messaging.multiformats.multibase import Base64UrlEncoder
+
+b64 = Base64UrlEncoder()
+
+
+class JWKResolver(DIDResolver):
+    """Resolve did:jwk."""
+
+    PATTERN = re.compile(r"^did:jwk:(?P<did>[A-Za-z0-9\-_]+)$")
+
+    async def resolve(self, did: str) -> dict:
+        """Resolve a did:jwk."""
+        if match := self.PATTERN.match(did):
+            encoded = match.group("did")
+        else:
+            raise DIDResolutionError(f"Invalid DID: {did}")
+
+        try:
+            jwk = json.loads(b64.decode(encoded))
+        except json.JSONDecodeError:
+            raise DIDResolutionError("Invalid JWK")
+
+        if not isinstance(jwk, dict):
+            raise DIDResolutionError("Invalid JWK")
+
+        if "kty" not in jwk:
+            raise DIDResolutionError("Invalid JWK")
+
+        doc = {
+            "@context": [
+                "https://www.w3.org/ns/did/v1",
+                "https://w3id.org/security/suites/jws-2020/v1",
+            ],
+            "id": f"did:jwk:{encoded}",
+            "verificationMethod": [
+                {
+                    "id": f"did:jwk:{encoded}#0",
+                    "type": "JsonWebKey2020",
+                    "controller": f"did:jwk:{encoded}",
+                    "publicKeyJwk": jwk,
+                }
+            ],
+        }
+
+        use = jwk.get("use")
+        if use == "sig":
+            doc.update(
+                {
+                    "assertionMethod": [f"did:jwk:{encoded}#0"],
+                    "authentication": [f"did:jwk:{encoded}#0"],
+                    "capabilityInvocation": [f"did:jwk:{encoded}#0"],
+                    "capabilityDelegation": [f"did:jwk:{encoded}#0"],
+                }
+            )
+        elif use == "enc":
+            doc.update({"keyAgreement": [f"did:jwk:{encoded}#0"]})
+
+        return doc
+
+    async def is_resolvable(self, did: str) -> bool:
+        """Return if did is resolvable by this resolver."""
+        return bool(self.PATTERN.match(did))