chore(dpop): tidy client implementation and tests

Author: nypdmax

src/mcp/client/auth/dpop.py

@@ -1,5 +1,4 @@
-"""
-DPoP (Demonstrating Proof-of-Possession) client implementation.
+"""DPoP (Demonstrating Proof-of-Possession) client implementation.
 
 RFC 9449: OAuth 2.0 Demonstrating Proof of Possession (DPoP).
 Provides DPoPKeyPair, DPoPProofGenerator, DPoPStorage for generating DPoP proof JWTs.
@@ -94,9 +93,7 @@ def generate(
             key: EllipticCurvePrivateKey | RSAPrivateKey = ec_generate(SECP256R1())
         elif algorithm == "RS256":
             if rsa_key_size < RSA_KEY_SIZE_DEFAULT:
-                raise ValueError(
-                    f"RSA key size must be at least {RSA_KEY_SIZE_DEFAULT} bits, got {rsa_key_size}"
-                )
+                raise ValueError(f"RSA key size must be at least {RSA_KEY_SIZE_DEFAULT} bits, got {rsa_key_size}")
             key = rsa_generate(public_exponent=_RSA_PUBLIC_EXPONENT, key_size=rsa_key_size)
         else:
             raise ValueError(f"Unsupported algorithm: {algorithm}")

tests/client/auth/test_dpop.py

@@ -46,9 +46,7 @@ def test_dpop_proof_includes_ath_when_credential_provided() -> None:
     gen = DPoPProofGeneratorImpl(pair)
     proof = gen.generate_proof("GET", "https://rs.example/res", credential="my-token")
     decoded = jwt.decode(proof, options={"verify_signature": False})
-    expected_ath = base64.urlsafe_b64encode(
-        hashlib.sha256(b"my-token").digest()
-    ).decode().rstrip("=")
+    expected_ath = base64.urlsafe_b64encode(hashlib.sha256(b"my-token").digest()).decode().rstrip("=")
     assert decoded["ath"] == expected_ath
 
 

tests/client/auth/test_dpop_integration.py

@@ -49,9 +49,7 @@ async def test_oauth2_protocol_initialize_dpop(client_metadata: OAuthClientMetad
 @pytest.mark.anyio
 async def test_oauth2_protocol_initialize_dpop_rs256(client_metadata: OAuthClientMetadata) -> None:
     """initialize_dpop should support RS256 algorithm."""
-    protocol = OAuth2Protocol(
-        client_metadata=client_metadata, dpop_enabled=True, dpop_algorithm="RS256"
-    )
+    protocol = OAuth2Protocol(client_metadata=client_metadata, dpop_enabled=True, dpop_algorithm="RS256")
     await protocol.initialize_dpop()
 
     jwk = protocol.get_dpop_public_key_jwk()
@@ -105,9 +103,7 @@ async def test_dpop_proof_generation(client_metadata: OAuthClientMetadata) -> No
     assert len(proof) > 0
 
     # Proof with access token binding
-    proof_with_ath = generator.generate_proof(
-        "GET", "https://api.example.com/resource", credential="access-token-123"
-    )
+    proof_with_ath = generator.generate_proof("GET", "https://api.example.com/resource", credential="access-token-123")
     assert proof_with_ath is not None
     assert proof_with_ath != proof