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Validate the iss authorization-response parameter (RFC 9207 / SEP-2468) (#2921)

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Marcelo Trylesinski 2026-06-20 16:54:18 +01:00 • committed by GitHub
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1 changed files with 335 additions and 103 deletions
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30
tests/interaction/auth/test_discovery.py
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@ -236,7 +236,10 @@ async def test_as_metadata_discovery_falls_back_through_the_spec_endpoint_order(
unrecognized field to prove the client's parser ignores unknown members (RFC 8414 §3.2).
"""
recorded, on_request = record_requests()
provider = InMemoryAuthorizationServerProvider()
asm = real_asm()
asm.issuer = AnyHttpUrl(authorization_server)
# The redirect iss must equal the issuer the client records from this metadata.
provider = InMemoryAuthorizationServerProvider(issuer=str(asm.issuer))
server = Server("guarded", on_list_tools=list_tools)
prm = ProtectedResourceMetadata(
@ -246,7 +249,7 @@ async def test_as_metadata_discovery_falls_back_through_the_spec_endpoint_order(
not_found=not_found,
serve={
PRM_PATH_SUFFIXED: metadata_body(prm),
serve_at: metadata_body(real_asm(), x_unknown_extension="ignored"),
serve_at: metadata_body(asm, x_unknown_extension="ignored"),
},
)
@ -311,23 +314,26 @@ async def test_as_metadata_advertises_authorize_token_registration_and_s256() ->
@requirement("client-auth:as-metadata-discovery:issuer-validation")
async def test_as_metadata_with_a_mismatched_issuer_is_accepted_and_the_flow_proceeds() -> None:
"""Authorization-server metadata whose `issuer` does not match the discovery URL is accepted.
async def test_as_metadata_with_a_mismatched_issuer_aborts_the_flow() -> None:
"""Authorization-server metadata whose `issuer` does not match the discovery URL is rejected.
RFC 8414 §3.3 requires the client to reject the document; the SDK parses and uses it
without comparing `issuer` to the URL it was fetched from. See the divergence on the
requirement. The served body carries an unrecognized field as a fold-in proof of
unknown-field tolerance.
RFC 8414 §3.3 / SEP-2468 require the client to reject the document; the SDK compares `issuer`
to the URL the metadata was fetched from and raises `OAuthFlowError` before any authorize or
token request is made.
"""
recorded, on_request = record_requests()
provider = InMemoryAuthorizationServerProvider()
server = Server("guarded", on_list_tools=list_tools)
metadata = real_asm()
metadata.issuer = AnyHttpUrl(f"{BASE_URL}/wrong-issuer")
app_shim = shim(serve={ASM_ROOT: metadata_body(metadata, x_unknown_extension="ignored")})
app_shim = shim(serve={ASM_ROOT: metadata_body(metadata)})
with anyio.fail_after(5):
async with connect_with_oauth(server, provider=provider, app_shim=app_shim) as (client, _):
result = await client.list_tools()
with pytest.RaisesGroup(
pytest.RaisesExc(OAuthFlowError, match="^Authorization server metadata issuer mismatch"),
flatten_subgroups=True,
):
await connect_with_oauth(server, provider=provider, app_shim=app_shim, on_request=on_request).__aenter__()
assert result.tools[0].name == "probe"
assert [r.path for r in recorded if r.path in ("/authorize", "/token")] == []