Files
turnstone/tests/test_mcp_oauth_discovery.py
Patrick Buckley b939919560 fix(mcp): harden Entra OBO OAuth review follow-ups for #706
Follow-up review of the #706 on-behalf-of / Entra ID MCP changes (#682).

security (PKCE downgrade): the AS-metadata "assume S256 when
code_challenge_methods_supported is absent" relaxation applied to BOTH the
RFC 8414 oauth-authorization-server document and the OIDC openid-configuration
document. Per RFC 8414 an omitted field on the oauth-authorization-server
document means the AS does NOT support PKCE, so this was fail-open. The client
always sends code_challenge_method=S256, making this discovery check the only
pre-flight that the AS enforces PKCE. Track which document won discovery and
assume S256 only for the OIDC document; the RFC 8414 document now fails closed.
Also log which discovery profile (rfc8414 vs oidc) answered, for operators
debugging an enterprise AS.

bug (consent loss): session-start pool priming called the refreshing token
lookup for every cold oauth_user server. A near-expiry token triggered a
refresh, and a transient refresh failure (network/5xx/429) deletes the token
and emits token_revoked — so a blip during a cold-pool warm (e.g. after a
reboot) silently revoked consent across servers the user wasn't even using.
Priming now reads the token directly and skips missing/near-expiry tokens;
a refresh that may fail stays on the lazy dispatch path.

perf/UX (blocking redirect): the OAuth callback awaited prime_user_server
(default 20s timeout), holding the consent redirect on a slow/unreachable MCP
server. Replaced with fire-and-forget schedule_prime_user_server that schedules
onto the mcp-loop (GC-safe, no unreferenced request-loop task) and returns at
once.

perf: prime a user's pools concurrently under a bound instead of serially, so
one slow upstream can't stall the rest.

hygiene: log (not silently swallow) prime scheduling failures at session start;
add exc_info to the prime-failure warning; guard run_coroutine_threadsafe
against a closed mcp-loop.

tests: per-document S256 + OIDC-fallback discovery cases; pool priming
(non-destructive on near-expiry, skips connected) and bound-token rotation
reconnect.
2026-06-25 20:42:22 -07:00

740 lines
29 KiB
Python

"""Discovery tests for the per-(user, server) MCP OAuth flow.
Covers PRM (RFC 9728) and AS metadata (RFC 8414) discovery, including:
- override URL takes precedence
- PRM happy path: server URL -> .well-known/oauth-protected-resource
-> ``authorization_servers[0]``
- PRM 401 + ``WWW-Authenticate: Bearer resource_metadata="..."`` follows
the URL.
- AS metadata without S256 -> :class:`MCPOAuthDiscoveryError`.
- SSRF rejection on AS issuer URL.
- In-memory cache hit/miss + persistent cache write to
``mcp_servers.oauth_as_issuer_cached``.
"""
from __future__ import annotations
import asyncio
import time
from typing import Any
from unittest.mock import AsyncMock, MagicMock, patch
import httpx
import pytest
from turnstone.core.mcp_oauth import (
ASMetadata,
MCPOAuthDiscoveryError,
_parse_prm_url_from_www_authenticate,
discover_authorization_server,
)
# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
def _mk_response(
status_code: int = 200,
json_body: Any = None,
headers: dict[str, str] | None = None,
) -> MagicMock:
"""Build a MagicMock that quacks like ``httpx.Response``."""
resp = MagicMock(spec=httpx.Response)
resp.status_code = status_code
resp.headers = headers or {}
resp.content = (str(json_body) if json_body is not None else "").encode("utf-8")
if json_body is not None:
resp.json.return_value = json_body
else:
resp.json.side_effect = ValueError("no body")
resp.text = str(json_body) if json_body is not None else ""
return resp
def _good_as_metadata_doc() -> dict[str, Any]:
return {
"issuer": "https://as.example.com",
"authorization_endpoint": "https://as.example.com/authorize",
"token_endpoint": "https://as.example.com/token",
"jwks_uri": "https://as.example.com/jwks",
"code_challenge_methods_supported": ["S256"],
"token_endpoint_auth_methods_supported": ["none", "client_secret_basic"],
"registration_endpoint": "https://as.example.com/register",
}
def _public_addr_patch():
return patch("socket.getaddrinfo", return_value=[(2, 1, 6, "", ("93.184.216.34", 0))])
def _mk_storage_mock(server_id: str = "srv-id") -> MagicMock:
storage = MagicMock()
storage.update_mcp_server.return_value = True
return storage
# ---------------------------------------------------------------------------
# PRM parser
# ---------------------------------------------------------------------------
class TestParsePRMUrl:
def test_extracts_resource_metadata_url(self) -> None:
header = (
'Bearer error="invalid_token", '
'resource_metadata="https://srv.example.com/.well-known/oauth-protected-resource"'
)
url = _parse_prm_url_from_www_authenticate(header)
assert url == "https://srv.example.com/.well-known/oauth-protected-resource"
def test_returns_none_when_absent(self) -> None:
assert _parse_prm_url_from_www_authenticate('Bearer realm="x"') is None
def test_handles_empty_header(self) -> None:
assert _parse_prm_url_from_www_authenticate("") is None
def test_handles_escaped_quote_in_value(self) -> None:
"""RFC 7230 quoted-string allows ``\\"`` — naive ``[^"]+`` truncates.
A malicious or buggy resource server could send an embedded
escaped quote; the parser must yield the unescaped value, not
the prefix up to the escaped quote.
"""
header = 'Bearer resource_metadata="https://srv.example.com/with\\"quote"'
url = _parse_prm_url_from_www_authenticate(header)
assert url == 'https://srv.example.com/with"quote'
def test_handles_escaped_backslash(self) -> None:
header = 'Bearer resource_metadata="https://srv.example.com/back\\\\slash"'
url = _parse_prm_url_from_www_authenticate(header)
assert url == "https://srv.example.com/back\\slash"
def test_unterminated_quoted_string_returns_none(self) -> None:
# Closing quote missing — naive regex would still match, but
# the proper parser should reject malformed input.
header = 'Bearer resource_metadata="https://srv.example.com/no-close'
assert _parse_prm_url_from_www_authenticate(header) is None
# ---------------------------------------------------------------------------
# discover_authorization_server happy paths
# ---------------------------------------------------------------------------
class TestDiscoveryOverride:
def test_override_url_skips_prm(self) -> None:
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, _good_as_metadata_doc()))
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert isinstance(meta, ASMetadata)
assert meta.token_endpoint == "https://as.example.com/token"
# Only the AS metadata URL was hit, not PRM.
called_urls = [c.args[0] for c in client.get.call_args_list]
assert all("oauth-authorization-server" in u for u in called_urls)
class TestDiscoveryPRM:
def test_prm_happy_path(self) -> None:
async def _get(url, *args, **kwargs):
if url.endswith("/oauth-protected-resource"):
return _mk_response(
200,
{
"resource": "https://mcp.example.com",
"authorization_servers": ["https://as.example.com"],
},
)
if url.endswith("/oauth-authorization-server"):
return _mk_response(200, _good_as_metadata_doc())
raise AssertionError(f"unexpected URL: {url}")
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url=None,
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert meta.issuer == "https://as.example.com"
def test_prm_401_follows_www_authenticate(self) -> None:
async def _get(url, *args, **kwargs):
if url == "https://mcp.example.com/.well-known/oauth-protected-resource":
return _mk_response(
401,
headers={
"www-authenticate": (
'Bearer error="invalid_token", '
"resource_metadata="
'"https://meta.example.com/prm"'
)
},
json_body=None,
)
if url == "https://meta.example.com/prm":
return _mk_response(
200,
{
"authorization_servers": ["https://as.example.com"],
},
)
if url.endswith("/oauth-authorization-server"):
return _mk_response(200, _good_as_metadata_doc())
raise AssertionError(f"unexpected URL: {url}")
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url=None,
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert meta.token_endpoint == "https://as.example.com/token"
def test_prm_401_without_resource_metadata_raises(self) -> None:
async def _get(url, *args, **kwargs):
return _mk_response(401, headers={"www-authenticate": "Basic realm=x"})
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url=None,
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
with pytest.raises(MCPOAuthDiscoveryError, match="resource_metadata"):
asyncio.run(_run())
# ---------------------------------------------------------------------------
# AS metadata validation
# ---------------------------------------------------------------------------
class TestASMetadataValidation:
def test_no_s256_raises(self) -> None:
doc = _good_as_metadata_doc()
doc["code_challenge_methods_supported"] = ["plain"]
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, doc))
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
with pytest.raises(MCPOAuthDiscoveryError, match="S256"):
asyncio.run(_run())
def test_missing_endpoints_raises(self) -> None:
doc = _good_as_metadata_doc()
del doc["token_endpoint"]
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, doc))
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
with pytest.raises(MCPOAuthDiscoveryError, match="missing required"):
asyncio.run(_run())
def test_third_party_endpoint_rejected(self) -> None:
doc = _good_as_metadata_doc()
doc["token_endpoint"] = "https://attacker.example.com/token"
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, doc))
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
with pytest.raises(MCPOAuthDiscoveryError, match="token_endpoint"):
asyncio.run(_run())
def test_ssrf_on_override_rejected(self) -> None:
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock()
storage = _mk_storage_mock()
async def _run():
# Resolve to private 10.x — SSRF guard fires before any HTTP call.
with patch(
"socket.getaddrinfo",
return_value=[(2, 1, 6, "", ("10.0.0.1", 0))],
):
await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://internal.corp.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
with pytest.raises(MCPOAuthDiscoveryError):
asyncio.run(_run())
client.get.assert_not_called()
class TestS256PerDocumentAndOIDCFallback:
"""PKCE S256 defaulting is per-discovery-document, and OIDC discovery is a
fallback to RFC 8414 (PR #706 follow-up).
The client always sends ``code_challenge_method=S256``, so the AS-metadata
check is the only PKCE-enforcement pre-flight. An ABSENT
``code_challenge_methods_supported`` is treated as "S256 supported" ONLY for
the OIDC ``openid-configuration`` document (where the field is optional and
Entra omits it); for the RFC 8414 ``oauth-authorization-server`` document an
absent field fails closed.
"""
@staticmethod
def _doc_without_code_challenge() -> dict[str, Any]:
doc = _good_as_metadata_doc()
del doc["code_challenge_methods_supported"]
return doc
def test_absent_field_on_oidc_doc_assumes_s256(self) -> None:
# RFC 8414 path 404s; the OIDC doc omits code_challenge_methods_supported
# -> assume S256 (Entra's shape) and discovery succeeds.
async def _get(url, *args, **kwargs):
if url.endswith("/oauth-authorization-server"):
return _mk_response(404, json_body=None)
if url.endswith("/openid-configuration"):
return _mk_response(200, self._doc_without_code_challenge())
raise AssertionError(f"unexpected URL: {url}")
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert isinstance(meta, ASMetadata)
assert meta.token_endpoint == "https://as.example.com/token"
def test_absent_field_on_rfc8414_doc_fails_closed(self) -> None:
# The RFC 8414 doc is served (200) but omits the field — must NOT assume
# S256. Per RFC 8414 an omitted field means "no PKCE advertised", so
# discovery fails closed rather than silently downgrading.
async def _get(url, *args, **kwargs):
if url.endswith("/oauth-authorization-server"):
return _mk_response(200, self._doc_without_code_challenge())
raise AssertionError(f"unexpected URL: {url}")
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
with pytest.raises(MCPOAuthDiscoveryError, match="S256"):
asyncio.run(_run())
def test_rfc8414_404_falls_back_to_openid_configuration(self) -> None:
# RFC 8414 path 404s; the OIDC doc (advertising S256) is parsed instead.
async def _get(url, *args, **kwargs):
if url.endswith("/oauth-authorization-server"):
return _mk_response(404, json_body=None)
if url.endswith("/openid-configuration"):
return _mk_response(200, _good_as_metadata_doc())
raise AssertionError(f"unexpected URL: {url}")
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert meta.issuer == "https://as.example.com"
assert meta.token_endpoint == "https://as.example.com/token"
# Both candidate URLs were tried, RFC 8414 first then OIDC.
called = [c.args[0] for c in client.get.call_args_list]
assert any("oauth-authorization-server" in u for u in called)
assert any("openid-configuration" in u for u in called)
# ---------------------------------------------------------------------------
# Caching
# ---------------------------------------------------------------------------
class TestMetadataCache:
def test_cache_miss_then_hit(self) -> None:
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, _good_as_metadata_doc()))
storage = _mk_storage_mock()
cache: dict[str, tuple[ASMetadata, float]] = {}
async def _run():
with _public_addr_patch():
first = await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
metadata_cache=cache,
)
second = await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer="https://as.example.com",
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
metadata_cache=cache,
)
return first, second
first, second = asyncio.run(_run())
assert first.token_endpoint == second.token_endpoint
# First call hit AS metadata; second call hit the cache.
assert client.get.call_count == 1
def test_cache_expiry_refetches(self) -> None:
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, _good_as_metadata_doc()))
storage = _mk_storage_mock()
# Pre-populate cache with a very stale entry.
stale_meta = ASMetadata(
issuer="https://as.example.com",
authorization_endpoint="https://as.example.com/authorize",
token_endpoint="https://as.example.com/token",
registration_endpoint=None,
revocation_endpoint=None,
jwks_uri=None,
code_challenge_methods_supported=("S256",),
token_endpoint_auth_methods_supported=(),
)
cache = {"https://as.example.com": (stale_meta, time.monotonic() - 10**6)}
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
metadata_cache=cache,
)
meta = asyncio.run(_run())
# Stale entry was bypassed -> we hit the network.
assert client.get.call_count == 1
assert meta.token_endpoint == "https://as.example.com/token"
def test_persistent_cache_write_on_first_resolution(self) -> None:
async def _get(url, *args, **kwargs):
if url.endswith("/oauth-protected-resource"):
return _mk_response(200, {"authorization_servers": ["https://as.example.com"]})
return _mk_response(200, _good_as_metadata_doc())
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url=None,
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
asyncio.run(_run())
# update_mcp_server was called once with the cached issuer.
storage.update_mcp_server.assert_called_once_with(
"srv-id", oauth_as_issuer_cached="https://as.example.com"
)
def test_persistent_cache_skip_when_already_cached(self) -> None:
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, _good_as_metadata_doc()))
storage = _mk_storage_mock()
async def _run():
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url=None,
cached_issuer="https://as.example.com",
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
asyncio.run(_run())
storage.update_mcp_server.assert_not_called()
# ---------------------------------------------------------------------------
# sec-3 — cached_issuer re-validated on read
# ---------------------------------------------------------------------------
class TestCachedIssuerSSRFRevalidation:
"""A cached issuer URL must still pass SSRF validation on every read.
Defense-in-depth: an admin who points ``oauth_as_issuer_cached`` at a
private address (or a hostname that has rebound to one) should not
bypass the guard just because the value was already in the row.
"""
def test_cached_issuer_rejected_clears_row_and_falls_through_to_prm(self) -> None:
async def _get(url: str, *args: Any, **kwargs: Any) -> MagicMock:
if url.endswith("/oauth-protected-resource"):
return _mk_response(200, {"authorization_servers": ["https://as.example.com"]})
if url.endswith("/oauth-authorization-server"):
return _mk_response(200, _good_as_metadata_doc())
raise AssertionError(f"unexpected URL: {url}")
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(side_effect=_get)
storage = _mk_storage_mock()
# cached_issuer points at a private host. SSRF guard fires on
# the cached value first, the row is cleared, and PRM
# discovery runs as a fallback.
async def _run() -> Any:
with patch(
"socket.getaddrinfo",
# Private resolution for "internal.corp", public for everything else.
side_effect=lambda host, *a, **kw: [
(2, 1, 6, "", ("10.0.0.1" if "internal" in host else "93.184.216.34", 0))
],
):
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url=None,
cached_issuer="https://internal.corp.example.com",
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert meta.token_endpoint == "https://as.example.com/token"
# The bad cached_issuer was cleared from the row.
clear_calls = [
c
for c in storage.update_mcp_server.call_args_list
if c.kwargs.get("oauth_as_issuer_cached") is None
]
assert clear_calls, "cached_issuer should have been cleared"
# ---------------------------------------------------------------------------
# revocation_endpoint parsing (RFC 8414)
# ---------------------------------------------------------------------------
class TestASMetadataRevocationEndpoint:
def test_as_metadata_parses_revocation_endpoint(self) -> None:
doc = _good_as_metadata_doc()
doc["revocation_endpoint"] = "https://as.example.com/revoke"
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, doc))
storage = _mk_storage_mock()
async def _run() -> ASMetadata:
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert meta.revocation_endpoint == "https://as.example.com/revoke"
def test_as_metadata_revocation_endpoint_absent(self) -> None:
doc = _good_as_metadata_doc()
doc.pop("revocation_endpoint", None)
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, doc))
storage = _mk_storage_mock()
async def _run() -> ASMetadata:
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
meta = asyncio.run(_run())
assert meta.revocation_endpoint is None
def test_as_metadata_revocation_endpoint_rejected_when_cross_origin(self) -> None:
doc = _good_as_metadata_doc()
doc["revocation_endpoint"] = "https://attacker.example.com/revoke"
client = MagicMock(spec=httpx.AsyncClient)
client.get = AsyncMock(return_value=_mk_response(200, doc))
storage = _mk_storage_mock()
async def _run() -> ASMetadata:
with _public_addr_patch():
return await discover_authorization_server(
server_name="srv-x",
server_url="https://mcp.example.com/sse",
override_url="https://as.example.com",
cached_issuer=None,
http_client=client,
storage=storage,
server_id="srv-id",
trusted_hosts=frozenset(),
)
with pytest.raises(MCPOAuthDiscoveryError, match="revocation_endpoint"):
asyncio.run(_run())