mag/GITEA-MCP
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Initial Commit

Browse Source
This commit is contained in:
Mark Gregory
2026-10-21 13:04:35 +01:00
commit 2c86cd435c
4963 changed files with 779038 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
.venv/lib/python3.11/site-packages/mcp/client/auth/extensions/__init__.py
View File
.venv/lib/python3.11/site-packages/mcp/client/auth/extensions/__pycache__/__init__.cpython-311.pyc
BIN
View File
Binary file not shown.
.venv/lib/python3.11/site-packages/mcp/client/auth/extensions/__pycache__/client_credentials.cpython-311.pyc
BIN
View File
Binary file not shown.
.venv/lib/python3.11/site-packages/mcp/client/auth/extensions/client_credentials.py
+567
View File
@@ -0,0 +1,567 @@
"""
OAuth client credential extensions for MCP.
Provides OAuth providers for machine-to-machine authentication flows:
- ClientCredentialsOAuthProvider: For client_credentials with client_id + client_secret
- PrivateKeyJWTOAuthProvider: For client_credentials with private_key_jwt authentication
(typically using a pre-built JWT from workload identity federation)
- RFC7523OAuthClientProvider: For jwt-bearer grant (RFC 7523 Section 2.1)
"""
import time
import warnings
from collections.abc import Awaitable, Callable
from typing import Any, Literal
from urllib.parse import urlparse
from uuid import uuid4
import httpx
import jwt
from pydantic import BaseModel, Field
from mcp.client.auth import OAuthClientProvider, OAuthFlowError, OAuthTokenError, TokenStorage
from mcp.client.auth.oauth2 import OAuthContext
from mcp.client.auth.utils import issuers_match
from mcp.shared.auth import OAuthClientInformationFull, OAuthClientMetadata
def _checked_issuer(issuer: str | None) -> str | None:
if issuer is None:
warnings.warn(
"Omitting `issuer` is deprecated and it will be required in 3.0. Without it, the MCP server "
"decides which authorization server receives this client's credentials; pass "
"issuer=<your authorization server's issuer URL> so they are only ever sent there.",
DeprecationWarning,
stacklevel=3,
)
return None
if urlparse(issuer).scheme not in ("http", "https"):
raise ValueError(f"issuer must be the authorization server's http(s) issuer URL, got {issuer!r}")
return issuer
def _preferred_authorization_server(advertised: list[str], issuer: str | None) -> str:
"""The advertised server matching the configured issuer if there is one, else the first."""
return next(
(server for server in advertised if issuer is not None and issuers_match(server, issuer)), advertised[0]
)
def _require_metadata_for_configured_issuer(context: OAuthContext, issuer: str | None) -> None:
"""With an issuer configured, a token request is only built from metadata discovered for that issuer.
Anything else held is dropped along with the tokens, so the next request starts discovery afresh
rather than refreshing against it.
"""
if issuer is None:
return
metadata = context.oauth_metadata
if metadata is not None and issuers_match(str(metadata.issuer), issuer):
return
context.oauth_metadata = None
context.clear_tokens()
if metadata is None:
raise OAuthFlowError(f"No authorization server metadata discovered for configured issuer {issuer}")
raise OAuthFlowError(f"Authorization server metadata issuer mismatch: {metadata.issuer} != {issuer}")
class ClientCredentialsOAuthProvider(OAuthClientProvider):
"""OAuth provider for client_credentials grant with client_id + client_secret.
This provider sets client_info directly, bypassing dynamic client registration.
Use this when you already have client credentials (client_id and client_secret).
Pass `issuer` to name the authorization server those credentials belong to: token
requests are then only built from authorization server metadata for that issuer, and
the flow stops if the MCP server leads anywhere else.
Example:
```python
provider = ClientCredentialsOAuthProvider(
server_url="https://api.example.com",
storage=my_token_storage,
client_id="my-client-id",
client_secret="my-client-secret",
issuer="https://auth.example.com",
)
```
"""
def __init__(
self,
server_url: str,
storage: TokenStorage,
client_id: str,
client_secret: str,
token_endpoint_auth_method: Literal["client_secret_basic", "client_secret_post"] = "client_secret_basic",
scopes: str | None = None,
issuer: str | None = None,
) -> None:
"""Initialize client_credentials OAuth provider.
Args:
server_url: The MCP server URL.
storage: Token storage implementation.
client_id: The OAuth client ID.
client_secret: The OAuth client secret.
token_endpoint_auth_method: Authentication method for token endpoint.
Either "client_secret_basic" (default) or "client_secret_post".
scopes: Optional space-separated list of scopes to request.
issuer: The issuer identifier of the authorization server that issued
`client_id` and `client_secret`. When set, token requests are only built from
discovered authorization server metadata whose `issuer` is exactly this string;
otherwise the flow stops with `OAuthFlowError`. Omitting it is deprecated
(`DeprecationWarning`) and it will be required in 3.0; until then, whichever
authorization server discovery yields is used.
"""
# Build minimal client_metadata for the base class
client_metadata = OAuthClientMetadata(
redirect_uris=None,
grant_types=["client_credentials"],
token_endpoint_auth_method=token_endpoint_auth_method,
scope=scopes,
)
super().__init__(server_url, client_metadata, storage, None, None, 300.0)
self._issuer = _checked_issuer(issuer)
# Store client_info to be set during _initialize - no dynamic registration needed
self._fixed_client_info = OAuthClientInformationFull(
redirect_uris=None,
client_id=client_id,
client_secret=client_secret,
grant_types=["client_credentials"],
token_endpoint_auth_method=token_endpoint_auth_method,
scope=scopes,
)
async def _initialize(self) -> None:
"""Load stored tokens and set pre-configured client_info."""
self.context.current_tokens = await self.context.storage.get_tokens()
self.context.client_info = self._fixed_client_info
self._initialized = True
def _select_authorization_server(self, advertised: list[str]) -> str:
return _preferred_authorization_server(advertised, self._issuer)
async def _perform_authorization(self) -> httpx.Request:
"""Perform client_credentials authorization."""
return await self._exchange_token_client_credentials()
async def _exchange_token_client_credentials(self) -> httpx.Request:
"""Build token exchange request for client_credentials grant."""
_require_metadata_for_configured_issuer(self.context, self._issuer)
token_data: dict[str, Any] = {
"grant_type": "client_credentials",
}
headers: dict[str, str] = {"Content-Type": "application/x-www-form-urlencoded"}
# Use standard auth methods (client_secret_basic, client_secret_post, none)
token_data, headers = self.context.prepare_token_auth(token_data, headers)
if self.context.should_include_resource_param(self.context.protocol_version):
token_data["resource"] = self.context.get_resource_url()
if self.context.client_metadata.scope:
token_data["scope"] = self.context.client_metadata.scope
token_url = self._get_token_endpoint()
return httpx.Request("POST", token_url, data=token_data, headers=headers)
def static_assertion_provider(token: str) -> Callable[[str], Awaitable[str]]:
"""Create an assertion provider that returns a static JWT token.
Use this when you have a pre-built JWT (e.g., from workload identity federation)
that doesn't need the audience parameter.
Example:
```python
provider = PrivateKeyJWTOAuthProvider(
server_url="https://api.example.com",
storage=my_token_storage,
client_id="my-client-id",
assertion_provider=static_assertion_provider(my_prebuilt_jwt),
issuer="https://auth.example.com",
)
```
Args:
token: The pre-built JWT assertion string.
Returns:
An async callback suitable for use as an assertion_provider.
"""
async def provider(audience: str) -> str:
return token
return provider
class SignedJWTParameters(BaseModel):
"""Parameters for creating SDK-signed JWT assertions.
Use `create_assertion_provider()` to create an assertion provider callback
for use with `PrivateKeyJWTOAuthProvider`.
Example:
```python
jwt_params = SignedJWTParameters(
issuer="my-client-id",
subject="my-client-id",
signing_key=private_key_pem,
)
provider = PrivateKeyJWTOAuthProvider(
server_url="https://api.example.com",
storage=my_token_storage,
client_id="my-client-id",
assertion_provider=jwt_params.create_assertion_provider(),
issuer="https://auth.example.com",
)
```
"""
issuer: str = Field(description="Issuer for JWT assertions (typically client_id).")
subject: str = Field(description="Subject identifier for JWT assertions (typically client_id).")
signing_key: str = Field(description="Private key for JWT signing (PEM format).")
signing_algorithm: str = Field(default="RS256", description="Algorithm for signing JWT assertions.")
lifetime_seconds: int = Field(default=300, description="Lifetime of generated JWT in seconds.")
additional_claims: dict[str, Any] | None = Field(default=None, description="Additional claims.")
def create_assertion_provider(self) -> Callable[[str], Awaitable[str]]:
"""Create an assertion provider callback for use with PrivateKeyJWTOAuthProvider.
Returns:
An async callback that takes the audience (authorization server issuer URL)
and returns a signed JWT assertion.
"""
async def provider(audience: str) -> str:
now = int(time.time())
claims: dict[str, Any] = {
"iss": self.issuer,
"sub": self.subject,
"aud": audience,
"exp": now + self.lifetime_seconds,
"iat": now,
"jti": str(uuid4()),
}
if self.additional_claims:
claims.update(self.additional_claims)
return jwt.encode(claims, self.signing_key, algorithm=self.signing_algorithm)
return provider
class PrivateKeyJWTOAuthProvider(OAuthClientProvider):
"""OAuth provider for client_credentials grant with private_key_jwt authentication.
Uses RFC 7523 Section 2.2 for client authentication via JWT assertion.
The JWT assertion's audience MUST be the authorization server's issuer identifier
(per RFC 7523bis security updates). The `assertion_provider` callback receives
this audience value and must return a JWT with that audience. Pass `issuer` to name
the authorization server this client is registered with: an assertion is then only
minted once metadata for that issuer has been discovered, and token requests are only
built from that metadata.
**Option 1: Pre-built JWT via Workload Identity Federation**
In production scenarios, the JWT assertion is typically obtained from a workload
identity provider (e.g., GCP, AWS IAM, Azure AD):
```python
async def get_workload_identity_token(audience: str) -> str:
# Fetch JWT from your identity provider
# The JWT's audience must match the provided audience parameter
return await fetch_token_from_identity_provider(audience=audience)
provider = PrivateKeyJWTOAuthProvider(
server_url="https://api.example.com",
storage=my_token_storage,
client_id="my-client-id",
assertion_provider=get_workload_identity_token,
issuer="https://auth.example.com",
)
```
**Option 2: Static pre-built JWT**
If you have a static JWT that doesn't need the audience parameter:
```python
provider = PrivateKeyJWTOAuthProvider(
server_url="https://api.example.com",
storage=my_token_storage,
client_id="my-client-id",
assertion_provider=static_assertion_provider(my_prebuilt_jwt),
issuer="https://auth.example.com",
)
```
**Option 3: SDK-signed JWT (for testing/simple setups)**
For testing or simple deployments, use `SignedJWTParameters.create_assertion_provider()`:
```python
jwt_params = SignedJWTParameters(
issuer="my-client-id",
subject="my-client-id",
signing_key=private_key_pem,
)
provider = PrivateKeyJWTOAuthProvider(
server_url="https://api.example.com",
storage=my_token_storage,
client_id="my-client-id",
assertion_provider=jwt_params.create_assertion_provider(),
issuer="https://auth.example.com",
)
```
"""
def __init__(
self,
server_url: str,
storage: TokenStorage,
client_id: str,
assertion_provider: Callable[[str], Awaitable[str]],
scopes: str | None = None,
issuer: str | None = None,
) -> None:
"""Initialize private_key_jwt OAuth provider.
Args:
server_url: The MCP server URL.
storage: Token storage implementation.
client_id: The OAuth client ID.
assertion_provider: Async callback that takes the audience (authorization
server's issuer identifier) and returns a JWT assertion. Use
`SignedJWTParameters.create_assertion_provider()` for SDK-signed JWTs,
`static_assertion_provider()` for pre-built JWTs, or provide your own
callback for workload identity federation.
scopes: Optional space-separated list of scopes to request.
issuer: The issuer identifier of the authorization server `client_id` is
registered with. When set, an assertion is only minted, and token requests
are only built, once authorization server metadata whose `issuer` is exactly this
string has been discovered; otherwise the flow stops with `OAuthFlowError`.
Omitting it is deprecated (`DeprecationWarning`) and it will be required in
3.0; until then, whichever authorization server discovery yields is used.
"""
# Build minimal client_metadata for the base class
client_metadata = OAuthClientMetadata(
redirect_uris=None,
grant_types=["client_credentials"],
token_endpoint_auth_method="private_key_jwt",
scope=scopes,
)
super().__init__(server_url, client_metadata, storage, None, None, 300.0)
self._assertion_provider = assertion_provider
self._issuer = _checked_issuer(issuer)
# Store client_info to be set during _initialize - no dynamic registration needed
self._fixed_client_info = OAuthClientInformationFull(
redirect_uris=None,
client_id=client_id,
grant_types=["client_credentials"],
token_endpoint_auth_method="private_key_jwt",
scope=scopes,
)
async def _initialize(self) -> None:
"""Load stored tokens and set pre-configured client_info."""
self.context.current_tokens = await self.context.storage.get_tokens()
self.context.client_info = self._fixed_client_info
self._initialized = True
def _select_authorization_server(self, advertised: list[str]) -> str:
return _preferred_authorization_server(advertised, self._issuer)
async def _perform_authorization(self) -> httpx.Request:
"""Perform client_credentials authorization with private_key_jwt."""
return await self._exchange_token_client_credentials()
async def _add_client_authentication_jwt(self, *, token_data: dict[str, Any]) -> None:
"""Add JWT assertion for client authentication to token endpoint parameters."""
if not self.context.oauth_metadata:
raise OAuthFlowError("Missing OAuth metadata for private_key_jwt flow") # pragma: no cover
# Audience MUST be the issuer identifier of the authorization server
# https://datatracker.ietf.org/doc/html/draft-ietf-oauth-rfc7523bis-01
audience = str(self.context.oauth_metadata.issuer)
assertion = await self._assertion_provider(audience)
# RFC 7523 Section 2.2: client authentication via JWT
token_data["client_assertion"] = assertion
token_data["client_assertion_type"] = "urn:ietf:params:oauth:client-assertion-type:jwt-bearer"
async def _exchange_token_client_credentials(self) -> httpx.Request:
"""Build token exchange request for client_credentials grant with private_key_jwt."""
_require_metadata_for_configured_issuer(self.context, self._issuer)
token_data: dict[str, Any] = {
"grant_type": "client_credentials",
}
headers: dict[str, str] = {"Content-Type": "application/x-www-form-urlencoded"}
# Add JWT client authentication (RFC 7523 Section 2.2)
await self._add_client_authentication_jwt(token_data=token_data)
if self.context.should_include_resource_param(self.context.protocol_version):
token_data["resource"] = self.context.get_resource_url()
if self.context.client_metadata.scope:
token_data["scope"] = self.context.client_metadata.scope
token_url = self._get_token_endpoint()
return httpx.Request("POST", token_url, data=token_data, headers=headers)
class JWTParameters(BaseModel):
"""JWT parameters."""
assertion: str | None = Field(
default=None,
description="JWT assertion for JWT authentication. "
"Will be used instead of generating a new assertion if provided.",
)
issuer: str | None = Field(default=None, description="Issuer for JWT assertions.")
subject: str | None = Field(default=None, description="Subject identifier for JWT assertions.")
audience: str | None = Field(default=None, description="Audience for JWT assertions.")
claims: dict[str, Any] | None = Field(default=None, description="Additional claims for JWT assertions.")
jwt_signing_algorithm: str | None = Field(default="RS256", description="Algorithm for signing JWT assertions.")
jwt_signing_key: str | None = Field(default=None, description="Private key for JWT signing.")
jwt_lifetime_seconds: int = Field(default=300, description="Lifetime of generated JWT in seconds.")
def to_assertion(self, with_audience_fallback: str | None = None) -> str:
if self.assertion is not None:
# Prebuilt JWT (e.g. acquired out-of-band)
assertion = self.assertion
else:
if not self.jwt_signing_key:
raise OAuthFlowError("Missing signing key for JWT bearer grant") # pragma: no cover
if not self.issuer:
raise OAuthFlowError("Missing issuer for JWT bearer grant") # pragma: no cover
if not self.subject:
raise OAuthFlowError("Missing subject for JWT bearer grant") # pragma: no cover
audience = self.audience if self.audience else with_audience_fallback
if not audience:
raise OAuthFlowError("Missing audience for JWT bearer grant") # pragma: no cover
now = int(time.time())
claims: dict[str, Any] = {
"iss": self.issuer,
"sub": self.subject,
"aud": audience,
"exp": now + self.jwt_lifetime_seconds,
"iat": now,
"jti": str(uuid4()),
}
claims.update(self.claims or {})
assertion = jwt.encode(
claims,
self.jwt_signing_key,
algorithm=self.jwt_signing_algorithm or "RS256",
)
return assertion
class RFC7523OAuthClientProvider(OAuthClientProvider):
"""OAuth client provider for RFC 7523 jwt-bearer grant.
.. deprecated::
Use :class:`ClientCredentialsOAuthProvider` for client_credentials with
client_id + client_secret, or :class:`PrivateKeyJWTOAuthProvider` for
client_credentials with private_key_jwt authentication instead.
This provider supports the jwt-bearer authorization grant (RFC 7523 Section 2.1)
where the JWT itself is the authorization grant.
"""
def __init__(
self,
server_url: str,
client_metadata: OAuthClientMetadata,
storage: TokenStorage,
redirect_handler: Callable[[str], Awaitable[None]] | None = None,
callback_handler: Callable[[], Awaitable[tuple[str, str | None]]] | None = None,
timeout: float = 300.0,
jwt_parameters: JWTParameters | None = None,
) -> None:
warnings.warn(
"RFC7523OAuthClientProvider is deprecated. Use ClientCredentialsOAuthProvider "
"or PrivateKeyJWTOAuthProvider instead.",
DeprecationWarning,
stacklevel=2,
)
super().__init__(server_url, client_metadata, storage, redirect_handler, callback_handler, timeout)
self.jwt_parameters = jwt_parameters
async def _exchange_token_authorization_code(
self, auth_code: str, code_verifier: str, *, token_data: dict[str, Any] | None = None
) -> httpx.Request: # pragma: no cover
"""Build token exchange request for authorization_code flow."""
token_data = token_data or {}
if self.context.client_metadata.token_endpoint_auth_method == "private_key_jwt":
self._add_client_authentication_jwt(token_data=token_data)
return await super()._exchange_token_authorization_code(auth_code, code_verifier, token_data=token_data)
async def _perform_authorization(self) -> httpx.Request: # pragma: no cover
"""Perform the authorization flow."""
if "urn:ietf:params:oauth:grant-type:jwt-bearer" in self.context.client_metadata.grant_types:
token_request = await self._exchange_token_jwt_bearer()
return token_request
else:
return await super()._perform_authorization()
def _add_client_authentication_jwt(self, *, token_data: dict[str, Any]): # pragma: no cover
"""Add JWT assertion for client authentication to token endpoint parameters."""
if not self.jwt_parameters:
raise OAuthTokenError("Missing JWT parameters for private_key_jwt flow")
if not self.context.oauth_metadata:
raise OAuthTokenError("Missing OAuth metadata for private_key_jwt flow")
# We need to set the audience to the issuer identifier of the authorization server
# https://datatracker.ietf.org/doc/html/draft-ietf-oauth-rfc7523bis-01#name-updates-to-rfc-7523
issuer = str(self.context.oauth_metadata.issuer)
assertion = self.jwt_parameters.to_assertion(with_audience_fallback=issuer)
# When using private_key_jwt, in a client_credentials flow, we use RFC 7523 Section 2.2
token_data["client_assertion"] = assertion
token_data["client_assertion_type"] = "urn:ietf:params:oauth:client-assertion-type:jwt-bearer"
# We need to set the audience to the resource server, the audience is difference from the one in claims
# it represents the resource server that will validate the token
token_data["audience"] = self.context.get_resource_url()
async def _exchange_token_jwt_bearer(self) -> httpx.Request:
"""Build token exchange request for JWT bearer grant."""
if not self.context.client_info:
raise OAuthFlowError("Missing client info") # pragma: no cover
if not self.jwt_parameters:
raise OAuthFlowError("Missing JWT parameters") # pragma: no cover
if not self.context.oauth_metadata:
raise OAuthTokenError("Missing OAuth metadata") # pragma: no cover
# We need to set the audience to the issuer identifier of the authorization server
# https://datatracker.ietf.org/doc/html/draft-ietf-oauth-rfc7523bis-01#name-updates-to-rfc-7523
issuer = str(self.context.oauth_metadata.issuer)
assertion = self.jwt_parameters.to_assertion(with_audience_fallback=issuer)
token_data = {
"grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
"assertion": assertion,
}
if self.context.should_include_resource_param(self.context.protocol_version): # pragma: no branch
token_data["resource"] = self.context.get_resource_url()
if self.context.client_metadata.scope: # pragma: no branch
token_data["scope"] = self.context.client_metadata.scope
token_url = self._get_token_endpoint()
return httpx.Request(
"POST", token_url, data=token_data, headers={"Content-Type": "application/x-www-form-urlencoded"}
)