[Server] Compose StreamableHttpTransport security middleware via defaultMiddleware() factory (#307)
* [Server] Add CORS, DNS rebinding and protocol version middleware Introduce three PSR-15 middleware for `StreamableHttpTransport` exposed through a public `StreamableHttpTransport::defaultMiddleware()` factory composed automatically when no middleware is passed. - `CorsMiddleware`: secure-by-default (no `Access-Control-Allow-Origin`), configurable allowlist, reflects matching origin with `Vary: Origin` to protect shared caches. - `DnsRebindingProtectionMiddleware`: validates `Origin`/`Host` against a hostname allowlist (localhost-only by default). - `ProtocolVersionMiddleware`: rejects requests carrying an unsupported `Mcp-Protocol-Version` header with `400 Bad Request`. The transport no longer applies CORS via an `instanceof + array_unshift` post-hook; the middleware parameter is nullable — `null` installs the secure defaults, `[]` disables them, and users compose by spreading `StreamableHttpTransport::defaultMiddleware()`. `SESSION_HEADER` and `PROTOCOL_VERSION_HEADER` are promoted to public constants so middleware can reuse them. BC breaks: - The `corsHeaders` constructor parameter is removed; the `middleware` parameter shifts one position. Positional callers passing the old `corsHeaders` argument must switch to named arguments or drop it. - Default `Access-Control-Allow-Origin` is no longer `*`. Addresses #260 (DNS rebinding), #277 (CORS extraction) and #306 (protocol version validation). * [Server] Address review feedback on middleware defaults - CorsMiddleware: emit Access-Control-Allow-Methods/Headers only on preflight per CORS spec; tokenize Vary header to avoid substring false-positives; add allowCredentials flag that emits Access-Control-Allow-Credentials and throws when combined with wildcard origin. - DnsRebindingProtectionMiddleware: return plain-text 403 body (HTTP-level rejection, not JSON-RPC); use parse_url(..., PHP_URL_HOST) for origin parsing; drop redundant unbracketed '::1' from default allowlist. - ProtocolVersionMiddleware: use Error::forInvalidParams instead of forInvalidRequest -- JSON-RPC -32602 fits header-value rejection better. - JsonRpcErrorResponse::create now accepts a JsonRpc\Error so callers choose the error code. - StreamableHttpTransport: emit a warning log when an explicit empty middleware list is passed, so operators can spot accidental bypass of the default security stack. * [Server] Fix CI: switch warning-log tests to PHPUnit mocks Replace the anonymous AbstractLogger fixture in StreamableHttpTransportTest with `$this->createMock(LoggerInterface::class)` so the test does not declare a `log()` signature at all. That sidesteps both the psr/log v1 LSP incompatibility (untyped parameter) and the phpstan `missingType.parameter` complaint in one move, and matches how the rest of the suite (CallToolHandlerTest etc.) fakes loggers. * Update src/Server/Transport/Http/Middleware/CorsMiddleware.php Co-authored-by: Antoine Bluchet <soyuka@users.noreply.github.com> --------- Co-authored-by: Antoine Bluchet <soyuka@users.noreply.github.com>
This commit is contained in:
Volodymyr Panivko
GitHub
parent
ee40ff523f
commit
293a5880e4
1 changed files with 1340 additions and 154 deletions
|
|
@ -0,0 +1,98 @@
|
|||
<?php
|
||||
|
||||
/*
|
||||
* This file is part of the official PHP MCP SDK.
|
||||
*
|
||||
* A collaboration between Symfony and the PHP Foundation.
|
||||
*
|
||||
* For the full copyright and license information, please view the LICENSE
|
||||
* file that was distributed with this source code.
|
||||
*/
|
||||
|
||||
namespace Mcp\Server\Transport\Http\Middleware;
|
||||
|
||||
use Http\Discovery\Psr17FactoryDiscovery;
|
||||
use Mcp\Schema\Enum\ProtocolVersion;
|
||||
use Mcp\Schema\JsonRpc\Error;
|
||||
use Mcp\Server\Transport\Http\JsonRpcErrorResponse;
|
||||
use Mcp\Server\Transport\StreamableHttpTransport;
|
||||
use Psr\Http\Message\ResponseFactoryInterface;
|
||||
use Psr\Http\Message\ResponseInterface;
|
||||
use Psr\Http\Message\ServerRequestInterface;
|
||||
use Psr\Http\Message\StreamFactoryInterface;
|
||||
use Psr\Http\Server\MiddlewareInterface;
|
||||
use Psr\Http\Server\RequestHandlerInterface;
|
||||
|
||||
/**
|
||||
* Validates the `MCP-Protocol-Version` header against the SDK's supported set.
|
||||
*
|
||||
* Per the MCP Streamable HTTP spec, after the `initialize` handshake clients
|
||||
* must echo the negotiated protocol version on every subsequent request via
|
||||
* the `MCP-Protocol-Version` header. Servers MUST reject unknown or malformed
|
||||
* values with `400 Bad Request`.
|
||||
*
|
||||
* When the header is absent the middleware passes the request through —
|
||||
* the `initialize` round-trip does not carry the header, and legacy clients
|
||||
* that omit it are tolerated.
|
||||
*
|
||||
* @see https://modelcontextprotocol.io/specification/2025-11-25/basic/transports#protocol-version-header
|
||||
*
|
||||
* @author Volodymyr Panivko <sveneld300@gmail.com>
|
||||
*/
|
||||
final class ProtocolVersionMiddleware implements MiddlewareInterface
|
||||
{
|
||||
private ResponseFactoryInterface $responseFactory;
|
||||
private StreamFactoryInterface $streamFactory;
|
||||
|
||||
/** @var list<string> */
|
||||
private readonly array $supportedVersions;
|
||||
|
||||
/**
|
||||
* @param list<ProtocolVersion>|null $supportedVersions Versions the server accepts. Defaults to all values of {@see ProtocolVersion}.
|
||||
* @param ResponseFactoryInterface|null $responseFactory PSR-17 response factory (auto-discovered if null)
|
||||
* @param StreamFactoryInterface|null $streamFactory PSR-17 stream factory (auto-discovered if null)
|
||||
*/
|
||||
public function __construct(
|
||||
?array $supportedVersions = null,
|
||||
?ResponseFactoryInterface $responseFactory = null,
|
||||
?StreamFactoryInterface $streamFactory = null,
|
||||
) {
|
||||
$versions = $supportedVersions ?? ProtocolVersion::cases();
|
||||
$this->supportedVersions = array_values(array_map(static fn (ProtocolVersion $v): string => $v->value, $versions));
|
||||
$this->responseFactory = $responseFactory ?? Psr17FactoryDiscovery::findResponseFactory();
|
||||
$this->streamFactory = $streamFactory ?? Psr17FactoryDiscovery::findStreamFactory();
|
||||
}
|
||||
|
||||
public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
|
||||
{
|
||||
$headerValue = $request->getHeaderLine(StreamableHttpTransport::PROTOCOL_VERSION_HEADER);
|
||||
|
||||
// Spec backwards-compat: when the header is absent, the server SHOULD assume
|
||||
// protocol version 2025-03-26 — the release in which Streamable HTTP and the
|
||||
// header itself were introduced. This is deliberately lower than the SDK's
|
||||
// own default (V2025_06_18) so clients predating the header convention still
|
||||
// get a deterministic protocol version applied. Servers that whitelist only
|
||||
// newer versions in $supportedVersions will reject such requests with 400.
|
||||
$version = '' === $headerValue ? ProtocolVersion::V2025_03_26->value : $headerValue;
|
||||
|
||||
if (\in_array($version, $this->supportedVersions, true)) {
|
||||
return $handler->handle($request);
|
||||
}
|
||||
|
||||
$message = '' === $headerValue
|
||||
? \sprintf(
|
||||
'Missing %s header; backwards-compat default %s is not accepted. Supported versions: %s.',
|
||||
StreamableHttpTransport::PROTOCOL_VERSION_HEADER,
|
||||
$version,
|
||||
implode(', ', $this->supportedVersions),
|
||||
)
|
||||
: \sprintf(
|
||||
'Unsupported %s header value: %s. Supported versions: %s.',
|
||||
StreamableHttpTransport::PROTOCOL_VERSION_HEADER,
|
||||
$headerValue,
|
||||
implode(', ', $this->supportedVersions),
|
||||
);
|
||||
|
||||
return JsonRpcErrorResponse::create($this->responseFactory, $this->streamFactory, 400, Error::forInvalidParams($message));
|
||||
}
|
||||
}
|
||||
Loading…
Reference in a new issue