@modelcontextprotocol/sdk
Version:
Model Context Protocol implementation for TypeScript
113 lines • 5.82 kB
JavaScript
"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.tokenHandler = tokenHandler;
const zod_1 = require("zod");
const express_1 = __importDefault(require("express"));
const cors_1 = __importDefault(require("cors"));
const pkce_challenge_1 = require("pkce-challenge");
const clientAuth_js_1 = require("../middleware/clientAuth.js");
const express_rate_limit_1 = require("express-rate-limit");
const allowedMethods_js_1 = require("../middleware/allowedMethods.js");
const errors_js_1 = require("../errors.js");
const TokenRequestSchema = zod_1.z.object({
grant_type: zod_1.z.string(),
});
const AuthorizationCodeGrantSchema = zod_1.z.object({
code: zod_1.z.string(),
code_verifier: zod_1.z.string(),
redirect_uri: zod_1.z.string().optional(),
resource: zod_1.z.string().url().optional(),
});
const RefreshTokenGrantSchema = zod_1.z.object({
refresh_token: zod_1.z.string(),
scope: zod_1.z.string().optional(),
resource: zod_1.z.string().url().optional(),
});
function tokenHandler({ provider, rateLimit: rateLimitConfig }) {
// Nested router so we can configure middleware and restrict HTTP method
const router = express_1.default.Router();
// Configure CORS to allow any origin, to make accessible to web-based MCP clients
router.use((0, cors_1.default)());
router.use((0, allowedMethods_js_1.allowedMethods)(["POST"]));
router.use(express_1.default.urlencoded({ extended: false }));
// Apply rate limiting unless explicitly disabled
if (rateLimitConfig !== false) {
router.use((0, express_rate_limit_1.rateLimit)({
windowMs: 15 * 60 * 1000, // 15 minutes
max: 50, // 50 requests per windowMs
standardHeaders: true,
legacyHeaders: false,
message: new errors_js_1.TooManyRequestsError('You have exceeded the rate limit for token requests').toResponseObject(),
...rateLimitConfig
}));
}
// Authenticate and extract client details
router.use((0, clientAuth_js_1.authenticateClient)({ clientsStore: provider.clientsStore }));
router.post("/", async (req, res) => {
res.setHeader('Cache-Control', 'no-store');
try {
const parseResult = TokenRequestSchema.safeParse(req.body);
if (!parseResult.success) {
throw new errors_js_1.InvalidRequestError(parseResult.error.message);
}
const { grant_type } = parseResult.data;
const client = req.client;
if (!client) {
// This should never happen
throw new errors_js_1.ServerError("Internal Server Error");
}
switch (grant_type) {
case "authorization_code": {
const parseResult = AuthorizationCodeGrantSchema.safeParse(req.body);
if (!parseResult.success) {
throw new errors_js_1.InvalidRequestError(parseResult.error.message);
}
const { code, code_verifier, redirect_uri, resource } = parseResult.data;
const skipLocalPkceValidation = provider.skipLocalPkceValidation;
// Perform local PKCE validation unless explicitly skipped
// (e.g. to validate code_verifier in upstream server)
if (!skipLocalPkceValidation) {
const codeChallenge = await provider.challengeForAuthorizationCode(client, code);
if (!(await (0, pkce_challenge_1.verifyChallenge)(code_verifier, codeChallenge))) {
throw new errors_js_1.InvalidGrantError("code_verifier does not match the challenge");
}
}
// Passes the code_verifier to the provider if PKCE validation didn't occur locally
const tokens = await provider.exchangeAuthorizationCode(client, code, skipLocalPkceValidation ? code_verifier : undefined, redirect_uri, resource ? new URL(resource) : undefined);
res.status(200).json(tokens);
break;
}
case "refresh_token": {
const parseResult = RefreshTokenGrantSchema.safeParse(req.body);
if (!parseResult.success) {
throw new errors_js_1.InvalidRequestError(parseResult.error.message);
}
const { refresh_token, scope, resource } = parseResult.data;
const scopes = scope === null || scope === void 0 ? void 0 : scope.split(" ");
const tokens = await provider.exchangeRefreshToken(client, refresh_token, scopes, resource ? new URL(resource) : undefined);
res.status(200).json(tokens);
break;
}
// Not supported right now
//case "client_credentials":
default:
throw new errors_js_1.UnsupportedGrantTypeError("The grant type is not supported by this authorization server.");
}
}
catch (error) {
if (error instanceof errors_js_1.OAuthError) {
const status = error instanceof errors_js_1.ServerError ? 500 : 400;
res.status(status).json(error.toResponseObject());
}
else {
const serverError = new errors_js_1.ServerError("Internal Server Error");
res.status(500).json(serverError.toResponseObject());
}
}
});
return router;
}
//# sourceMappingURL=token.js.map