feat: support Authentication and Authorization for the proxy

packages/cli/package.json

@@ -45,6 +45,7 @@
         "@zenstackhq/orm": "workspace:*",
         "@zenstackhq/schema": "workspace:*",
         "@zenstackhq/sdk": "workspace:*",
+        "@zenstackhq/plugin-policy": "workspace:*",
         "@zenstackhq/server": "workspace:*",
         "chokidar": "^5.0.0",
         "colors": "1.4.0",
@@ -98,4 +99,4 @@
         "node": ">=20"
     },
     "funding": "https://github.com/sponsors/zenstackhq"
-}
+}

packages/cli/src/actions/proxy.ts

@@ -12,6 +12,7 @@
 import { PostgresDialect } from '@zenstackhq/orm/dialects/postgres';
 import { SqliteDialect } from '@zenstackhq/orm/dialects/sqlite';
 import type { SchemaDef } from '@zenstackhq/orm/schema';
+import { PolicyPlugin } from '@zenstackhq/plugin-policy';
 import { RPCApiHandler } from '@zenstackhq/server/api';
 import { ZenStackMiddleware } from '@zenstackhq/server/express';
 import type BetterSqlite3 from 'better-sqlite3';
@@ -20,21 +21,72 @@
 import express from 'express';
 import { createJiti } from 'jiti';
 import type { createPool as MysqlCreatePool } from 'mysql2';
+import { verify } from 'node:crypto';
 import path from 'node:path';
 import type { Pool as PgPoolType } from 'pg';
 import { CliError } from '../cli-error';
 import { getVersion } from '../utils/version-utils';
 import { getOutputPath, getSchemaFile, loadSchemaDocument } from './action-utils';
+import { z } from 'zod';
 
 type Options = {
     output?: string;
     schema?: string;
-    port?: number;
+    port: number;
     logLevel?: string[];
     databaseUrl?: string;
+    studioAuthKey?: string;
+    signatureToleranceSecs: number;
 };
 
+export const ProxyAuthError = {
+    MISSING_SIGNATURE_HEADER: 'Missing x-zenstack-signature header',
+    INVALID_TIMESTAMP: 'Request timestamp is expired or invalid',
+    INVALID_SIGNATURE_FORMAT: 'Invalid x-zenstack-signature format',
+} as const;
+
+type ProxyAuthErrorCode = keyof typeof ProxyAuthError;
+
+function rejectAuth(res: express.Response, code: ProxyAuthErrorCode) {
+    return res.status(401).json({ code, message: ProxyAuthError[code] });
+}
+/**
+ * Represents the identity claim embedded in the Authorization header.
+ * The bearer token is a plain base64-encoded JSON string.
+ */
+const UserClaimSchema = z.discriminatedUnion('type', [
+    z.object({ type: z.literal('superUser') }),
+    z.object({ type: z.literal('user'), data: z.record(z.string(), z.unknown()) }),
+]);
+
+type UserClaim = z.infer<typeof UserClaimSchema>;
+
+/**
+ * Accepts a public key in either PEM format or as a raw base64 / base64url DER string
+ * (without the `-----BEGIN PUBLIC KEY-----` markers) and always returns a PEM string.
+ */
+function normalizePublicKey(key: string): string {
+    key = key.trim();
+    if (key.startsWith('-----BEGIN PUBLIC KEY-----')) {
+        return key;
+    }
+    // Convert base64url → standard base64, then wrap in PEM markers.
+    const b64 = key.replace(/-/g, '+').replace(/_/g, '/');
+    return `-----BEGIN PUBLIC KEY-----\n${b64}\n-----END PUBLIC KEY-----`;
+}
+
 export async function run(options: Options) {
+    // Resolve public key: CLI arg takes precedence, then ZENSTACK_STUDIO_AUTH_KEY env var.
+    options = { ...options, studioAuthKey: options.studioAuthKey ?? process.env['ZENSTACK_STUDIO_AUTH_KEY'] };
+    if (!options.studioAuthKey) {
+        console.warn(
+            colors.yellow(
+                'Warning: This proxy has no authentication. Do not expose it to the public network.\n' +
+                    'To secure it, get an API key from ZenStack Studio and set it via the ZENSTACK_STUDIO_AUTH_KEY environment variable.',
+            ),
+        );
+    }
+
     const allowedLogLevels = ['error', 'query'] as const;
     const log = options.logLevel?.filter((level): level is (typeof allowedLogLevels)[number] =>
         allowedLogLevels.includes(level as any),
@@ -104,7 +156,14 @@
         throw new CliError(`Failed to connect to the database: ${err instanceof Error ? err.message : String(err)}`);
     }
 
-    startServer(db, schemaModule.schema, options);
+    // If a studioAuthKey is provided, create an authDb with the policy plugin
+    let authDb: ClientContract<SchemaDef> | undefined;
+    if (options.studioAuthKey) {
+        authDb = db.$use(new PolicyPlugin()) as ClientContract<SchemaDef>;
+        console.log(colors.gray('Access policy plugin enabled for authorization.'));
+    }
+
+    startServer(db, schemaModule.schema, options, authDb);
 }
 
 function evaluateUrl(schemaUrl: ConfigExpr) {
@@ -198,17 +257,41 @@
     }
 }
 
-export function createProxyApp(client: ClientContract<SchemaDef>, schema: SchemaDef): express.Application {
+export function createProxyApp(
+    client: ClientContract<SchemaDef>,
+    schema: SchemaDef,
+    auth?: {
+        studioAuthKey: string;
+        authDb: ClientContract<SchemaDef>;
+        /** Seconds within which a signed request is considered valid. Defaults to 60. */
+        signatureToleranceSecs: number;
+    },
+): express.Application {
     const app = express();
     app.use(cors());
-    app.use(express.json({ limit: '5mb' }));
+    app.use(
+        express.json({
+            limit: '5mb',
+            verify: (req, _res, buf) => {
+                // Capture the raw body string for use in signature verification.
+                (req as express.Request & { rawBody?: string }).rawBody = buf.toString('utf8');
+            },
+        }),
+    );
     app.use(express.urlencoded({ extended: true, limit: '5mb' }));
 
+    if (auth?.studioAuthKey) {
+        // Apply signature-verification middleware to all authenticated endpoints.
+        const toleranceSecs = auth.signatureToleranceSecs;
+        const normalizedKey = normalizePublicKey(auth.studioAuthKey);
+        app.use(['/api/model', '/api/schema'], createSignatureMiddleware(normalizedKey, toleranceSecs));
+    }
+
     app.use(
         '/api/model',
         ZenStackMiddleware({
             apiHandler: new RPCApiHandler({ schema }),
-            getClient: () => client,
+            getClient: (req) => resolveClient(client, auth?.authDb, req),
         }),
     );
 
@@ -219,8 +302,146 @@
     return app;
 }
 
-function startServer(client: ClientContract<SchemaDef>, schema: any, options: Options) {
-    const app = createProxyApp(client, schema);
+/**
+ * Creates an Express middleware that verifies the ed25519 signature on every request.
+ *
+ * The signature header format is: `t=<unix-timestamp>,v1=<base64url-signature>`
+ *
+ * The signed message is constructed as:
+ *   - GET requests:  `<raw-query-string><timestamp>[<authorizationToken>]`
+ *   - Other methods: `<raw-body><timestamp>[<authorizationToken>]`
+ *
+ * `authorizationToken` is the bearer token value from the `Authorization` header (if present).
+ */
+function createSignatureMiddleware(publicKey: string, toleranceSeconds: number) {
+    // Throttle invalid-signature warnings to at most once per 60 seconds.
+    let lastInvalidSigWarnAt = 0;
+    const WARN_THROTTLE_SECS = 60;
+
+    function warnInvalidSignature() {
+        const now = Math.floor(Date.now() / 1000);
+        if (now - lastInvalidSigWarnAt >= WARN_THROTTLE_SECS) {
+            lastInvalidSigWarnAt = now;
+            console.warn(
+                colors.yellow(
+                    'Warning: Received a request with an invalid signature. ' +
+                        'Please double-check whether you have the correct public API key configured.',
+                ),
+            );
+        }
+    }
+
+    return (req: express.Request, res: express.Response, next: express.NextFunction) => {
+        const signatureHeader = req.headers['x-zenstack-signature'];
+        if (!signatureHeader || typeof signatureHeader !== 'string') {
+            return rejectAuth(res, 'MISSING_SIGNATURE_HEADER');
+        }
+
+        const parts = signatureHeader.split(',');
+        const timestampPart = parts.find((p) => p.startsWith('t='));
+        const sigPart = parts.find((p) => p.startsWith('v1='));
+        if (!timestampPart || !sigPart) {
+            return rejectAuth(res, 'INVALID_SIGNATURE_FORMAT');
+        }
+        const timestamp = timestampPart.substring(2);
+        const sig = sigPart.substring(3);
+
+        // Replay-attack prevention: reject requests whose timestamp deviates
+        // from server time by more than the configured tolerance.
+        const requestTime = parseInt(timestamp, 10);
+        const now = Math.floor(Date.now() / 1000);
+        if (isNaN(requestTime) || Math.abs(now - requestTime) > toleranceSeconds) {
+            return rejectAuth(res, 'INVALID_TIMESTAMP');
+        }
+
+        // Payload: raw query string for GET/DELETE, raw body for other methods.
+        let payload: string;
+        if (req.method === 'GET' || req.method === 'DELETE') {
+            const qMark = req.originalUrl.indexOf('?');
+            payload = qMark >= 0 ? req.originalUrl.substring(qMark + 1) : '';
+        } else {
+            payload = (req as express.Request & { rawBody?: string }).rawBody ?? '';
+        }
+
+        // authorizationToken is the bearer token value (if present).
+        const authHeader = req.headers['authorization'];
+        const authorizationToken = authHeader && authHeader.startsWith('Bearer ') ? authHeader.substring(7) : undefined;
+
+        const message = authorizationToken ? `${payload}${timestamp}${authorizationToken}` : `${payload}${timestamp}`;
+
+        try {
+            const isValid = verify(null, Buffer.from(message, 'utf8'), publicKey, Buffer.from(sig, 'base64url'));
+            if (!isValid) {
+                warnInvalidSignature();
+                return rejectAuth(res, 'INVALID_SIGNATURE_FORMAT');
+            }
+        } catch {
+            warnInvalidSignature();
+            return rejectAuth(res, 'INVALID_SIGNATURE_FORMAT');
+        }
+
+        return next();
+    };
+}
+
+/**
+ * Resolves the appropriate client for a request based on the Authorization header.
+ *
+ * - No studioAuthKey configured (authDb is undefined): always return the base client.
+ * - SuperUser claim: return the base client (full access, no policy enforcement).
+ * - Regular user claim: return authDb with the user identity set via $setAuth.
+ * - No / invalid token: return the base client.
+ */
+function resolveClient(
+    client: ClientContract<SchemaDef>,
+    authDb: ClientContract<SchemaDef> | undefined,
+    req: express.Request,
+): ClientContract<SchemaDef> {
+    if (!authDb) {
+        return client;
+    }
+
+    const authHeader = req.headers['authorization'];
+    if (!authHeader?.startsWith('Bearer ')) {
+        return authDb;
+    }
+
+    const token = authHeader.substring(7);
+    let claim: UserClaim;
+    try {
+        claim = UserClaimSchema.parse(JSON.parse(Buffer.from(token, 'base64').toString('utf8')));
+    } catch (err) {
+        console.error(
+            colors.red(`Failed to parse user claim from token: ${err instanceof Error ? err.message : String(err)}`),
+        );
+        return authDb;
+    }
+
+    if (claim.type === 'superUser') {
+        // SuperUser has full access without policy enforcement, so we return the base client directly.
+        return client;
+    } else {
+        return authDb.$setAuth(claim.data) as ClientContract<SchemaDef>;
+    }
+}
+
+function startServer(
+    client: ClientContract<SchemaDef>,
+    schema: any,
+    options: Options,
+    authDb?: ClientContract<SchemaDef>,
+) {
+    const app = createProxyApp(
+        client,
+        schema,
+        options.studioAuthKey
+            ? {
+                  studioAuthKey: options.studioAuthKey,
+                  authDb: authDb!,
+                  signatureToleranceSecs: options.signatureToleranceSecs,
+              }
+            : undefined,
+    );
 
     const server = app.listen(options.port, () => {
         console.log(`ZenStack proxy server is running on port: ${options.port}`);

packages/cli/src/index.ts

@@ -263,6 +263,26 @@ Arguments following -- are passed to the seed script. E.g.: "zen db seed -- --us
         .addOption(new Option('-o, --output <path>', 'output directory for `zen generate` command'))
         .addOption(new Option('-d, --databaseUrl <url>', 'database connection URL'))
         .addOption(new Option('-l, --logLevel <level...>', 'Query log levels (e.g., query, error)'))
+        .addOption(
+            new Option(
+                '--studioAuthKey <key>',
+                'Authentication key from ZenStack Studio. When set, the proxy will only accept requests signed by your Studio project.\nCan also be set via the ZENSTACK_STUDIO_AUTH_KEY environment variable. ',
+            ),
+        )
+        .addOption(
+            new Option(
+                '--signatureToleranceSecs <seconds>',
+                'Maximum age (in seconds) of a signed request before it is rejected as a replay. Defaults to 60.',
+            )
+                .default(60)
+                .argParser((v) => {
+                    const parsed = parseInt(v, 10);
+                    if (isNaN(parsed) || parsed < 0) {
+                        throw new CliError(`--signatureToleranceSecs must be a positive integer, got: ${v}`);
+                    }
+                    return parsed;
+                }),
+        )
         .addOption(noVersionCheckOption)
         .action(proxyAction);