Add auth controls and headers

source/services/router.ts

@@ -1,7 +1,11 @@
-import type { RouteDefinition, RouteModule } from '../routes/types.ts';
-import { ApplicationError } from '../errors/index.ts';
+import { z } from 'zod';
+import { toExtendedJson } from '@xo-cash/utils';
+
+import type { RequestHeaders, RouteDefinition, RouteModule } from '../routes/types.ts';
+import { ApplicationError, UnauthorizedError } from '../errors/index.ts';
 import { ApplicationRouteStream } from './route-stream.ts';
 import type { BaseStream } from './stream/base-stream.ts';
+import type { AuthSecp256k1 } from '../auth/auth.ts';
 
 /** Canonical request produced by every transport adapter. */
 export type ApplicationRequest = {
@@ -12,14 +16,38 @@ export type ApplicationRequest = {
     /** Transport-decoded application payload. */
     body?: unknown;
 
+    /** Transport-normalized request headers, keyed by lowercase name. */
+    headers?: RequestHeaders;
+
     /** Optional correlation ID supplied by a multiplexed transport. */
     requestId?: string;
 };
 
+export type ApplicationRouterDependencies = {
+
+    /** Authentication service. */
+    auth: AuthSecp256k1;
+};
+
+const accountSchema = z
+    .object({
+        'x-public-key': z.string(),
+        'x-signature': z.string(),
+        'x-timestamp': z.coerce.number(),
+    })
+    .transform((data) => ({
+        publicKey: data['x-public-key'],
+        signature: data['x-signature'],
+        timestamp: data['x-timestamp'],
+    }));
+
 /** Exact-match application routing shared by every wire transport. */
 export class ApplicationRouter {
     /** @param routes - Validated route table keyed by exact path. */
-    private constructor(private readonly routes: ReadonlyMap<string, RouteDefinition>) {}
+    private constructor(
+        private readonly deps: ApplicationRouterDependencies,
+        private readonly routes: ReadonlyMap<string, RouteDefinition>,
+    ) {}
 
     /**
      * Load and validate the complete route table before accepting traffic.
@@ -27,7 +55,7 @@ export class ApplicationRouter {
      * @param routeModules - Route modules whose handlers will be registered.
      * @returns A ready-to-dispatch router instance.
      */
-    static async create(routeModules: RouteModule[]): Promise<ApplicationRouter> {
+    static async create(deps: ApplicationRouterDependencies, routeModules: RouteModule[]): Promise<ApplicationRouter> {
         const routes = new Map<string, RouteDefinition>();
 
         // Collect routes from every module and reject duplicates at startup.
@@ -42,7 +70,7 @@ export class ApplicationRouter {
             }
         }
 
-        return new ApplicationRouter(routes);
+        return new ApplicationRouter(deps, routes);
     }
 
     /**
@@ -52,12 +80,33 @@ export class ApplicationRouter {
      * @param connection - Shared connection stream for this transport session.
      */
     async dispatch(request: ApplicationRequest, connection: BaseStream): Promise<void> {
+        // Authenticate the headers on the request.
+        const { publicKey, signature, timestamp } = accountSchema.parse(request.headers);
+
+        // Make sure the request signature is valid and hasnt been used before
+        await this.deps.auth.verifyUniqueRequest(signature);
+
+        // Ensure that the headers are present.
+        if (!publicKey || !signature || !timestamp) {
+            throw new UnauthorizedError('Missing authentication headers');
+        }
+
+        // Compile the signature payload as `Path:Timestamp:Body`
+        const signaturePayload = `${timestamp}:${request.path}:${toExtendedJson(request.body)}`;
+
+        // Verify the signature of the request.
+        const verified = await this.deps.auth.verifySignature(publicKey, signature, signaturePayload);
+        if (!verified) {
+            throw new UnauthorizedError('Invalid signature');
+        }
+
+        // Get the route from the routes map.
         const route = this.routes.get(request.path);
         if (!route) {
             throw new ApplicationError(404, `No route found for ${request.path}`);
         }
 
-        const stream = new ApplicationRouteStream(connection, request.body, request.requestId);
+        const stream = new ApplicationRouteStream(connection, request.body, request.path, request.requestId, request.headers);
         await route.handler(stream);
     }