Feat: Added JWT verification endpoint

.env.sample

@@ -43,4 +43,6 @@ SENTRY_DSN=
 # CORS
 CORS_ALLOWED_ORIGINS=https://example.com
 CORS_ALLOWED_HEADERS=Content-Type,Authorization,x-application-id
-CORS_ALLOWED_METHODS=GET,PUT,POST,DELETE,PATCH,OPTIONS
+CORS_ALLOWED_METHODS=GET,PUT,POST,DELETE,PATCH,OPTIONS
+
+JWKS_URI=

package.json

@@ -47,6 +47,7 @@
     "flagsmith-nodejs": "^2.5.2",
     "got": "^11.8.2",
     "helmet": "^7.0.0",
+    "jwks-rsa": "^3.1.0",
     "passport": "^0.5.2",
     "passport-http": "^0.3.0",
     "passport-jwt": "^4.0.1",

src/api/api.controller.ts

@@ -358,4 +358,11 @@ export class ApiController {
   ): Promise<any> {
     return await this.apiService.loginWithOtp(user, authHeader);
   }
+
+  @Get('verify-jwt')
+  async verifyJwt(
+    @Headers('authorization') token: string,
+  ): Promise<{ authenticated: boolean; user?: any }> {
+    return this.apiService.verifyJwt(token);
+  }
 }

src/api/api.service.ts

@@ -30,7 +30,7 @@ const CryptoJS = require('crypto-js');
 // eslint-disable-next-line @typescript-eslint/no-var-requires
 const AES = require('crypto-js/aes');
 import Flagsmith from 'flagsmith-nodejs';
-
+const jwksClient = require('jwks-rsa');;
 CryptoJS.lib.WordArray.words;
 
 @Injectable()
@@ -44,6 +44,13 @@ export class ApiService {
     private readonly configResolverService: ConfigResolverService,
   ) {}
 
+  private readonly jwksClient = jwksClient({
+    jwksUri: this.configService.get('JWKS_URI'),
+    cache: true,
+    cacheMaxEntries: 5,
+    cacheMaxAge: 86400000,
+  });
+
   login(user: any, authHeader: string): Promise<SignupResponse> {
     return this.fusionAuthService
       .login(user, authHeader)
@@ -646,4 +653,15 @@ export class ApiService {
     }
     return registration;
   }
+
+  async verifyJwt(token: string): Promise<{ authenticated: boolean; user?: any }> {
+    try {
+      const decodedToken = await this.jwksClient.getSigningKey(token);
+      const signingKey = decodedToken.getPublicKey();
+      return { authenticated: true, user: decodedToken.payload };
+    } catch (error) {
+      console.error('JWT Verification Error:', error);
+      return { authenticated: false };
+    }
+  }
 }