Code with Ktor and Auth0

This is the article trying to study:

• Ktor API with Auth0
• Ktor API with Auth0 RBAC

Setup API app

1. Setup Auth0 account.

2. Install Ktor Authentication plugin

    val jwkProvider = JwkProviderBuilder(System.getenv("ISSUER"))
    .cached(10, 24, TimeUnit.HOURS)
    .rateLimited(10, 1, TimeUnit.MINUTES)
    .build()
   
    install(Authentication) {
        jwt("auth0") {
            verifier(jwkProvider, System.getenv("ISSUER"))
            validate { credential -> validateCreds(credential) }
        }
    }
   

3. Add validate Credentials method

   fun validateCreds(credential: JWTCredential): JWTPrincipal? {
    val containsAudience = credential.payload.audience.contains(System.getenv("AUDIENCE"))
   
    if (containsAudience) {
        return JWTPrincipal(credential.payload)
    }
   
    return null
   }
   

4. Add authenticate layer to the routes

   routing {
    authenticate("auth0") {
        get("/api/messages/protected") {
            call.respondText(
                """{"message": "The API successfully validated your access token."}""",
                contentType = ContentType.Application.Json
            )
        }
    }
   }
   

5. Environment security variables for API app

    export ISSUER=https://<yourdomain>.auth0.com
    export AUDIENCE=<api audience>
   

6. Run the API app

Setup Frontend app

1. Environment security variables for UI app

    export REACT_APP_AUTH0_DOMAIN=yourdomain.auth0.com
    export REACT_APP_AUTH0_CLIENT_ID=abcdefghigklmnop
    export REACT_APP_AUTH0_AUDIENCE=ktordemo
    export REACT_APP_API_SERVER_URL=http://localhost:6060
   

2. Run the API and UI apps

   npm install
   npm start
   

Bullet points to take away:

• Auth0 Service
• CodeSandBox Tool