Verify Amazon Cognito JWT in Ktor

Verify_Cognito_JWT_in_Ktor.md

(In Ktor: 1.6.2)

• application.conf

  ...
  jwt {
      issuer = "https://cognito-idp.ap-northeast-1.amazonaws.com/__SPECIFY_POOL_ID_HERE__"
      audience = "__SPECIFY_CLIENT_ID_HERE__"
      realm = "ktor sample app"
  }
  

• Security.kt

  import com.auth0.jwk.JwkProviderBuilder
  import io.ktor.application.*
  import io.ktor.auth.*
  import io.ktor.auth.jwt.*
  import java.util.concurrent.TimeUnit
  
  fun Application.configureSecurity() {
      authentication {
          jwt {
              realm = environment.config.property("jwt.realm").getString()
              val jwtAudience = environment.config.property("jwt.audience").getString()
              val issuer = environment.config.property("jwt.issuer").getString()
              val jwkProvider = JwkProviderBuilder(issuer)
                  .cached(10, 24, TimeUnit.HOURS)
                  .rateLimited(10, 1, TimeUnit.MINUTES)
                  .build()
  
              verifier(jwkProvider, issuer) {
                  acceptLeeway(3)
              }
  
              validate { credential ->
                  if (credential.payload.audience.contains(jwtAudience)) JWTPrincipal(credential.payload)
                  else null
              }
          }
      }
  }