defineAuthChallenge.go

package main

import (
	"context"
	"errors"
	"fmt"
	"log"

	"github.com/aws/aws-lambda-go/lambda"
)

func main() {
	lambda.Start(defineAuthChallenge)
}

type Req map[string]interface{}

func defineAuthChallenge(ctx context.Context, req Req) (interface{}, error) {
	fmt.Println("called define auth challenge")

	for k, v := range req {
		log.Println(fmt.Sprintf("%s => %v", k, v))
	}

	request, isErr := req["request"].(map[string]interface{})
	if !isErr {
		return nil, errors.New("cannot convert request")
	}

	response, isErr := req["response"].(map[string]interface{})
	if !isErr {
		return nil, errors.New("cannot convert response")
	}

	processedResponse, err := processSession(request["session"], response)
	req["response"] = processedResponse
	log.Println(fmt.Sprintf("response: %v", req["response"]))

	return req, err
}

func processSession(session interface{}, res map[string]interface{}) (map[string]interface{}, error) {
	sessions, isErr := session.([]interface{})
	if !isErr {
		return nil, errors.New("failed convert session")
	}

	switch len(sessions) {
	case 0:
		res["issueTokens"] = false
		res["failAuthentication"] = false
		res["challengeName"] = "CUSTOM_CHALLENGE"
		return res, nil
	case 1:
		sess, isErr := sessions[0].(map[string]interface{})
		if !isErr {
			return nil, errors.New("failed convert session ###")
		}
		if sess["challengeMetadata"].(string) == "SECRET_CHALLENGE" && sess["challengeName"].(string) == "CUSTOM_CHALLENGE" && sess["challengeResult"].(bool) {
			res["issueTokens"] = true
			res["failAuthentication"] = false
			return res, nil
		}
	default:
		log.Println("DEFAULT!")
	}

	res["issueTokens"] = false
	res["failAuthentication"] = true

	return res, nil
}