Unable to verify secret hash for client in Amazon Cognito Userpools

Question

I am stuck at "Amazon Cognito Identity user pools" process.

I tried all possible codes for authenticating user in cognito userpools. But I always get error saying "Error: Unable to verify secret hash for client 4b*******fd".

Here is code:

AWS.config.region = 'us-east-1'; // Region
AWS.config.credentials = new AWS.CognitoIdentityCredentials({
    IdentityPoolId: 'us-east-1:b64bb629-ec73-4569-91eb-0d950f854f4f'
});

AWSCognito.config.region = 'us-east-1';
AWSCognito.config.credentials = new AWS.CognitoIdentityCredentials({
    IdentityPoolId: 'us-east-1:b6b629-er73-9969-91eb-0dfffff445d'
});

AWSCognito.config.update({accessKeyId: 'AKIAJNYLRONAKTKBXGMWA', secretAccessKey: 'PITHVAS5/UBADLU/dHITesd7ilsBCm'})

var poolData = { 
    UserPoolId : 'us-east-1_l2arPB10',
    ClientId : '4bmsrr65ah3oas5d4sd54st11k'
};
var userPool = new AWSCognito.CognitoIdentityServiceProvider.CognitoUserPool(poolData);

var userData = {
     Username : '[email protected]',
     Pool : userPool
};

var cognitoUser = new AWSCognito.CognitoIdentityServiceProvider.CognitoUser(userData);

cognitoUser.confirmRegistration('123456', true,function(err, result) {
if (err) {
    alert(err);
    return;
}
console.log('call result: ' + result);
});

Answer 1

It seems that currently AWS Cognito doesn't handle client secret perfectly. It will work in the near future but as for now it is still a beta version.

For me it is working fine for an app without a client secret but fails for an app with a client secret.

So in your user pool try to create a new app without generating a client secret. Then use that app to signup a new user or to confirm registration.

Answer 2

According to the Docs: http://docs.aws.amazon.com/cognito/latest/developerguide/setting-up-the-javascript-sdk.html

The Javascript SDK doesn't support Apps with a Client Secret.

The instructions now state that you need to uncheck the "Generate Client Secret" when creating the app for the User Pool.

Answer 3

This might be a fews years late but just uncheck the "Generate client secret" option" and it will work for your web clients.

Answer 4

Since everyone else has posted their language, here's node (and it works in the browser with browserify-crypto, automatically used if you use webpack or browserify):

const crypto = require('crypto');

...

crypto.createHmac('SHA256', clientSecret)
  .update(username + clientId)
  .digest('base64')

Answer 5

I had the same problem in the .net SDK.

Here's how I solved in, in case anyone else needs it:

public static class CognitoHashCalculator
{
    public static string GetSecretHash(string username, string appClientId, string appSecretKey)
    {
        var dataString = username + appClientId;

        var data = Encoding.UTF8.GetBytes(dataString);
        var key = Encoding.UTF8.GetBytes(appSecretKey);

        return Convert.ToBase64String(HmacSHA256(data, key));
    }

    public static byte[] HmacSHA256(byte[] data, byte[] key)
    {
        using (var shaAlgorithm = new System.Security.Cryptography.HMACSHA256(key))
        {
            var result = shaAlgorithm.ComputeHash(data);
            return result;
        }
    }
}

Signing up then looks like this:

public class CognitoSignUpController
{
    private readonly IAmazonCognitoIdentityProvider _amazonCognitoIdentityProvider;

    public CognitoSignUpController(IAmazonCognitoIdentityProvider amazonCognitoIdentityProvider)
    {
        _amazonCognitoIdentityProvider = amazonCognitoIdentityProvider;
    }

    public async Task<bool> SignUpAsync(string userName, string password, string email)
    {
        try
        {
            var request = CreateSignUpRequest(userName, password, email);
            var authResp = await _amazonCognitoIdentityProvider.SignUpAsync(request);

            return true;
        }
        catch
        {
            return false;
        }
    }

    private static SignUpRequest CreateSignUpRequest(string userName, string password, string email)
    {
        var clientId = ConfigurationManager.AppSettings["ClientId"];
        var clientSecretId = ConfigurationManager.AppSettings["ClientSecretId"];

        var request = new SignUpRequest
        {
            ClientId = clientId,
            SecretHash = CognitoHashCalculator.GetSecretHash(userName, clientId, clientSecretId),
            Username = userName,
            Password = password,
        };

        request.UserAttributes.Add("email", email);
        return request;
    }
}

Answer 6

Amazon mention how Computing SecretHash Values for Amazon Cognito in their documentation with Java application code. Here this code works with boto 3 Python SDK.

You can find your App clients in left side menu under General settings. Get those App client id and App client secret to create SECRET_HASH. For your better understand I commented out all the outputs of each and every line.

import hashlib
import hmac
import base64

app_client_secret = 'u8f323eb3itbr3731014d25spqtv5r6pu01olpp5tm8ebicb8qa'
app_client_id = '396u9ekukfo77nhcfbmqnrec8p'
username = 'wasdkiller'

# convert str to bytes
key = bytes(app_client_secret, 'latin-1')  # b'u8f323eb3itbr3731014d25spqtv5r6pu01olpp5tm8ebicb8qa'
msg = bytes(username + app_client_id, 'latin-1')  # b'wasdkiller396u9ekukfo77nhcfbmqnrec8p'

new_digest = hmac.new(key, msg, hashlib.sha256).digest()  # b'P$#\xd6\xc1\xc0U\xce\xc1$\x17\xa1=\x18L\xc5\x1b\xa4\xc8\xea,\x92\xf5\xb9\xcdM\xe4\x084\xf5\x03~'
SECRET_HASH = base64.b64encode(new_digest).decode()  # UCQj1sHAVc7BJBehPRhMxRukyOoskvW5zU3kCDT1A34=

In the boto 3 documentation, we can see lot of time ask about SECRET_HASH. So above code lines help you to create this SECRET_HASH.

If you don't want to use SECRET_HASH just uncheck Generate client secret when creating an app.

Answer 7

For anybody interested in using AWS Lambda to sign up a user using the AWS JS SDK, these are the steps I did:

Create another lambda function in python to generate the key:

import hashlib
import hmac
import base64

secretKey = "key"
clientId = "clientid"
digest = hmac.new(secretKey,
                  msg=username + clientId,
                  digestmod=hashlib.sha256
                 ).digest()
signature = base64.b64encode(digest).decode()

Call the function through the nodeJS function in AWS. The signature acted as the secret hash for Cognito

Note: The answer is based heavily off George Campbell's answer in the following link: Calculating a SHA hash with a string + secret key in python

Answer 8

Solution for golang. Seems like this should be added to the SDK.

import (
    "crypto/hmac"
    "crypto/sha256"
    "encoding/base64"
)

func SecretHash(username, clientID, clientSecret string) string {
    mac := hmac.New(sha256.New, []byte(clientSecret))
    mac.Write([]byte(username + ClientID))
    return base64.StdEncoding.EncodeToString(mac.Sum(nil))
}

Answer 9

Solution for NodeJS with SecretHash

It seems silly that AWS removed the secret key from the SDK as it will not be exposed in NodeJS.

I got it working in NodeJS by intercepting fetch and adding in the hashed key using @Simon Buchan's answer.

cognito.js

import { CognitoUserPool, CognitoUserAttribute, CognitoUser } from 'amazon-cognito-identity-js'
import crypto from 'crypto'
import * as fetchIntercept from './fetch-intercept'

const COGNITO_SECRET_HASH_API = [
  'AWSCognitoIdentityProviderService.ConfirmForgotPassword',
  'AWSCognitoIdentityProviderService.ConfirmSignUp',
  'AWSCognitoIdentityProviderService.ForgotPassword',
  'AWSCognitoIdentityProviderService.ResendConfirmationCode',
  'AWSCognitoIdentityProviderService.SignUp',
]

const CLIENT_ID = 'xxx'
const CLIENT_SECRET = 'xxx'
const USER_POOL_ID = 'xxx'

const hashSecret = (clientSecret, username, clientId) => crypto.createHmac('SHA256', clientSecret)
  .update(username + clientId)
  .digest('base64')

fetchIntercept.register({
  request(url, config) {
    const { headers } = config
    if (headers && COGNITO_SECRET_HASH_API.includes(headers['X-Amz-Target'])) {
      const body = JSON.parse(config.body)
      const { ClientId: clientId, Username: username } = body
      // eslint-disable-next-line no-param-reassign
      config.body = JSON.stringify({
        ...body,
        SecretHash: hashSecret(CLIENT_SECRET, username, clientId),
      })
    }
    return [url, config]
  },
})

const userPool = new CognitoUserPool({
  UserPoolId: USER_POOL_ID,
  ClientId: CLIENT_ID,
})

const register = ({ email, password, mobileNumber }) => {
  const dataEmail = { Name: 'email', Value: email }
  const dataPhoneNumber = { Name: 'phone_number', Value: mobileNumber }

  const attributeList = [
    new CognitoUserAttribute(dataEmail),
    new CognitoUserAttribute(dataPhoneNumber),
  ]

  return userPool.signUp(email, password, attributeList, null, (err, result) => {
    if (err) {
      console.log((err.message || JSON.stringify(err)))
      return
    }
    const cognitoUser = result.user
    console.log(`user name is ${cognitoUser.getUsername()}`)
  })
}

export {
  register,
}

fetch-inceptor.js (Forked and edited for NodeJS from Fork of https://github.com/werk85/fetch-intercept/blob/develop/src/index.js)

let interceptors = []

if (!global.fetch) {
  try {
    // eslint-disable-next-line global-require
    global.fetch = require('node-fetch')
  } catch (err) {
    throw Error('No fetch available. Unable to register fetch-intercept')
  }
}
global.fetch = (function (fetch) {
  return (...args) => interceptor(fetch, ...args)
}(global.fetch))

const interceptor = (fetch, ...args) => {
  const reversedInterceptors = interceptors.reduce((array, _interceptor) => [_interceptor].concat(array), [])
  let promise = Promise.resolve(args)

  // Register request interceptors
  reversedInterceptors.forEach(({ request, requestError }) => {
    if (request || requestError) {
      promise = promise.then(_args => request(..._args), requestError)
    }
  })

  // Register fetch call
  promise = promise.then(_args => fetch(..._args))

  // Register response interceptors
  reversedInterceptors.forEach(({ response, responseError }) => {
    if (response || responseError) {
      promise = promise.then(response, responseError)
    }
  })

  return promise
}

const register = (_interceptor) => {
  interceptors.push(_interceptor)
  return () => {
    const index = interceptors.indexOf(_interceptor)
    if (index >= 0) {
      interceptors.splice(index, 1)
    }
  }
}

const clear = () => {
  interceptors = []
}

export {
  register,
  clear,
}

Answer 10

A quick fix for the above mentioned problem statement would be to delete the existing "App Client" and crate a new one with unchecked Generate client secret

Note : Don't forget to change the app client string in the code.

Answer 11

In Java you could use this code:

private String getSecretHash(String email, String appClientId, String appSecretKey) throws Exception {
    byte[] data = (email + appClientId).getBytes("UTF-8");
    byte[] key = appSecretKey.getBytes("UTF-8");

    return Base64.encodeAsString(HmacSHA256(data, key));
}

static byte[] HmacSHA256(byte[] data, byte[] key) throws Exception {
    String algorithm = "HmacSHA256";
    Mac mac = Mac.getInstance(algorithm);
    mac.init(new SecretKeySpec(key, algorithm));
    return mac.doFinal(data);
}

Answer 12

this is a sample php code that I use to generate the secret hash

<?php
    $userId = "aaa";
    $clientId = "bbb";
    $clientSecret = "ccc";
    $s = hash_hmac('sha256', $userId.$clientId, $clientSecret, true);
    echo base64_encode($s);
?>

in this case the result is:

DdSuILDJ2V84zfOChcn6TfgmlfnHsUYq0J6c01QV43I=

Answer 13

for JAVA and .NET you need to pass the secret has in the auth parameters with the name SECRET_HASH.

AdminInitiateAuthRequest request = new AdminInitiateAuthRequest
{
  ClientId = this.authorizationSettings.AppClientId,
  AuthFlow = AuthFlowType.ADMIN_NO_SRP_AUTH,
  AuthParameters = new Dictionary<string, string>
  {
    {"USERNAME", username},
    {"PASSWORD", password},
    {
      "SECRET_HASH", EncryptionHelper.GetSecretHash(username, AppClientId, AppClientSecret)
    }
  },
  UserPoolId = this.authorizationSettings.UserPoolId
};

And it should work.

Answer 14

C++ with the Qt Framework

QByteArray MyObject::secretHash(
     const QByteArray& email,
     const QByteArray& appClientId, 
     const QByteArray& appSecretKey)
{
            QMessageAuthenticationCode code(QCryptographicHash::Sha256);
            code.setKey(appSecretKey);
            code.addData(email);
            code.addData(appClientId);
            return code.result().toBase64();
};

Answer 15

Here is my 1 command, and it works (Confirmed :))

EMAIL="[email protected]" \
CLIENT_ID="[CLIENT_ID]" \
CLIENT_SECRET="[CLIENT_ID]" \
&& SECRET_HASH=$(echo -n "${EMAIL}${CLIENT_ID}" | openssl dgst -sha256 -hmac "${CLIENT_SECRET}" | xxd -r -p | openssl base64) \
&& aws cognito-idp ...  --secret-hash "${SECRET_HASH}"