I need implement logic for forgot password with aws lambda. I have cognito user pool with users and i need implement lambda for forgot password. How can i do it? Thanks in advance.
You can use AWS SDK to invoke the Cognito-forgot password from LAMBDA. you can refer to this documentation. You may have to provide the User pool Client and Username of the user along with the request.
Note: Your Lambda execution policy should have cognito-idp:ForgotPassword
Here is the Documentation for implementing with Nodejs.
const AWS = require('aws-sdk');
export.handler = async (event) => {
const params = {
ClientId: 'USER POOL CLIENT ID',
Username: 'USERNAME'
}
const cognitoidentityserviceprovider = new AWS.CognitoIdentityServiceProvider();
const response = cognitoidentityserviceprovider.forgotPassword(params).promise();
return response;
}
I already deploy a static web site use AWS S3 and use AWS cognito to handle User Sign in.
The web Site is https://www.tianboqing.com
The HTML page have a Button,When user Click the button,the url will redirect to cognito sign in url.
'https://tianboqing.auth.us-east-1.amazoncognito.com/login?
client_id=4fgb77l991egfiubejfqep3e6e&response_type=token&scope=aws.cognito.signin.user.admin&redirect_uri=https://www.tianboqing.com';
const handleClick = (event) => {
window.location.href =
'https://tianboqing.auth.us-east-1.amazoncognito.com/login?...
};
document.querySelector('button').addEventListener('click', handleClick);
When User sign In,The Cognito will return a new url like this:
https://www.tianboqing.com/#access_token=eyJraWQiOiJrNFdXeWpRZXZiSlwvN3JNRUlVMzFHS0p4YmtBZHpXMExwN0xMT0tiS1BHRT0iLCJhbGciOiJSUzI1NiJ9.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.xKToMEhhSCqSy9ip0ikmdezY9XRz0GIlIdESSThEuLabWL4rFTw1XRQi4Z9OeDLZcmHyemZt0A1o1OvqZLFyrEHLmRAoyg5SIGD2Ic6tExS1PAmmX8Fe3uF7f851DtKMeapxsaNYyaLE3v-_vkJkDwRvUNoz8nOMUCYB3JKJxGPBlMz1yfn-3CXejepKLYeYYDOUaCPmyErfCy84_eQ-ZoEZFd3bH4vZXDNJKFj6W5_C4IZHuIAJveep3dYVq9cLWy3m8BWOAKWVxk6jTt1w0xI5og5jJiEIPn8Ok10WL1s4eEzAN04AYj6e05uzw4Ka_ip4y7VCdnndnTuWAx_5wQ&expires_in=3600&token_type=Bearer
Which contain the access_token to parse.
My question is,How the code can know the new url which contain access_token is return.
Do I need front route or async await or something?
const handleClick = (event) => {
window.location.href =
'https://tianboqing.auth.us-east-1.amazoncognito.com/login?client_id=...';
};
How to get the user token so I can use it to post to dynamodb?
I will suggest to use API Gateway, where you can add Cognito Authorizer for each and every API you deploy to interact with DynamoDB.
Here is the official documentation you can go through to setup your API-Gateway with Cognito, that you want to use to save records in DynamoDB.
You can grab that access token from the Cognito return page and save it as Session Storage in the front-end using JavaScript.
window.sessionStorage.setItem("accessToken", YourAccessToken);
Use the above stored accessToken as Authorization Header when you call that API via AJAX.
var tok = window.sessionStorage.getItem("accessToken")
var xhr = new XMLHttpRequest();
xhr.open("POST", "URL");
xhr.setRequestHeader("Authorization", tok);
xhr.send();
Instead of url forwarding, you can use AWS-Cognito javascript SDK and use Javascript (via AJAX) to authorize a user.
var cognitoUser = new AmazonCognitoIdentity.CognitoUser({
Username: username,
Pool: userPool
});
var authenticationData = new AmazonCognitoIdentity.AuthenticationDetails({
Username: username,
Password: password
});
cognitoUser.authenticateUser(authenticationData, {
onSuccess: function (result) {
// your code here on success
},
onFailure: function (err) {
// your code here if error occurs
}
});
I recently started working with AWS. I have integrated AWS Amplify using cognito user pools for my user management(login&signup) and it went perfect(User pool gets updated whenever a new user registers). Now i have added an Cognito Post confirmation trigger to save the registered email into database and here is my trigger codevar mysql = require('mysql');
var config = require('./config.json');
var pool = mysql.createPool({
host : config.dbhost,
user : config.dbuser,
password : config.dbpassword,
database : config.dbname
});
exports.handler = (event, context, callback) => {
let inserts = [event.request.userAttributes.email];
context.callbackWaitsForEmptyEventLoop = false; //prevents duplicate entry
pool.getConnection(function(error, connection) {
connection.query({
sql: 'INSERT INTO users (Email) VALUES (?);',
timeout: 40000, // 40s
values: inserts
}, function (error, results, fields) {
// And done with the connection.
connection.release();
// Handle error after the release.
if (error) callback(error);
else callback(null, results);
});
});
};
whenever a user registers and confirms his email this trigger invokes and throws me this error
"Unrecognizable Lambda Output Cognito ". Even though it throws me this error in the background my DB is getting inserted with new registered email, but i am unable to redirect my page due to this. Any help will be appreciated. Thanks
Aravind
Short answer: Replace callback(null, results); to callback(null, event);
Reason: You have to return the result that Cognito will use it for continue the authentication workflow. In this case, this is event object.
The goal is to implement a social provider auth flow as described in User Pools App Integration and Federation.
One important thing that I want to satisfy, is to merge user pool accounts that have the same email address.
I am accomplishing that by calling adminLinkProviderForUser within the PreSignUp_ExternalProvider cognito lambda trigger.
So with this, everything works. The new social provided user is being registered and linked with the already existing Cognito (user+pass) user.
However, the authentication flow, from user's perspective doesn't complete. It fails at the last step where the callback uri (defined in cognito user pool) is being called:
error: invalid_request
error_description: Already found an entry for username Facebook_10155611263152353
But then, if the user retries the social auth flow, everything works, and would get session tokens that represent the original Cognito User Pool user (the one that already had that email).
Note that I'm testing the auth flow on an empty User Pool, zero user accounts.
For all the poor souls fighting with this issue still in 2020 the same way I did:
I have eventually fixed the issue by catching the "Already found an entry for username" in my client application and repeating the entire auth flow once more.
Luckily the error only gets fired on the initial external provider signup but not in the subsequent signins of the same user (cause it happens during signup trigger, duh).
I'm taking a wild guess, but here is what I think is happening:
In my case, the facebook provider was getting succesfully linked with
the pre-existing cognito email/password user. new Facebook userpool
entry linking to the email/password user was succesfully created.
Still, it seems
like cognito tried to register the fully isolated Facebook_id user
during the internal signup process (even though a link user entry with the same username was already created in the previous step). Since the "link user" with the
username Facebook_id was already existing, cognito threw an
"Already found an entry for username Facebook_id error" internal error.
This error has been repeatedly voiced over to the AWS developers since 2017 and there are even some responses of them working on it, but in 2020, it's still not fixed.
Yes, this is how it is currently setup. If you try to link users using PreSignUp trigger, the first time won't work. A better way to handle this(I think) would be to provide an option in your UI to link external accounts on sign-in. In the pre-signup trigger, search for a user with the same unique attribute (say email) and see if the sign up is from external provider. Then show a message such as email already exists. Login in & use this menu/option to link. Haven't tested this though.
To elaborate on #agent420's answer, this is what I am currently using (Typescript example).
When a social identity attempts to sign up and the email address already exists I catch this using the PreSignUp trigger and then return an error message to the user. Inside the app, on the user's profile page, there is an option to link an identity provider which calls the adminLinkProviderForUser API.
import {
Context,
CognitoUserPoolTriggerEvent,
CognitoUserPoolTriggerHandler,
} from 'aws-lambda';
import * as aws from 'aws-sdk';
import { noTryAsync } from 'no-try';
export const handle: CognitoUserPoolTriggerHandler = async (
event: CognitoUserPoolTriggerEvent,
context: Context,
callback: (err, event: CognitoUserPoolTriggerEvent) => void,
): Promise<any> => {
context.callbackWaitsForEmptyEventLoop = false;
const { email } = event.request.userAttributes;
// pre sign up with external provider
if (event.triggerSource === 'PreSignUp_ExternalProvider') {
// check if a user with the email address already exists
const sp = new aws.CognitoIdentityServiceProvider();
const { error } = await noTryAsync(() =>
sp
.adminGetUser({
UserPoolId: 'your-user-pool-id',
Username: email,
})
.promise(),
);
if (error && !(error instanceof aws.AWSError)) {
throw error;
} else if (error instanceof aws.AWSError && error.code !== 'UserNotFoundException') {
throw error;
}
}
callback(null, event);
};
I finally got this thing working in a non-weird way where users have to authorize twice or other things.
Process explained:
User tries to authenticate using an identity provider, for the first time => PreSignUp lambda kicks in and check if user exists via email
1a. If the user exists, it will throw an error, eg. CONFIRM_IDENTITY_LINK_token that I'm capturing on the client.
token is a base64 string with the username and identity id ("username:facebook_123456")
1b. If the username does not exist, I create a new user with a temporary password and throw an error FORCE_CHANGE_PASSWORD_token. Same token but I add the temporary password to this time.
In the client I have one callback route '/authorize' => this is the one you set up as a callback URL in Cognito, and 2 extra routes: '/confirm-password' and '/configure-password'.
In the /authorize route I'm capturing the errors and getting the attached tokens and redirect to the extra routes: 1a => /configure-password?token=token and 1b => /confirm-password?token=token
For "/confirm-password" I ask the user to confirm its current password in order to authorize linking with the provider, then use the token to log him in with the identity id as clientMetadata, eg "{"LINK_PROVIDER": "facebbok_12345678"}"
On login, I have a PostAuthentication lambda which checks for the "LINK_PROVIDER" in the clientMetadata, and links it to the user.
For "/configure-password" I parse the token and do a "shallow" login with the credentials from the token and identity id as client metadata (same as above) then prompt the user to configure a new password for his account.
I know it might seem a little bit restrictive but I find it better than to authorize twice.
Also, this does not create extra users for identities in the user pool.
Code examples:
PreSignUp lambda
export async function handler(event: PreSignUpTriggerEvent) {
try {
const { userPoolId, triggerSource, request, userName } = event
if (triggerSource === 'PreSignUp_ExternalProvider') {
// Check if user exists in cognito
let currentUser = await getUserByEmail(userPoolId, request.userAttributes.email)
if (currentUser) {
// User exists, thow error with identity id
const identity = Buffer.from(`${currentUser}:${userName}`).toString('base64')
throw new Error(`CONFIRM_USER_IDENTITY_${identity}`)
}
// Create new Cognito user with temp password
const tempPassword = generatePassword()
currentUser = await createNewUser(userPoolId, request.userAttributes, tempPassword)
// Throw error with token
const state = Buffer.from(`${currentUser}:${tempPassword}:${userName}`).toString('base64')
throw new Error(`FORCE_CHANGE_PASSWORD_${state}`)
}
return event
} catch (error) {
throw new Error(error)
}
}
PostAuthentication lambda
export async function handler(event: PostAuthenticationTriggerEvent) {
try {
const { userPoolId, request, userName } = event
if (request.clientMetadata?.LINK_IDENTITY) {
const identity = request.clientMetadata['LINK_IDENTITY']
// Link identity to user
await linkIdentityProvider(userPoolId, userName, identity)
}
return event
} catch (error) {
console.error(error)
throw new Error('Internal server error')
}
}
We faced the same issue and tried various hacks to get around it. As we started to use SignInWithApple, we couldn't handle it with the 'double turnaround' because Apple always wants the user to enter their email and password, not like Google, where the second time, everything works automatically. So the solution we ended up building was to store the Cognito/IdP ID (Google_1234, SignInWithApple_XXXX.XXX.XXX) in our database but still create a native Cognito user that isn't linked via Cognito.
The native user is created to make unlinking easier because first, we get rid of the data (IdP user-id) we store in our database and then the Cognito IdP user. The user can then proceed using the Native Cognito user. Then we have a middleware component in place that allows us to have JWT in the external IdP or Cognito native format and translates so we can use both versions. As long as the user uses an IdP/SSO, we reset the Native users' password to a very long random value and prevent resetting it, so they must use the IdP.
So whatever you are trying to do, prevent using the admin-link-provider-for-user command!
The same code in JavaScript getUser has been called instead of listUsers. It is also assumed that all users have their email id as their username.
const aws = require('aws-sdk');
exports.handler = async (event, context, callback) => {
console.log("event" + JSON.stringify(event));
const cognitoidentityserviceprovider = new aws.CognitoIdentityServiceProvider({apiVersion: '2016-04-18'});
const emailId = event.request.userAttributes.email
const userName = event.userName
const userPoolId = event.userPoolId
var params = {
UserPoolId: userPoolId,
Username: userName
};
var createUserParams = {
UserPoolId: userPoolId,
Username: emailId,
UserAttributes: [
{
Name: "email",
Value: emailId
},
],
TemporaryPassword: "xxxxxxxxx"
};
var googleUserNameSplitArr = userName.split("_");
var adminLinkUserParams = {
DestinationUser: {
ProviderAttributeName: 'UserName',
ProviderAttributeValue: emailId,
ProviderName: "Cognito"
},
SourceUser: {
ProviderAttributeName: "Cognito_Subject",
ProviderAttributeValue: googleUserNameSplitArr[1],
ProviderName: 'Google'
},
UserPoolId: userPoolId
};
var addUserToGroupParams = {
GroupName: "Student",
UserPoolId: userPoolId,
Username: emailId
};
if (userName.startsWith("Google_")) {
await cognitoidentityserviceprovider.adminGetUser(params, function (err, data) {
if (err) {
console.log("No user present")
console.log(err, err.stack);
cognitoidentityserviceprovider.adminCreateUser(createUserParams, function (err, data) {
if (err) console.log(err, err.stack);
else {
console.log("User Created ")
cognitoidentityserviceprovider.adminAddUserToGroup(addUserToGroupParams, function (err, data) {
if (err) console.log(err, err.stack);
else {
console.log("added user to group");
console.log(data);
}
});
cognitoidentityserviceprovider.adminLinkProviderForUser(adminLinkUserParams, function (err, data) {
if (err) console.log(err, err.stack);
else {
console.log("user linked");
console.log(data);
}
});
console.log(data);
}
});
} else {
console.log("user already present")
cognitoidentityserviceprovider.adminLinkProviderForUser(adminLinkUserParams, function (err, data) {
if (err) console.log(err, err.stack); // an error occurred
else {
console.log("userlinked since user already existed");
console.log(data);
}
});
console.log(data);
}
});
}
console.log("after the function custom");
callback(null, event);
};
This is a well know error. I handle it by retrying the request after this error and it will work. The error is because there is not way in the SDK to let it know to the pool that you already link the Federation Credentials to an user and it try to create a new user with those credentials
I wanted to have the feature of having a user seamlessly being able to login with one social provider (ex: Facebook) and then another one (Google).
I struggled with the retry process, especially with Google Login. At the signup process, if a user have several accounts, he will need to process twice the account selection.
What I ended up doing is just using Cognito for the client side code and token generation and have a lambda in the pre signup process mapping userIds with their email in a custom DB (Postgres or DynamoDB).
Then when a user query my API, based on their userId (whether it's a FacebookId or a cognito email userId, I am querying the DB to find the linked email and I am able to authenticate any users and their data like this.
Did this bug all of a sudden stop happening on 2/21/23? We didn't change anything but now this is no longer happening to users on their first time signing up. We also noticed that the UI for how Cognito is showing linked users is different - there is just 1 cognito account you're able to see in Cognito instead of multiple. You can still see the federated linked accounts in the identities property though
I'm working on an AWS API Gateway implementation with a Lambda backend. I use the API Gateway integration with the Cognito Userpools (fairly new) instead of building a custom authorizer using Lambda (which was the recommended way before it was integrated).
I've created a proof of concept (javascript) that authenticates a user with Cognito and then makes a call to the API Gateway with those credentials. So, basically, the end call to the API Gateway is with the JWT token that I received from Cognito (result.idToken.jwtToken) in the Authorization header. This all works and I can validate that only with this token you can access the API.
All working fine, but now I want to get access to the Cognito identity in my Lambda; for instance the identy id or the name or email. I have read how to map all the parameters, but I'm actually just using the standard 'Method Request Passthrough' template in the integration request. I log all the parameters in the lambda and all the 'cognito' parameters are empty.
I've looked through many similar questions and they all propose to enable the 'Invoke with caller credentials' checkbox on the integration request. That makes perfect sense.
However, this checkbox can only be enabled if you are using AWS_IAM as authorization and not if you have selected your cognito UserPool. So it is just not possible to select it and is actually disabled.
Does anybody know what to do in this case? Is this still work in progress, or is there a reason why you can't enable this and get the cognito credentials in your Lambda?
Many thanks.
If you need to log the user information in your backend, you can use $context.authorizer.claims.sub and $context.authorizer.claims.email to get the sub and email for your Cognito user pool.
Here is the documentation about Use Amazon Cognito Your User Pool in API Gateway
For anyone else still struggling to obtain the IdentityId in a Lambda Function invoked via API-Gateway with a Cognito User Pool Authorizer, I finally was able to use the jwtToken passed into the Authorization header to get the IdentityId by using the following code in my JavaScript Lambda Function:
const IDENTITY_POOL_ID = "us-west-2:7y812k8a-1w26-8dk4-84iw-2kdi849sku72"
const USER_POOL_ID = "cognito-idp.us-west-2.amazonaws.com/us-west-2_an976DxVk"
const { CognitoIdentityClient } = require("#aws-sdk/client-cognito-identity");
const { fromCognitoIdentityPool } = require("#aws-sdk/credential-provider-cognito-identity");
exports.handler = async (event,context) => {
const cognitoidentity = new CognitoIdentityClient({
credentials: fromCognitoIdentityPool({
client: new CognitoIdentityClient(),
identityPoolId: IDENTITY_POOL_ID,
logins: {
[USER_POOL_ID]:event.headers.Authorization
}
}),
});
var credentials = await cognitoidentity.config.credentials()
var identity_ID = credentials.identityId
console.log( identity_ID)
const response = {
statusCode: 200,
headers: {
"Access-Control-Allow-Headers": "*",
"Access-Control-Allow-Origin": "*",
"Access-Control-Allow-Methods" : "OPTIONS,POST,GET,PUT"
},
body:JSON.stringify(identity_ID)
};
return response;
}
After a Cognito User has signed in to my application, I can use the Auth directive of aws-amplify and fetch() in my React-Native app to invoke the lambda function shown above by sending a request to my API-Gateway trigger (authenticated with a Cognito User Pool Authorizer) by calling the following code:
import { Auth } from 'aws-amplify';
var APIGatewayEndpointURL = 'https://5lstgsolr2.execute-api.us-west-2.amazonaws.com/default/-'
var response = {}
async function getIdentityId () {
var session = await Auth.currentSession()
var IdToken = await session.getIdToken()
var jwtToken = await IdToken.getJwtToken()
var payload = {}
await fetch(APIGatewayEndpointURL, {method:"POST", body:JSON.stringify(payload), headers:{Authorization:jwtToken}})
.then(async(result) => {
response = await result.json()
console.log(response)
})
}
More info on how to Authenticate using aws-amplify can be found here https://docs.amplify.aws/ui/auth/authenticator/q/framework/react-native/#using-withauthenticator-hoc