I am using AWS amplify with Angular and I followed the instructions to setup Amplify, add backend and then auth.
I also created a user in cognito pool and used it to login in my angular app. I am able to see AccessToken, IdToken and RefreshToken in the browser network tab. As per the guide I have to use these to obtain the pool tokens using which I can get temporary aws credentials to access aws services. I want to access pubsub to show messages being sent to aws iot_core.
But I was unable to find any information of how exactly we use these 3 tokens to access AWS resources..? Can anybody shed some light on this?
async signIn() {
Auth.signIn('xxxxx', 'xxxxx')
.then(user => {
if (user.challengeName === 'NEW_PASSWORD_REQUIRED') {
const { requiredAttributes } = user.challengeParam; // the array of required attributes,
e.g ['email', 'phone_number']
Auth.completeNewPassword(
user, // the Cognito User Object
'xxx', // the new password
// OPTIONAL, the required attributes
{
email: 'xxxx#example.com',
}
).then(user => {
// at this time the user is logged in if no MFA required
console.log(user);
}).catch(e => {
console.log(e);
});
} else {
console.log("Connecting to AWS IoT...")
//Apply plugin with configuration
Amplify.addPluggable(new AWSIoTProvider({
aws_pubsub_region: 'us-east',
aws_pubsub_endpoint: 'wss://xxxxx-ats.iot.us-east-1.amazonaws.com/mqtt',
}));
console.log("hello")
}
}).catch(e => {
console.log(e);
});
}
As per the Amplify docs on PubSub you have to:
Create IAM policies for AWS IoT
Attach your policy to your Amazon Cognito Identity
Allow the Amazon Cognito Authenticated Role to access IoT Services
https://docs.amplify.aws/lib/pubsub/getting-started/q/platform/js/#step-1-create-iam-policies-for-aws-iot
var normalAuth = async (username, password) => {
try{
var user = await Auth.signIn(username, password)
console.log(user)
if(user.challengeName === "NEW_PASSWORD_REQUIRED"){
console.log("assigning new password!")
user = await Auth.completeNewPassword(user, "password") // give the user a new password. this would NOT be included in any kind of production code, its only here as a work around
console.log(user)
} // work around. users created in the console are only given temporary passwords, and as such have no authorization
// setting a new password will fix this
console.log(await Auth.currentCredentials()) // THIS THROWS AN ERROR?!?!
setAuthState(false) // auth is no longer in progress
}
catch(error){
console.error(error)
}
}
I'm trying to grab the tokens from my Amplify user after authenticating but I'm receiving the error
No Cognito Identity pool provided for unauthenticated access
This is pretty strange because I'm not using an identity pool at all. My baseline assumption was that I shouldn't need to provide an identity pool ID at all in my amplify config.
config looks like this
var amplifyConfig = {
Auth: {
mandatorySignIn: false,
region: "us-east-1",
userPoolId: "mypoolid",
userPoolWebClientId: "myclientid"
}
}
The really weird part is that the tokens are actually there in user after I authenticate. It's only when I try and retrieve them this way specifically that an error is thrown.
Any idea what's going on here?
I'm trying to implement auth via link without password. E.g. user enter his email -> cognito send an email with link that user can click and login. It
It is supported by cognito via custom challenge. E.g. https://aws-amplify.github.io/amplify-js/media/authentication_guide#using-a-custom-challenge
I have created DefineAuthChallenge, CreateAuthChallenge, VerifyAuthChallenge lambda function that associated with my cognito pool. CreateAuthChallenge generate code that is send to user email with link to site.
Next i was planning to grab that code from url on site and login user via it like its in docs
Auth.signIn(username)
.then(user => {
if (user.challengeName === 'CUSTOM_CHALLENGE') {
Auth.sendCustomChallengeAnswer(user, challengeResponse)
.then(user => console.log(user))
.catch(err => console.log(err));
} else {
console.log(user);
}
})
.catch(err => console.log(err));
But here is the problem. Auth.sendCustomChallengeAnswer require user object that is passed from Auth.signIn. But if user just click link from email there wont be any user object at all. And amplify lib dont save that middle session user object, so on page reload its lost. It is saving only if auth completed to its storage https://github.com/aws-amplify/amplify-js/blob/master/packages/amazon-cognito-identity-js/src/CognitoUser.js#L175
So the question is how can i save & reconstruct user object from Auth.signIn function on page reload. Or if there a better approach to sign in via link without password?
To solve this first you need to save username and session into localstorage or cookies. Then when user go through link this code can be used:
const userPoolData = {
UserPoolId: process.env.COGNITO_POOL_ID,
ClientId: process.env.COGNITO_POOL_WEB_CLIENT_ID,
Storage: customStorageClass // default is localstorage
}
const userPool = new CognitoUserPool(userPoolData)
const userData = {
Username: getUsernameFromCookiesOrLocalstorage,
Pool: userPool,
Storage: customStorageClass // default is localstorage
}
const user = new CognitoUser(userData)
user.Session = getSessionFromCookiesOrLocalstorage
Auth.sendCustomChallengeAnswer(user, code)
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 am creating a web application, in which I use REST for user interface and for REST API I use using Loopback. My user, acl, rollmapping, role table are in mySQL. In my project i am able control access permission when i am trying with loopback UI(after login and setting the access token). But when I am trying with admin on rest UI I am able to login but not able to control the access, in admin on rest I have give all the url and everything in authClient.jsx. My authClient.jsx file:
const request = new Request('http://localhost:3004/api/Users/login', {
method: 'POST',
body: JSON.stringify({ email, password }),
headers: new Headers({ 'Content-Type': 'application/json' })
});
Can anybody help me fix this issue?
You need to use AOR Permissions
https://github.com/marmelab/aor-permissions
This will handle all authentication and role based access.
On the API side you will need to create a custom Login Method that will also return the user role in the request.
something like below
User.customLogin = (credentials, cb) => {
User.login(credentials, 'User', function(err, token) {
if (err) {
console.error(err)
return cb(err)
}
app.models.RoleMapping.findOne({where: {principalId: token.userId}, include: {relation: 'role'}}, function(err, rolemap) {
if (err) {
console.error(err)
return cb(err)
}
token.role = rolemap.role().name
return cb(null, token)
})
})
}
Save the user role in localStorage on login and then you can use AOR permissions to show role based views to every user.
EDIT:
According to AOR star contributor #gildas below. AOR Permissions is going to be deprecated and all features moved to AOR Core. So please check your versions of AOR and decide accordingly.