How can I fix sign out bug on AWS Cognito with flutter? - amazon-web-services

I'm doing an app using flutter that uses AWS Cognito for authentication, but every time the user sign of the app this black screen appears, I've searched but could not find out what is wrong, can anyone help me?
Here is my authentication code:
signIn(username, password, context) async {
try {
SignInResult res =
await Amplify.Auth.signIn(username: username, password: password);
if (res.isSignedIn) {
Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => HomePage()));
}
print(username);
} on AuthException catch (e) {
print(e.message);
}
}
signOut() async {
try {
await Amplify.Auth.signOut();
} on AuthException catch (e) {
print(e.message);
}
}
And this is how I'm calling the function:
leading: IconButton(
onPressed: () {
AuthService().signOut();
Navigator.of(context).pushReplacementNamed('/');
},
icon: Icon(Icons.arrow_back)),
the black screen that appears

When logging out your user with Cognito, you need to pass a redirect URI in your request, so Cognito knows what to do after the sign out has happened. This URI also has to be registered as a possible URL in your app client configuration, in order to determine whether or not this is intended or malicious behaviour.
As you've stated in the comments on your question, you have not configured any sign out URI. So Cognito redirects to a blank page since it has no information on how to proceed otherwise.
(edit)

This issue appears to only affect android at the moment.
To overcome this issue, you can do a global sign out so that the browser redirect is skipped. Note that globalSignOut on iOS seems to trigger AWS auth exceptions which is why I used Platform.isAndroid.
import 'dart:io' show Platform;
final SignOutResult res = await Amplify.Auth.signOut(
options: const SignOutOptions(globalSignOut: Platform.isAndroid),
);

Related

AWS Amplify post request fails with "status code 403 at node_modules/axios"

I configured and initialized AWS Amplify for my ReactNative/Expo app and added a REST Api. Im new to AWS in general, but im assuming that once I add the API, my project is populated with amplify/backend folders and files and is ready for consumption.
So i tried to create a simple post request to create an item in my DynamoDB table with
import { Amplify, API } from "aws-amplify";
import awsconfig from "./src/aws-exports";
Amplify.configure(awsconfig);
const enterData = async () => {
API.post("API", "/", {
body: {
dateID: "testing",
},
headers: {
Authorization: `Bearer ${(await Auth.currentSession())
.getIdToken()
.getJwtToken()}`
}
})
.then((result) => {
// console.log(JSON.parse(result));
})
.catch((err) => {
console.log(err);
});
};
const signIn = async () => {
Auth.signIn('test#test.com', 'testpassword')
.then((data) => {
console.log(data)
enterData() //enterData is attempted after signin is confirmed.
})
.catch((err) => {
console.log(err)
})
}
signIn()
I did not touch anything else in my project folder besides including the above in my App.tsx because im unsure if i need to and where. I got a 403 error code and it "points" to the axios package but im not sure if issue is related to aws integration.
I configured the REST Api with restricted access where Authenticated users are allowed to CRUD, and guests are allowed to Read. How could I even check if I am considered an "Authorized User" .
Yes, AWS Amplify API category uses Axios under the hood so axios is related to your problem.
Probably you get 403 because you didn't authorized, for Rest API's you need to set authorization headers,
I don't know how is your config but you can take help from this page. Please review the "Define Authorization Rules" section under the API(REST) section.
https://docs.amplify.aws/lib/restapi/authz/q/platform/js/#customizing-http-request-headers
To check authorization methods, you can use "Auth" class like that also you can see auth class usage in the above link.
import { Amplify, API, Auth } from "aws-amplify";
https://aws-amplify.github.io/amplify-js/api/classes/authclass.html

Flutter AWS Cognito Token showing invalid signature

I am stared developing a flutter project with AWS Cognito login features. In flutter, AWS Cognito login was working fine and I am getting the access token but when checking that in API or JWT its shows the error "Invalid Signature".
I add the below code for the AWS Cognito login features. I have installed the amplify_auth_cognito: '<1.0.0' in pubspec.yaml file to create the AWS Cognito login features in the app. Login codes working fine and perfectly but the token which returns from that code shows "Invalid Signature".
Future<String> _signIn(LoginData data) async {
try {
SignInResult res = await Amplify.Auth.signIn(
username: data.name,
password: data.password,
);
final resp = await Amplify.Auth.fetchAuthSession(
options: CognitoSessionOptions(getAWSCredentials: true),
);
if (resp.isSignedIn) {
final sess = resp as CognitoAuthSession;
print("TOKEN FROM THE COGNITO: ${sess.userPoolTokens.accessToken}");
}
setState(() {
isSignedIn = res.isSignedIn;
});
if (isSignedIn) {
_btnController.success();
AWSConfigurationHelper().getUserDetails();
Timer(Duration(seconds: 1), () {
_btnController.reset();
Navigator.pushReplacementNamed(context, DeviceList.routeName);
});
}
} on AuthError catch (e) {
Alert(
context: context,
type: AlertType.error,
title: "Login Failed",
desc: e.cause.toString(), //e.toString(),
).show();
_btnController.error();
Timer(Duration(seconds: 1), () {
_btnController.reset();
});
print(e.cause);
for (final exception in e.exceptionList) {
print(exception.exception);
print(exception.detail);
}
return 'Log In Error: ' + e.toString();
}}
My pubspec.yaml file screenshot was attached. In that file I am using amplify_auth_cognito: '<1.0.0' for the Cognito login.
I am new to this Flutter so I really need someone help to fix this problem. I have done the AWS Cognito Login features in iOS and web with the same AWS credentials but there I am not getting this type of "Invalid Signature" issue in the access token. Someone, please help me because I am not any good link where this type of issue has been discussed.
Thanks in advance

How to link my mobile hub with my existing cognito user pool? (Part 2)

I am sorry to do this, but I don't have enough reputation to comment on this issue: How to link my mobile hub with my existing cognito user pool?, and the answer provided didn't quite solve my problem.
To explain a little better, I am using the React Native build-out for AWS Mobile Hub. I have "successfully" authenticated, but Amplify keeps using the pre-configured (automatically integrated) User Pool. This requires the user to enter a phone number as part of the sign up process, but we don't have that field for sign up.
I have linked my Cognito User Pool to the pre-configured (automatically integrated) Identity Pool under "Authentication Providers" as #andrew-c suggested in the issue above. I edited the 'aws_user_pools_id' property to point to my custom User Pool, as suggested in the issue above.
When I console.log() the User Pool property, that I passed into my Amplify configuration, it gives me my custom User Pool.
When I console.log() the response from the Authentication success, I also see my custom User Pool. But the user keeps getting saved into, and authenticated against the model (namely, phone_number is required) of the pre-configured (automatically integrated) User Pool. I.e. that's where my users show up after sign-up.
Does anyone know what I'm missing?
Here's what I'm seeing in the console:
That's what I get when running this code:
const attributes = {
name: this.state.name,
birthdate: this.state.birthdate,
phone_number: '+011234567890',
}
try {
console.log(Auth.signUp);
this.setState({ loading: true });
const response = await Auth.signUp({
username: this.state.email,
password: this.state.password,
attributes,
validationData: [],
});
console.log(`SignUp::onSignUp(): Response#1 = ${JSON.stringify(response, null, 2)}`);
if (response.userConfirmed === false) {
this.setState({ authData: response, modalShowing: true, loading: false });
} else {
this.onAuthStateChange('default', { username: response.username });
}
} catch (err) {
console.log(`SignUp::onSignUp(): Error ${JSON.stringify(err, null, 2)}`);
this.setState({ error: err.message, loading: false });
}
And the relevant imports:
import Amplify, { Auth } from 'aws-amplify';
import aws_exports from '../../aws-exports';
Amplify.configure(aws_exports);
So suffice it to say I would really like to not require a phone number on sign up, and I figured this would be the easiest way, but if anyone knows what I'm missing or has a better path for me to go down, please let me know. Thanks folks!

Cognito auth flow fails with "Already found an entry for username Facebook_10155611263153532"

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

ember-simple-auth is not saving auth response to session

I'm using ember-simple-auth and I can see that the authentication token is returned and that my custom authenticator is putting it (code-wise) into the session.
I can use wireshark to see that the token comes back but I can't debug into the authenticator code - I can't even use debug statements as the redirect wipes the network session on google chrome.
However, it isn't in the session (google chrome tools) and the session isn't considered authenticated.
Why is the lock code correctly popping up the auth0 dialog but not saving the session? I don't really think it is something with this code but rather a config or initialization setting I'm unaware of.
I expect the session to be saved in the _setupFutureEvents as the first thing it does.
Any ideas what I can try to get it to work?
(/app/authenticators/lock.js) authenticate (options) {
return new Ember.RSVP.Promise((res) => {
this.get('lock').show(options, (err, profile, jwt, accessToken, state, refreshToken) => {
if (err) {
this.onAuthError(err);
} else {
var sessionData = { profile, jwt, accessToken, refreshToken };
// pass the NEW auth0 session data into future events
this.afterAuth(sessionData).then(response => res(this._setupFutureEvents(response)));
}
});
});
},
afterAuth (data) {
return Ember.RSVP.resolve(data);
},
_setupFutureEvents (data) {
// set the session info here
this.get('sessionData').setProperties(data);
this._clearJobs();
this._scheduleExpire();
if (this.get('hasRefreshToken')) {
this._scheduleRefresh();
}
return this.get('sessionData');
},