Develop Reference

Firebase security rules data.exists() not working

Following the post here I created a simple security rule and cloud function that gets called to see if a username already exists. The problem is that the security rule write check always passes and just sets the new value in that location (/username_lookup/user1).
When I try to write at this location using the realtime database rules simulator it works as expected, i.e. the write is blocked.
Can someone spot the problem?
The firebase security rule
"rules": {
"username_lookup": {
"$username": {
// not readable, cannot get a list of usernames!
// can only write if this username is not already in the db
".write": "!data.exists()",
// can only write my own uid into this index
".validate": "newData.val() === auth.uid"
}
}
}
And the cloud function
var fb = admin.database().ref();
createUser(uid, username);
function createUser(userId, usrname) {
fb.child('username_lookup').child(usrname).set(userId, function(unerr) {
if(unerr) {
res.setHeader('Content-Type', 'application/json');
res.send(JSON.stringify({error: "the_error_code" }));
}
});
}
Screenshot of the username_lookup object/index

You Cloud Functions access the Firebase database through:
var fb = admin.database().ref();
As you can see, the module is admin which indicates that you're using the Firebase Admin SDK. One of the key traits of the Firebase Admin SDK is:
Read and write Realtime Database data with full admin privileges.
source: https://firebase.google.com/docs/admin/setup
So the Admin SDK actually bypasses your security rules.
It's also a pretty bad practice to use an error handler for basic flow control.
Instead, use a Firebase transaction to read/write the location with the name in an atomic way:
fb.child('username_lookup').child(usrname).transaction(function(value) {
if (value) {
res.setHeader('Content-Type', 'application/json');
res.send(JSON.stringify({error: "the_error_code" }));
return; // abort the transaction
}
else {
return userId;
}
});

Azure using wrong callback url during implicit flow login

I'm currently struggling with a weird problem in azure active directory implicit flow oauth authentication. I've implemented a spa webapp using msal.js to login users to their microsoft accont.
The userAgentApplication is executed as shown below:
userAgentApplication = new
Msal.UserAgentApplication(client_id,null,function(errorDes,token,error,tokenType)
{
if(error) {
console.log(JSON.stringify(error));
return;
}
},{ redirectUri: 'https://example.com/app/msalCallback.html' });
When they click login executing the is piece of code:
logInPopup = function() {
var uaa = userAgentApplication;
return new Promise(function(resolve,reject) {
uaa.loginPopup([
'https://graph.microsoft.com/user.read'
]).then(function(token) {
//signin success
console.log(token);
var user = uaa.getUser();
console.log(JSON.stringify(user));
resolve(user);
}, function(error) {
console.log(JSON.stringify(error));
reject(error);
});
})
}
The popup comes up and the user tries to login but the following error comes up:
Microsoft account is experiencing technical problems. Please try again later.
In the url the error parameters string is:
error_description=The provided value for the input parameter
'redirect_uri' is not valid The expected value is
'https://login.live.com/oauth20_desktop.srf' or a URL which matches
the redirect URI registered for this client application.
Upon further research I found that though I configured the redirect uri to be
https://example.com/app/msalCallback.html
(Which I confirmed on the application registration page to be true)
The redirect_uri of the /oauth2/v2.0/authorise url in the login popup page is:
redirect_uri=https://example.com/app/
Which is weird but the above uri is not random one. It is in fact the callback uri for a previous previously registered but now deleted app with the same name.
Further investigation showed that when I config Msal to use the old the redirect_uri login passes.
I'm fresh out of ideas. It looks like a bug in the azure network but wanted to know if anyone else has had this problem or at least point me in the right direction towards getting in contact with azure to find a fix.
Thanks in advance

I've found the cause of the problem after carefully reviewing the msal.js documentation i found that i was setting the redirectUri incorrectly. The correct way is as follows:
var userAgentApplication = new
Msal.UserAgentApplication(client_id,null,function(errorDes,token,error,tokenType)
{
if(error) {
console.log(JSON.stringify(error));
return;
}
});
userAgentApplication.redirectUri = 'https://example.com/app/msalCallback.html'
Hope that helps.
regards

Link Facebook to Firebase Anonymous Auth without calling Facebook API

I am creating anonymous sessions in my Firebase application to save user data before they create their accounts. I saw that Firebase allows linking a Facebook login to an anonymous account which sounds really neat, but a caveat of this process seems to be that I have to grab the Facebook token myself, outside the warmth and comfort of the awesome Firebase API, which seems strangely un-developed given how much of the login flow Firebase seems to do on behalf of apps.
A code sample of how to connect an anonymous account from their account linking docs:
var credential = firebase.auth.FacebookAuthProvider.credential(
response.authResponse.accessToken);
Naturally, I want to use Firebase's way of getting a token
var provider = new firebase.auth.FacebookAuthProvider();
firebase.auth().signInWithPopup(provider).then(function(result) {
// result.token or whatever would appear here
});
But if I were to run that, I would lose my anonymous session (and my anonymous user ID, which we want the new Facebook login to use).
Is there anyway to get a Facebook Token out of Firebase's auth mechanism without logging the user in and losing the anonymous session that I'm trying to convert into a Facebook Login-able account? (The goal is to not have to call the Facebook API myself, especially as I'll be adding Google here as well)

I think you're looking to #linkWithPopup or #linkWithRedirect:
var provider = new firebase.auth.FacebookAuthProvider();
user.linkWithPopup(provider).then(function(result) {
console.log('Party 🎉');
});
If for some reason that doesn't cut it, you could always opt to do yourself:
Sign in the user anonymously, and store the user somewhere
Sign in the user with the provider and store the token somewhere
Delete the provider user and then link the account with the token
Quick and dirty example:
var googleToken;
var anonUser;
firebase.auth().signInAnonymously().then(function(user) {
anonUser = user;
}).catch(function(error) {
console.error("Anon sign in failed", error);
});
function signInWithGoogle() {
var provider = new firebase.auth.GoogleAuthProvider();
firebase.auth().signInWithPopup(provider).then(function(result) {
googleToken = result.credential.idToken;
}).catch(function(error) {
console.error("Google sign in failed", error);
})
}
function deleteAndLink() {
firebase.auth().currentUser.delete().then(function() {
var credential =
firebase.auth.GoogleAuthProvider.credential(googleToken);
anonUser.link(googleCredential);
}).then(function() {
console.log("Link succeeded");
}).catch(function(error) {
console.error("Something went wrong", error);
});
}

AWS Cognito - Developer Authenticated Identities in JavaScript(Browser)

I have trouble getting credentials in a browser script.
The authentication server returns cognito_identityId and cognito_token.
Then I set a Cookie:
$.cookie('cognito_identityId')
$.cookie('cognito_token')
I tried to get credentials in 4 ways on the browser, and all Failed:
CognitoIdentityCredentials
AWS.config.credentials = new AWS.CognitoIdentityCredentials({
IdentityPoolId: 'us-east-1:xxxxxxxxxxxx'
IdentityId: $.cookie('cognito_identityId'),
Logins: {
'myauth': $.cookie('cognito_token')
}
});
// => Error: Missing required key 'IdentityId' in params
assumeRoleWithWebIdentity
var params = {
RoleArn: 'arn:aws:iam::xxxxxxxxxxxx:role/Cognito_xxxxxxxAuth_Role',
RoleSessionName: 'xxxxxxxxxxx',
WebIdentityToken: $.cookie('cognito_token'),
DurationSeconds: 900,
ProviderId: 'myauth'
};
var sts = new AWS.STS({apiVersion: '2011-06-15'});
sts.assumeRoleWithWebIdentity(params, function(err, data) {
if (err) console.log(err, err.stack); // an error occurred
else console.log(data); // successful response
});
// => AccessDenied: Not authorized to perform sts:AssumeRoleWithWebIdentity
PolicyDocument
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "",
"Effect": "Allow",
"Principal": {
"Federated": "cognito-identity.amazonaws.com"
},
"Action": "sts:AssumeRoleWithWebIdentity",
"Condition": {
"StringEquals": {
"cognito-identity.amazonaws.com:aud": "us-east-1:xxxxxxxxxxxxx"
},
"ForAnyValue:StringLike": {
"cognito-identity.amazonaws.com:amr": "authenticated"
}
}
}
]
}
GetCredentialsForIdentity
var params = {
IdentityId: $.cookie('cognito_identityId'),
Logins: {
"myauth": $.cookie('oauth.io_token')
}
};
var cognitoidentity = new AWS.CognitoIdentity({apiVersion: '2014-06-30'});
cognitoidentity.getCredentialsForIdentity(params, function(err, data) {
if (err) {
console.log(err, err.stack); // an error occurred
}
else {
console.log(data); // successful response
}
});
// => InvalidParameterException: Please provide a valid public provider
WebIdentityCredentials
AWS.config.credentials = new AWS.WebIdentityCredentials({
RoleArn: 'arn:aws:iam::xxxxxxxx:role/Cognito_xxxxxxxxxxAuth_Role',
WebIdentityToken: $.cookie('cognito_token')
});
// => Error: There were 2 validation errors:
// * MissingRequiredParameter: Missing required key 'IdentityPoolId' in params
// * MissingRequiredParameter: Missing required key 'IdentityId' in params
Questions:
What am I doing wrong?
What is the correct way to use this?
Thank you.
Thank you for your kindness.
I tyied your advice, but did not change.
Error messages.
POST https://cognito-identity.us-east-1.amazonaws.com/ 400 (Bad Request)
POST https://cognito-identity.us-east-1.amazonaws.com/ 400 (Bad Request)
Error: Missing required key 'IdentityId' in params
at fail (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:2163:37)
at validateStructure (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:2084:14)
at validateMember (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:2110:21)
at validate (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:2059:10)
at Request.VALIDATE_PARAMETERS (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:800:32)
at Request.callListeners (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:3913:20)
at callNextListener (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:3903:12)
at chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:787:9
at finish (chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:126:7)
at chrome-extension://hmjdjbikinkmjbilihjibcihbkbjdgjf/bower_components/aws-sdk-js/dist/aws-sdk.js:142:9
There are source code below link.
https://github.com/bisque33/my-custom-dictionary
and server side is a AWS Lambda Function.
var aws = require('aws-sdk');
aws.config.region = 'us-east-1';
var cognitoidentity = new aws.CognitoIdentity();
var identityPoolId = 'us-east-1:0dccff0d-5fd7-4d14-b38f-d27204feaecc';
console.log('Loading function');
exports.handler = function(event, context) {
console.log('token: %s', event.token);
var params = {
IdentityPoolId: identityPoolId,
Logins: {
'oauth.io': event.token
}
};
cognitoidentity.getOpenIdTokenForDeveloperIdentity(params,function(err,data){
if(err){
console.log(err);
context.fail('Something went wrong');
}else{
context.succeed(data);
}
});
};
This program is Google-Chrome-Extension.
AWS Lambda Function returns token by getOpenIdTokenForDeveloperIdentity.
app/scripts/popup.js calls Lambda Function and set cookies.
app/scripts/background.js calls AWS.config.credentials.get, and returns error.
Am I using it wrong?
Update for Additional Information
Thank you for the additional information.
Error appears on 104 line on background.js
AWS.config.credentials.get(function(){
and 115 line on background.js
dataset.synchronize(
And, My explaination was not enough. Facebook authentication needs the domain(ex. http :// example.com). However, Google-Chrome-Ext does not have domain. It has a domain 'chrome-extension://xxxxxxxxxxxxxxxxxxxx'. Then, I use https://oauth.io. It proxies any authentication and accepts chrome-extension domain.
Popup.js does Facebook authentication through oauth.io sdk. It gets a facebook token, and gives to getOpenIdTokenForDeveloperIdentity. I think facebook token.substr(0,14) is unique. But, If it is wrong, I use another unique identifier(ex. email-address.)
Sorry, I was wrong. AWS.config.credentials.get gives an Error:
Error: Invalid login token.
And, dataset.synchronize shows this Error:
Error: Missing required key 'IdentityId' in params

The first approach you have, using CognitoIdentityCredentials, is most likely the best approach for you to take. I can't spot exactly what's causing the error for you but lets try a couple things:
When using Developer Authenticated Identities, you do need to specify the IdentityId when initializing CognitoIdentityCredentials. You need to get the IdentityId value from the call to GetOpenIdTokenForDeveloperIdentity. However, you shouldn't need to preserve the IdentityId value in a cookie as CognitoIdentityCredentials will cache the id by default in the browser's local storage.
As for your Logins map: It looks like you're trying to use Developer Authenticated Identities. With the JavaScript SDK, use the key 'cognito-identity.amazonaws.com' and make sure the value is the token returned from your backend's call to getOpenIdTokenForDeveloperIdentity.
If you continue to have problem using the CognitoIdentityCredentials approach, please reply here with some more info such as the exact method/code you're calling when you receive the error message, and the traced output (i.e. with console.log('%o',..)) of the params input just before your call to the CognitoIdentityCredentials constructor.
Update Based on Additional Information Provided
I still need to know exactly which line of code you receive the error on, but based on the information provided I think I can still help...
Based on what I see in background.js, it looks like you're trying to initialize CognitoIdentityCredentials using a Developer Authenticated Identities provider. This is where I'm guessing that you're receiving the error.
However, in Popup.js, it looks like you're trying to authenticate the user with Facebook. If you're authenticating your users with Facebook, you should just pass the facebook access token into your Logins map when using Cognito. Just use graph.facebook.com as the key in the Logins map and the access token from Facebook. More detail on how to do this is in the Facebook Integration topic of the Amazon Cognito developer guide.
Facebook vs Developer Authenticated Identities
We can get Developer Authenticated Identities to work for you, but in this case, it doesn't look like the right solution for you since you're not actually doing any additional authentication on the identity in your Lambda function and the unique user identifier that you're passing into the getOpenIdTokenForDeveloperIdentity operation appears to be the facebook token, which is not good by the way since the token itself will change between user sessions even for the same user. Usually a good unique identifier is an email address or a user id used by an internal system.
Facebook Login & Redirects
Since you're ultimately trying to use Facebook for login and Amazon Cognito has built-in integration for Facebook, the best thing for you to do is get an access token from Facebook and pass in the Facebook token to Cognito's login map directly. I'm not sure if this will work with Auth.io or not (I'm just not familiar with it), but as long as Auth.io gives your JavaScript code a bonefide facebook token and you add the same Facebook App ID to both Auth.io and Amazon Cognito's Console, it should work. However, you mentioned you want to use Auth.io to avoid Facebook doing a redirect to a landing page. I could be mistaken, but I'm pretty sure if you're using Facebook's JavaScript SDK you won't need a redirect page. You should only need the redirect page if you're doing Facebook's Manually Build a Login Flow.

I receive an "FirebaseSimpleLogin: An unknown error occurred" in Firebase when I try to log in with Twitter

Yesterday, I discovered Firebase and started to use it. I deployed an edited version (I just changed the CSS) of the chat app provided by Firebase, Everything went OK until I added Twitter Logging option. I couldn't authenticate my app with Twitter even though I followed these instructions and I activated "Sign in with Twitter" from Twitter Application Management Panel.
This is the code I'm using in my chat app to log in (anything else is related to Twitter logging in my code):
// instatiate the FirebaseSimpleLogin and monitor the user's auth state
var chatRef = new Firebase('https://ranchat.firebaseIO.com');
var auth = new FirebaseSimpleLogin(chatRef, function(error, user) {
if (error) {
// an error occurred while attempting login
alert(error);
} else if (user) {
// user authenticated with Firebase
alert('Welcome' + user.username);
} else {
// user is logged out
}
});
// attempt to log the user in with your preferred authentication provider
$('#twlog').click(function(){
auth.login('twitter', {
RememberMe: true
});
});
These are the Firebase Rules I'm using
{
"rules": {
".read": true,
"$comment": {
".write": "!data.exists() && newData.child('twitter_id').val() == auth.id"
}
}
}
And this is what happens after press Twitter Log button in my app
Error: FirebaseSimpleLogin: An unknown error occurred
Honesly, I don't know why it happening. Would you give a hand?

I found the solution thanks to #RobDiMarco.
The error was occuring due to an incorrect copy of Twitter API ID and API Secret into my Firebase Forge. I just needed to copy these and then paste it here.

The terminology is very confusing in Firebase Simple Login documentation. Firebase requires three things:
Twitter App ID (used in the client call), which is the "API key" from API keys tab in your Twitter application settings page
Twitter Consumer Key (entered into Firebase Forge), which is also the "API key"
Twitter Consumer Secret (entered into Firebase Forge), which is the "API secret" from the same tab