Develop Reference

Deleting a user from Azure Active Directory B2C Android/Java

I have an Android application in which I'm using Azure AD B2C to authenticate users. Users login and logout of the application as needed. I would like to give the user the option to delete their own account.
I understand that I need to use the Azure AD Graph API to delete the user. This is what I have so far:
According to this link, it looks like deleting a user from a personal account (which is what the B2C users are using) is not possible. Is that correct?
Here's my code snippet for the Graph API call. Feel free to ignore it if I'm off track and there is a better way to solve this.
I believe I need a separate access token than what my app currently has (as the graph API requires other API consent). So, I'm getting the access token as follows:
AcquireTokenParameters parameters = new AcquireTokenParameters.Builder()
.startAuthorizationFromActivity(getActivity())
.fromAuthority(B2CConfiguration.getAuthorityFromPolicyName(B2CConfiguration.Policies.get("SignUpSignIn")))
.withScopes(B2CConfiguration.getGraphAPIScopes())
.withPrompt(Prompt.CONSENT)
.withCallback(getGraphAPIAuthCallback())
.build();
taxApp.acquireToken(parameters);
In the getGraphAPIAuthCallback() method, I'm calling the Graph API using a separate thread (in the background):
boolean resp = new DeleteUser().execute(authenticationResult.getAccessToken()).get();
Finally, in my DeleterUser() AsyncTask, I'm doing the following:
#Override
protected Boolean doInBackground(String... aToken) {
final String asToken = aToken[0];
//this method will be running on background thread so don't update UI from here
//do your long running http tasks here,you dont want to pass argument and u can access the parent class' variable url over here
IAuthenticationProvider mAuthenticationProvider = new IAuthenticationProvider() {
#Override
public void authenticateRequest(final IHttpRequest request) {
request.addHeader("Authorization",
"Bearer " + asToken);
}
};
final IClientConfig mClientConfig = DefaultClientConfig
.createWithAuthenticationProvider(mAuthenticationProvider);
final IGraphServiceClient graphClient = new GraphServiceClient.Builder()
.fromConfig(mClientConfig)
.buildClient();
try {
graphClient.getMe().buildRequest().delete();
} catch (Exception e) {
Log.d(AccountSettingFragment.class.toString(), "Error deleting user. Error Details: " + e.getStackTrace());
}
return true;
}
Currently, my app fails when trying to get an access token with a null pointer exception:
com.microsoft.identity.client.exception.MsalClientException: Attempt to invoke virtual method 'long java.lang.Long.longValue()' on a null object reference
Any idea what I need to do to provide the user the option to users to delete their own account? Thank you!

Thanks for the help, #allen-wu. Due to his help, this azure feedback request and this azure doc, I was able to figure out how to get and delete users silently (without needing intervention).
As #allen-wu stated, you cannot have a user delete itself. So, I decided to have the mobile app call my server-side NodeJS API when the user clicks the 'Delete Account' button (as I do not want to store the client secret in the android app) and have the NodeJS API call the Azure AD endpoint to delete the user silently. The one caveat is that admin consent is needed the first time you try to auth. Also, I have only tested this for Graph API. I'm not a 100% sure if it works for other APIs as well.
Here are the steps:
Create your application in your AAD B2C tenant. Create a client secret and give it the following API permissions: Directory.ReadWrite.All ;
AuditLog.Read.All (I'm not a 100% sure if we need the AuditLog permission. I haven't tested without it yet).
In a browser, paste the following link:
GET https://login.microsoftonline.com/{tenant}/adminconsent?
client_id=6731de76-14a6-49ae-97bc-6eba6914391e
&state=12345
&redirect_uri=http://localhost/myapp/permissions
Login using an existing admin account and provide the consent to the app.
Once you've given admin consent, you do not have to repeat steps 1-3 again. Next, make the following call to get an access token:
POST https://login.microsoftonline.com/{B2c_tenant_name}.onmicrosoft.com/oauth2/v2.0/token
In the body, include your client_id, client_secret, grant_type (the value for which should be client_credentials) and scope (value should be 'https://graph.microsoft.com/.default')
Finally, you can call the Graph API to manage your users, including deleting them:
DELETE https://graph.microsoft.com/v1.0/users/{upn}
Don't forget to include the access token in the header. I noticed that in Postman, the graph api had a bug and returned an error if I include the word 'Bearer' at the start of the Authorization header. Try without it and it works. I haven't tried it in my NodeJS API yet, so, can't comment on it so far.
#allen-wu also suggested using the ROPC flow, which I have not tried yet, so, cannot compare the two approaches.
I hope this helps!

There is a line of code: graphClient.getUsers("").buildRequest().delete();
It seems that you didn't put the user object id in it.
However, we can ignore this problem because Microsoft Graph doesn't allow a user to delete itself.
Here is the error when I try to do it.
{
"error": {
"code": "Request_BadRequest",
"message": "The principal performing this request cannot delete itself.",
"innerError": {
"request-id": "8f44118f-0e49-431f-a0a0-80bdd954a7f0",
"date": "2020-06-04T06:41:14"
}
}
}

Register a New User with the Mobile SDK for Android on AWS Cognito

Im trying to develop a sing up for AWS Cognito in Android. I just checked the official doc but in the Register a New User section there is only the sample for using SignUpHandler.
Checking other sections, for example Using the JavaScript SDK there is a clear sample using
userPool.signUp('username', 'password', attributeList, null, function(err, result)
Im trying to implement this aproach transpolating the javascript example. But I was wondering if there is any complete sample of sign up for Android?
Thanks in advance!!

The handler you noticed is a parameter for the call to sign up, much like 'function(err, result) in the JS example. Take a look at this part of the docs, it shows how to use that handler. From the example you screenshotted, it might look like this:
userPool.signUpInBackground(userId, password, userAttributes, null, handler);

Here is a complete sample using the link sugested by Jeff:
CognitoUserAttributes attributes = new CognitoUserAttributes();
attributes.addAttribute("phone_number","+15555555555");
attributes.addAttribute("email","email#mydomain.com");
cognitoUserPool.signUp('username', 'password', attributes, null, new SignUpHandler() {
#Override
public void onSuccess(CognitoUser cognitoUser, boolean b, CognitoUserCodeDeliveryDetails cognitoUserCodeDeliveryDetails) {
// If the sign up was successful, "user" is a CognitoUser object of the user who was signed up.
// "codeDeliveryDetails" will contain details about where the confirmation codes will be delivered.
}
#Override
public void onFailure(Exception e) {
// Sign up failed, code check the exception for cause and perform remedial actions.
}
});
The sections Examples of Using User Pools with the Mobile SDK for Android seems to be outdated.
Hope to help somebody else ;)

Consume WebAPI2 site from Android client with Google Authentication

I've been wracking my brain these past two days to try and understand how to use the authentication built into ASP.NET's WebAPI 2 using Google as an external authentication, and not being familiar with OAuth 2, I'm quite lost. I have followed this tutorial to set up the sign-in button on my Android client and send the "idToken" to the Web API. I've also followed this (now out of date) tutorial on setting up Google as an external login.
The problem happens when I try to send it I get {"error":"unsupported_grant_type"} as a response. Some other tutorials lead me to believe that the POST to mysite.com/token does not contain the correct data. This means I'm either building the request incorrectlyon the client, I'm somehow handling it incorrectly on the backend, I'm sending it to the wrong url, or I'm doing something entirely else wrong.
I found this SO answer which says to get a URL from /api/Accounts/ExternalLogins, but the sign-in button already gives me the access token that would supply to me (if I understand that correctly).
If someone could help me out here on what the exact process should be from start to finish, that would be amazing.
UPDATE: Okay, so here are some things that I've learned since I asked this question.
website.com/token URI is the redirect for the built in OAuth server in the WebAPI2 template. This is not useful for this particular problem.
The id_token is an encoded JWT token.
The website.com/signin-google URI is the redirect for normal Google login, but does not accept these tokens.
I may have to write my own AuthenticationFilter that uses the Google Client library to authorize through the Google API.
UPDATE 2: I'm still working on getting this AuthenticationFilter Implementation. Things seem to be going well at this point, but I'm getting stuck on some things. I've been using this example to get the token verification code, and this tutorial to get the AuthenticationFilter code. The result is a mix of both of them. I'll post it here as an answer once it's complete.
Here are my current problems:
Producing an IPrincipal as output. The verification example makes a ClaimPrincipal, but the AuthenticationFilter example code uses a UserManager to match the username to an existing user and returns that principal. The ClaimsPrincipal as created in the verification example directly does not auto-associate with the existing user, so I need to attempt to match some element of the claims to an existing user. So how do I do that?
I still have an incomplete idea of what a proper flow for this is. I'm currently using the Authentication header to pass my id_token string using a custom scheme: "goog_id_token". The client must send their id_token for every method called on the API with this custom AuthenticationFilter. I have no idea how this would usually be done in a professional environment. It seems like a common enough use case that there would be tons of information about it, but I haven't seen it. I have seen the normal OAuth2 flow, and since I'm only using an ID Token, and not an Access Token I'm a bit lost on what an ID Token is supposed to be used for, where it falls in a flow, and where it's supposed to live in an HTTP packet. And because I didn't know these things, I've kind of been making it up as I go along.

Wow, I did it. I figured it out. I... I can't believe it.
As metioned in my question Update 2, this code is assembled from Google's official API C# example and Microsoft's Custom AuthenticationFilter tutorial and code example. I'm going to paste the AuthorizeAsync() here and go over what each block of code does. If you think you see an issue, please feel free to mention it.
public async Task AuthenticateAsync(HttpAuthenticationContext context, CancellationToken cancellationToken)
{
bool token_valid = false;
HttpRequestMessage request = context.Request;
// 1. Look for credentials in the request
//Trace.TraceInformation(request.ToString());
string idToken = request.Headers.Authorization.Parameter.ToString();
The client adds the Authorization header field with the scheme followed by a single space, followed by the id token. It looks something like Authorization: id-token-goog IaMS0m3.Tok3nteXt.... Putting the ID token in the body as given in the google documentation made no sense in this filter so I decided to put it in the header. For some reason it was difficult to pull custom headers from the HTTP packets so I just decided to use the Authorization header with a custom scheme followed by the ID token.
// 2. If there are no credentials, do nothing.
if (idToken == null)
{
Trace.TraceInformation("No credentials.");
return;
}
// 3. If there are credentials, but the filter does not recognize
// the authentication scheme, do nothing.
if (request.Headers.Authorization.Scheme != "id-token-goog")
// Replace this with a more succinct Scheme title.
{
Trace.TraceInformation("Bad scheme.");
return;
}
This whole point of a filter is to ignore requests that the filter doesn't govern (unfamiliar auth schemes, etc), and make judgement on requests that it's supposed to govern. Allow valid authentication to pass to the downstream AuthorizeFilter or directly to the Controller.
I made up the scheme "id-token-goog" because I had no idea if there was an existing scheme for this use case. If there is, somebody please let me know and I'll fix it. I guess it doesn't particularly matter at the moment as long as my clients all know the scheme.
// 4. If there are credentials that the filter understands, try to validate them.
if (idToken != null)
{
JwtSecurityToken token = new JwtSecurityToken(idToken);
JwtSecurityTokenHandler jsth = new JwtSecurityTokenHandler();
// Configure validation
Byte[][] certBytes = getCertBytes();
Dictionary<String, X509Certificate2> certificates =
new Dictionary<String, X509Certificate2>();
for (int i = 0; i < certBytes.Length; i++)
{
X509Certificate2 certificate =
new X509Certificate2(certBytes[i]);
certificates.Add(certificate.Thumbprint, certificate);
}
{
// Set up token validation
TokenValidationParameters tvp = new TokenValidationParameters()
{
ValidateActor = false, // check the profile ID
ValidateAudience =
(CLIENT_ID != ConfigurationManager
.AppSettings["GoogClientID"]), // check the client ID
ValidAudience = CLIENT_ID,
ValidateIssuer = true, // check token came from Google
ValidIssuer = "accounts.google.com",
ValidateIssuerSigningKey = true,
RequireSignedTokens = true,
CertificateValidator = X509CertificateValidator.None,
IssuerSigningKeyResolver = (s, securityToken, identifier, parameters) =>
{
return identifier.Select(x =>
{
// TODO: Consider returning null here if you have case sensitive JWTs.
/*if (!certificates.ContainsKey(x.Id))
{
return new X509SecurityKey(certificates[x.Id]);
}*/
if (certificates.ContainsKey(x.Id.ToUpper()))
{
return new X509SecurityKey(certificates[x.Id.ToUpper()]);
}
return null;
}).First(x => x != null);
},
ValidateLifetime = true,
RequireExpirationTime = true,
ClockSkew = TimeSpan.FromHours(13)
};
This is all unchanged from the Google example. I have almost no idea what it does. This basically does some magic in creating a JWTSecurityToken, a parsed, decoded version of the token string, and sets up the validation parameters. I'm not sure why the bottom portion of this section is in it's own statement block, but it has something to do with the CLIENT_ID and that comparison. I'm not sure when or why the value of CLIENT_ID would ever change, but apparently it's necessary...
try
{
// Validate using the provider
SecurityToken validatedToken;
ClaimsPrincipal cp = jsth.ValidateToken(idToken, tvp, out validatedToken);
if (cp != null)
{
cancellationToken.ThrowIfCancellationRequested();
ApplicationUserManager um =
context
.Request
.GetOwinContext()
.GetUserManager<ApplicationUserManager>();
Get the user manager from the OWIN context. I had to dig around in context intellisense until I found GetOwinCOntext(), and then found that I had to add using Microsoft.Aspnet.Identity.Owin; in order to add the partial class that included the method GetUserManager<>().
ApplicationUser au =
await um
.FindAsync(
new UserLoginInfo(
"Google",
token.Subject)
);
This was the very last thing I had to fix. Again, I had to dig through um Intellisense to find all of the Find functions and their overrides. I had noticed from the Identity Framework-created tables in my database that there is one called UserLogin, whose rows contain a provider, a provider key, and a user FK. The FindAsync() takes a UserLoginInfo object, which contains only a provider string and a provider key. I had a hunch that these two things were now related. I had also recalled that there was a field in the token format that included a key-looking field that was a long number that started with a 1.
validatedToken seems to be basically empty, not null, but an empty SecurityToken. This is why I use token instead of validatedToken. I'm thinking there must be something wrong with this, but since the cp is not null, which is a valid check for a failed validation, it makes enough sense that the original token is valid.
// If there is no user with those credentials, return
if (au == null)
{
return;
}
ClaimsIdentity identity =
await um
.ClaimsIdentityFactory
.CreateAsync(um, au, "Google");
context.Principal = new ClaimsPrincipal(identity);
token_valid = true;
Here I have to create a new ClaimsPrincipal since the one created above in validation is empty (apparently that's correct). Took a guess on what the third parameter of CreateAsync() should be. It seems to work that way.
}
}
catch (Exception e)
{
// Multiple certificates are tested.
if (token_valid != true)
{
Trace.TraceInformation("Invalid ID Token.");
context.ErrorResult =
new AuthenticationFailureResult(
"Invalid ID Token.", request);
}
if (e.Message.IndexOf("The token is expired") > 0)
{
// TODO: Check current time in the exception for clock skew.
Trace.TraceInformation("The token is expired.");
context.ErrorResult =
new AuthenticationFailureResult(
"Token is expired.", request);
}
Trace.TraceError("Error occurred: " + e.ToString());
}
}
}
}
The rest is just exception catching.
Thanks for checking this out. Hopefully you can look at my sources and see which components came from which codebase.

Android: work with Parse database for an IncrementKey column at Parse

I am working on a Android app and is using Parse Database, and would like to add a IncrementKey function such that when a new image is added to the database, the image_id column would increase itself by 1.
Reference: https://www.parse.com/questions/incrementkey
Question:
However, googled for a long while, there are no explicit example to show how to get it work... it involves cloud code at parse. Would there be any hints on how could that be done?
Thanks!

To create a beforeSave trigger for Image (replace where relevant, I've assumed this is your Class that holds the images and counter column - these are properties of the same Object)
file: ./cloud_code/cloud/main.js or a filepath required by main.js
Parse.Cloud.beforeSave("Image", function(request, response) {
//check if this is a new or existing Image
if (!request.object.isNew()) {
//image exists, save as normal
response.success();
} else {
//find the last image saved
var checkImage = Parse.Object.extend("Image");
var imagesQuery = new Parse.Query(checkImage);
imagesQuery.select("image_id"); //save memory by only requesting image_id
imagesQuery.descending("image_id"); //sort, make sure image_id is a Number
imagesQuery.first().then(
function(lastImage) {
//increase the id by 1
var newId = lastImage.get("image_id") + 1;
//save the current object with the new id
request.object.set("image_id", newId);
response.success(); //this saves your request.object
},
function (error)
response.error(error);
}
);
}
});
Resources
Cloud code guide: https://parse.com/docs/cloudcode/guide
Cloud code beforeSave modify: https://parse.com/docs/cloudcode/guide#cloud-code-modifying-objects-on-save
Retrieving objects: https://www.parse.com/docs/js_guide#objects-retrieving
Increment (updating an existing field): https://parse.com/docs/js/guide#objects-counters
See also Parse cloudcode beforeSave obtain pre-updated object (the other way around)
Read the Cloud code guide to learn how to e.g. install the CLI tools to deploy your Cloud Code and check the Cloud logs for debugging.
Disclaimer: code above is untested but based on working functions
Note: use isNew() in a beforeSave handler, existed in an afterSave handler. There's a reported bug for existed in Parse Cloud Code versions 1.6.* - see Parse request.object.existed() return false

Android: Using server-side when working with Parse

Me and my friend are working on an app., and we wish to use Parse.com as our data base from which we can retrieve info.
We can't decide what is the best way to access the data on Parse. For the sake of the example, our app. (i.e. client side) needs something stored on the Parse data base (say some number) - should it directly run the query using the Parse API, or should it make a request to a server side, let it retrieve that number from Parse, and send it back to the client?
We know there's no definite answer, but we couldn't find answer regarding this specific situation. We read this post: When to use client-side or server-side?,
but this not exactly the same case.
I claim that we should try to seperate as much as possible from client side and data bases, and leave these queries run by someone who's in charge (server), where my friend claims this adds unnecessary complication, since it's very natural to use the tools supplied by Parse to access the data base from the client side, without the need for a protocol etc.
We'd appriciate any advice,
Thank you.

In general, go right ahead and make a normal call.
I'd encourage you to do that first in any case, to get everything working on both ends.
Then if necessary go to Cloud Code.
If you are going to do more than one platform (ie iOS and Android), cloud code can be a huge timesaver.
BUT don't forget that for simple calls, cloud code is a waste of time. "Normal" Parse calls are amazingly, incredibly, amazingly, fast and quick to work with.
There is absolutely nothing "wrong" with using normal Parse calls - so do that.
Regarding the question, when do you literally have to use a cloud code call -- you'll know, because you won't be able to do it with a normal call :)
Don't forget very often you can simply use "afterSave" or "beforeSave" in cloud code, to do a huge amount of work. You often don't literally need to go to a "custom call" in cloud code.
Here's a fantastic
Rule of thumb for Parse cloud code --------->
If you have to do "more than one thing" ... in that case you will likely have to make it a cloud code function. If you have to do "three or more things" then DEFINITELY make it a cloud code function.
That's a good rule of thumb.
(Again, as I say, often just an "afterSave" or similar works brilliantly...rather than literally writing a full custom call.)
Here's a typical example of a cloud call that saves 18 billion lines of code in all the platforms covered by the dotcom. First the cloud code...
Parse.Cloud.define("clientRequestHandleInvite", function(request, response)
{
// called from the client, to accept an invite from invitorPerson
var thisUserObj = request.user;
var invitorPersonId = request.params.invitorPersonId;
var theMode = request.params.theMode;
// theMode is likely "accept" or "ignore"
console.log( "clientRequestAcceptInvite called.... invitorPersonId " + invitorPersonId + " By user: " + thisUserObj.id );
console.log( "clientRequestAcceptInvite called.... theMode is " + theMode );
if ( invitorPersonId == undefined || invitorPersonId == "" )
{
response.error("Problem in clientRequestAcceptInvite, 'invitorPersonId' missing or blank?");
return;
}
var query = new Parse.Query(Parse.User);
query.get(
invitorPersonId,
{
success: function(theInvitorPersonObject)
{
console.log("clientRequestFriendRemove ... internal I got the userObj ...('no response' mode)");
if ( theMode == "accept" )
{
createOneNewHaf( thisUserObj, theInvitorPersonObject );
createOneNewHaf( theInvitorPersonObject, thisUserObj );
}
// in both cases "accept" or "ignore", delete the invite in question:
// and on top of that you have to do it both ways
deleteFromInvites( theInvitorPersonObject, thisUserObj );
deleteFromInvites( thisUserObj, theInvitorPersonObject );
// (those further functions exist in the cloud code)
// for now we'll just go with the trick of LETTING THOSE RUN
// so DO NOT this ........... response.success( "removal attempt underway" );
// it's a huge problem with Parse that (so far, 2014) is poorly handled:
// READ THIS:
// parse.com/questions/can-i-use-a-cloud-code-function-within-another-cloud-code-function
},
error: function(object,error)
{
console.log("clientRequestAcceptInvite ... internal unusual failure: " + error.code + " " + error.message);
response.error("Problem, internal problem?");
return;
}
}
);
}
);
If you are new to Parse it's incredibly hard to figure out how to call these from Android or iOS! Here's that one being called from Android ...
this will save you a day of messing about with HashMaps :)
private static void handleInvite( ParseUser invitor, final boolean accepted )
{
String invitorId = invitor.getObjectId();
// you must SEND IDs, NOT PARSEUSER OBJECTS to cloud code. Sucks!
String cloudKode;
cloudKode = (accepted? "accept" : "ignore");
HashMap<String, Object> dict = new HashMap<String, Object>();
dict.put( "invitorPersonId", invitorId );
dict.put( "theMode", cloudKode );
Toast.makeText(State.mainContext, "contacting...", Toast.LENGTH_SHORT).show();
ParseCloud.callFunctionInBackground(
"clientRequestHandleInvite",
dict,
new FunctionCallback<Object>()
{
#Override
public void done(Object s, ParseException e)
{
Toast.makeText(State.mainContext, "blah", Toast.LENGTH_SHORT).show();
// be careful with handling the exception on return...
}
});
}
And here's the same cloud call from iOS ... well for now, until you have to do it in SWIFT
-(void)tableView:(UITableView *)tableView
commitEditingStyle:(UITableViewCellEditingStyle)editingStyle
forRowAtIndexPath:(NSIndexPath *)indexPath
{
int thisRow = indexPath.row;
PFUser *delFriend = [self.theFriends objectAtIndex:thisRow];
NSLog(#"you wish to delete .. %#", [delFriend fullName] );
// note, this cloud call is happily is set and forget
// there's no return either way. life's like that sometimes
[PFCloud callFunctionInBackground:#"clientRequestFriendRemove"
withParameters:#{
#"removeThisFriendId":delFriend.objectId
}
block:^(NSString *serverResult, NSError *error)
{
if (!error)
{
NSLog(#"ok, Return (string) %#", serverResult);
}
}];
[self back]; // that simple
}
Note For the iOS/Swift experience, click to: How to make this Parse.com cloud code call? which includes comments from the Parse.com team. Hope it saves someone some typing, cheers