Develop Reference

OkHttp POST request set withCredentials to True?

Can't get past Django Rest Framework Token Authorization because I can't set withCredentials=true using OkHttp RequestBuilder. (I'm referring to this https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/withCredentials)
In javascript using axios.post this works fine. I'm having trouble converting this post request to android using OkHttp request builder.
Request builder only seems to give setter methods for Header and Body of post Request?
Tried reading through OkHttp documentation and I've also tried to send withCredentials=True as a header
Django Rest Framework backend not recognizing the token and not resolving the bearer token to a user.
If no class authenticates, request.user will be set to an instance > of django.contrib.auth.models.AnonymousUser, and request.auth > will be set to None.

I'm going to assume here that withCredentials is a query parameter.
Appending ?withCredentials=true. to the end of the URL will probably get things going for you.
An example in full might look like https://www.example.com?withCredentials=true.
With multiple parameters, it may look like https://www.example.com?withCredentials=true&otherParam=Stuff.

Account Manager + Cookie Based Authentication

Is it possible to use Android Account Manager using Cookie-based authentication? How (a code with a explanation would be much appreciated)?
I have seen many examples regarding authentication token, but that is not the case. I have just implemented cookie-based authentication on Python FLASK.
OBS.: I'm using Android Volley for the requests of the application.

All you need to do is to add this line in onCreate in your Application class:
CookieHandler.setDefault(new CookieManager());
this line will make your HttpUrlConnection hold cookies like browser, and since most of the http agents like Volley or okHttp are based on HttpUrlConnection they also will hold your cookies )

Android LoginActivity using standard http request

I'm using LoginActivity template and I'm trying to login to a website with email and password using a standard http request. The site doesn't provide an API so I'm thinking of somehow mirroring the site login to fill the email and password boxes on the page then sending the login request.
Think of logging in to stackoverflow for example by taking the input of an email and password TextView (s) and sending a standard http request to the authentication server with those credentials exactly how it would happen in the browser (same requests and addresses).
I haven't done anything like this before and I have no idea if it's even possible so please forgive any ignorance on my part.

This is done in Android in a similar fashion as in the web browser. Namely, you will send a POST request with proper parameters, let's say a JSON Object for the sake of explaining which contains something like:
{
username: 'myUsername'
password: 'mypass'
}
This will get processed and if your credentials are correct, you will get a response which may contain a variety of data, among which the accessToken (it may be called a slight variation of this).
You are supposed to remember this access token and use it to fetch any other data from the site, because that token is used from there on to authenticate you. I have an API I personally made, and I send the accessToken as a parameter in every request for a resource that is unavailable to the unregistered user.
As for the technical side, I'm using a nifty library called OkHttp for sending the Http requests, and it's quite rewarding and easy to use. Here's a code snippet to see what I'm talking about:
//JSON is a media type for parsing json
//json is a json string containing payload e.g. username and pass like in the example
OkHttpClient httpClient = new OkHttpClient();
RequestBody body = RequestBody.create(JSON, json);
Request request = new Request.Builder()
.url(url)
.post(body)
.build();
Response response = httpClient.newCall(request).execute();
The only thing left to to for you is to properly parse the response. You can find various solutions on this topic, but I personally use 2 approaches, BufferedReader for huge responses using response.body().byteStream(), and plain old String for not-so-large responses using response.body().string().
This is not a short, but very thorough explanation, so feel free to ask for clarification if you do not get some part.

Assuming that you need to log in to sites like StackOverflow from your app with standard http request. That is simply impossible. Because no organizations will allow third party sites/apps handling their users' credentials. If they intend to share their resource with third party most organizations follow this procedure:
First they provide api for you to use.
With that api only you can make users to login i.e you can't handle those credentials
Then they give a token to you corresponding to the user.
With that token you can perform subsequent requests.
If the organization doesn't provide api then they most probably are in situation of not allowing third party sites/apps to access their users' resource.

Secure android application made by ionic framework

I'm working on an android apps. I am using ionic framework. In some pages I need to get data from a web server and the result is an object json.
My problem is if some one arrives to GET the pages where I get the json data, one can fetch all my database data by changing the http request.
Is there any way that can improve security of my apps?

You should make some kind of authentication mechanism, for example, a token in the header, that way you know wether the user has access to that resource or not.
So when you make your request you can generate a configuration for that particular request.
Example:
var url = "http://yourserver.com/api/your/path";
var config = {
"headers": {
"Authorization": "Bearer someBearerFromTheServer"
}
};
$http.get(url, config);
The backend implementation for this to work depends on the language you use. Here google is your best friend.
A more advanced way to do this, is to use interceptors in the $http service and attach the token to the header in every request, but be careful, you should secure this so you won't send your credentials to every request you make (sometimes your app might need to request data from another server).
You can read more about $http services and its configurations in the $http service documentation.
Regards

Verifying user credentials with REST API?

I've set up a REST API on my site in order to return information from my database.
I'm implementing login and registration on my app right now. However, I'm not sure how to handle verifying user credentials (checking if an email is already registered, if a password meets its requirements, etc).
Since my REST API is not open to the public, would it be safe to pass the data like this:
/users/verify/email/{email_address}
/users/verify/password/{password}
Or is there a better (safer) way to do this? In other words, how can I authenticate and validate users when the login/register?

In REST you're talking about resources. A resource will have some state expressed through their properties.
With your example I would ask myself: "why verify an email", "why verify a password". Because you want to verify if a user can be registered.
So your resource will not be an email or a password but a user.
Verification is an action. Something which does not go well with a REST architecture.
What do you want to verify? You want to register a new user but also verify if he's allowed to register. So you'll try with some conditions to add a user to your collection of users. In REST with HTTP this can be done with a POST which acts like an add(User). The logic behind the request can then implement the verification rules on the user.
To post data just use the content body and use the headers for additional info. So I'd change my API to:
HTTP method: POST
Path: /users
Content-Type: application/json
Body:
{"email_address":"qsdfg#sdfgh.com", "password":"qlmkdjfmqlsk"}
Which simplifies your API to a single entrypoint for adding a user. Allowing or refusing to register the user can be communicated through the use of HTTP status codes and messages.
Of course sending passwords in plaintext is not a good practice but you can setup a secure connection with SSL or TLS to communicate.
Sending sensitive data in a URL is not a good practice btw. Servers can log the url which will show everyone with access to the log the password of the user.
The login is a bit different but not that much.
You'd need a resource which uniquely links a user to his conversation with your system.
HTTP method: POST
Path: /authentication
Content-Type: application/json
Body:
{"email_address":"qsdfg#sdfgh.com", "password":"qlmkdjfmqlsk"}
Response
Status-Code: 200
Content:
unique-id-to-my-user
The authentication could call your user api to enforce the rules and then generate the id.
You could use an OAuth2 implementation to handle this.

If your web service is Asp.Net WebAPI which will return an access token for the valid user, you can use Http POST request with username and password as body content.
For sample code, please take a look at my answer in the following question
Implementing Oauth2 with login credentials from native login page
For better security, use Https instead of Http.
Hope this helps!

You can use POST method.
/register with name, email, password for User registration
/login with email, password for User login.
Just make sure that you do not pass the password in clear. Perform some kind of encryption on it.