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How does server return JWT token to the client?

This is my first encounter with a JWT token and I'd like to know how is this token returned to the client after it's first created.
Should it come in the Authorization : Bearer header ?
Usually, it's the client that passes the token in Authorization : Bearer header on each request.
I'd like to know how does the server pass this token to the client after user has authenticated and the token gets created. Also in the same header? In a different header?
In my situation, the server will be generating the token not as a response but as part of the request.
For example:-
A user will login to a portal, then click on a link to an authorized application. The JWT containing user claims will be passed to the authorized application as part of the request.
What is the best approach here? GET or POST? Header (which)? Query string? POST body?
Thank you!

there is no standard for how to return JWT token to the client, however, check this URL, it answers your question
https://github.com/dwyl/hapi-auth-jwt2/issues/82#issuecomment-129873082
putting the JWT token in the Authorization header gives us flexibility to send an actual response in a web application. For a REST-only App/API you are free to send the JWT as the response body or a cookie. What matters is how the client stores the JWT and sends it back to the Server, which is done in the Authorization header (or Cookie or URL Token if you prefer) 👍
As for this existing in the "wild", I have not seen an example of the server sending an Authorisation header to the client, but there is nothing in the spec to suggest this is an anti-pattern.
see: http://self-issued.info/docs/draft-ietf-oauth-v2-bearer.html
If you want to stick to the guidelines you would do follow this example: http://self-issued.info/docs/draft-ietf-oauth-v2-bearer.html#ExAccTokResp

One may be interested to know that the OAuth 2.0 standard specifies the response body for that purpose:
5.1. Successful Response
The authorization server issues an access token and optional refresh
token, and constructs the response by adding the following parameters
to the entity-body of the HTTP response with a 200 (OK) status code:
access_token
REQUIRED. The access token issued by the authorization server.
[...]

How to use token based authorization on REST?

So after reading lots about BasicAuth, OAuth, JWT... etc. i came up with this question.
I have a client where some ppl can log in (Authentication is done). When ppl want to do an api call they use the clients GUI and the client is sending some requests to the a webservice endpoint.
host/resources/{id}
//id=path, res=post
public Response updateResourceById(String id, Resource res) {
....
So a typical update call could be
POST host/resources/1234 -d={ some json for a resource }
Now i don't want every user to have all rights for every reosurce, so i would
need to add some info about the user who is doing a request.
For this i was thinking to use some JSON Token with some payload (or any user info at all). But i was wondering how to send this token correctly in a RESTful API.
My first idea would be to change the code to something like this:
//id=path, token=post
public Response updateResourceById(String id, Token token) {
...
The endpoint would not change only the POST data.
Would this be correct or are there other approaches?
Edit: Also possible would be sending the Token via HTTP Header.

Sending credentials in HTTP
In HTTP, the credentials should be sent in the standard HTTP Authorization header.
Have a look at the RFC 7235, the current reference for authentication in HTTP 1.1:
4.2. Authorization
The Authorization header field allows a user agent to authenticate
itself with an origin server -- usually, but not necessarily, after
receiving a 401 (Unauthorized) response. Its value consists of
credentials containing the authentication information of the user
agent for the realm of the resource being requested.
Authorization = credentials
[...]
Please note that the name of this HTTP header is unfortunate because it carries authentication data instead of authorization. Anyways, this is the standard header for sending credentials.
In a token based authentication, the tokens are credentials. In this approach, hard credentials such as username and password are exchanged for a token that is sent in each request to identify a user.
It never hurts to say that you should use HTTPS when sending sensitive data, such as credentials, over the wire. HTTPS will protect your application against the man-in-the-middle attack.
Reading the authentication token in JAX-RS
You can read the Authorization header in a JAX-RS application as following and then check if the token is valid:
#GET
public Response myMethod(#HeaderParam("Authorization") String token) {
...
}
However, a better approach would be using a ContainerRequestFilter, keeping your endpoints leans and focused on the business logic. For more information on token based authentication and on how to use a ContainerRequestFilter, have a look at this question.

Does it needs to pass username:password combination in any request with basic auth?

I confused with basic http authorization. It is needed to send every request to server with Authorization header or just first one and after that browser rember auth tokens like session id?

You have to send the Authorization header on each request. But for example Chrome remembers the auth tokens and sends it automatically on each request.

Using basic authentication, every request needs to have an Authorization HTTP header in the format:
Authorization: Basic <base64(username:password)>
where the username and password are concatenated using a colon (':') and the resulting string is base64 encoded.
If the Authorization header is not part of the request, or the credentials inside are not valid, the server should respond with an HTTP 401 Unauthorized response and include a HTTP header like:
WWW-Authenticate: Basic realm="myRealm"
Basic authentication is an implicit authentication scheme, so after the user enters valid credential, the browser will send them along with each page request.
For AJAX requests you'll need to attach this header from code. However, you really should not use basic authentication to protect an API, for a number of reasons:
You'd force the client to hold those credentials in code, where they can easily be stolen.
You must use HTTPS with basic authentication as base64 encoding gives no protection of the credentials at all.
Username/password combinations are usually valid much longer than an access token, thereby increasing the risk if they get stolen.
Password validation should be a slow process to mitigate brute force attacks, where token validation is just verifying a digital signature.
Having to send the username/password over the wire every time increases the attack surface for someone trying to break the encryption.
Better alternatives to protect web APIs are token based authentication schemes like OAuth2 or HMAC based authentication schemes like Hawk or AWS

Ya that's correct , so for first time when user logs in , his credentials are verified against some data , if correct , a auth token is generated.
Auth token is pretty much a self contained entity (which stores some data signed with a key)
this token gets stores at client side(usually along with a refresh token)
for all subsequent requests , this token is kept in Authorization header(Bearer+token)
When server receives this token , it decrypts it with the key , which it used earlier to sign that token. And uses that stored data
If that auth token is expired , refresh token comes into play.
some links to begin with
On a high level, how does OAuth 2 work?
and jwt.io to get the feel of tokens

CSRF Protection: Methods to send CSRF token for each request

My initial code generated tokens for the requests that could alter state of my database, like CRUD operations. The token was generated for each request. Sent to client side in JSON-format along with other data and I expected this token to be returned with the request and changed it after completion of the request. But, as I implemented it to only parts of my code (CRUD operations), I was told to redo it and make it web-app wide. I think the best way to do this is with filters.
My problem is, how do I make the client send "the token" for each request? Do I set it in cookies? What are my options? Please advice.

best way is , all links should be GET request, and within get requests no modification should be made to application state. So for GET requests there will be no need for CSRF tokens.
For POST request s which make modifications in application state you have to generate, csrf hidden fields in your forms and validate the token in server during form submit.

passing parameter in http header with REST service

Right now i'm using java to build rest service, and trying to use spring security to securing my service.
I have a few parameter that server needs to process the service (ex: application ID, username, password, consumer ID) . For username and password, I put in on http header "authorization", encoded with base64. Is there a way to put another parameters above (ex. AppID, consID) into http header?
Some sample of code would help, thanks.

You can put whatever you want in a whatever header you like. You can create custom headers. So you can have a App-Id header where you pass the appId. Alternatively you can pass those as parameters in the URL. That way you'll get rid of the option that some (stupid) proxy trims your headers.
Btw, I would suggest not to send the password, unless you are using https. Generally, I can recommend two similar scenarios:
use OAuth - let the user grant access to the API client via the OAuth dance. The client ends up with a token which it uses on each request.
use a custom, simplified token scheme - login once (with username and password, over https), and send a short-lived token in response. Each subsequent request can be made over an unsecured connection by providing the token, and (optionally) some HMAC of the request parameters, using a consumer secret as a key, so that you can verify the client is legit.