Java RESTful client [RESTEasy or Apache HttpClient] - NTLM on the other side

Question

How to call RESTful webservice (from Java - using RESTEasy/Apache HttpClient) which requires NTLM authentication within Active Directory, without necessity of entering user data again (domain, username, password) - user is already authenticated in Windows?

GET http://some_server/restapi/books

This works perfectly from web browsers or even java.net.URL library - user is not getting prompted for credentials, no 401 authentication errors - simply 200 OK is returned.

How to do the same using Apache HttpClient or RESTEasy client?

Answer 1

You can do that with this structure;

1. When user first enter username and password, you can check user detail on active directory and if success, create an access_token by using username and password. It may be sha-256 encryption(Refer here for creating sha-256)
2. Save that access_token to your db and give it an expire time.
3. After successful access_token creation, respond that access token to user.
4. From now, you can use access_token for service requests

You need to save access token on client side like local storage. Same as if you are useing http client, you can give that access_token in header.