REQ003.UC001 Obtain tokens using Password Credentials Grant

Preconditions:

• User enters login and password into the remote client
• Remote client is registered in the portal and is initialized with client_id

Events flow:

1. Client requests portal authorization endpoint
2. Portal authenticates the client using the provided user credentials
3. Portal generates Access Token and Refresh Token and returns to client

Postconditions:

• Client application receives valid Access Token and Refresh Token, Access Token and Refresh Token are saved on the portal side
• Or client application receives an error when the tokens cannot be granted

RFC: https://tools.ietf.org/html/rfc6749#section-4.3