Passwords with Keyboard Mode and APRSLink
As of November, 2015, both keyboard mode and the APRS gateway allow access with your Winlink password to the CMS using a simple challenge/response protocol. Your password is never sent in the clear over the air.
LOGIN
Send any command to initiate login. The CMS will respond with a challenge consisting of three digits who's values represent positions of characters within your password.
[RESPONSE]
This is a six character response to the login challenge. Respond with three password characters corresponding to the positions in the challenge plus three additional characters of your choosing (in any order). Example: Password is ABC123. Login challenge is: 425. You send '1B2AZ5'. ABZ21TY would also be valid since it contains the characters 1, B, and 2.
-Lee, K0QED
Winlink Development Team