How to check checkpassword (this will launch “id” when authenticated):
% perl -e ‘printf “%s\0%s\0Y123456\0″,”real-user”,”password”‘ | /bin/checkpassword id 3<&0
And for cmd5checkpw:
% perl -e ‘printf “%s\0%s\0%s\0″,”user-in-plaintext”,”challenge-in-plaintext”, “response-in-hex” ‘ | /bin/cmd5checkpw id 3<&0
I’ve found that md5c.c distributed with cmd5checkpw doesn’t work correctly on x86_64 (amd64) architecture, and this problem can be solved by getting md5c.c + md5.h + config.h (we need to run ./configure script once) from fetchmail tarball.
Just one more thing: how to check cram-md5/plain/login auth by telnet (in Japanese):
http://nai.homelinux.net/telnet_smtp_auth.html