The implemented PAM protocol is based on the following steps

1 . AUTH_PLUG_REQ_AN is sent by passing a context containing a_user, a_pw and a_ttl (defaulted to 60)

2 . irods server responds with a temporary password

3 . A a new connection is created (a combination of disconnect + connect).

4 . The temporary password is used to login as a native protocol

To use PAM set authentication_scheme='pam' when creating the iRODSSession object

iRODSSession(user='yourPAMuser', password='yourPAMpassword, authentication_scheme='pam', [...])

As a plus:
- created a generic AuthPluginMessage to replace the GSIAuthMessage
- added more constants for better readability