This module intercepts the user's name and password. If the name is ftp or anonymous, the user's password is broken up at the @ delimiter into a PAM_RUSER and a PAM_RHOST part; these pam-items being set accordingly. The username (PAM_USER) is set to ftp. In this case the module succeeds. Alternatively, the module sets the PAM_AUTHTOK item with the entered password and fails.
Add the following line to /etc/pam.d/ftpd to handle ftp style anonymous login:
# # ftpd; add ftp-specifics. These lines enable anonymous ftp over # standard UN*X access (the listfile entry blocks access to # users listed in /etc/ftpusers) # auth sufficient pam_ftp.so auth required pam_unix.so use_first_pass auth required pam_listfile.so \ onerr=succeed item=user sense=deny file=/etc/ftpusers
pam_ftp was written by Andrew G. Morgan <email@example.com>.