Sftp login does not write to /var/log/wtmp

I have a script on my apache box that locks out users that dont login within 60 days. It has always worked just fine but we recently switched to using sftp. Unfortunately sftp does not write an entry to /var/log/wtmp when the user authenticates, so when i run the last command, they dont show up.

How do I handle this situation assuming I am unable to move away from sftp? Is there a way to add something in Pam to make sftp write to var/log/wtmp?

Thanks in advance.

Sftp is a SSH subsystem. While SSH can make use of PAM doubt sftp can be made to. OTOH prior to using sftp a succesful logon with SSH is required. If you would grep the logs for the "sftp subsystem" message then within a range of -A5 or so you should find the users SSH login to correlate with.

Unspawn, thank you for the response. I'll try hacking a script together and I'll post what I come up with.