[CentOS] Authenticate SCP against a mysql database?

Hi,

I'm using a mysql backend for authenticating vsftpd users on centos5. Is
it possible to have scp connections to this server also authenticate
against the same database? My guess is I can use pam in a way or two,
but I'm not very familiar with messing around with pam, so I was hoping
somebody had some info/solution.

I would also like to make sure it's only scp connections allowed for
these users stored in the db, while system user can login with ssh as
well.


/Christopher