pg_shadow and pgcrypto

Hi all,

I'm currently performing a hash check for password verification. I'm
generating an md5 hash or checking for plain text in pg_shadow. However,
outside of these two "out-of-the-box" options, what if someone is using
pg-crypto or any other PAM ? How can I differentiate between say md5 and
pgcrypto ? I see the md5 is prefixed in hash in pg_shadow. I was
wondering what other prefixes may exist, say for pgcrypto. If you have an
examples of what a pgcrypto or any other PAM hash would look like (or what
they would at least begin with), that would be great.

Thanks,
Frank

Frank Cavaliero
Database Administrator
IBM Infosphere Guardium