openpam_nullconv(3) on FreeBSD
The text 18c5eb88ca65, as FreeBSD 9.1-RELEASE, FreeBSD 9.0-RELEASE, FreeBSD 8.4-RELEASE, FreeBSD 8.3-RELEASE, FreeBSD 8.2-RELEASE, FreeBSD 8.1-RELEASE, FreeBSD 8.0-RELEASE, FreeBSD 7.4-RELEASE, FreeBSD 7.3-RELEASE, FreeBSD 7.2-RELEASE, FreeBSD 7.1-RELEASE, FreeBSD 6.4-RELEASE shipped it.
null conversation function