ubpasschk – check password in/etc/shadow
Ubpasschk is a utility supplied to support the password checking functions of UNIBASE programs.
On the original Unix systems, the user’s password was stored encrypted in the file /etc/passwd. As this file is generally readable it became easy to run password cracking programs against the encrypted passwords.
Improved security, particularly C2, has produced a variation to this. In many systems a separate file,/etc/shadow, holds the encrypted passwords. As this is not generally readable, user level programs can’t run password cracking programs against it. This has lead to a problem for UNIBASE security as it can’t read/etc/shadow either.
Ubpasschk is a “setuidroot” program that takes two lines of input user login id and unencrypted password. The password is encrypted and checked against the password in/etc/shadow.
As exit code of O indicates a valid password.
UNIBASE programs will automatically call this program when and if required.