It expects the application to put the password into a PAM environment variable. The source is found in reauth.tar.gz . The other one is a clone of kpasswd. I've taken passwd from the SimplePAMApps-0.54 package and changed it to resemble Transarc's real kpasswd as much as possible. It accepts the same options and interactions as the original.
Source code is found in kpasswd.tar.gz .
This one isn't completely pammified. The original package is a radius daemon with its own user and password management. Only as a supplement you can configure that the daemon does the normal UNIX authentication verification. And this part is replaced by calls to the PAM authentication and account management functions. Source code is found in radius-1.16.1.pam1.tar.gz .