PAM_SERVICE

- The service name (which identifies that PAM stack that the PAM functions will use to authenticate the program).

PAM_USER

- The username of the entity under whose identity service will be given. That is, following authentication, PAM_USER identifies the local entity that gets to use the service. Note, this value can be mapped from something (eg., "anonymous") to something else (eg. "guest119") by any module in the PAM stack. As such an application should consult the value of PAM_USER after each call to a PAM function.

PAM_USER_PROMPT

- The string used when prompting for a user's name. The default value for this string is a localized version of "login: ".

PAM_TTY

- The terminal name prefixed by `/dev/` for device files. In the past, graphical X-based applications used to store the $DISPLAY variable here, but with the introduction of PAM_XDISPLAY this usage is deprecated.

PAM_RUSER

- The requesting user name: local name for a locally requesting user or a remote user name for a remote requesting user.

  Generally an application or module will attempt to supply the value that is most strongly authenticated (a local account before a remote one. The level of trust in this value is embodied in the actual authentication stack associated with the application, so it is ultimately at the discretion of the system administrator.

  PAM_RUSER@PAM_RHOST should always identify the requesting user. In some cases, PAM_RUSER may be NULL. In such situations, it is unclear who the requesting entity is.

PAM_RHOST

- The requesting hostname (the hostname of the machine from which the PAM_RUSER entity is requesting service). That is PAM_RUSER@PAM_RHOST does identify the requesting user. In some applications, PAM_RHOST may be NULL. In such situations, it is unclear where the authentication request is originating from.

PAM_AUTHTOK

- The authentication token (often a password). This token should be ignored by all module functions besides

  pam_sm_authenticate

  3 and

  pam_sm_chauthtok

  3 . In the former function it is used to pass the most recent authentication token from one stacked module to another. In the latter function the token is used for another purpose. It contains the currently active authentication token.

PAM_OLDAUTHTOK

- The old authentication token. This token should be ignored by all module functions except

  pam_sm_chauthtok

  3 .

PAM_CONV

- The pam_conv structure. See

  pam_conv

  3 .