NAME

       pam_get_item - getting PAM information

SYNOPSIS

       #include <security/pam_modules.h>

       int pam_get_item(const pam_handle_t *pamh, int item_type, const void **item);

DESCRIPTION

       The pam_get_item function allows applications and PAM service modules to access and
       retrieve PAM information of item_type. Upon successful return, item contains a pointer to
       the value of the corresponding item. Note, this is a pointer to the actual data and should
       not be free()'ed or over-written! The following values are supported for item_type:

       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/ if it is a device file; for graphical, X-based,
           applications the value for this item should be the $DISPLAY variable.

       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).

       The following additional items are specific to Linux-PAM and should not be used in
       portable applications:

       PAM_FAIL_DELAY
           A function pointer to redirect centrally managed failure delays. See
           pam_fail_delay(3).

       PAM_XDISPLAY
           The name of the X display. For graphical, X-based applications the value for this item
           should be the $DISPLAY variable. This value may be used independently of PAM_TTY for
           passing the name of the display.

       PAM_XAUTHDATA
           A pointer to a structure containing the X authentication data required to make a
           connection to the display specified by PAM_XDISPLAY, if such information is necessary.
           See pam_xauth_data(3).

       PAM_AUTHTOK_TYPE
           The default action is for the module to use the following prompts when requesting
           passwords: "New UNIX password: " and "Retype UNIX password: ". The example word UNIX
           can be replaced with this item, by default it is empty. This item is used by
           pam_get_authtok(3).

       If a service module wishes to obtain the name of the user, it should not use this
       function, but instead perform a call to pam_get_user(3).

       Only a service module is privileged to read the authentication tokens, PAM_AUTHTOK and
       PAM_OLDAUTHTOK.

RETURN VALUES

       PAM_BAD_ITEM
           The application attempted to set an undefined or inaccessible item.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_PERM_DENIED
           The value of item was NULL.

       PAM_SUCCESS
           Data was successful updated.

       PAM_SYSTEM_ERR
           The pam_handle_t passed as first argument was invalid.

SEE ALSO

       pam_set_item(3), pam_strerror(3)