pam_get_item(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | COLOPHON

PAM_GET_ITEM(3)             Linux-PAM Manual             PAM_GET_ITEM(3)

NAME         top

       pam_get_item - getting PAM informations

SYNOPSIS         top

       #include <security/pam_modules.h>

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

DESCRIPTION         top

       The pam_get_item function allows applications and PAM service
       modules to access and retrieve PAM informations 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         top

       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         top

       pam_set_item(3), pam_strerror(3)

COLOPHON         top

       This page is part of the linux-pam (Pluggable Authentication
       Modules for Linux) project.  Information about the project can be
       found at ⟨http://www.linux-pam.org/⟩.  If you have a bug report
       for this manual page, see ⟨//www.linux-pam.org/⟩.  This page was
       obtained from the tarball Linux-PAM-1.3.0.tar.bz2 fetched from
       ⟨http://www.linux-pam.org/library/⟩ on 2021-04-01.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

Linux-PAM Manual               04/01/2016                PAM_GET_ITEM(3)

Pages that refer to this page: pam(3)pam_authenticate(3)pam_chauthtok(3)pam_conv(3)pam_end(3)pam_fail_delay(3)pam_get_user(3)pam_set_item(3)pam_start(3)pam_xauth_data(3)access.conf(5)