misc_conv(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | STANDARDS | COLOPHON

MISC_CONV(3)                Linux-PAM Manual                MISC_CONV(3)

NAME         top

       misc_conv - text based conversation function

SYNOPSIS         top

       #include <security/pam_misc.h>

       int misc_conv(int num_msg, const struct pam_message **msgm,
                     struct pam_response **response, void *appdata_ptr);

DESCRIPTION         top

       The misc_conv function is part of libpam_misc and not of the
       standard libpam library. This function will prompt the user with
       the appropriate comments and obtain the appropriate inputs as
       directed by authentication modules.

       In addition to simply slotting into the appropriate pam_conv(3),
       this function provides some time-out facilities. The function
       exports five variables that can be used by an application
       programmer to limit the amount of time this conversation function
       will spend waiting for the user to type something. The five
       variables are as follows:

       time_t pam_misc_conv_warn_time;
           This variable contains the time (as returned by time(2)) that
           the user should be first warned that the clock is ticking. By
           default it has the value 0, which indicates that no such
           warning will be given. The application may set its value to
           sometime in the future, but this should be done prior to
           passing control to the Linux-PAM library.

       const char *pam_misc_conv_warn_line;
           Used in conjunction with pam_misc_conv_warn_time, this
           variable is a pointer to the string that will be displayed
           when it becomes time to warn the user that the timeout is
           approaching. Its default value is a translated version of
           “...Time is running out...”, but this can be changed by the
           application prior to passing control to Linux-PAM.

       time_t pam_misc_conv_die_time;
           This variable contains the time (as returned by time(2)) that
           the will time out. By default it has the value 0, which
           indicates that the conversation function will not timeout.
           The application may set its value to sometime in the future,
           but this should be done prior to passing control to the
           Linux-PAM library.

       const char *pam_misc_conv_die_line;
           Used in conjunction with pam_misc_conv_die_time, this
           variable is a pointer to the string that will be displayed
           when the conversation times out. Its default value is a
           translated version of “...Sorry, your time is up!”, but this
           can be changed by the application prior to passing control to
           Linux-PAM.

       int pam_misc_conv_died;
           Following a return from the Linux-PAM library, the value of
           this variable indicates whether the conversation has timed
           out. A value of 1 indicates the time-out occurred.

       The following two function pointers are available for supporting
       binary prompts in the conversation function. They are optimized
       for the current incarnation of the libpamc library and are
       subject to change.

       int (*pam_binary_handler_fn)(void *appdata, pamc_bp_t *prompt_p);
           This function pointer is initialized to NULL but can be
           filled with a function that provides machine-machine (hidden)
           message exchange. It is intended for use with hidden
           authentication protocols such as RSA or Diffie-Hellman key
           exchanges. (This is still under development.)

       int (*pam_binary_handler_free)(void *appdata, pamc_bp_t
       *delete_me);
           This function pointer is initialized to
           PAM_BP_RENEW(delete_me, 0, 0), but can be redefined as
           desired by the application.

SEE ALSO         top

       pam_conv(3), pam(8)

STANDARDS         top

       The misc_conv function is part of the libpam_misc Library and not
       defined in any standard.

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 project's upstream Git repository
       ⟨https://github.com/linux-pam/linux-pam.git⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-12-18.)  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               12/22/2023                   MISC_CONV(3)