phpman > man > misc_conv(3)

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



NAME
       misc_conv - text based conversation function

SYNOPSIS
       #include <security/pam_misc.h>

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

DESCRIPTION
       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
       pam_conv(3), pam(7)

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



Linux-PAM Manual                             06/08/2020                                 MISC_CONV(3)