misc_conv
3
Linux-PAM Manual
misc_conv
text based conversation function
#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_conv3
, 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
time2
) 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
time2
) 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_conv3
,
pam8
STANDARDS
The misc_conv function is part of the
libpam_misc Library and not defined in any
standard.