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<refentry id="misc_conv">
<refmeta>
<refentrytitle>misc_conv</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo class='setdesc'>Linux-PAM Manual</refmiscinfo>
</refmeta>
<refnamediv id="misc_conv-name">
<refname>misc_conv</refname>
<refpurpose>text based conversation function</refpurpose>
</refnamediv>
<!-- body begins here -->
<refsynopsisdiv>
<funcsynopsis id="misc_conv-synopsis">
<funcsynopsisinfo>#include <security/pam_misc.h></funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>misc_conv</function></funcdef>
<paramdef>int <parameter>num_msg</parameter></paramdef>
<paramdef>const struct pam_message **<parameter>msgm</parameter></paramdef>
<paramdef>struct pam_response **<parameter>response</parameter></paramdef>
<paramdef>void *<parameter>appdata_ptr</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 id='misc_conv-description'>
<title>DESCRIPTION</title>
<para>
The <function>misc_conv</function> function is part of
<command>libpam_misc</command> and not of the standard
<command>libpam</command> library. This function will prompt
the user with the appropriate comments and obtain the appropriate
inputs as directed by authentication modules.
</para>
<para>
In addition to simply slotting into the appropriate <citerefentry>
<refentrytitle>pam_conv</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>, 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 variabls are as follows:
</para>
<variablelist>
<varlistentry>
<term><type>time_t</type> <varname>pam_misc_conv_warn_time</varname>;</term>
<listitem>
<para>
This variable contains the <emphasis>time</emphasis> (as
returned by <citerefentry>
<refentrytitle>time</refentrytitle><manvolnum>2</manvolnum>
</citerefentry>) that the user should be first warned that
the clock is ticking. By default it has the value
<returnvalue>0</returnvalue>, 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 <emphasis>Linux-PAM</emphasis> library.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><type>const char *</type><varname>pam_misc_conv_warn_line</varname>;</term>
<listitem>
<para>
Used in conjuction with
<varname>pam_misc_conv_warn_time</varname>, 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
<quote>...Time is running out...</quote>, but this can be
changed by the application prior to passing control to
<emphasis>Linux-PAM</emphasis>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><type>time_t</type> <varname>pam_misc_conv_die_time</varname>;</term>
<listitem>
<para>
This variable contains the <emphasis>time</emphasis> (as
returned by <citerefentry>
<refentrytitle>time</refentrytitle><manvolnum>2</manvolnum>
</citerefentry>) that the will time out. By default it has
the value <returnvalue>0</returnvalue>, 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
<emphasis>Linux-PAM</emphasis> library.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><type>const char *</type><varname>pam_misc_conv_die_line</varname>;</term>
<listitem>
<para>
Used in conjuction with
<varname>pam_misc_conv_die_time</varname>, 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
<quote>...Sorry, your time is up!</quote>, but this can be
changed by the application prior to passing control to
<emphasis>Linux-PAM</emphasis>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><type>int</type> <varname>pam_misc_conv_died</varname>;</term>
<listitem>
<para>
Following a return from the <emphasis>Linux-PAM</emphasis>
libraray, the value of this variable indicates whether the
conversation has timed out. A value of
<returnvalue>1</returnvalue> indicates the time-out occurred.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The following two function pointers are available for supporting
binary prompts in the conversation function. They are optimized
for the current incarnation of the <command>libpamc</command>
library and are subject to change.
</para>
<variablelist>
<varlistentry>
<term>
<type>int</type> <varname>(*pam_binary_handler_fn)</varname>(<type>void *</type><varname>appdata</varname>, <type>pamc_bp_t *</type><varname>prompt_p</varname>);
</term>
<listitem>
<para>
This function pointer is initialized to
<returnvalue>NULL</returnvalue> 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.)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<type>int</type> <varname>(*pam_binary_handler_free)</varname>(<type>void *</type><varname>appdata</varname>, <type>pamc_bp_t *</type><varname>delete_me</varname>);
</term>
<listitem>
<para>
This function pointer is initialized to
<function>PAM_BP_RENEW(delete_me, 0, 0)</function>, but can be
redefined as desired by the application.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='misc_conv-see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>pam_conv</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>
</para>
</refsect1>
<refsect1 id='misc_conv-standards'>
<title>STANDARDS</title>
<para>
The <function>misc_conv</function> function is part of the
<command>libpam_misc</command> Library and not defined in any
standard.
</para>
</refsect1>
</refentry>