pam_misc: make length of misc_conv() configurable

Add --with-misc-conv-bufsize=<number> option to configure to allow
a longer buffer size for libpam_misc's misc_conv() function (it still
defaults to 512 bytes).

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

configure.ac

@@ -648,6 +648,13 @@ case "$enable_unix" in
   *) AC_MSG_ERROR([bad value $enable_unix for --enable-unix option]) ;;
 esac
 
+AC_ARG_WITH([misc-conv-bufsize],
+AS_HELP_STRING([--with-misc-conv-bufsize=<number>],
+    [Size of input buffer for libpam_misc's misc_conv() conversation function, default=512]),
+    [],
+    [with_misc_conv_bufsize=512])
+AC_DEFINE_UNQUOTED(PAM_MISC_CONV_BUFSIZE, $with_misc_conv_bufsize, [libpam_misc misc_conv() buffer size.])
+
 AM_CONDITIONAL([COND_BUILD_PAM_KEYINIT], [test "$have_key_syscalls" = 1])
 AM_CONDITIONAL([COND_BUILD_PAM_LASTLOG], [test "$ac_cv_func_logwtmp" = yes])
 AM_CONDITIONAL([COND_BUILD_PAM_NAMESPACE], [test "$ac_cv_func_unshare" = yes])

libpam_misc/misc_conv.c

@@ -18,7 +18,7 @@
 #include <security/pam_appl.h>
 #include <security/pam_misc.h>
 
-#define INPUTSIZE PAM_MAX_RESP_SIZE          /* maximum length of input+1 */
+#define INPUTSIZE PAM_MISC_CONV_BUFSIZE      /* maximum length of input+1 */
 #define CONV_ECHO_ON  1                            /* types of echo state */
 #define CONV_ECHO_OFF 0