NetBSD-5.0.2/dist/openpam/lib/openpam_ttyconv.c
/*-
* Copyright (c) 2002-2003 Networks Associates Technology, Inc.
* Copyright (c) 2004-2007 Dag-Erling Smørgrav
* All rights reserved.
*
* This software was developed for the FreeBSD Project by ThinkSec AS and
* Network Associates Laboratories, the Security Research Division of
* Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: openpam_ttyconv.c,v 1.11 2008/01/27 01:23:00 christos Exp $
*/
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <paths.h>
#include <security/pam_appl.h>
#include "openpam_impl.h"
int openpam_ttyconv_timeout = 0;
static void
timeout(int sig)
{
/*LINTED unused*/
(void)sig;
}
static char *
prompt(const char *msg, FILE *infp, FILE *outfp, FILE *errfp)
{
char buf[PAM_MAX_RESP_SIZE];
struct sigaction action, saved_action;
sigset_t saved_sigset, sigs;
unsigned int saved_alarm;
int eof, error, fd;
size_t len;
char *retval;
char ch;
saved_alarm = 0;
sigemptyset(&sigs);
sigaddset(&sigs, SIGINT);
sigaddset(&sigs, SIGTSTP);
sigprocmask(SIG_SETMASK, &sigs, &saved_sigset);
action.sa_handler = &timeout;
action.sa_flags = 0;
sigemptyset(&action.sa_mask);
sigaction(SIGALRM, &action, &saved_action);
fputs(msg, outfp);
fflush(outfp);
#ifdef HAVE_FPURGE
fpurge(infp);
#endif
fd = fileno(infp);
buf[0] = '\0';
eof = error = 0;
saved_alarm = 0;
if (openpam_ttyconv_timeout >= 0)
saved_alarm = alarm((unsigned int)openpam_ttyconv_timeout);
ch = '\0';
for (len = 0; ch != '\n' && !eof && !error; ++len) {
switch (read(fd, &ch, (size_t)1)) {
case 1:
if (len < PAM_MAX_RESP_SIZE - 1) {
buf[len + 1] = '\0';
buf[len] = ch;
}
break;
case 0:
eof = 1;
break;
default:
error = errno;
break;
}
}
if (openpam_ttyconv_timeout >= 0)
alarm(0);
sigaction(SIGALRM, &saved_action, NULL);
sigprocmask(SIG_SETMASK, &saved_sigset, NULL);
if (saved_alarm > 0)
alarm(saved_alarm);
if (error == EINTR)
fputs(" timeout!", errfp);
if (error || eof) {
fputs("\n", errfp);
memset(buf, 0, sizeof(buf));
return (NULL);
}
/* trim trailing whitespace */
for (len = strlen(buf); len > 0; --len)
if (buf[len - 1] != '\r' && buf[len - 1] != '\n')
break;
buf[len] = '\0';
retval = strdup(buf);
memset(buf, 0, sizeof(buf));
return (retval);
}
static char *
prompt_echo_off(const char *msg, FILE *infp, FILE *outfp, FILE *errfp)
{
struct termios tattr;
tcflag_t lflag;
char *ret;
int fd;
fd = fileno(infp);
if (tcgetattr(fd, &tattr) != 0) {
openpam_log(PAM_LOG_ERROR, "tcgetattr(): %m");
return (NULL);
}
lflag = tattr.c_lflag;
tattr.c_lflag &= ~ECHO;
if (tcsetattr(fd, TCSAFLUSH, &tattr) != 0) {
openpam_log(PAM_LOG_ERROR, "tcsetattr(): %m");
return (NULL);
}
ret = prompt(msg, infp, outfp, errfp);
tattr.c_lflag = lflag;
(void)tcsetattr(fd, TCSANOW, &tattr);
if (ret != NULL)
fputs("\n", outfp);
return (ret);
}
/*
* OpenPAM extension
*
* Simple tty-based conversation function
*/
int
openpam_ttyconv(int n,
const struct pam_message **msg,
struct pam_response **resp,
void *data)
{
struct pam_response *aresp;
int i;
FILE *infp, *outfp, *errfp;
ENTER();
/*LINTED unused*/
(void)data;
if (n <= 0 || n > PAM_MAX_NUM_MSG)
RETURNC(PAM_CONV_ERR);
if ((aresp = calloc((size_t)n, sizeof *aresp)) == NULL)
RETURNC(PAM_BUF_ERR);
/*
* read and write to /dev/tty if possible; else read from
* stdin and write to stderr.
*/
if ((outfp = infp = errfp = fopen(_PATH_TTY, "w+")) == NULL) {
errfp = stderr;
outfp = stderr;
infp = stdin;
}
for (i = 0; i < n; ++i) {
aresp[i].resp_retcode = 0;
aresp[i].resp = NULL;
switch (msg[i]->msg_style) {
case PAM_PROMPT_ECHO_OFF:
aresp[i].resp = prompt_echo_off(msg[i]->msg, infp,
outfp, errfp);
if (aresp[i].resp == NULL)
goto fail;
break;
case PAM_PROMPT_ECHO_ON:
aresp[i].resp = prompt(msg[i]->msg, infp, outfp, errfp);
if (aresp[i].resp == NULL)
goto fail;
break;
case PAM_ERROR_MSG:
fputs(msg[i]->msg, errfp);
if (strlen(msg[i]->msg) > 0 &&
msg[i]->msg[strlen(msg[i]->msg) - 1] != '\n')
fputc('\n', errfp);
break;
case PAM_TEXT_INFO:
fputs(msg[i]->msg, outfp);
if (strlen(msg[i]->msg) > 0 &&
msg[i]->msg[strlen(msg[i]->msg) - 1] != '\n')
fputc('\n', outfp);
break;
default:
goto fail;
}
}
if (infp != stdin)
(void)fclose(infp);
*resp = aresp;
RETURNC(PAM_SUCCESS);
fail:
if (infp != stdin)
(void)fclose(infp);
for (i = 0; i < n; ++i) {
if (aresp[i].resp != NULL) {
memset(aresp[i].resp, 0, strlen(aresp[i].resp));
FREE(aresp[i].resp);
}
}
memset(aresp, 0, n * sizeof *aresp);
FREE(aresp);
*resp = NULL;
RETURNC(PAM_CONV_ERR);
/*NOTREACHED*/
}
/*
* Error codes:
*
* PAM_SYSTEM_ERR
* PAM_BUF_ERR
* PAM_CONV_ERR
*/
/**
* The =openpam_ttyconv function is a standard conversation function
* suitable for use on TTY devices.
* It should be adequate for the needs of most text-based interactive
* programs.
*
* The =openpam_ttyconv function displays a prompt to, and reads in a
* password from /dev/tty. If this file is not accessible, =openpam_ttyconv
* displays the prompt on the standard error output and reads from the
* standard input.
*
* The =openpam_ttyconv function allows the application to specify a
* timeout for user input by setting the global integer variable
* :openpam_ttyconv_timeout to the length of the timeout in seconds.
*
* >openpam_nullconv
* >pam_prompt
* >pam_vprompt
* >getpass
*/