diff options
Diffstat (limited to 'lib/openpam_ttyconv.c')
| -rw-r--r-- | lib/openpam_ttyconv.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/lib/openpam_ttyconv.c b/lib/openpam_ttyconv.c new file mode 100644 index 0000000..a6820b9 --- /dev/null +++ b/lib/openpam_ttyconv.c @@ -0,0 +1,248 @@ +/*- + * 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 408 2007-12-21 11:36:24Z des $ + */ + +#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 <security/pam_appl.h> + +#include "openpam_impl.h" + +int openpam_ttyconv_timeout = 0; + +static void +timeout(int sig) +{ + + (void)sig; +} + +static char * +prompt(const char *msg) +{ + char buf[PAM_MAX_RESP_SIZE]; + struct sigaction action, saved_action; + sigset_t saved_sigset, sigset; + unsigned int saved_alarm; + int eof, error, fd; + size_t len; + char *retval; + char ch; + + sigemptyset(&sigset); + sigaddset(&sigset, SIGINT); + sigaddset(&sigset, SIGTSTP); + sigprocmask(SIG_SETMASK, &sigset, &saved_sigset); + action.sa_handler = &timeout; + action.sa_flags = 0; + sigemptyset(&action.sa_mask); + sigaction(SIGALRM, &action, &saved_action); + fputs(msg, stdout); + fflush(stdout); +#ifdef HAVE_FPURGE + fpurge(stdin); +#endif + fd = fileno(stdin); + buf[0] = '\0'; + eof = error = 0; + saved_alarm = 0; + if (openpam_ttyconv_timeout >= 0) + saved_alarm = alarm(openpam_ttyconv_timeout); + ch = '\0'; + for (len = 0; ch != '\n' && !eof && !error; ++len) { + switch (read(fd, &ch, 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!", stderr); + if (error || eof) { + fputs("\n", stderr); + 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) +{ + struct termios tattr; + tcflag_t lflag; + char *ret; + int fd; + + fd = fileno(stdin); + 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); + tattr.c_lflag = lflag; + (void)tcsetattr(fd, TCSANOW, &tattr); + if (ret != NULL) + fputs("\n", stdout); + 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; + + ENTER(); + (void)data; + if (n <= 0 || n > PAM_MAX_NUM_MSG) + RETURNC(PAM_CONV_ERR); + if ((aresp = calloc(n, sizeof *aresp)) == NULL) + RETURNC(PAM_BUF_ERR); + 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); + if (aresp[i].resp == NULL) + goto fail; + break; + case PAM_PROMPT_ECHO_ON: + aresp[i].resp = prompt(msg[i]->msg); + if (aresp[i].resp == NULL) + goto fail; + break; + case PAM_ERROR_MSG: + fputs(msg[i]->msg, stderr); + if (strlen(msg[i]->msg) > 0 && + msg[i]->msg[strlen(msg[i]->msg) - 1] != '\n') + fputc('\n', stderr); + break; + case PAM_TEXT_INFO: + fputs(msg[i]->msg, stdout); + if (strlen(msg[i]->msg) > 0 && + msg[i]->msg[strlen(msg[i]->msg) - 1] != '\n') + fputc('\n', stdout); + break; + default: + goto fail; + } + } + *resp = aresp; + RETURNC(PAM_SUCCESS); + fail: + 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); +} + +/* + * 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 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 + */ |
