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/*-
* Copyright (c) 2001,2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by ThinkSec AS and
* NAI Labs, 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/openpam.h>
#define ENV_ITEM(n) { (n), #n }
static struct {
int item;
const char *name;
} env_items[] = {
ENV_ITEM(PAM_SERVICE),
ENV_ITEM(PAM_USER),
ENV_ITEM(PAM_TTY),
ENV_ITEM(PAM_RHOST),
ENV_ITEM(PAM_RUSER),
};
static int
_pam_exec(pam_handle_t *pamh __unused, int flags __unused,
int argc, const char *argv[])
{
int childerr, envlen, i, nitems, pam_err, status;
char *env, **envlist, **tmp;
pid_t pid;
if (argc < 1)
return (PAM_SERVICE_ERR);
/*
* XXX For additional credit, divert child's stdin/stdout/stderr
* to the conversation function.
*/
/*
* Set up the child's environment list. It consists of the PAM
* environment, plus a few hand-picked PAM items.
*/
envlist = pam_getenvlist(pamh);
for (envlen = 0; envlist[envlen] != NULL; ++envlen)
/* nothing */ ;
nitems = sizeof(env_items) / sizeof(*env_items);
tmp = realloc(envlist, (envlen + nitems + 1) * sizeof(*envlist));
if (tmp == NULL) {
openpam_free_envlist(envlist);
return (PAM_BUF_ERR);
}
envlist = tmp;
for (i = 0; i < nitems; ++i) {
const void *item;
char *envstr;
pam_err = pam_get_item(pamh, env_items[i].item, &item);
if (pam_err != PAM_SUCCESS || item == NULL)
continue;
asprintf(&envstr, "%s=%s", env_items[i].name, item);
if (envstr == NULL) {
openpam_free_envlist(envlist);
return (PAM_BUF_ERR);
}
envlist[envlen++] = envstr;
envlist[envlen] = NULL;
}
/*
* Fork and run the command. By using vfork() instead of fork(),
* we can distinguish between an execve() failure and a non-zero
* exit code from the command.
*/
childerr = 0;
if ((pid = vfork()) == 0) {
execve(argv[0], (char * const *)argv, (char * const *)envlist);
childerr = errno;
_exit(1);
}
openpam_free_envlist(envlist);
if (pid == -1) {
openpam_log(PAM_LOG_ERROR, "vfork(): %m");
return (PAM_SYSTEM_ERR);
}
if (waitpid(pid, &status, 0) == -1) {
openpam_log(PAM_LOG_ERROR, "waitpid(): %m");
return (PAM_SYSTEM_ERR);
}
if (childerr != 0) {
openpam_log(PAM_LOG_ERROR, "execve(): %m");
return (PAM_SYSTEM_ERR);
}
if (WIFSIGNALED(status)) {
openpam_log(PAM_LOG_ERROR, "%s caught signal %d%s",
argv[0], WTERMSIG(status),
WCOREDUMP(status) ? " (core dumped)" : "");
return (PAM_SYSTEM_ERR);
}
if (!WIFEXITED(status)) {
openpam_log(PAM_LOG_ERROR, "unknown status 0x%x", status);
return (PAM_SYSTEM_ERR);
}
if (WEXITSTATUS(status) != 0) {
openpam_log(PAM_LOG_ERROR, "%s returned code %d",
argv[0], WEXITSTATUS(status));
return (PAM_SYSTEM_ERR);
}
return (PAM_SUCCESS);
}
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (_pam_exec(pamh, flags, argc, argv));
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (_pam_exec(pamh, flags, argc, argv));
}
PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (_pam_exec(pamh, flags, argc, argv));
}
PAM_EXTERN int
pam_sm_open_session(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (_pam_exec(pamh, flags, argc, argv));
}
PAM_EXTERN int
pam_sm_close_session(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (_pam_exec(pamh, flags, argc, argv));
}
PAM_EXTERN int
pam_sm_chauthtok(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (_pam_exec(pamh, flags, argc, argv));
}
PAM_MODULE_ENTRY("pam_exec");
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