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/*
* pam_unix authentication management
*
* Copyright Alexander O. Yuriev, 1996. All rights reserved.
* NIS+ support by Thorsten Kukuk <kukuk@weber.uni-paderborn.de>
* Copyright Jan Rękorajski, 1999. All rights reserved.
*
* 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, and the entire permission notice in its entirety,
* including the disclaimer of warranties.
* 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.
*
* ALTERNATIVELY, this product may be distributed under the terms of
* the GNU Public License, in which case the provisions of the GPL are
* required INSTEAD OF the above restrictions. (This clause is
* necessary due to a potential bad interaction between the GPL and
* the restrictions contained in a BSD-style copyright.)
*
* THIS SOFTWARE IS PROVIDED ``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 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 "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <syslog.h>
#include <security/_pam_macros.h>
#include <security/pam_modules.h>
#include <security/pam_ext.h>
#include "support.h"
/*
* PAM framework looks for these entry-points to pass control to the
* authentication module.
*/
/* Fun starts here :)
* pam_sm_authenticate() performs UNIX/shadow authentication
*
* First, if shadow support is available, attempt to perform
* authentication using shadow passwords. If shadow is not
* available, or user does not have a shadow password, fallback
* onto a normal UNIX authentication
*/
#define AUTH_RETURN \
do { \
D(("recording return code for next time [%d]", \
retval)); \
*ret_data = retval; \
pam_set_data(pamh, "unix_setcred_return", \
(void *) ret_data, setcred_free); \
D(("done. [%s]", pam_strerror(pamh, retval))); \
return retval; \
} while (0)
static void
setcred_free (pam_handle_t *pamh UNUSED, void *ptr, int err UNUSED)
{
if (ptr)
free (ptr);
}
int
pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
unsigned long long ctrl;
int retval, *ret_data = NULL;
const char *name;
const char *p;
D(("called."));
ctrl = _set_ctrl(pamh, flags, NULL, NULL, NULL, argc, argv);
/* Get a few bytes so we can pass our return value to
pam_sm_setcred() and pam_sm_acct_mgmt(). */
ret_data = malloc(sizeof(int));
if (!ret_data) {
D(("cannot malloc ret_data"));
pam_syslog(pamh, LOG_CRIT,
"pam_unix_auth: cannot allocate ret_data");
return PAM_BUF_ERR;
}
/* get the user'name' */
retval = pam_get_user(pamh, &name, NULL);
if (retval == PAM_SUCCESS) {
/*
* Various libraries at various times have had bugs related to
* '+' or '-' as the first character of a user name. Don't
* allow this characters here.
*/
if (name[0] == '-' || name[0] == '+') {
pam_syslog(pamh, LOG_NOTICE, "bad username [%s]", name);
retval = PAM_USER_UNKNOWN;
AUTH_RETURN;
}
if (on(UNIX_DEBUG, ctrl))
pam_syslog(pamh, LOG_DEBUG, "username [%s] obtained", name);
} else {
if (retval == PAM_CONV_AGAIN) {
D(("pam_get_user/conv() function is not ready yet"));
/* it is safe to resume this function so we translate this
* retval to the value that indicates we're happy to resume.
*/
retval = PAM_INCOMPLETE;
} else if (on(UNIX_DEBUG, ctrl)) {
pam_syslog(pamh, LOG_DEBUG, "could not obtain username");
}
AUTH_RETURN;
}
/* if this user does not have a password... */
if (_unix_blankpasswd(pamh, ctrl, name)) {
pam_syslog(pamh, LOG_DEBUG, "user [%s] has blank password; authenticated without it", name);
name = NULL;
retval = PAM_SUCCESS;
AUTH_RETURN;
}
/* get this user's authentication token */
retval = pam_get_authtok(pamh, PAM_AUTHTOK, &p , NULL);
if (retval != PAM_SUCCESS) {
if (retval != PAM_CONV_AGAIN) {
pam_syslog(pamh, LOG_CRIT,
"auth could not identify password for [%s]", name);
} else {
D(("conversation function is not ready yet"));
/*
* it is safe to resume this function so we translate this
* retval to the value that indicates we're happy to resume.
*/
retval = PAM_INCOMPLETE;
}
name = NULL;
AUTH_RETURN;
}
D(("user=%s, password=[%s]", name, p));
/* verify the password of this user */
retval = _unix_verify_password(pamh, name, p, ctrl);
name = p = NULL;
AUTH_RETURN;
}
/*
* The only thing _pam_set_credentials_unix() does is initialization of
* UNIX group IDs.
*
* Well, everybody but me on linux-pam is convinced that it should not
* initialize group IDs, so I am not doing it but don't say that I haven't
* warned you. -- AOY
*/
int
pam_sm_setcred (pam_handle_t *pamh, int flags,
int argc, const char **argv)
{
int retval;
const void *pretval = NULL;
unsigned long long ctrl;
D(("called."));
ctrl = _set_ctrl(pamh, flags, NULL, NULL, NULL, argc, argv);
retval = PAM_SUCCESS;
D(("recovering return code from auth call"));
/* We will only find something here if UNIX_LIKE_AUTH is set --
don't worry about an explicit check of argv. */
if (on(UNIX_LIKE_AUTH, ctrl)
&& pam_get_data(pamh, "unix_setcred_return", &pretval) == PAM_SUCCESS
&& pretval) {
retval = *(const int *)pretval;
pam_set_data(pamh, "unix_setcred_return", NULL, NULL);
D(("recovered data indicates that old retval was %d", retval));
}
return retval;
}
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