/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright 1998 Juniper Networks, Inc.
* All rights reserved.
* Copyright (c) 2002-2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* Portions of 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>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <login_cap.h>
#include <netdb.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <syslog.h>
#include <time.h>
#include <unistd.h>
#include <libutil.h>
#ifdef YP
#include <ypclnt.h>
#endif
#define PAM_SM_AUTH
#define PAM_SM_ACCOUNT
#define PAM_SM_PASSWORD
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_mod_misc.h>
#define PASSWORD_HASH "md5"
#define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */
#define SALTSIZE 32
#define LOCKED_PREFIX "*LOCKED*"
#define LOCKED_PREFIX_LEN (sizeof(LOCKED_PREFIX) - 1)
static void makesalt(char [SALTSIZE + 1]);
static char password_hash[] = PASSWORD_HASH;
#define PAM_OPT_LOCAL_PASS "local_pass"
#define PAM_OPT_NIS_PASS "nis_pass"
/*
* authentication management
*/
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags,
int argc __unused, const char *argv[] __unused)
{
login_cap_t *lc;
struct passwd *pwd;
int retval;
const char *pass, *user, *realpw, *prompt;
const char *emptypasswd = "";
if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) {
user = getlogin();
} else {
retval = pam_get_user(pamh, &user, NULL);
if (retval != PAM_SUCCESS)
return (retval);
}
pwd = getpwnam(user);
PAM_LOG("Got user: %s", user);
if (pwd != NULL) {
PAM_LOG("Doing real authentication");
realpw = pwd->pw_passwd;
if (realpw[0] == '\0') {
if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) &&
openpam_get_option(pamh, PAM_OPT_NULLOK))
return (PAM_SUCCESS);
PAM_LOG("Password is empty, using fake password");
realpw = "*";
}
/*
* Check whether the saved password hash matches the one
* generated from an empty password - as opposed to empty
* saved password hash, which is handled above.
*/
if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) &&
openpam_get_option(pamh, PAM_OPT_EMPTYOK) &&
strcmp(crypt(emptypasswd, realpw), realpw) == 0)
return (PAM_SUCCESS);
lc = login_getpwclass(pwd);
} else {
PAM_LOG("Doing dummy authentication");
realpw = "*";
lc = login_getclass(NULL);
}
prompt = login_getcapstr(lc, "passwd_prompt", NULL, NULL);
retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, prompt);
login_close(lc);
if (retval != PAM_SUCCESS)
return (retval);
PAM_LOG("Got password");
if (strnlen(pass, _PASSWORD_LEN + 1) > _PASSWORD_LEN) {
PAM_LOG("Password is too long, using fake password");
realpw = "*";
}
if (strcmp(crypt(pass, realpw), realpw) == 0)
return (PAM_SUCCESS);
PAM_VERBOSE_ERROR("UNIX authentication refused");
return (PAM_AUTH_ERR);
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
return (PAM_SUCCESS);
}
/*
* account management
*/
PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
struct addrinfo hints, *res;
struct passwd *pwd;
struct timeval tp;
login_cap_t *lc;
time_t warntime;
int retval;
const char *user;
const void *rhost, *tty;
char rhostip[MAXHOSTNAMELEN] = "";
retval = pam_get_user(pamh, &user, NULL);
if (retval != PAM_SUCCESS)
return (retval);
if (user == NULL || (pwd = getpwnam(user)) == NULL)
return (PAM_SERVICE_ERR);
PAM_LOG("Got user: %s", user);
retval = pam_get_item(pamh, PAM_RHOST, &rhost);
if (retval != PAM_SUCCESS)
return (retval);
retval = pam_get_item(pamh, PAM_TTY, &tty);
if (retval != PAM_SUCCESS)
return (retval);
if (*pwd->pw_passwd == '\0' &&
(flags & PAM_DISALLOW_NULL_AUTHTOK) != 0)
return (PAM_NEW_AUTHTOK_REQD);
if (strncmp(pwd->pw_passwd, LOCKED_PREFIX, LOCKED_PREFIX_LEN) == 0)
return (PAM_AUTH_ERR);
lc = login_getpwclass(pwd);
if (lc == NULL) {
PAM_LOG("Unable to get login class for user %s", user);
return (PAM_SERVICE_ERR);
}
PAM_LOG("Got login_cap");
if (pwd->pw_change || pwd->pw_expire)
gettimeofday(&tp, NULL);
/*
* Check pw_expire before pw_change - no point in letting the
* user change the password on an expired account.
*/
if (pwd->pw_expire) {
warntime = login_getcaptime(lc, "warnexpire",
DEFAULT_WARN, DEFAULT_WARN);
if (tp.tv_sec >= pwd->pw_expire) {
login_close(lc);
return (PAM_ACCT_EXPIRED);
} else if (pwd->pw_expire - tp.tv_sec < warntime &&
(flags & PAM_SILENT) == 0) {
pam_error(pamh, "Warning: your account expires on %s",
ctime(&pwd->pw_expire));
}
}
retval = PAM_SUCCESS;
if (pwd->pw_change) {
warntime = login_getcaptime(lc, "warnpassword",
DEFAULT_WARN, DEFAULT_WARN);
if (tp.tv_sec >= pwd->pw_change) {
retval = PAM_NEW_AUTHTOK_REQD;
} else if (pwd->pw_change - tp.tv_sec < warntime &&
(flags & PAM_SILENT) == 0) {
pam_error(pamh, "Warning: your password expires on %s",
ctime(&pwd->pw_change));
}
}
/*
* From here on, we must leave retval untouched (unless we
* know we're going to fail), because we need to remember
* whether we're supposed to return PAM_SUCCESS or
* PAM_NEW_AUTHTOK_REQD.
*/
if (rhost && *(const char *)rhost != '\0') {
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
if (getaddrinfo(rhost, NULL, &hints, &res) == 0) {
getnameinfo(res->ai_addr, res->ai_addrlen,
rhostip, sizeof(rhostip), NULL, 0,
NI_NUMERICHOST);
}
if (res != NULL)
freeaddrinfo(res);
}
/*
* Check host / tty / time-of-day restrictions
*/
if (!auth_hostok(lc, rhost, rhostip) ||
!auth_ttyok(lc, tty) ||
!auth_timeok(lc, time(NULL)))
retval = PAM_AUTH_ERR;
login_close(lc);
return (retval);
}
/*
* password management
*
* standard Unix and NIS password changing
*/
PAM_EXTERN int
pam_sm_chauthtok(pam_handle_t *pamh, int flags,
int argc __unused, const char *argv[] __unused)
{
#ifdef YP
struct ypclnt *ypclnt;
const void *yp_domain, *yp_server;
#endif
char salt[SALTSIZE + 1];
login_cap_t *lc;
struct passwd *pwd, *old_pwd;
const char *user, *old_pass, *new_pass;
char *encrypted;
time_t passwordtime;
int pfd, tfd, retval;
if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF))
user = getlogin();
else {
retval = pam_get_user(pamh, &user, NULL);
if (retval != PAM_SUCCESS)
return (retval);
}
pwd = getpwnam(user);
if (pwd == NULL)
return (PAM_AUTHTOK_RECOVERY_ERR);
PAM_LOG("Got user: %s", user);
if (flags & PAM_PRELIM_CHECK) {
PAM_LOG("PRELIM round");
if (getuid() == 0 &&
(pwd->pw_fields & _PWF_SOURCE) == _PWF_FILES)
/* root doesn't need the old password */
return (pam_set_item(pamh, PAM_OLDAUTHTOK, ""));
#ifdef YP
if (getuid() == 0 &&
(pwd->pw_fields & _PWF_SOURCE) == _PWF_NIS) {
yp_domain = yp_server = NULL;
(void)pam_get_data(pamh, "yp_domain", &yp_domain);
(void)pam_get_data(pamh, "yp_server", &yp_server);
ypclnt = ypclnt_new(yp_domain, "passwd.byname", yp_server);
if (ypclnt == NULL)
return (PAM_BUF_ERR);
if (ypclnt_connect(ypclnt) == -1) {
ypclnt_free(ypclnt);
return (PAM_SERVICE_ERR);
}
retval = ypclnt_havepasswdd(ypclnt);
ypclnt_free(ypclnt);
if (retval == 1)
return (pam_set_item(pamh, PAM_OLDAUTHTOK, ""));
else if (retval == -1)
return (PAM_SERVICE_ERR);
}
#endif
if (pwd->pw_passwd[0] == '\0'
&& openpam_get_option(pamh, PAM_OPT_NULLOK)) {
/*
* No password case. XXX Are we giving too much away
* by not prompting for a password?
* XXX check PAM_DISALLOW_NULL_AUTHTOK
*/
old_pass = "";
retval = PAM_SUCCESS;
} else {
retval = pam_get_authtok(pamh,
PAM_OLDAUTHTOK, &old_pass, NULL);
if (retval != PAM_SUCCESS)
return (retval);
}
PAM_LOG("Got old password");
/* always encrypt first */
encrypted = crypt(old_pass, pwd->pw_passwd);
if (old_pass[0] == '\0' &&
!openpam_get_option(pamh, PAM_OPT_NULLOK))
return (PAM_PERM_DENIED);
if (strcmp(encrypted, pwd->pw_passwd) != 0)
return (PAM_PERM_DENIED);
}
else if (flags & PAM_UPDATE_AUTHTOK) {
PAM_LOG("UPDATE round");
retval = pam_get_authtok(pamh,
PAM_OLDAUTHTOK, &old_pass, NULL);
if (retval != PAM_SUCCESS)
return (retval);
PAM_LOG("Got old password");
/* get new password */
for (;;) {
retval = pam_get_authtok(pamh,
PAM_AUTHTOK, &new_pass, NULL);
if (retval != PAM_TRY_AGAIN)
break;
pam_error(pamh, "Mismatch; try again, EOF to quit.");
}
PAM_LOG("Got new password");
if (retval != PAM_SUCCESS) {
PAM_VERBOSE_ERROR("Unable to get new password");
return (retval);
}
if (getuid() != 0 && new_pass[0] == '\0' &&
!openpam_get_option(pamh, PAM_OPT_NULLOK))
return (PAM_PERM_DENIED);
if ((old_pwd = pw_dup(pwd)) == NULL)
return (PAM_BUF_ERR);
lc = login_getclass(pwd->pw_class);
if (login_setcryptfmt(lc, password_hash, NULL) == NULL)
openpam_log(PAM_LOG_ERROR,
"can't set password cipher, relying on default");
/* set password expiry date */
pwd->pw_change = 0;
passwordtime = login_getcaptime(lc, "passwordtime", 0, 0);
if (passwordtime > 0)
pwd->pw_change = time(NULL) + passwordtime;
login_close(lc);
makesalt(salt);
pwd->pw_passwd = crypt(new_pass, salt);
#ifdef YP
switch (old_pwd->pw_fields & _PWF_SOURCE) {
case _PWF_FILES:
#endif
retval = PAM_SERVICE_ERR;
if (pw_init(NULL, NULL))
openpam_log(PAM_LOG_ERROR, "pw_init() failed");
else if ((pfd = pw_lock()) == -1)
openpam_log(PAM_LOG_ERROR, "pw_lock() failed");
else if ((tfd = pw_tmp(-1)) == -1)
openpam_log(PAM_LOG_ERROR, "pw_tmp() failed");
else if (pw_copy(pfd, tfd, pwd, old_pwd) == -1)
openpam_log(PAM_LOG_ERROR, "pw_copy() failed");
else if (pw_mkdb(pwd->pw_name) == -1)
openpam_log(PAM_LOG_ERROR, "pw_mkdb() failed");
else
retval = PAM_SUCCESS;
pw_fini();
#ifdef YP
break;
case _PWF_NIS:
yp_domain = yp_server = NULL;
(void)pam_get_data(pamh, "yp_domain", &yp_domain);
(void)pam_get_data(pamh, "yp_server", &yp_server);
ypclnt = ypclnt_new(yp_domain,
"passwd.byname", yp_server);
if (ypclnt == NULL) {
retval = PAM_BUF_ERR;
} else if (ypclnt_connect(ypclnt) == -1 ||
ypclnt_passwd(ypclnt, pwd, old_pass) == -1) {
openpam_log(PAM_LOG_ERROR, "%s", ypclnt->error);
retval = PAM_SERVICE_ERR;
} else {
retval = PAM_SUCCESS;
}
ypclnt_free(ypclnt);
break;
default:
openpam_log(PAM_LOG_ERROR, "unsupported source 0x%x",
pwd->pw_fields & _PWF_SOURCE);
retval = PAM_SERVICE_ERR;
}
#endif
free(old_pwd);
}
else {
/* Very bad juju */
retval = PAM_ABORT;
PAM_LOG("Illegal 'flags'");
}
return (retval);
}
/* Mostly stolen from passwd(1)'s local_passwd.c - markm */
static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */
"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
static void
to64(char *s, long v, int n)
{
while (--n >= 0) {
*s++ = itoa64[v&0x3f];
v >>= 6;
}
}
/* Salt suitable for traditional DES and MD5 */
static void
makesalt(char salt[SALTSIZE + 1])
{
int i;
/* These are not really random numbers, they are just
* numbers that change to thwart construction of a
* dictionary.
*/
for (i = 0; i < SALTSIZE; i += 4)
to64(&salt[i], arc4random(), 4);
salt[SALTSIZE] = '\0';
}
PAM_MODULE_ENTRY("pam_unix");
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