diff options
Diffstat (limited to 'Linux-PAM/modules/pam_unix/unix_chkpwd.c')
| -rw-r--r-- | Linux-PAM/modules/pam_unix/unix_chkpwd.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/Linux-PAM/modules/pam_unix/unix_chkpwd.c b/Linux-PAM/modules/pam_unix/unix_chkpwd.c new file mode 100644 index 00000000..11ac3aac --- /dev/null +++ b/Linux-PAM/modules/pam_unix/unix_chkpwd.c @@ -0,0 +1,184 @@ +/* + * This program is designed to run setuid(root) or with sufficient + * privilege to read all of the unix password databases. It is designed + * to provide a mechanism for the current user (defined by this + * process' uid) to verify their own password. + * + * The password is read from the standard input. The exit status of + * this program indicates whether the user is authenticated or not. + * + * Copyright information is located at the end of the file. + * + */ + +#include "config.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <syslog.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <pwd.h> +#include <shadow.h> +#include <signal.h> +#include <time.h> + +#include <security/_pam_types.h> +#include <security/_pam_macros.h> + +#include "passverify.h" + +static int _check_expiry(const char *uname) +{ + struct spwd *spent; + struct passwd *pwent; + int retval; + int daysleft; + + retval = get_account_info(uname, &pwent, &spent); + if (retval != PAM_SUCCESS) { + helper_log_err(LOG_ALERT, "could not obtain user info (%s)", uname); + printf("-1\n"); + return retval; + } + + if (spent == NULL) { + printf("-1\n"); + return retval; + } + + retval = check_shadow_expiry(spent, &daysleft); + printf("%d\n", daysleft); + return retval; +} + +int main(int argc, char *argv[]) +{ + char pass[MAXPASS + 1]; + char *option; + int npass, nullok; + int blankpass = 0; + int retval = PAM_AUTH_ERR; + char *user; + char *passwords[] = { pass }; + + /* + * Catch or ignore as many signal as possible. + */ + setup_signals(); + + /* + * we establish that this program is running with non-tty stdin. + * this is to discourage casual use. It does *NOT* prevent an + * intruder from repeatadly running this program to determine the + * password of the current user (brute force attack, but one for + * which the attacker must already have gained access to the user's + * account). + */ + + if (isatty(STDIN_FILENO) || argc != 3 ) { + helper_log_err(LOG_NOTICE + ,"inappropriate use of Unix helper binary [UID=%d]" + ,getuid()); + fprintf(stderr + ,"This binary is not designed for running in this way\n" + "-- the system administrator has been informed\n"); + sleep(10); /* this should discourage/annoy the user */ + return PAM_SYSTEM_ERR; + } + + /* + * Determine what the current user's name is. + * We must thus skip the check if the real uid is 0. + */ + if (getuid() == 0) { + user=argv[1]; + } + else { + user = getuidname(getuid()); + /* if the caller specifies the username, verify that user + matches it */ + if (strcmp(user, argv[1])) { + return PAM_AUTH_ERR; + } + } + + option=argv[2]; + + if (strcmp(option, "chkexpiry") == 0) + /* Check account information from the shadow file */ + return _check_expiry(argv[1]); + /* read the nullok/nonull option */ + else if (strcmp(option, "nullok") == 0) + nullok = 1; + else if (strcmp(option, "nonull") == 0) + nullok = 0; + else + return PAM_SYSTEM_ERR; + + /* read the password from stdin (a pipe from the pam_unix module) */ + + npass = read_passwords(STDIN_FILENO, 1, passwords); + + if (npass != 1) { /* is it a valid password? */ + helper_log_err(LOG_DEBUG, "no password supplied"); + *pass = '\0'; + } + + if (*pass == '\0') { + blankpass = 1; + } + + retval = helper_verify_password(user, pass, nullok); + + memset(pass, '\0', MAXPASS); /* clear memory of the password */ + + /* return pass or fail */ + + if (retval != PAM_SUCCESS) { + if (!nullok || !blankpass) + /* no need to log blank pass test */ + helper_log_err(LOG_NOTICE, "password check failed for user (%s)", user); + return PAM_AUTH_ERR; + } else { + return PAM_SUCCESS; + } +} + +/* + * Copyright (c) Andrew G. Morgan, 1996. All rights reserved + * Copyright (c) Red Hat, Inc., 2007,2008. 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. + */ |