diff options
Diffstat (limited to 'modules/pam_pwhistory/pam_pwhistory.c')
| -rw-r--r-- | modules/pam_pwhistory/pam_pwhistory.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/modules/pam_pwhistory/pam_pwhistory.c b/modules/pam_pwhistory/pam_pwhistory.c new file mode 100644 index 00000000..cf4fc078 --- /dev/null +++ b/modules/pam_pwhistory/pam_pwhistory.c @@ -0,0 +1,230 @@ +/* + * pam_pwhistory module + * + * Copyright (c) 2008, 2012 Thorsten Kukuk + * Author: Thorsten Kukuk <kukuk@thkukuk.de> + * + * 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. + */ + +#if defined(HAVE_CONFIG_H) +#include <config.h> +#endif + +#include <pwd.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <shadow.h> +#include <syslog.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include <security/pam_modules.h> +#include <security/pam_modutil.h> +#include <security/pam_ext.h> +#include <security/_pam_macros.h> + +#include "opasswd.h" +#include "pam_inline.h" + +#define DEFAULT_BUFLEN 2048 + +struct options_t { + int debug; + int enforce_for_root; + int remember; + int tries; +}; +typedef struct options_t options_t; + + +static void +parse_option (pam_handle_t *pamh, const char *argv, options_t *options) +{ + const char *str; + + if (strcasecmp (argv, "try_first_pass") == 0) + /* ignore */; + else if (strcasecmp (argv, "use_first_pass") == 0) + /* ignore */; + else if (strcasecmp (argv, "use_authtok") == 0) + /* ignore, handled by pam_get_authtok */; + else if (strcasecmp (argv, "debug") == 0) + options->debug = 1; + else if ((str = pam_str_skip_icase_prefix(argv, "remember=")) != NULL) + { + options->remember = strtol(str, NULL, 10); + if (options->remember < 0) + options->remember = 0; + if (options->remember > 400) + options->remember = 400; + } + else if ((str = pam_str_skip_icase_prefix(argv, "retry=")) != NULL) + { + options->tries = strtol(str, NULL, 10); + if (options->tries < 0) + options->tries = 1; + } + else if (strcasecmp (argv, "enforce_for_root") == 0) + options->enforce_for_root = 1; + else if (pam_str_skip_icase_prefix(argv, "authtok_type=") != NULL) + { /* ignore, for pam_get_authtok */; } + else + pam_syslog (pamh, LOG_ERR, "pam_pwhistory: unknown option: %s", argv); +} + + +/* This module saves the current crypted password in /etc/security/opasswd + and then compares the new password with all entries in this file. */ + +int +pam_sm_chauthtok (pam_handle_t *pamh, int flags, int argc, const char **argv) +{ + struct passwd *pwd; + const char *newpass; + const char *user; + int retval, tries; + options_t options; + + memset (&options, 0, sizeof (options)); + + /* Set some default values, which could be overwritten later. */ + options.remember = 10; + options.tries = 1; + + /* Parse parameters for module */ + for ( ; argc-- > 0; argv++) + parse_option (pamh, *argv, &options); + + if (options.debug) + pam_syslog (pamh, LOG_DEBUG, "pam_sm_chauthtok entered"); + + + if (options.remember == 0) + return PAM_IGNORE; + + retval = pam_get_user (pamh, &user, NULL); + if (retval != PAM_SUCCESS) + return retval; + + if (flags & PAM_PRELIM_CHECK) + { + if (options.debug) + pam_syslog (pamh, LOG_DEBUG, + "pam_sm_chauthtok(PAM_PRELIM_CHECK)"); + + return PAM_SUCCESS; + } + + pwd = pam_modutil_getpwnam (pamh, user); + if (pwd == NULL) + return PAM_USER_UNKNOWN; + + if ((strcmp(pwd->pw_passwd, "x") == 0) || + ((pwd->pw_passwd[0] == '#') && + (pwd->pw_passwd[1] == '#') && + (strcmp(pwd->pw_name, pwd->pw_passwd + 2) == 0))) + { + struct spwd *spw = pam_modutil_getspnam (pamh, user); + if (spw == NULL) + return PAM_USER_UNKNOWN; + + retval = save_old_pass (pamh, user, pwd->pw_uid, spw->sp_pwdp, + options.remember, options.debug); + if (retval != PAM_SUCCESS) + return retval; + } + else + { + retval = save_old_pass (pamh, user, pwd->pw_uid, pwd->pw_passwd, + options.remember, options.debug); + if (retval != PAM_SUCCESS) + return retval; + } + + newpass = NULL; + tries = 0; + while ((newpass == NULL) && (tries < options.tries)) + { + retval = pam_get_authtok (pamh, PAM_AUTHTOK, &newpass, NULL); + if (retval != PAM_SUCCESS && retval != PAM_TRY_AGAIN) + { + if (retval == PAM_CONV_AGAIN) + retval = PAM_INCOMPLETE; + return retval; + } + tries++; + + if (options.debug) + { + if (newpass) + pam_syslog (pamh, LOG_DEBUG, "got new auth token"); + else + pam_syslog (pamh, LOG_DEBUG, "got no auth token"); + } + + if (newpass == NULL || retval == PAM_TRY_AGAIN) + continue; + + if (options.debug) + pam_syslog (pamh, LOG_DEBUG, "check against old password file"); + + if (check_old_pass (pamh, user, newpass, + options.debug) != PAM_SUCCESS) + { + if (getuid() || options.enforce_for_root || + (flags & PAM_CHANGE_EXPIRED_AUTHTOK)) + { + pam_error (pamh, + _("Password has been already used. Choose another.")); + newpass = NULL; + /* Remove password item, else following module will use it */ + pam_set_item (pamh, PAM_AUTHTOK, (void *) NULL); + } + else + pam_info (pamh, + _("Password has been already used.")); + } + } + + if (newpass == NULL && tries >= options.tries) + { + if (options.debug) + pam_syslog (pamh, LOG_DEBUG, "Aborted, too many tries"); + return PAM_MAXTRIES; + } + + return PAM_SUCCESS; +} |