/***************************************************************************** * * File ..................: mbpasswd.c * Purpose ...............: setuid root version of passwd * Last modification date : 10-Aug-2001 * Shadow Suite (c) ......: Julianne Frances Haugh * ***************************************************************************** * Copyright (C) 1997-2001 * * Michiel Broek FIDO: 2:280/2802 * Beekmansbos 10 * 1971 BV IJmuiden * the Netherlands * * This file is part of MBSE BBS. * * This BBS is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2, or (at your option) any * later version. * * MBSE BBS is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with MBSE BBS; see the file COPYING. If not, write to the Free * Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. *****************************************************************************/ #include "../config.h" #include #include #include #ifdef HAVE_SYS_RESOURCE_H #include #endif #include #include #include #include #include #include #include #include #include #include #if defined(SHADOW_PASSWORD) #include #endif #ifdef HAVE_USERSEC_H #include #include #include #endif #include "encrypt.h" #include "rad64.h" #include "myname.h" #include "xmalloc.h" #include "pwio.h" #include "shadowio.h" #include "mbpasswd.h" #ifndef AGING #if defined(SHADOW_PASSWORD) #define AGING 1 #endif #else #if !defined(SHADOW_PASSWORD) #undef AGING #endif #endif static int do_update_age = 0; #ifndef PAM static char crypt_passwd[128]; /* The "old-style" password, if present */ static int do_update_pwd = 0; #endif #ifdef SHADOW_PASSWORD static void check_password(const struct passwd *, const struct spwd *); #else /* !SHADOW_PASSWORD */ static void check_password(const struct passwd *); #endif /* !SHADOW_PASSWORD */ #ifndef DAY #define DAY (24L*3600L) #endif #define WEEK (7*DAY) #define SCALE DAY /* * string to use for the pw_passwd field in /etc/passwd when using * shadow passwords - most systems use "x" but there are a few * exceptions, so it can be changed here if necessary. --marekm */ #ifndef SHADOW_PASSWD_STRING #define SHADOW_PASSWD_STRING "x" #endif /* * Global variables */ static char *name; /* The name of user whose password is being changed */ static char *myname; /* The current user's name */ static int force; /* Force update of locked passwords */ #ifndef __FreeBSD__ static void fail_exit(int status) { // gr_unlock(); #ifdef SHADOWGRP if (is_shadow_grp) sgr_unlock(); #endif #ifdef SHADOWPWD if (is_shadow_pwd) spw_unlock(); #endif pw_unlock(); exit(status); } static void oom(void) { fprintf(stderr, "mbpasswd: out of memory\n"); fail_exit(E_FAILURE); } /* * insert_crypt_passwd - add an "old-style" password to authentication string * result now malloced to avoid overflow, just in case. --marekm */ static char *insert_crypt_passwd(const char *string, char *passwd) { #ifdef AUTH_METHODS if (string && *string) { char *cp, *result; result = xmalloc(strlen(string) + strlen(passwd) + 1); cp = result; while (*string) { if (string[0] == ';') { *cp++ = *string++; } else if (string[0] == '@') { while (*string && *string != ';') *cp++ = *string++; } else { while (*passwd) *cp++ = *passwd++; while (*string && *string != ';') string++; } } *cp = '\0'; return result; } #endif return xstrdup(passwd); } #endif /* FreeBSD */ #ifndef __FreeBSD__ static char *update_crypt_pw(char *cp) { if (do_update_pwd) cp = insert_crypt_passwd(cp, crypt_passwd); return cp; } #endif /* * pwd_init - ignore signals, and set resource limits to safe * values. Call this before modifying password files, so that * it is less likely to fail in the middle of operation. */ void pwd_init(void) { #ifdef HAVE_SYS_RESOURCE_H struct rlimit rlim; #ifdef RLIMIT_CORE rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); #endif rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY; #ifdef RLIMIT_AS setrlimit(RLIMIT_AS, &rlim); #endif #ifdef RLIMIT_CPU setrlimit(RLIMIT_CPU, &rlim); #endif #ifdef RLIMIT_DATA setrlimit(RLIMIT_DATA, &rlim); #endif #ifdef RLIMIT_FSIZE setrlimit(RLIMIT_FSIZE, &rlim); #endif #ifdef RLIMIT_NOFILE setrlimit(RLIMIT_NOFILE, &rlim); #endif #ifdef RLIMIT_RSS setrlimit(RLIMIT_RSS, &rlim); #endif #ifdef RLIMIT_STACK setrlimit(RLIMIT_STACK, &rlim); #endif #else /* !HAVE_SYS_RESOURCE_H */ set_filesize_limit(30000); /* don't know how to set the other limits... */ #endif /* !HAVE_SYS_RESOURCE_H */ signal(SIGALRM, SIG_IGN); signal(SIGHUP, SIG_IGN); signal(SIGINT, SIG_IGN); signal(SIGPIPE, SIG_IGN); signal(SIGQUIT, SIG_IGN); signal(SIGTERM, SIG_IGN); #ifdef SIGTSTP signal(SIGTSTP, SIG_IGN); #endif #ifdef SIGTTOU signal(SIGTTOU, SIG_IGN); #endif umask(077); } /* * isexpired - determine if account is expired yet * * isexpired calculates the expiration date based on the * password expiration criteria. */ #ifdef SHADOW_PASSWORD int isexpired(const struct passwd *pw, const struct spwd *sp) { #else int isexpired(const struct passwd *pw) { #endif long now; #ifdef HAVE_USERSEC_H int minage = 0; int maxage = 10000; int curage = 0; struct userpw *pu; #endif now = time ((time_t *) 0) / SCALE; #ifdef SHADOW_PASSWORD if (!sp) sp = pwd_to_spwd(pw); /* * Quick and easy - there is an expired account field * along with an inactive account field. Do the expired * one first since it is worse. */ if (sp->sp_expire > 0 && now >= sp->sp_expire) return 3; /* * Last changed date 1970-01-01 (not very likely) means that * the password must be changed on next login (passwd -e). * * The check for "x" is a workaround for RedHat NYS libc bug - * if /etc/shadow doesn't exist, getspnam() still succeeds and * returns sp_lstchg==0 (must change password) instead of -1! */ if (sp->sp_lstchg == 0 && !strcmp(pw->pw_passwd, SHADOW_PASSWD_STRING)) return 1; if (sp->sp_lstchg > 0 && sp->sp_max >= 0 && sp->sp_inact >= 0 && now >= sp->sp_lstchg + sp->sp_max + sp->sp_inact) return 2; #endif #ifdef HAVE_USERSEC_H /*{*/ /* * The aging information lives someplace else. Get it from the * login.cfg file */ if (getconfattr (SC_SYS_PASSWD, SC_MINAGE, &minage, SEC_INT)) minage = -1; if (getconfattr (SC_SYS_PASSWD, SC_MAXAGE, &maxage, SEC_INT)) maxage = -1; pu = getuserpw (pw->pw_name); curage = (time (0) - pu->upw_lastupdate) / (7*86400L); if (maxage != -1 && curage > maxage) return 1; #else /*} !HAVE_USERSEC_H */ /* * The last and max fields must be present for an account * to have an expired password. A maximum of >10000 days * is considered to be infinite. */ #ifdef SHADOWPWD if (sp->sp_lstchg == -1 || sp->sp_max == -1 || sp->sp_max >= (10000L*DAY/SCALE)) return 0; #endif #ifdef ATT_AGE if (pw->pw_age[0] == '\0' || pw->pw_age[0] == '/') return 0; #endif /* * Calculate today's day and the day on which the password * is going to expire. If that date has already passed, * the password has expired. */ #ifdef SHADOWPWD if (now >= sp->sp_lstchg + sp->sp_max) return 1; #endif #ifdef ATT_AGE if (a64l (pw->pw_age + 2) + c64i (pw->pw_age[1]) < now / 7) return 1; #endif #endif /*} HAVE_USERSEC_H */ return 0; } /* * check_password - test a password to see if it can be changed * * check_password() sees if the invoker has permission to change the * password for the given user. */ #ifdef SHADOW_PASSWORD static void check_password(const struct passwd *pw, const struct spwd *sp) { #else static void check_password(const struct passwd *pw) { #endif time_t now, last, ok; int exp_status; #ifdef HAVE_USERSEC_H struct userpw *pu; #endif #ifdef SHADOW_PASSWORD exp_status = isexpired(pw, sp); #else exp_status = isexpired(pw); #endif time(&now); #ifdef SHADOW_PASSWORD /* * If the force flag is set (for new users) this check is skipped. */ if (force == 1) return; /* * Expired accounts cannot be changed ever. Passwords * which are locked may not be changed. Passwords where * min > max may not be changed. Passwords which have * been inactive too long cannot be changed. */ if (sp->sp_pwdp[0] == '!' || exp_status > 1 || (sp->sp_max >= 0 && sp->sp_min > sp->sp_max)) { fprintf (stderr, "The password for %s cannot be changed.\n", sp->sp_namp); syslog(LOG_WARNING, "password locked for %s", sp->sp_namp); closelog(); exit (E_NOPERM); } /* * Passwords may only be changed after sp_min time is up. */ last = sp->sp_lstchg * SCALE; ok = last + (sp->sp_min > 0 ? sp->sp_min * SCALE : 0); #else /* !SHADOW_PASSWORD */ if (pw->pw_passwd[0] == '!' || exp_status > 1) { fprintf (stderr, "The password for %s cannot be changed.\n", pw->pw_name); syslog(LOG_WARNING, "password locked for %s", pw->pw_name); closelog(); exit (E_NOPERM); } #ifdef ATT_AGE /* * Can always be changed if there is no age info */ if (! pw->pw_age[0]) return; last = a64l (pw->pw_age + 2) * WEEK; ok = last + c64i (pw->pw_age[1]) * WEEK; #else /* !ATT_AGE */ #ifdef HAVE_USERSEC_H pu = getuserpw(pw->pw_name); last = pu ? pu->upw_lastupdate : 0L; ok = last + (minage > 0 ? minage * WEEK : 0); #else last = 0; ok = 0; #endif #endif /* !ATT_AGE */ #endif /* !SHADOW_PASSWORD */ if (now < ok) { fprintf(stderr, "Sorry, the password for %s cannot be changed yet.\n", pw->pw_name); syslog(LOG_WARNING, "now < minimum age for `%s'", pw->pw_name); closelog(); exit (E_NOPERM); } } /* * pwd_to_spwd - create entries for new spwd structure * * pwd_to_spwd() creates a new (struct spwd) containing the * information in the pointed-to (struct passwd). * * This function is borrowed from the Shadow Password Suite. */ #ifdef SHADOW_PASSWORD struct spwd *pwd_to_spwd(const struct passwd *pw) { static struct spwd sp; /* * Nice, easy parts first. The name and passwd map directly * from the old password structure to the new one. */ sp.sp_namp = pw->pw_name; sp.sp_pwdp = pw->pw_passwd; #ifdef ATT_AGE /* * AT&T-style password aging maps the sp_min, sp_max, and * sp_lstchg information from the pw_age field, which appears * after the encrypted password. */ if (pw->pw_age[0]) { sp.sp_max = (c64i(pw->pw_age[0]) * WEEK) / SCALE; if (pw->pw_age[1]) sp.sp_min = (c64i(pw->pw_age[1]) * WEEK) / SCALE; else sp.sp_min = (10000L * DAY) / SCALE; if (pw->pw_age[1] && pw->pw_age[2]) sp.sp_lstchg = (a64l(pw->pw_age + 2) * WEEK) / SCALE; else sp.sp_lstchg = time((time_t *) 0) / SCALE; } else #endif { /* * Defaults used if there is no pw_age information. */ sp.sp_min = 0; sp.sp_max = (10000L * DAY) / SCALE; sp.sp_lstchg = time((time_t *) 0) / SCALE; } /* * These fields have no corresponding information in the password * file. They are set to uninitialized values. */ sp.sp_warn = -1; sp.sp_expire = -1; sp.sp_inact = -1; sp.sp_flag = -1; return &sp; } #endif /* * new_password - validate old password and replace with new * (both old and new in global "char crypt_passwd[128]") */ static int new_password(const struct passwd *pw, char *newpasswd) { char *cp; /* Pointer to getpass() response */ char pass[200]; /* New password */ #ifdef HAVE_LIBCRACK_HIST int HistUpdate P_((const char *, const char *)); #endif sprintf(pass, "%s", newpasswd); /* * Encrypt the password, then wipe the cleartext password. */ cp = pw_encrypt(pass, crypt_make_salt()); memset(&pass, 0, sizeof(pass)); #ifdef HAVE_LIBCRACK_HIST HistUpdate(pw->pw_name, crypt_passwd); #endif STRFCPY(crypt_passwd, cp); return 0; } #ifndef __FreeBSD__ static void update_noshadow(int shadow_locked) { const struct passwd *pw; struct passwd *npw; #ifdef ATT_AGE char age[5]; long week = time((time_t *) 0) / WEEK; char *cp; #endif /* * call this with shadow_locked != 0 to avoid calling lckpwdf() * twice (which will fail). XXX - pw_lock(), pw_unlock(), * spw_lock(), spw_unlock() really should track the lock count * and call lckpwdf() only before the first lock, and ulckpwdf() * after the last unlock. */ if (!pw_lock()) { fprintf(stderr, "Cannot lock the password file; try again later.\n"); syslog(LOG_WARNING, "can't lock password file"); exit(E_PWDBUSY); } if (!pw_open(O_RDWR)) { fprintf(stderr, "Cannot open the password file.\n"); syslog(LOG_ERR, "can't open password file"); fail_exit(E_MISSING); } pw = pw_locate(name); if (!pw) { fprintf(stderr, "mbpasswd: user %s not found in /etc/passwd\n", name); fail_exit(E_NOPERM); } npw = __pw_dup(pw); if (!npw) oom(); npw->pw_passwd = update_crypt_pw(npw->pw_passwd); #ifdef ATT_AGE memset(age, 0, sizeof(age)); STRFCPY(age, npw->pw_age); /* * Just changing the password - update the last change date * if there is one, otherwise the age just disappears. */ if (do_update_age) { if (strlen(age) > 2) { cp = l64a(week); age[2] = cp[0]; age[3] = cp[1]; } else { age[0] = '\0'; } } if (xflg) { if (age_max > 0) age[0] = i64c((age_max + 6) / 7); else age[0] = '.'; if (age[1] == '\0') age[1] = '.'; } if (nflg) { if (age[0] == '\0') age[0] = 'z'; if (age_min > 0) age[1] = i64c((age_min + 6) / 7); else age[1] = '.'; } /* * The last change date is added by -n or -x if it's * not already there. */ if ((nflg || xflg) && strlen(age) <= 2) { cp = l64a(week); age[2] = cp[0]; age[3] = cp[1]; } /* * Force password change - if last change date is * present, it will be set to (today - max - 1 week). * Otherwise, just set min = max = 0 (will disappear * when password is changed). */ if (eflg) { if (strlen(age) > 2) { cp = l64a(week - c64i(age[0]) - 1); age[2] = cp[0]; age[3] = cp[1]; } else { strcpy(age, ".."); } } npw->pw_age = age; #endif if (!pw_update(npw)) { fprintf(stderr, "Error updating the password entry.\n"); syslog(LOG_ERR, "error updating password entry"); fail_exit(E_FAILURE); } #ifdef NDBM if (pw_dbm_present() && !pw_dbm_update(npw)) { fprintf(stderr, _("Error updating the DBM password entry.\n")); SYSLOG((LOG_ERR, DBMERROR2)); fail_exit(E_FAILURE); } endpwent(); #endif if (!pw_close()) { fprintf(stderr, "Cannot commit password file changes.\n"); syslog(LOG_ERR, "can't rewrite password file"); fail_exit(E_FAILURE); } pw_unlock(); } #endif /* Not __FreeBSD__ */ #ifdef SHADOW_PASSWORD static void update_shadow(void) { const struct spwd *sp; struct spwd *nsp; if (!spw_lock()) { fprintf(stderr, "Cannot lock the password file; try again later.\n"); syslog(LOG_WARNING, "can't lock password file"); exit(E_PWDBUSY); } if (!spw_open(O_RDWR)) { fprintf(stderr, "Cannot open the password file.\n"); syslog(LOG_ERR, "can't open password file"); fail_exit(E_FAILURE); } sp = spw_locate(name); if (!sp) { /* Try to update the password in /etc/passwd instead. */ spw_close(); update_noshadow(1); spw_unlock(); return; } nsp = __spw_dup(sp); if (!nsp) oom(); nsp->sp_pwdp = update_crypt_pw(nsp->sp_pwdp); if (do_update_age) nsp->sp_lstchg = time((time_t *) 0) / SCALE; if (!spw_update(nsp)) { fprintf(stderr, "Error updating the password entry.\n"); syslog(LOG_ERR, "error updating password entry"); fail_exit(E_FAILURE); } #ifdef NDBM if (sp_dbm_present() && !sp_dbm_update(nsp)) { fprintf(stderr, _("Error updating the DBM password entry.\n")); SYSLOG((LOG_ERR, DBMERROR2)); fail_exit(E_FAILURE); } endspent(); #endif if (!spw_close()) { fprintf(stderr, "Cannot commit password file changes.\n"); syslog(LOG_ERR, "can't rewrite password file"); fail_exit(E_FAILURE); } spw_unlock(); } #endif /* SHADOWPWD */ /* * Function will set a new password in the users password file. * Note that this function must run setuid root! */ int main(int argc, char *argv[]) { const struct passwd *pw; const struct group *gr; #ifdef SHADOW_PASSWORD const struct spwd *sp; #endif char *cp; #ifdef __FreeBSD__ char temp[81]; char cmd[256]; #endif /* * Get my username */ pw = get_my_pwent(); if (!pw) { fprintf(stderr, "mbpasswd: Cannot determine your user name.\n"); exit(1); } myname = xstrdup(pw->pw_name); /* * Get my groupname, this must be "bbs", other users may not * use this program, not even root. */ gr = getgrgid(pw->pw_gid); if (!gr) { fprintf(stderr, "mbpasswd: Cannot determine group name.\n"); exit(E_NOPERM); } if (strcmp(gr->gr_name, (char *)"bbs")) { fprintf(stderr, "mbpasswd: You are not a member of group \"bbs\".\n"); exit(E_NOPERM); } // NOOT dit programma moet kontroleren of het is aangeroepen door mbsebbs. // ook kontroleren of de originele uid en gid correct zijn. // Gewone stervelingen mogen dit niet kunnen starten. // Dit programma is een groot security gat. if (argc != 4) { printf("\nmbpasswd commandline:\n\n"); printf("mbpasswd [-opt] [username] [newpassword]\n"); printf("options are: -n normal password change\n"); printf(" -f forced password change\n"); exit(E_FAILURE); } if (strncmp(argv[1], "-f", 2) == 0) force = 1; else force = 0; /* * Check stringlengths */ if (strlen(argv[2]) > 16) { fprintf(stderr, "mbpasswd: Username too long\n"); exit(E_FAILURE); } if (strlen(argv[3]) > 16) { fprintf(stderr, "mbpasswd: Password too long\n"); exit(E_FAILURE); } name = strdup(argv[2]); if ((pw = getpwnam(name)) == NULL) { fprintf(stderr, "mbpasswd: Unknown user %s\n", name); exit(E_FAILURE); } openlog("mbpasswd", LOG_PID|LOG_CONS|LOG_NOWAIT, LOG_AUTH); #ifdef SHADOW_PASSWORD sp = getspnam(name); if (!sp) sp = pwd_to_spwd(pw); cp = sp->sp_pwdp; #else cp = pw->pw_passwd; #endif /* * See if the user is permitted to change the password. * Otherwise, go ahead and set a new password. */ #ifdef SHADOW_PASSWORD check_password(pw, sp); #else check_password(pw); #endif if (new_password(pw, argv[3])) { fprintf(stderr, "The password for %s is unchanged.\n", name); syslog(LOG_ERR, "The password for %s is unchanged", name); closelog(); exit(E_FAILURE); } do_update_pwd = 1; do_update_age = 1; /* * Before going any further, raise the ulimit to prevent * colliding into a lowered ulimit, and set the real UID * to root to protect against unexpected signals. Any * keyboard signals are set to be ignored. */ pwd_init(); if (setuid(0)) { fprintf(stderr, "Cannot change ID to root.\n"); syslog(LOG_ERR, "can't setuid(0)"); closelog(); exit(E_FAILURE); } #ifndef __FreeBSD__ #ifdef HAVE_USERSEC_H update_userpw(pw->pw_passwd); #else /* !HAVE_USERSEC_H */ #ifdef SHADOW_PASSWORD if (spw_file_present()) update_shadow(); else #endif update_noshadow(0); #endif /* !HAVE_USERSEC_H */ #else /* __FreeBSD__ */ /* * FreeBSD has no interface (that I know of) to change the users password, * but they do have a utility that does it. We will use that. */ if ((access("/usr/bin/chpass", X_OK)) == 0) strcpy(temp, "/usr/bin/chpass"); else if ((access("/usr/sbin/chpass", X_OK)) == 0) strcpy(temp, "/usr/sbin/chpass"); else if ((access("/bin/chpass", X_OK)) == 0) strcpy(temp, "/bin/chpass"); else if ((access("/sbin/chpass", X_OK)) == 0) strcpy(temp, "/sbin/chpass"); else { fprintf(stderr, "mbpasswd: Can't find chpass\n"); syslog(LOG_INFO, "Can't find chpass"); closelog(); exit(E_FAILURE); } sprintf(cmd, "%s -p \"%s\" %s", temp, crypt_passwd, name); if (system(cmd) != 0) { perror("mbpasswd: failed to change password\n"); syslog(LOG_INFO, "password change for `%s' failed", name); closelog(); exit(E_FAILURE); } #endif /* __FreeBSD__ */ syslog(LOG_INFO, "password for `%s' changed by user `%s'", name, myname); closelog(); exit(E_SUCCESS); }