/* * check_perms - check if the caller is allowed to add a group * * Non-root users are only allowed to change their gecos field. * (see also may_change_field()) * * Non-root users must be authenticated. * * It will not return if the user is not allowed. */ static void check_perms (const struct passwd *pw) { #ifdef USE_PAM pam_handle_t *pamh = NULL; int retval; struct passwd *pampw; #endif /* * Non-privileged users are only allowed to change the gecos field * if the UID of the user matches the current real UID. */ if (!amroot && pw->pw_uid != getuid ()) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); closelog (); exit (E_NOPERM); } #ifdef WITH_SELINUX /* * If the UID of the user does not match the current real UID, * check if the change is allowed by SELinux policy. */ if ((pw->pw_uid != getuid ()) && (is_selinux_enabled () > 0) && (selinux_check_passwd_access (PASSWD__CHFN) != 0)) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); closelog (); exit (E_NOPERM); } #endif #ifndef USE_PAM /* * Non-privileged users are optionally authenticated (must enter the * password of the user whose information is being changed) before * any changes can be made. Idea from util-linux chfn/chsh. * --marekm */ if (!amroot && getdef_bool ("CHFN_AUTH")) { passwd_check (pw->pw_name, pw->pw_passwd, "chfn"); } #else /* !USE_PAM */ pampw = getpwuid (getuid ()); /* local, no need for xgetpwuid */ if (NULL == pampw) { fprintf (stderr, _("%s: Cannot determine your user name.\n"), Prog); exit (E_NOPERM); } retval = pam_start ("chfn", pampw->pw_name, &conv, &pamh); if (PAM_SUCCESS == retval) { retval = pam_authenticate (pamh, 0); } if (PAM_SUCCESS == retval) { retval = pam_acct_mgmt (pamh, 0); } if (PAM_SUCCESS != retval) { fprintf (stderr, _("%s: PAM: %s\n"), Prog, pam_strerror (pamh, retval)); SYSLOG((LOG_ERR, "%s", pam_strerror (pamh, retval))); if (NULL != pamh) { (void) pam_end (pamh, retval); } exit (E_NOPERM); } (void) pam_end (pamh, retval); #endif /* USE_PAM */ }
/* * chfn - change a user's password file information * * This command controls the GECOS field information in the password * file entry. * * The valid options are * * -f full name * -r room number * -w work phone number * -h home phone number * -o other information (*) * * (*) requires root permission to execute. */ int main (int argc, char **argv) { char *cp; /* temporary character pointer */ const struct passwd *pw; /* password file entry */ struct passwd pwent; /* modified password file entry */ char old_gecos[BUFSIZ]; /* buffer for old GECOS fields */ char new_gecos[BUFSIZ]; /* buffer for new GECOS fields */ int flag; /* flag currently being processed */ int fflg = 0; /* -f - set full name */ int rflg = 0; /* -r - set room number */ int wflg = 0; /* -w - set work phone number */ int hflg = 0; /* -h - set home phone number */ int oflg = 0; /* -o - set other information */ char *user; #ifdef USE_PAM pam_handle_t *pamh = NULL; struct passwd *pampw; int retval; #endif sanitize_env (); setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); /* * This command behaves different for root and non-root * users. */ amroot = (getuid () == 0); /* * Get the program name. The program name is used as a * prefix to most error messages. */ Prog = Basename (argv[0]); OPENLOG ("chfn"); /* * The remaining arguments will be processed one by one and executed * by this command. The name is the last argument if it does not * begin with a "-", otherwise the name is determined from the * environment and must agree with the real UID. Also, the UID will * be checked for any commands which are restricted to root only. */ while ((flag = getopt (argc, argv, "f:r:w:h:o:")) != EOF) { switch (flag) { case 'f': if (!may_change_field ('f')) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); exit (E_NOPERM); } fflg++; STRFCPY (fullnm, optarg); break; case 'h': if (!may_change_field ('h')) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); exit (E_NOPERM); } hflg++; STRFCPY (homeph, optarg); break; case 'r': if (!may_change_field ('r')) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); exit (E_NOPERM); } rflg++; STRFCPY (roomno, optarg); break; case 'o': if (!amroot) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); exit (E_NOPERM); } oflg++; STRFCPY (slop, optarg); break; case 'w': if (!may_change_field ('w')) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); exit (E_NOPERM); } wflg++; STRFCPY (workph, optarg); break; default: usage (); } } /* * Get the name of the user to check. It is either the command line * name, or the name getlogin() returns. */ if (optind < argc) { user = argv[optind]; pw = getpwnam (user); if (!pw) { fprintf (stderr, _("%s: unknown user %s\n"), Prog, user); exit (E_NOPERM); } } else { pw = get_my_pwent (); if (!pw) { fprintf (stderr, _ ("%s: Cannot determine your user name.\n"), Prog); exit (E_NOPERM); } user = xstrdup (pw->pw_name); } #ifdef USE_NIS /* * Now we make sure this is a LOCAL password entry for this user ... */ if (__ispwNIS ()) { char *nis_domain; char *nis_master; fprintf (stderr, _("%s: cannot change user `%s' on NIS client.\n"), Prog, user); if (!yp_get_default_domain (&nis_domain) && !yp_master (nis_domain, "passwd.byname", &nis_master)) { fprintf (stderr, _ ("%s: `%s' is the NIS master for this client.\n"), Prog, nis_master); } exit (E_NOPERM); } #endif /* * Non-privileged users are only allowed to change the gecos field * if the UID of the user matches the current real UID. */ if (!amroot && pw->pw_uid != getuid ()) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); closelog (); exit (E_NOPERM); } #ifdef WITH_SELINUX /* * If the UID of the user does not match the current real UID, * check if the change is allowed by SELinux policy. */ if ((pw->pw_uid != getuid ()) && (selinux_check_passwd_access (PASSWD__CHFN) != 0)) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); closelog (); exit (E_NOPERM); } #endif #ifndef USE_PAM /* * Non-privileged users are optionally authenticated (must enter the * password of the user whose information is being changed) before * any changes can be made. Idea from util-linux chfn/chsh. * --marekm */ if (!amroot && getdef_bool ("CHFN_AUTH")) passwd_check (pw->pw_name, pw->pw_passwd, "chfn"); #else /* !USE_PAM */ retval = PAM_SUCCESS; pampw = getpwuid (getuid ()); if (pampw == NULL) { retval = PAM_USER_UNKNOWN; } if (retval == PAM_SUCCESS) { retval = pam_start ("chfn", pampw->pw_name, &conv, &pamh); } if (retval == PAM_SUCCESS) { retval = pam_authenticate (pamh, 0); if (retval != PAM_SUCCESS) { pam_end (pamh, retval); } } if (retval == PAM_SUCCESS) { retval = pam_acct_mgmt (pamh, 0); if (retval != PAM_SUCCESS) { pam_end (pamh, retval); } } if (retval != PAM_SUCCESS) { fprintf (stderr, _("%s: PAM authentication failed\n"), Prog); exit (E_NOPERM); } #endif /* USE_PAM */ /* * Now get the full name. It is the first comma separated field in * the GECOS field. */ STRFCPY (old_gecos, pw->pw_gecos); cp = copy_field (old_gecos, fflg ? (char *) 0 : fullnm, slop); /* * Now get the room number. It is the next comma separated field, * if there is indeed one. */ if (cp) cp = copy_field (cp, rflg ? (char *) 0 : roomno, slop); /* * Now get the work phone number. It is the third field. */ if (cp) cp = copy_field (cp, wflg ? (char *) 0 : workph, slop); /* * Now get the home phone number. It is the fourth field. */ if (cp) cp = copy_field (cp, hflg ? (char *) 0 : homeph, slop); /* * Anything left over is "slop". */ if (cp && !oflg) { if (slop[0]) strcat (slop, ","); strcat (slop, cp); } /* * If none of the fields were changed from the command line, let the * user interactively change them. */ if (!fflg && !rflg && !wflg && !hflg && !oflg) { printf (_("Changing the user information for %s\n"), user); new_fields (); } /* * Check all of the fields for valid information */ if (valid_field (fullnm, ":,=")) { fprintf (stderr, _("%s: invalid name: \"%s\"\n"), Prog, fullnm); closelog (); exit (E_NOPERM); } if (valid_field (roomno, ":,=")) { fprintf (stderr, _("%s: invalid room number: \"%s\"\n"), Prog, roomno); closelog (); exit (E_NOPERM); } if (valid_field (workph, ":,=")) { fprintf (stderr, _("%s: invalid work phone: \"%s\"\n"), Prog, workph); closelog (); exit (E_NOPERM); } if (valid_field (homeph, ":,=")) { fprintf (stderr, _("%s: invalid home phone: \"%s\"\n"), Prog, homeph); closelog (); exit (E_NOPERM); } if (valid_field (slop, ":")) { fprintf (stderr, _("%s: \"%s\" contains illegal characters\n"), Prog, slop); closelog (); exit (E_NOPERM); } /* * Build the new GECOS field by plastering all the pieces together, * if they will fit ... */ if (strlen (fullnm) + strlen (roomno) + strlen (workph) + strlen (homeph) + strlen (slop) > (unsigned int) 80) { fprintf (stderr, _("%s: fields too long\n"), Prog); closelog (); exit (E_NOPERM); } snprintf (new_gecos, sizeof new_gecos, "%s,%s,%s,%s%s%s", fullnm, roomno, workph, homeph, slop[0] ? "," : "", slop); /* * 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. */ if (setuid (0)) { fprintf (stderr, _("Cannot change ID to root.\n")); SYSLOG ((LOG_ERR, "can't setuid(0)")); closelog (); exit (E_NOPERM); } pwd_init (); /* * The passwd entry is now ready to be committed back to the * password file. Get a lock on the file and open it. */ if (!pw_lock ()) { fprintf (stderr, _ ("Cannot lock the password file; try again later.\n")); SYSLOG ((LOG_WARN, "can't lock /etc/passwd")); closelog (); exit (E_NOPERM); } if (!pw_open (O_RDWR)) { fprintf (stderr, _("Cannot open the password file.\n")); pw_unlock (); SYSLOG ((LOG_ERR, "can't open /etc/passwd")); closelog (); exit (E_NOPERM); } /* * Get the entry to update using pw_locate() - we want the real one * from /etc/passwd, not the one from getpwnam() which could contain * the shadow password if (despite the warnings) someone enables * AUTOSHADOW (or SHADOW_COMPAT in libc). --marekm */ pw = pw_locate (user); if (!pw) { pw_unlock (); fprintf (stderr, _("%s: %s not found in /etc/passwd\n"), Prog, user); exit (E_NOPERM); } /* * Make a copy of the entry, then change the gecos field. The other * fields remain unchanged. */ pwent = *pw; pwent.pw_gecos = new_gecos; /* * Update the passwd file entry. If there is a DBM file, update that * entry as well. */ if (!pw_update (&pwent)) { fprintf (stderr, _("Error updating the password entry.\n")); pw_unlock (); SYSLOG ((LOG_ERR, "error updating passwd entry")); closelog (); exit (E_NOPERM); } /* * Changes have all been made, so commit them and unlock the file. */ if (!pw_close ()) { fprintf (stderr, _("Cannot commit password file changes.\n")); pw_unlock (); SYSLOG ((LOG_ERR, "can't rewrite /etc/passwd")); closelog (); exit (E_NOPERM); } if (!pw_unlock ()) { fprintf (stderr, _("Cannot unlock the password file.\n")); SYSLOG ((LOG_ERR, "can't unlock /etc/passwd")); closelog (); exit (E_NOPERM); } SYSLOG ((LOG_INFO, "changed user `%s' information", user)); nscd_flush_cache ("passwd"); #ifdef USE_PAM if (retval == PAM_SUCCESS) pam_end (pamh, PAM_SUCCESS); #endif /* USE_PAM */ closelog (); exit (E_SUCCESS); }
int main (int argc, char **argv) { const struct spwd *sp; uid_t ruid; gid_t rgid; const struct passwd *pw; /* * Get the program name so that error messages can use it. */ Prog = Basename (argv[0]); sanitize_env (); (void) setlocale (LC_ALL, ""); (void) bindtextdomain (PACKAGE, LOCALEDIR); (void) textdomain (PACKAGE); process_root_flag ("-R", argc, argv); #ifdef WITH_AUDIT audit_help_open (); #endif OPENLOG ("chage"); ruid = getuid (); rgid = getgid (); amroot = (ruid == 0); #ifdef WITH_SELINUX if (amroot && (is_selinux_enabled () > 0)) { amroot = (selinux_check_passwd_access (PASSWD__ROOTOK) == 0); } #endif process_flags (argc, argv); check_perms (); if (!spw_file_present ()) { fprintf (stderr, _("%s: the shadow password file is not present\n"), Prog); SYSLOG ((LOG_WARN, "can't find the shadow password file")); closelog (); exit (E_SHADOW_NOTFOUND); } open_files (lflg); /* Drop privileges */ if (lflg && ( (setregid (rgid, rgid) != 0) || (setreuid (ruid, ruid) != 0))) { fprintf (stderr, _("%s: failed to drop privileges (%s)\n"), Prog, strerror (errno)); fail_exit (E_NOPERM); } pw = pw_locate (argv[optind]); if (NULL == pw) { fprintf (stderr, _("%s: user '%s' does not exist in %s\n"), Prog, argv[optind], pw_dbname ()); closelog (); fail_exit (E_NOPERM); } STRFCPY (user_name, pw->pw_name); #ifdef WITH_TCB if (shadowtcb_set_user (pw->pw_name) == SHADOWTCB_FAILURE) { fail_exit (E_NOPERM); } #endif user_uid = pw->pw_uid; sp = spw_locate (argv[optind]); get_defaults (sp); /* * Print out the expiration fields if the user has requested the * list option. */ if (lflg) { if (!amroot && (ruid != user_uid)) { fprintf (stderr, _("%s: Permission denied.\n"), Prog); fail_exit (E_NOPERM); } #ifdef WITH_AUDIT audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "display aging info", user_name, (unsigned int) user_uid, 1); #endif list_fields (); fail_exit (E_SUCCESS); } /* * If none of the fields were changed from the command line, let the * user interactively change them. */ if (!mflg && !Mflg && !dflg && !Wflg && !Iflg && !Eflg) { printf (_("Changing the aging information for %s\n"), user_name); if (new_fields () == 0) { fprintf (stderr, _("%s: error changing fields\n"), Prog); fail_exit (E_NOPERM); } #ifdef WITH_AUDIT else { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "change all aging information", user_name, (unsigned int) user_uid, 1); } #endif } else { #ifdef WITH_AUDIT if (Mflg) { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "change max age", user_name, (unsigned int) user_uid, 1); } if (mflg) { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "change min age", user_name, (unsigned int) user_uid, 1); } if (dflg) { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "change last change date", user_name, (unsigned int) user_uid, 1); } if (Wflg) { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "change passwd warning", user_name, (unsigned int) user_uid, 1); } if (Iflg) { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "change inactive days", user_name, (unsigned int) user_uid, 1); } if (Eflg) { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "change passwd expiration", user_name, (unsigned int) user_uid, 1); } #endif } update_age (sp, pw); close_files (); SYSLOG ((LOG_INFO, "changed password expiry for %s", user_name)); closelog (); exit (E_SUCCESS); }