/* $NetBSD: klogin.c,v 1.20 2005/01/20 15:41:14 xtraeme Exp $ */ /*- * Copyright (c) 1990, 1993, 1994 * The Regents of the University of California. 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, 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. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 #ifndef lint #if 0 static char sccsid[] = "@(#)klogin.c 8.3 (Berkeley) 4/2/94"; #endif __RCSID("$NetBSD: klogin.c,v 1.20 2005/01/20 15:41:14 xtraeme Exp $"); #endif /* not lint */ #ifdef KERBEROS #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define INITIAL_TICKET "krbtgt" #define VERIFY_SERVICE "rcmd" int notickets; int krb_configured; char *krbtkfile_env; char *tty; extern int has_ccache; static char tkt_location[MAXPATHLEN]; /* a pointer to this is returned... */ int klogin(struct passwd *, char *, char *, char *); void kdestroy(void); /* * Attempt to log the user in using Kerberos authentication * * return 0 on success (will be logged in) * 1 if Kerberos failed (try local password in login) */ int klogin(struct passwd *pw, char *instance, char *localhost, char *password) { int kerror; AUTH_DAT authdata; KTEXT_ST ticket; struct hostent *hp; unsigned long faddr; char realm[REALM_SZ], savehost[MAXHOSTNAMELEN]; krb_configured = 1; /* * Root logins don't use Kerberos. * If we have a realm, try getting a ticket-granting ticket * and using it to authenticate. Otherwise, return * failure so that we can try the normal passwd file * for a password. If that's ok, log the user in * without issuing any tickets. */ if (strcmp(pw->pw_name, "root") == 0 || krb_get_lrealm(realm, 0) != KSUCCESS) { krb_configured = 0; return (1); } /* * get TGT for local realm * tickets are stored in a file named TKT_ROOT plus uid plus tty * except for user.root tickets. */ if (strcmp(instance, "root") != 0) (void)snprintf(tkt_location, sizeof tkt_location, "%s%d.%s", TKT_ROOT, pw->pw_uid, tty); else (void)snprintf(tkt_location, sizeof tkt_location, "%s_root_%d.%s", TKT_ROOT, pw->pw_uid, tty); krbtkfile_env = tkt_location; has_ccache = 1; (void)krb_set_tkt_string(tkt_location); /* * Set real as well as effective ID to 0 for the moment, * to make the kerberos library do the right thing. */ if (setuid(0) < 0) { warnx("setuid"); return (1); } kerror = krb_get_pw_in_tkt(pw->pw_name, instance, realm, INITIAL_TICKET, realm, DEFAULT_TKT_LIFE, password); /* * If we got a TGT, get a local "rcmd" ticket and check it so as to * ensure that we are not talking to a bogus Kerberos server. * * There are 2 cases where we still allow a login: * 1: the VERIFY_SERVICE doesn't exist in the KDC * 2: local host has no srvtab, as (hopefully) indicated by a * return value of RD_AP_UNDEC from krb_rd_req(). */ if (kerror != INTK_OK) { if (kerror != INTK_BADPW && kerror != KDC_PR_UNKNOWN) { syslog(LOG_ERR, "Kerberos intkt error: %s", krb_err_txt[kerror]); dest_tkt(); } return (1); } if (chown(TKT_FILE, pw->pw_uid, pw->pw_gid) < 0) syslog(LOG_ERR, "chown tkfile (%s): %m", TKT_FILE); (void)strlcpy(savehost, krb_get_phost(localhost), sizeof(savehost)); /* * if the "VERIFY_SERVICE" doesn't exist in the KDC for this host, * still allow login with tickets, but log the error condition. */ kerror = krb_mk_req(&ticket, VERIFY_SERVICE, savehost, realm, 33); if (kerror == KDC_PR_UNKNOWN) { syslog(LOG_NOTICE, "warning: TGT not verified (%s); %s.%s not registered, or srvtab is wrong?", krb_err_txt[kerror], VERIFY_SERVICE, savehost); notickets = 0; /* * but for security, don't allow root instances in under * this condition! */ if (strcmp(instance, "root") == 0) { syslog(LOG_ERR, "Kerberos %s root instance login refused\n", pw->pw_name); dest_tkt(); return (1); } return (0); } if (kerror != KSUCCESS) { warnx("unable to use TGT: (%s)", krb_err_txt[kerror]); syslog(LOG_NOTICE, "unable to use TGT: (%s)", krb_err_txt[kerror]); dest_tkt(); return (1); } if (!(hp = gethostbyname(localhost))) { syslog(LOG_ERR, "couldn't get local host address"); dest_tkt(); return (1); } memmove((void *)&faddr, (void *)hp->h_addr, sizeof(faddr)); kerror = krb_rd_req(&ticket, VERIFY_SERVICE, savehost, faddr, &authdata, ""); if (kerror == KSUCCESS) { notickets = 0; return (0); } /* undecipherable: probably didn't have a srvtab on the local host */ if (kerror == RD_AP_UNDEC) { syslog(LOG_NOTICE, "krb_rd_req: (%s)\n", krb_err_txt[kerror]); dest_tkt(); return (1); } /* failed for some other reason */ warnx("unable to verify %s ticket: (%s)", VERIFY_SERVICE, krb_err_txt[kerror]); syslog(LOG_NOTICE, "couldn't verify %s ticket: %s", VERIFY_SERVICE, krb_err_txt[kerror]); dest_tkt(); return (1); } void kdestroy(void) { char *file = krbtkfile_env; int i, fd; extern int errno; struct stat statb; char buf[BUFSIZ]; #ifdef TKT_SHMEM char shmidname[MAXPATHLEN]; #endif /* TKT_SHMEM */ if (krbtkfile_env == NULL) return; errno = 0; if (lstat(file, &statb) < 0) goto out; if (!S_ISREG(statb.st_mode) #ifdef notdef || statb.st_mode & 077 #endif ) goto out; if ((fd = open(file, O_RDWR, 0)) < 0) goto out; memset(buf, 0, BUFSIZ); for (i = 0; i < statb.st_size; i += BUFSIZ) if (write(fd, buf, BUFSIZ) != BUFSIZ) { (void) fsync(fd); (void) close(fd); goto out; } (void) fsync(fd); (void) close(fd); (void) unlink(file); out: if (errno != 0) return; #ifdef TKT_SHMEM /* * handle the shared memory case */ (void)strlcpy(shmidname, file, sizeof(shmidname)); (void)strlcat(shmidname, ".shm", sizeof(shmidname)); if (krb_shm_dest(shmidname) != KSUCCESS) return; #endif /* TKT_SHMEM */ return; } #endif