+++ /dev/null
-/*
- * Copyright (c) 1999 Dug Song. 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.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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.
- */
-
-#include "includes.h"
-RCSID("$OpenBSD: auth-krb4.c,v 1.29 2003/02/21 10:34:48 mpech Exp $");
-
-#include "ssh.h"
-#include "ssh1.h"
-#include "packet.h"
-#include "xmalloc.h"
-#include "log.h"
-#include "servconf.h"
-#include "uidswap.h"
-#include "auth.h"
-
-#ifdef AFS
-#include "radix.h"
-#endif
-
-#ifdef KRB4
-extern ServerOptions options;
-
-static int
-krb4_init(void *context)
-{
- static int cleanup_registered = 0;
- Authctxt *authctxt = (Authctxt *)context;
- const char *tkt_root = TKT_ROOT;
- struct stat st;
- int fd;
-
- if (!authctxt->krb4_ticket_file) {
- /* Set unique ticket string manually since we're still root. */
- authctxt->krb4_ticket_file = xmalloc(MAXPATHLEN);
-#ifdef AFS
- if (lstat("/ticket", &st) != -1)
- tkt_root = "/ticket/";
-#endif /* AFS */
- snprintf(authctxt->krb4_ticket_file, MAXPATHLEN, "%s%u_%ld",
- tkt_root, authctxt->pw->pw_uid, (long)getpid());
- krb_set_tkt_string(authctxt->krb4_ticket_file);
- }
- /* Register ticket cleanup in case of fatal error. */
- if (!cleanup_registered) {
- fatal_add_cleanup(krb4_cleanup_proc, authctxt);
- cleanup_registered = 1;
- }
- /* Try to create our ticket file. */
- if ((fd = mkstemp(authctxt->krb4_ticket_file)) != -1) {
- close(fd);
- return (1);
- }
- /* Ticket file exists - make sure user owns it (just passed ticket). */
- if (lstat(authctxt->krb4_ticket_file, &st) != -1) {
- if (st.st_mode == (S_IFREG | S_IRUSR | S_IWUSR) &&
- st.st_uid == authctxt->pw->pw_uid)
- return (1);
- }
- /* Failure - cancel cleanup function, leaving ticket for inspection. */
- log("WARNING: bad ticket file %s", authctxt->krb4_ticket_file);
-
- fatal_remove_cleanup(krb4_cleanup_proc, authctxt);
- cleanup_registered = 0;
-
- xfree(authctxt->krb4_ticket_file);
- authctxt->krb4_ticket_file = NULL;
-
- return (0);
-}
-
-/*
- * try krb4 authentication,
- * return 1 on success, 0 on failure, -1 if krb4 is not available
- */
-int
-auth_krb4_password(Authctxt *authctxt, const char *password)
-{
- AUTH_DAT adata;
- KTEXT_ST tkt;
- struct hostent *hp;
- struct passwd *pw;
- char localhost[MAXHOSTNAMELEN], phost[INST_SZ], realm[REALM_SZ];
- u_int32_t faddr;
- int r;
-
- if ((pw = authctxt->pw) == NULL)
- return (0);
-
- /*
- * Try Kerberos password authentication only for non-root
- * users and only if Kerberos is installed.
- */
- if (pw->pw_uid != 0 && krb_get_lrealm(realm, 1) == KSUCCESS) {
- /* Set up our ticket file. */
- if (!krb4_init(authctxt)) {
- log("Couldn't initialize Kerberos ticket file for %s!",
- pw->pw_name);
- goto failure;
- }
- /* Try to get TGT using our password. */
- r = krb_get_pw_in_tkt((char *) pw->pw_name, "", realm,
- "krbtgt", realm, DEFAULT_TKT_LIFE, (char *)password);
- if (r != INTK_OK) {
- debug("Kerberos v4 password authentication for %s "
- "failed: %s", pw->pw_name, krb_err_txt[r]);
- goto failure;
- }
- /* Successful authentication. */
- chown(tkt_string(), pw->pw_uid, pw->pw_gid);
-
- /*
- * Now that we have a TGT, try to get a local
- * "rcmd" ticket to ensure that we are not talking
- * to a bogus Kerberos server.
- */
- gethostname(localhost, sizeof(localhost));
- strlcpy(phost, (char *)krb_get_phost(localhost),
- sizeof(phost));
- r = krb_mk_req(&tkt, KRB4_SERVICE_NAME, phost, realm, 33);
-
- if (r == KSUCCESS) {
- if ((hp = gethostbyname(localhost)) == NULL) {
- log("Couldn't get local host address!");
- goto failure;
- }
- memmove((void *)&faddr, (void *)hp->h_addr,
- sizeof(faddr));
-
- /* Verify our "rcmd" ticket. */
- r = krb_rd_req(&tkt, KRB4_SERVICE_NAME, phost,
- faddr, &adata, "");
- if (r == RD_AP_UNDEC) {
- /*
- * Probably didn't have a srvtab on
- * localhost. Disallow login.
- */
- log("Kerberos v4 TGT for %s unverifiable, "
- "no srvtab installed? krb_rd_req: %s",
- pw->pw_name, krb_err_txt[r]);
- goto failure;
- } else if (r != KSUCCESS) {
- log("Kerberos v4 %s ticket unverifiable: %s",
- KRB4_SERVICE_NAME, krb_err_txt[r]);
- goto failure;
- }
- } else if (r == KDC_PR_UNKNOWN) {
- /*
- * Disallow login if no rcmd service exists, and
- * log the error.
- */
- log("Kerberos v4 TGT for %s unverifiable: %s; %s.%s "
- "not registered, or srvtab is wrong?", pw->pw_name,
- krb_err_txt[r], KRB4_SERVICE_NAME, phost);
- goto failure;
- } else {
- /*
- * TGT is bad, forget it. Possibly spoofed!
- */
- debug("WARNING: Kerberos v4 TGT possibly spoofed "
- "for %s: %s", pw->pw_name, krb_err_txt[r]);
- goto failure;
- }
- /* Authentication succeeded. */
- return (1);
- } else
- /* Logging in as root or no local Kerberos realm. */
- debug("Unable to authenticate to Kerberos.");
-
- failure:
- krb4_cleanup_proc(authctxt);
-
- if (!options.kerberos_or_local_passwd)
- return (0);
-
- /* Fall back to ordinary passwd authentication. */
- return (-1);
-}
-
-void
-krb4_cleanup_proc(void *context)
-{
- Authctxt *authctxt = (Authctxt *)context;
- debug("krb4_cleanup_proc called");
- if (authctxt->krb4_ticket_file) {
- (void) dest_tkt();
- xfree(authctxt->krb4_ticket_file);
- authctxt->krb4_ticket_file = NULL;
- }
-}
-
-int
-auth_krb4(Authctxt *authctxt, KTEXT auth, char **client, KTEXT reply)
-{
- AUTH_DAT adat = {0};
- Key_schedule schedule;
- struct sockaddr_in local, foreign;
- char instance[INST_SZ];
- socklen_t slen;
- u_int cksum;
- int r, s;
-
- s = packet_get_connection_in();
-
- slen = sizeof(local);
- memset(&local, 0, sizeof(local));
- if (getsockname(s, (struct sockaddr *) & local, &slen) < 0)
- debug("getsockname failed: %.100s", strerror(errno));
- slen = sizeof(foreign);
- memset(&foreign, 0, sizeof(foreign));
- if (getpeername(s, (struct sockaddr *) & foreign, &slen) < 0) {
- debug("getpeername failed: %.100s", strerror(errno));
- fatal_cleanup();
- }
- instance[0] = '*';
- instance[1] = 0;
-
- /* Get the encrypted request, challenge, and session key. */
- if ((r = krb_rd_req(auth, KRB4_SERVICE_NAME, instance,
- 0, &adat, ""))) {
- debug("Kerberos v4 krb_rd_req: %.100s", krb_err_txt[r]);
- return (0);
- }
- des_key_sched((des_cblock *) adat.session, schedule);
-
- *client = xmalloc(MAX_K_NAME_SZ);
- (void) snprintf(*client, MAX_K_NAME_SZ, "%s%s%s@%s", adat.pname,
- *adat.pinst ? "." : "", adat.pinst, adat.prealm);
-
- /* Check ~/.klogin authorization now. */
- if (kuserok(&adat, authctxt->user) != KSUCCESS) {
- log("Kerberos v4 .klogin authorization failed for %s to "
- "account %s", *client, authctxt->user);
- xfree(*client);
- *client = NULL;
- return (0);
- }
- /* Increment the checksum, and return it encrypted with the
- session key. */
- cksum = adat.checksum + 1;
- cksum = htonl(cksum);
-
- /* If we can't successfully encrypt the checksum, we send back an
- empty message, admitting our failure. */
- if ((r = krb_mk_priv((u_char *) & cksum, reply->dat, sizeof(cksum) + 1,
- schedule, &adat.session, &local, &foreign)) < 0) {
- debug("Kerberos v4 mk_priv: (%d) %s", r, krb_err_txt[r]);
- reply->dat[0] = 0;
- reply->length = 0;
- } else
- reply->length = r;
-
- /* Clear session key. */
- memset(&adat.session, 0, sizeof(adat.session));
- return (1);
-}
-#endif /* KRB4 */
-
-#ifdef AFS
-int
-auth_krb4_tgt(Authctxt *authctxt, const char *string)
-{
- CREDENTIALS creds;
- struct passwd *pw;
-
- if ((pw = authctxt->pw) == NULL)
- goto failure;
-
- temporarily_use_uid(pw);
-
- if (!radix_to_creds(string, &creds)) {
- log("Protocol error decoding Kerberos v4 TGT");
- goto failure;
- }
- if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */
- strlcpy(creds.service, "krbtgt", sizeof creds.service);
-
- if (strcmp(creds.service, "krbtgt")) {
- log("Kerberos v4 TGT (%s%s%s@%s) rejected for %s",
- creds.pname, creds.pinst[0] ? "." : "", creds.pinst,
- creds.realm, pw->pw_name);
- goto failure;
- }
- if (!krb4_init(authctxt))
- goto failure;
-
- if (in_tkt(creds.pname, creds.pinst) != KSUCCESS)
- goto failure;
-
- if (save_credentials(creds.service, creds.instance, creds.realm,
- creds.session, creds.lifetime, creds.kvno, &creds.ticket_st,
- creds.issue_date) != KSUCCESS) {
- debug("Kerberos v4 TGT refused: couldn't save credentials");
- goto failure;
- }
- /* Successful authentication, passed all checks. */
- chown(tkt_string(), pw->pw_uid, pw->pw_gid);
-
- debug("Kerberos v4 TGT accepted (%s%s%s@%s)",
- creds.pname, creds.pinst[0] ? "." : "", creds.pinst, creds.realm);
- memset(&creds, 0, sizeof(creds));
-
- restore_uid();
-
- return (1);
-
- failure:
- krb4_cleanup_proc(authctxt);
- memset(&creds, 0, sizeof(creds));
- restore_uid();
-
- return (0);
-}
-
-int
-auth_afs_token(Authctxt *authctxt, const char *token_string)
-{
- CREDENTIALS creds;
- struct passwd *pw;
- uid_t uid;
-
- if ((pw = authctxt->pw) == NULL)
- return (0);
-
- if (!radix_to_creds(token_string, &creds)) {
- log("Protocol error decoding AFS token");
- return (0);
- }
- if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */
- strlcpy(creds.service, "afs", sizeof creds.service);
-
- if (strncmp(creds.pname, "AFS ID ", 7) == 0)
- uid = atoi(creds.pname + 7);
- else
- uid = pw->pw_uid;
-
- if (kafs_settoken(creds.realm, uid, &creds)) {
- log("AFS token (%s@%s) rejected for %s",
- creds.pname, creds.realm, pw->pw_name);
- memset(&creds, 0, sizeof(creds));
- return (0);
- }
- debug("AFS token accepted (%s@%s)", creds.pname, creds.realm);
- memset(&creds, 0, sizeof(creds));
-
- return (1);
-}
-#endif /* AFS */
andersk / gssapi-openssh.git / commitdiff
