2 * Copyright (c) 1999 Dug Song. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 RCSID("$OpenBSD: auth-krb4.c,v 1.28 2002/09/26 11:38:43 markus Exp $");
27 RCSID("$FreeBSD: src/crypto/openssh/auth-krb4.c,v 1.2.2.7 2003/02/03 17:31:06 des Exp $");
43 extern ServerOptions options;
46 krb4_init(void *context)
48 static int cleanup_registered = 0;
49 Authctxt *authctxt = (Authctxt *)context;
50 const char *tkt_root = TKT_ROOT;
54 if (!authctxt->krb4_ticket_file) {
55 /* Set unique ticket string manually since we're still root. */
56 authctxt->krb4_ticket_file = xmalloc(MAXPATHLEN);
58 if (lstat("/ticket", &st) != -1)
59 tkt_root = "/ticket/";
61 snprintf(authctxt->krb4_ticket_file, MAXPATHLEN, "%s%u_%ld",
62 tkt_root, authctxt->pw->pw_uid, (long)getpid());
63 krb_set_tkt_string(authctxt->krb4_ticket_file);
65 /* Register ticket cleanup in case of fatal error. */
66 if (!cleanup_registered) {
67 fatal_add_cleanup(krb4_cleanup_proc, authctxt);
68 cleanup_registered = 1;
70 /* Try to create our ticket file. */
71 if ((fd = mkstemp(authctxt->krb4_ticket_file)) != -1) {
75 /* Ticket file exists - make sure user owns it (just passed ticket). */
76 if (lstat(authctxt->krb4_ticket_file, &st) != -1) {
77 if (st.st_mode == (S_IFREG | S_IRUSR | S_IWUSR) &&
78 st.st_uid == authctxt->pw->pw_uid)
81 /* Failure - cancel cleanup function, leaving ticket for inspection. */
82 log("WARNING: bad ticket file %s", authctxt->krb4_ticket_file);
84 fatal_remove_cleanup(krb4_cleanup_proc, authctxt);
85 cleanup_registered = 0;
87 xfree(authctxt->krb4_ticket_file);
88 authctxt->krb4_ticket_file = NULL;
94 * try krb4 authentication,
95 * return 1 on success, 0 on failure, -1 if krb4 is not available
98 auth_krb4_password(Authctxt *authctxt, const char *password)
104 char localhost[MAXHOSTNAMELEN], phost[INST_SZ], realm[REALM_SZ];
108 if ((pw = authctxt->pw) == NULL)
112 * Try Kerberos password authentication only for non-root
113 * users and only if Kerberos is installed.
115 if (pw->pw_uid != 0 && krb_get_lrealm(realm, 1) == KSUCCESS) {
116 /* Set up our ticket file. */
117 if (!krb4_init(authctxt)) {
118 log("Couldn't initialize Kerberos ticket file for %s!",
122 /* Try to get TGT using our password. */
123 r = krb_get_pw_in_tkt((char *) pw->pw_name, "", realm,
124 "krbtgt", realm, DEFAULT_TKT_LIFE, (char *)password);
126 debug("Kerberos v4 password authentication for %s "
127 "failed: %s", pw->pw_name, krb_err_txt[r]);
130 /* Successful authentication. */
131 chown(tkt_string(), pw->pw_uid, pw->pw_gid);
134 * Now that we have a TGT, try to get a local
135 * "rcmd" ticket to ensure that we are not talking
136 * to a bogus Kerberos server.
138 gethostname(localhost, sizeof(localhost));
139 strlcpy(phost, (char *)krb_get_phost(localhost),
141 r = krb_mk_req(&tkt, KRB4_SERVICE_NAME, phost, realm, 33);
144 if ((hp = gethostbyname(localhost)) == NULL) {
145 log("Couldn't get local host address!");
148 memmove((void *)&faddr, (void *)hp->h_addr,
151 /* Verify our "rcmd" ticket. */
152 r = krb_rd_req(&tkt, KRB4_SERVICE_NAME, phost,
154 if (r == RD_AP_UNDEC) {
156 * Probably didn't have a srvtab on
157 * localhost. Disallow login.
159 log("Kerberos v4 TGT for %s unverifiable, "
160 "no srvtab installed? krb_rd_req: %s",
161 pw->pw_name, krb_err_txt[r]);
163 } else if (r != KSUCCESS) {
164 log("Kerberos v4 %s ticket unverifiable: %s",
165 KRB4_SERVICE_NAME, krb_err_txt[r]);
168 } else if (r == KDC_PR_UNKNOWN) {
170 * Disallow login if no rcmd service exists, and
173 log("Kerberos v4 TGT for %s unverifiable: %s; %s.%s "
174 "not registered, or srvtab is wrong?", pw->pw_name,
175 krb_err_txt[r], KRB4_SERVICE_NAME, phost);
179 * TGT is bad, forget it. Possibly spoofed!
181 debug("WARNING: Kerberos v4 TGT possibly spoofed "
182 "for %s: %s", pw->pw_name, krb_err_txt[r]);
185 /* Authentication succeeded. */
188 /* Logging in as root or no local Kerberos realm. */
189 debug("Unable to authenticate to Kerberos.");
192 krb4_cleanup_proc(authctxt);
194 if (!options.kerberos_or_local_passwd)
197 /* Fall back to ordinary passwd authentication. */
202 krb4_cleanup_proc(void *context)
204 Authctxt *authctxt = (Authctxt *)context;
205 debug("krb4_cleanup_proc called");
206 if (authctxt->krb4_ticket_file) {
208 xfree(authctxt->krb4_ticket_file);
209 authctxt->krb4_ticket_file = NULL;
214 auth_krb4(Authctxt *authctxt, KTEXT auth, char **client, KTEXT reply)
217 Key_schedule schedule;
218 struct sockaddr_in local, foreign;
219 char instance[INST_SZ];
224 s = packet_get_connection_in();
226 slen = sizeof(local);
227 memset(&local, 0, sizeof(local));
228 if (getsockname(s, (struct sockaddr *) & local, &slen) < 0)
229 debug("getsockname failed: %.100s", strerror(errno));
230 slen = sizeof(foreign);
231 memset(&foreign, 0, sizeof(foreign));
232 if (getpeername(s, (struct sockaddr *) & foreign, &slen) < 0) {
233 debug("getpeername failed: %.100s", strerror(errno));
239 /* Get the encrypted request, challenge, and session key. */
240 if ((r = krb_rd_req(auth, KRB4_SERVICE_NAME, instance,
242 debug("Kerberos v4 krb_rd_req: %.100s", krb_err_txt[r]);
245 des_key_sched((des_cblock *) adat.session, schedule);
247 *client = xmalloc(MAX_K_NAME_SZ);
248 (void) snprintf(*client, MAX_K_NAME_SZ, "%s%s%s@%s", adat.pname,
249 *adat.pinst ? "." : "", adat.pinst, adat.prealm);
251 /* Check ~/.klogin authorization now. */
252 if (kuserok(&adat, authctxt->user) != KSUCCESS) {
253 log("Kerberos v4 .klogin authorization failed for %s to "
254 "account %s", *client, authctxt->user);
259 /* Increment the checksum, and return it encrypted with the
261 cksum = adat.checksum + 1;
262 cksum = htonl(cksum);
264 /* If we can't successfully encrypt the checksum, we send back an
265 empty message, admitting our failure. */
266 if ((r = krb_mk_priv((u_char *) & cksum, reply->dat, sizeof(cksum) + 1,
267 schedule, &adat.session, &local, &foreign)) < 0) {
268 debug("Kerberos v4 mk_priv: (%d) %s", r, krb_err_txt[r]);
274 /* Clear session key. */
275 memset(&adat.session, 0, sizeof(&adat.session));
282 auth_krb4_tgt(Authctxt *authctxt, const char *string)
287 if ((pw = authctxt->pw) == NULL)
290 temporarily_use_uid(pw);
292 if (!radix_to_creds(string, &creds)) {
293 log("Protocol error decoding Kerberos v4 TGT");
296 if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */
297 strlcpy(creds.service, "krbtgt", sizeof creds.service);
299 if (strcmp(creds.service, "krbtgt")) {
300 log("Kerberos v4 TGT (%s%s%s@%s) rejected for %s",
301 creds.pname, creds.pinst[0] ? "." : "", creds.pinst,
302 creds.realm, pw->pw_name);
305 if (!krb4_init(authctxt))
308 if (in_tkt(creds.pname, creds.pinst) != KSUCCESS)
311 if (save_credentials(creds.service, creds.instance, creds.realm,
312 creds.session, creds.lifetime, creds.kvno, &creds.ticket_st,
313 creds.issue_date) != KSUCCESS) {
314 debug("Kerberos v4 TGT refused: couldn't save credentials");
317 /* Successful authentication, passed all checks. */
318 chown(tkt_string(), pw->pw_uid, pw->pw_gid);
320 debug("Kerberos v4 TGT accepted (%s%s%s@%s)",
321 creds.pname, creds.pinst[0] ? "." : "", creds.pinst, creds.realm);
322 memset(&creds, 0, sizeof(creds));
329 krb4_cleanup_proc(authctxt);
330 memset(&creds, 0, sizeof(creds));
337 auth_afs_token(Authctxt *authctxt, const char *token_string)
343 if ((pw = authctxt->pw) == NULL)
346 if (!radix_to_creds(token_string, &creds)) {
347 log("Protocol error decoding AFS token");
350 if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */
351 strlcpy(creds.service, "afs", sizeof creds.service);
353 if (strncmp(creds.pname, "AFS ID ", 7) == 0)
354 uid = atoi(creds.pname + 7);
358 if (kafs_settoken(creds.realm, uid, &creds)) {
359 log("AFS token (%s@%s) rejected for %s",
360 creds.pname, creds.realm, pw->pw_name);
361 memset(&creds, 0, sizeof(creds));
364 debug("AFS token accepted (%s@%s)", creds.pname, creds.realm);
365 memset(&creds, 0, sizeof(creds));