1 /*
2 * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "krb5_locl.h"
35
36 static krb5_error_code
add_addrs(krb5_context context,krb5_addresses * addr,struct addrinfo * ai)37 add_addrs(krb5_context context,
38 krb5_addresses *addr,
39 struct addrinfo *ai)
40 {
41 krb5_error_code ret;
42 unsigned n, i;
43 void *tmp;
44 struct addrinfo *a;
45
46 n = 0;
47 for (a = ai; a != NULL; a = a->ai_next)
48 ++n;
49
50 tmp = realloc(addr->val, (addr->len + n) * sizeof(*addr->val));
51 if (tmp == NULL && (addr->len + n) != 0) {
52 ret = ENOMEM;
53 krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
54 goto fail;
55 }
56 addr->val = tmp;
57 for (i = addr->len; i < (addr->len + n); ++i) {
58 addr->val[i].addr_type = 0;
59 krb5_data_zero(&addr->val[i].address);
60 }
61 i = addr->len;
62 for (a = ai; a != NULL; a = a->ai_next) {
63 krb5_address ad;
64
65 ret = krb5_sockaddr2address (context, a->ai_addr, &ad);
66 if (ret == 0) {
67 if (krb5_address_search(context, &ad, addr))
68 krb5_free_address(context, &ad);
69 else
70 addr->val[i++] = ad;
71 }
72 else if (ret == KRB5_PROG_ATYPE_NOSUPP)
73 krb5_clear_error_message (context);
74 else
75 goto fail;
76 addr->len = i;
77 }
78 return 0;
79 fail:
80 krb5_free_addresses (context, addr);
81 return ret;
82 }
83
84 /**
85 * Forward credentials for client to host hostname , making them
86 * forwardable if forwardable, and returning the blob of data to sent
87 * in out_data. If hostname == NULL, pick it from server.
88 *
89 * @param context A kerberos 5 context.
90 * @param auth_context the auth context with the key to encrypt the out_data.
91 * @param hostname the host to forward the tickets too.
92 * @param client the client to delegate from.
93 * @param server the server to delegate the credential too.
94 * @param ccache credential cache to use.
95 * @param forwardable make the forwarded ticket forwabledable.
96 * @param out_data the resulting credential.
97 *
98 * @return Return an error code or 0.
99 *
100 * @ingroup krb5_credential
101 */
102
103 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_fwd_tgt_creds(krb5_context context,krb5_auth_context auth_context,const char * hostname,krb5_principal client,krb5_principal server,krb5_ccache ccache,int forwardable,krb5_data * out_data)104 krb5_fwd_tgt_creds (krb5_context context,
105 krb5_auth_context auth_context,
106 const char *hostname,
107 krb5_principal client,
108 krb5_principal server,
109 krb5_ccache ccache,
110 int forwardable,
111 krb5_data *out_data)
112 {
113 krb5_flags flags = 0;
114 krb5_creds creds;
115 krb5_error_code ret;
116 krb5_const_realm client_realm;
117
118 flags |= KDC_OPT_FORWARDED;
119
120 if (forwardable)
121 flags |= KDC_OPT_FORWARDABLE;
122
123 if (hostname == NULL &&
124 krb5_principal_get_type(context, server) == KRB5_NT_SRV_HST) {
125 const char *inst = krb5_principal_get_comp_string(context, server, 0);
126 const char *host = krb5_principal_get_comp_string(context, server, 1);
127
128 if (inst != NULL &&
129 strcmp(inst, "host") == 0 &&
130 host != NULL &&
131 krb5_principal_get_comp_string(context, server, 2) == NULL)
132 hostname = host;
133 }
134
135 client_realm = krb5_principal_get_realm(context, client);
136
137 memset (&creds, 0, sizeof(creds));
138 creds.client = client;
139
140 ret = krb5_make_principal(context,
141 &creds.server,
142 client_realm,
143 KRB5_TGS_NAME,
144 client_realm,
145 NULL);
146 if (ret)
147 return ret;
148
149 ret = krb5_get_forwarded_creds (context,
150 auth_context,
151 ccache,
152 flags,
153 hostname,
154 &creds,
155 out_data);
156 return ret;
157 }
158
159 /**
160 * Gets tickets forwarded to hostname. If the tickets that are
161 * forwarded are address-less, the forwarded tickets will also be
162 * address-less.
163 *
164 * If the ticket have any address, hostname will be used for figure
165 * out the address to forward the ticket too. This since this might
166 * use DNS, its insecure and also doesn't represent configured all
167 * addresses of the host. For example, the host might have two
168 * adresses, one IPv4 and one IPv6 address where the later is not
169 * published in DNS. This IPv6 address might be used communications
170 * and thus the resulting ticket useless.
171 *
172 * @param context A kerberos 5 context.
173 * @param auth_context the auth context with the key to encrypt the out_data.
174 * @param ccache credential cache to use
175 * @param flags the flags to control the resulting ticket flags
176 * @param hostname the host to forward the tickets too.
177 * @param in_creds the in client and server ticket names. The client
178 * and server components forwarded to the remote host.
179 * @param out_data the resulting credential.
180 *
181 * @return Return an error code or 0.
182 *
183 * @ingroup krb5_credential
184 */
185
186 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_forwarded_creds(krb5_context context,krb5_auth_context auth_context,krb5_ccache ccache,krb5_flags flags,const char * hostname,krb5_creds * in_creds,krb5_data * out_data)187 krb5_get_forwarded_creds (krb5_context context,
188 krb5_auth_context auth_context,
189 krb5_ccache ccache,
190 krb5_flags flags,
191 const char *hostname,
192 krb5_creds *in_creds,
193 krb5_data *out_data)
194 {
195 krb5_error_code ret;
196 krb5_creds *out_creds;
197 krb5_addresses addrs, *paddrs;
198 KRB_CRED cred;
199 KrbCredInfo *krb_cred_info;
200 EncKrbCredPart enc_krb_cred_part;
201 size_t len;
202 unsigned char *buf;
203 size_t buf_size;
204 krb5_kdc_flags kdc_flags;
205 krb5_crypto crypto;
206 struct addrinfo *ai;
207 krb5_creds *ticket;
208
209 paddrs = NULL;
210 addrs.len = 0;
211 addrs.val = NULL;
212
213 ret = krb5_get_credentials(context, 0, ccache, in_creds, &ticket);
214 if(ret == 0) {
215 if (ticket->addresses.len)
216 paddrs = &addrs;
217 krb5_free_creds (context, ticket);
218 } else {
219 krb5_boolean noaddr;
220 krb5_appdefault_boolean(context, NULL,
221 krb5_principal_get_realm(context,
222 in_creds->client),
223 "no-addresses", KRB5_ADDRESSLESS_DEFAULT,
224 &noaddr);
225 if (!noaddr)
226 paddrs = &addrs;
227 }
228
229 /*
230 * If tickets have addresses, get the address of the remote host.
231 */
232
233 if (paddrs != NULL) {
234
235 ret = getaddrinfo (hostname, NULL, NULL, &ai);
236 if (ret) {
237 krb5_error_code ret2 = krb5_eai_to_heim_errno(ret, errno);
238 krb5_set_error_message(context, ret2,
239 N_("resolving host %s failed: %s",
240 "hostname, error"),
241 hostname, gai_strerror(ret));
242 return ret2;
243 }
244
245 ret = add_addrs (context, &addrs, ai);
246 freeaddrinfo (ai);
247 if (ret)
248 return ret;
249 }
250
251 kdc_flags.b = int2KDCOptions(flags);
252
253 ret = krb5_get_kdc_cred (context,
254 ccache,
255 kdc_flags,
256 paddrs,
257 NULL,
258 in_creds,
259 &out_creds);
260 krb5_free_addresses (context, &addrs);
261 if (ret)
262 return ret;
263
264 memset (&cred, 0, sizeof(cred));
265 cred.pvno = 5;
266 cred.msg_type = krb_cred;
267 ALLOC_SEQ(&cred.tickets, 1);
268 if (cred.tickets.val == NULL) {
269 ret = ENOMEM;
270 krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
271 goto out2;
272 }
273 ret = decode_Ticket(out_creds->ticket.data,
274 out_creds->ticket.length,
275 cred.tickets.val, &len);
276 if (ret)
277 goto out3;
278
279 memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
280 ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1);
281 if (enc_krb_cred_part.ticket_info.val == NULL) {
282 ret = ENOMEM;
283 krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
284 goto out4;
285 }
286
287 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
288 krb5_timestamp sec;
289 int32_t usec;
290
291 krb5_us_timeofday (context, &sec, &usec);
292
293 ALLOC(enc_krb_cred_part.timestamp, 1);
294 if (enc_krb_cred_part.timestamp == NULL) {
295 ret = ENOMEM;
296 krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
297 goto out4;
298 }
299 *enc_krb_cred_part.timestamp = sec;
300 ALLOC(enc_krb_cred_part.usec, 1);
301 if (enc_krb_cred_part.usec == NULL) {
302 ret = ENOMEM;
303 krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
304 goto out4;
305 }
306 *enc_krb_cred_part.usec = usec;
307 } else {
308 enc_krb_cred_part.timestamp = NULL;
309 enc_krb_cred_part.usec = NULL;
310 }
311
312 if (auth_context->local_address && auth_context->local_port && paddrs) {
313
314 ret = krb5_make_addrport (context,
315 &enc_krb_cred_part.s_address,
316 auth_context->local_address,
317 auth_context->local_port);
318 if (ret)
319 goto out4;
320 }
321
322 if (auth_context->remote_address) {
323 if (auth_context->remote_port) {
324 krb5_boolean noaddr;
325 krb5_const_realm srealm;
326
327 srealm = krb5_principal_get_realm(context, out_creds->server);
328 /* Is this correct, and should we use the paddrs == NULL
329 trick here as well? Having an address-less ticket may
330 indicate that we don't know our own global address, but
331 it does not necessary mean that we don't know the
332 server's. */
333 krb5_appdefault_boolean(context, NULL, srealm, "no-addresses",
334 FALSE, &noaddr);
335 if (!noaddr) {
336 ret = krb5_make_addrport (context,
337 &enc_krb_cred_part.r_address,
338 auth_context->remote_address,
339 auth_context->remote_port);
340 if (ret)
341 goto out4;
342 }
343 } else {
344 ALLOC(enc_krb_cred_part.r_address, 1);
345 if (enc_krb_cred_part.r_address == NULL) {
346 ret = ENOMEM;
347 krb5_set_error_message(context, ret,
348 N_("malloc: out of memory", ""));
349 goto out4;
350 }
351
352 ret = krb5_copy_address (context, auth_context->remote_address,
353 enc_krb_cred_part.r_address);
354 if (ret)
355 goto out4;
356 }
357 }
358
359 /* fill ticket_info.val[0] */
360
361 enc_krb_cred_part.ticket_info.len = 1;
362
363 krb_cred_info = enc_krb_cred_part.ticket_info.val;
364
365 copy_EncryptionKey (&out_creds->session, &krb_cred_info->key);
366 ALLOC(krb_cred_info->prealm, 1);
367 copy_Realm (&out_creds->client->realm, krb_cred_info->prealm);
368 ALLOC(krb_cred_info->pname, 1);
369 copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname);
370 ALLOC(krb_cred_info->flags, 1);
371 *krb_cred_info->flags = out_creds->flags.b;
372 ALLOC(krb_cred_info->authtime, 1);
373 *krb_cred_info->authtime = out_creds->times.authtime;
374 ALLOC(krb_cred_info->starttime, 1);
375 *krb_cred_info->starttime = out_creds->times.starttime;
376 ALLOC(krb_cred_info->endtime, 1);
377 *krb_cred_info->endtime = out_creds->times.endtime;
378 ALLOC(krb_cred_info->renew_till, 1);
379 *krb_cred_info->renew_till = out_creds->times.renew_till;
380 ALLOC(krb_cred_info->srealm, 1);
381 copy_Realm (&out_creds->server->realm, krb_cred_info->srealm);
382 ALLOC(krb_cred_info->sname, 1);
383 copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname);
384 ALLOC(krb_cred_info->caddr, 1);
385 copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr);
386
387 krb5_free_creds (context, out_creds);
388
389 /* encode EncKrbCredPart */
390
391 ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size,
392 &enc_krb_cred_part, &len, ret);
393 free_EncKrbCredPart (&enc_krb_cred_part);
394 if (ret) {
395 free_KRB_CRED(&cred);
396 return ret;
397 }
398 if(buf_size != len)
399 krb5_abortx(context, "internal error in ASN.1 encoder");
400
401 /**
402 * Some older of the MIT gssapi library used clear-text tickets
403 * (warped inside AP-REQ encryption), use the krb5_auth_context
404 * flag KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED to support those
405 * tickets. The session key is used otherwise to encrypt the
406 * forwarded ticket.
407 */
408
409 if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) {
410 cred.enc_part.etype = ENCTYPE_NULL;
411 cred.enc_part.kvno = NULL;
412 cred.enc_part.cipher.data = buf;
413 cred.enc_part.cipher.length = buf_size;
414 } else {
415 /*
416 * Here older versions then 0.7.2 of Heimdal used the local or
417 * remote subkey. That is wrong, the session key should be
418 * used. Heimdal 0.7.2 and newer have code to try both in the
419 * receiving end.
420 */
421
422 ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto);
423 if (ret) {
424 free(buf);
425 free_KRB_CRED(&cred);
426 return ret;
427 }
428 ret = krb5_encrypt_EncryptedData (context,
429 crypto,
430 KRB5_KU_KRB_CRED,
431 buf,
432 len,
433 0,
434 &cred.enc_part);
435 free(buf);
436 krb5_crypto_destroy(context, crypto);
437 if (ret) {
438 free_KRB_CRED(&cred);
439 return ret;
440 }
441 }
442
443 ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret);
444 free_KRB_CRED (&cred);
445 if (ret)
446 return ret;
447 if(buf_size != len)
448 krb5_abortx(context, "internal error in ASN.1 encoder");
449 out_data->length = len;
450 out_data->data = buf;
451 return 0;
452 out4:
453 free_EncKrbCredPart(&enc_krb_cred_part);
454 out3:
455 free_KRB_CRED(&cred);
456 out2:
457 krb5_free_creds (context, out_creds);
458 return ret;
459 }
460