1/* 2 * Copyright (c) 1997 - 2004 Kungliga Tekniska H��gskolan 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 36static krb5_error_code 37add_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; 79fail: 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 103krb5_error_code KRB5_LIB_FUNCTION 104krb5_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_build_principal(context, 141 &creds.server, 142 strlen(client_realm), 143 client_realm, 144 KRB5_TGS_NAME, 145 client_realm, 146 NULL); 147 if (ret) 148 return ret; 149 150 ret = krb5_get_forwarded_creds (context, 151 auth_context, 152 ccache, 153 flags, 154 hostname, 155 &creds, 156 out_data); 157 return ret; 158} 159 160/** 161 * Gets tickets forwarded to hostname. If the tickets that are 162 * forwarded are address-less, the forwarded tickets will also be 163 * address-less. 164 * 165 * If the ticket have any address, hostname will be used for figure 166 * out the address to forward the ticket too. This since this might 167 * use DNS, its insecure and also doesn't represent configured all 168 * addresses of the host. For example, the host might have two 169 * adresses, one IPv4 and one IPv6 address where the later is not 170 * published in DNS. This IPv6 address might be used communications 171 * and thus the resulting ticket useless. 172 * 173 * @param context A kerberos 5 context. 174 * @param auth_context the auth context with the key to encrypt the out_data. 175 * @param ccache credential cache to use 176 * @param flags the flags to control the resulting ticket flags 177 * @param hostname the host to forward the tickets too. 178 * @param in_creds the in client and server ticket names. The client 179 * and server components forwarded to the remote host. 180 * @param out_data the resulting credential. 181 * 182 * @return Return an error code or 0. 183 * 184 * @ingroup krb5_credential 185 */ 186 187krb5_error_code KRB5_LIB_FUNCTION 188krb5_get_forwarded_creds (krb5_context context, 189 krb5_auth_context auth_context, 190 krb5_ccache ccache, 191 krb5_flags flags, 192 const char *hostname, 193 krb5_creds *in_creds, 194 krb5_data *out_data) 195{ 196 krb5_error_code ret; 197 krb5_creds *out_creds; 198 krb5_addresses addrs, *paddrs; 199 KRB_CRED cred; 200 KrbCredInfo *krb_cred_info; 201 EncKrbCredPart enc_krb_cred_part; 202 size_t len; 203 unsigned char *buf; 204 size_t buf_size; 205 krb5_kdc_flags kdc_flags; 206 krb5_crypto crypto; 207 struct addrinfo *ai; 208 krb5_creds *ticket; 209 210 paddrs = NULL; 211 addrs.len = 0; 212 addrs.val = NULL; 213 214 ret = krb5_get_credentials(context, 0, ccache, in_creds, &ticket); 215 if(ret == 0) { 216 if (ticket->addresses.len) 217 paddrs = &addrs; 218 krb5_free_creds (context, ticket); 219 } else { 220 krb5_boolean noaddr; 221 krb5_appdefault_boolean(context, NULL, 222 krb5_principal_get_realm(context, 223 in_creds->client), 224 "no-addresses", KRB5_ADDRESSLESS_DEFAULT, 225 &noaddr); 226 if (!noaddr) 227 paddrs = &addrs; 228 } 229 230 /* 231 * If tickets have addresses, get the address of the remote host. 232 */ 233 234 if (paddrs != NULL) { 235 236 ret = getaddrinfo (hostname, NULL, NULL, &ai); 237 if (ret) { 238 krb5_error_code ret2 = krb5_eai_to_heim_errno(ret, errno); 239 krb5_set_error_message(context, ret2, 240 N_("resolving host %s failed: %s", 241 "hostname, error"), 242 hostname, gai_strerror(ret)); 243 return ret2; 244 } 245 246 ret = add_addrs (context, &addrs, ai); 247 freeaddrinfo (ai); 248 if (ret) 249 return ret; 250 } 251 252 kdc_flags.b = int2KDCOptions(flags); 253 254 ret = krb5_get_kdc_cred (context, 255 ccache, 256 kdc_flags, 257 paddrs, 258 NULL, 259 in_creds, 260 &out_creds); 261 krb5_free_addresses (context, &addrs); 262 if (ret) 263 return ret; 264 265 memset (&cred, 0, sizeof(cred)); 266 cred.pvno = 5; 267 cred.msg_type = krb_cred; 268 ALLOC_SEQ(&cred.tickets, 1); 269 if (cred.tickets.val == NULL) { 270 ret = ENOMEM; 271 krb5_set_error_message(context, ret, N_("malloc: out of memory", "")); 272 goto out2; 273 } 274 ret = decode_Ticket(out_creds->ticket.data, 275 out_creds->ticket.length, 276 cred.tickets.val, &len); 277 if (ret) 278 goto out3; 279 280 memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part)); 281 ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1); 282 if (enc_krb_cred_part.ticket_info.val == NULL) { 283 ret = ENOMEM; 284 krb5_set_error_message(context, ret, N_("malloc: out of memory", "")); 285 goto out4; 286 } 287 288 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { 289 krb5_timestamp sec; 290 int32_t usec; 291 292 krb5_us_timeofday (context, &sec, &usec); 293 294 ALLOC(enc_krb_cred_part.timestamp, 1); 295 if (enc_krb_cred_part.timestamp == NULL) { 296 ret = ENOMEM; 297 krb5_set_error_message(context, ret, N_("malloc: out of memory", "")); 298 goto out4; 299 } 300 *enc_krb_cred_part.timestamp = sec; 301 ALLOC(enc_krb_cred_part.usec, 1); 302 if (enc_krb_cred_part.usec == NULL) { 303 ret = ENOMEM; 304 krb5_set_error_message(context, ret, N_("malloc: out of memory", "")); 305 goto out4; 306 } 307 *enc_krb_cred_part.usec = usec; 308 } else { 309 enc_krb_cred_part.timestamp = NULL; 310 enc_krb_cred_part.usec = NULL; 311 } 312 313 if (auth_context->local_address && auth_context->local_port && paddrs) { 314 315 ret = krb5_make_addrport (context, 316 &enc_krb_cred_part.s_address, 317 auth_context->local_address, 318 auth_context->local_port); 319 if (ret) 320 goto out4; 321 } 322 323 if (auth_context->remote_address) { 324 if (auth_context->remote_port) { 325 krb5_boolean noaddr; 326 krb5_const_realm srealm; 327 328 srealm = krb5_principal_get_realm(context, out_creds->server); 329 /* Is this correct, and should we use the paddrs == NULL 330 trick here as well? Having an address-less ticket may 331 indicate that we don't know our own global address, but 332 it does not necessary mean that we don't know the 333 server's. */ 334 krb5_appdefault_boolean(context, NULL, srealm, "no-addresses", 335 FALSE, &noaddr); 336 if (!noaddr) { 337 ret = krb5_make_addrport (context, 338 &enc_krb_cred_part.r_address, 339 auth_context->remote_address, 340 auth_context->remote_port); 341 if (ret) 342 goto out4; 343 } 344 } else { 345 ALLOC(enc_krb_cred_part.r_address, 1); 346 if (enc_krb_cred_part.r_address == NULL) { 347 ret = ENOMEM; 348 krb5_set_error_message(context, ret, 349 N_("malloc: out of memory", "")); 350 goto out4; 351 } 352 353 ret = krb5_copy_address (context, auth_context->remote_address, 354 enc_krb_cred_part.r_address); 355 if (ret) 356 goto out4; 357 } 358 } 359 360 /* fill ticket_info.val[0] */ 361 362 enc_krb_cred_part.ticket_info.len = 1; 363 364 krb_cred_info = enc_krb_cred_part.ticket_info.val; 365 366 copy_EncryptionKey (&out_creds->session, &krb_cred_info->key); 367 ALLOC(krb_cred_info->prealm, 1); 368 copy_Realm (&out_creds->client->realm, krb_cred_info->prealm); 369 ALLOC(krb_cred_info->pname, 1); 370 copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname); 371 ALLOC(krb_cred_info->flags, 1); 372 *krb_cred_info->flags = out_creds->flags.b; 373 ALLOC(krb_cred_info->authtime, 1); 374 *krb_cred_info->authtime = out_creds->times.authtime; 375 ALLOC(krb_cred_info->starttime, 1); 376 *krb_cred_info->starttime = out_creds->times.starttime; 377 ALLOC(krb_cred_info->endtime, 1); 378 *krb_cred_info->endtime = out_creds->times.endtime; 379 ALLOC(krb_cred_info->renew_till, 1); 380 *krb_cred_info->renew_till = out_creds->times.renew_till; 381 ALLOC(krb_cred_info->srealm, 1); 382 copy_Realm (&out_creds->server->realm, krb_cred_info->srealm); 383 ALLOC(krb_cred_info->sname, 1); 384 copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname); 385 ALLOC(krb_cred_info->caddr, 1); 386 copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr); 387 388 krb5_free_creds (context, out_creds); 389 390 /* encode EncKrbCredPart */ 391 392 ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size, 393 &enc_krb_cred_part, &len, ret); 394 free_EncKrbCredPart (&enc_krb_cred_part); 395 if (ret) { 396 free_KRB_CRED(&cred); 397 return ret; 398 } 399 if(buf_size != len) 400 krb5_abortx(context, "internal error in ASN.1 encoder"); 401 402 /** 403 * Some older of the MIT gssapi library used clear-text tickets 404 * (warped inside AP-REQ encryption), use the krb5_auth_context 405 * flag KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED to support those 406 * tickets. The session key is used otherwise to encrypt the 407 * forwarded ticket. 408 */ 409 410 if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) { 411 cred.enc_part.etype = ENCTYPE_NULL; 412 cred.enc_part.kvno = NULL; 413 cred.enc_part.cipher.data = buf; 414 cred.enc_part.cipher.length = buf_size; 415 } else { 416 /* 417 * Here older versions then 0.7.2 of Heimdal used the local or 418 * remote subkey. That is wrong, the session key should be 419 * used. Heimdal 0.7.2 and newer have code to try both in the 420 * receiving end. 421 */ 422 423 ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto); 424 if (ret) { 425 free(buf); 426 free_KRB_CRED(&cred); 427 return ret; 428 } 429 ret = krb5_encrypt_EncryptedData (context, 430 crypto, 431 KRB5_KU_KRB_CRED, 432 buf, 433 len, 434 0, 435 &cred.enc_part); 436 free(buf); 437 krb5_crypto_destroy(context, crypto); 438 if (ret) { 439 free_KRB_CRED(&cred); 440 return ret; 441 } 442 } 443 444 ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret); 445 free_KRB_CRED (&cred); 446 if (ret) 447 return ret; 448 if(buf_size != len) 449 krb5_abortx(context, "internal error in ASN.1 encoder"); 450 out_data->length = len; 451 out_data->data = buf; 452 return 0; 453 out4: 454 free_EncKrbCredPart(&enc_krb_cred_part); 455 out3: 456 free_KRB_CRED(&cred); 457 out2: 458 krb5_free_creds (context, out_creds); 459 return ret; 460} 461