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 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 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 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