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 36 RCSID("$Id: get_for_creds.c 22504 2008-01-21 15:49:58Z lha $"); 37 38 static krb5_error_code 39 add_addrs(krb5_context context, 40 krb5_addresses *addr, 41 struct addrinfo *ai) 42 { 43 krb5_error_code ret; 44 unsigned n, i; 45 void *tmp; 46 struct addrinfo *a; 47 48 n = 0; 49 for (a = ai; a != NULL; a = a->ai_next) 50 ++n; 51 52 tmp = realloc(addr->val, (addr->len + n) * sizeof(*addr->val)); 53 if (tmp == NULL && (addr->len + n) != 0) { 54 krb5_set_error_string(context, "malloc: out of memory"); 55 ret = ENOMEM; 56 goto fail; 57 } 58 addr->val = tmp; 59 for (i = addr->len; i < (addr->len + n); ++i) { 60 addr->val[i].addr_type = 0; 61 krb5_data_zero(&addr->val[i].address); 62 } 63 i = addr->len; 64 for (a = ai; a != NULL; a = a->ai_next) { 65 krb5_address ad; 66 67 ret = krb5_sockaddr2address (context, a->ai_addr, &ad); 68 if (ret == 0) { 69 if (krb5_address_search(context, &ad, addr)) 70 krb5_free_address(context, &ad); 71 else 72 addr->val[i++] = ad; 73 } 74 else if (ret == KRB5_PROG_ATYPE_NOSUPP) 75 krb5_clear_error_string (context); 76 else 77 goto fail; 78 addr->len = i; 79 } 80 return 0; 81 fail: 82 krb5_free_addresses (context, addr); 83 return ret; 84 } 85 86 /** 87 * Forward credentials for client to host hostname , making them 88 * forwardable if forwardable, and returning the blob of data to sent 89 * in out_data. If hostname == NULL, pick it from server. 90 * 91 * @param context A kerberos 5 context. 92 * @param auth_context the auth context with the key to encrypt the out_data. 93 * @param hostname the host to forward the tickets too. 94 * @param client the client to delegate from. 95 * @param server the server to delegate the credential too. 96 * @param ccache credential cache to use. 97 * @param forwardable make the forwarded ticket forwabledable. 98 * @param out_data the resulting credential. 99 * 100 * @return Return an error code or 0. 101 * 102 * @ingroup krb5_credential 103 */ 104 105 krb5_error_code KRB5_LIB_FUNCTION 106 krb5_fwd_tgt_creds (krb5_context context, 107 krb5_auth_context auth_context, 108 const char *hostname, 109 krb5_principal client, 110 krb5_principal server, 111 krb5_ccache ccache, 112 int forwardable, 113 krb5_data *out_data) 114 { 115 krb5_flags flags = 0; 116 krb5_creds creds; 117 krb5_error_code ret; 118 krb5_const_realm client_realm; 119 120 flags |= KDC_OPT_FORWARDED; 121 122 if (forwardable) 123 flags |= KDC_OPT_FORWARDABLE; 124 125 if (hostname == NULL && 126 krb5_principal_get_type(context, server) == KRB5_NT_SRV_HST) { 127 const char *inst = krb5_principal_get_comp_string(context, server, 0); 128 const char *host = krb5_principal_get_comp_string(context, server, 1); 129 130 if (inst != NULL && 131 strcmp(inst, "host") == 0 && 132 host != NULL && 133 krb5_principal_get_comp_string(context, server, 2) == NULL) 134 hostname = host; 135 } 136 137 client_realm = krb5_principal_get_realm(context, client); 138 139 memset (&creds, 0, sizeof(creds)); 140 creds.client = client; 141 142 ret = krb5_build_principal(context, 143 &creds.server, 144 strlen(client_realm), 145 client_realm, 146 KRB5_TGS_NAME, 147 client_realm, 148 NULL); 149 if (ret) 150 return ret; 151 152 ret = krb5_get_forwarded_creds (context, 153 auth_context, 154 ccache, 155 flags, 156 hostname, 157 &creds, 158 out_data); 159 return ret; 160 } 161 162 /** 163 * Gets tickets forwarded to hostname. If the tickets that are 164 * forwarded are address-less, the forwarded tickets will also be 165 * address-less. 166 * 167 * If the ticket have any address, hostname will be used for figure 168 * out the address to forward the ticket too. This since this might 169 * use DNS, its insecure and also doesn't represent configured all 170 * addresses of the host. For example, the host might have two 171 * adresses, one IPv4 and one IPv6 address where the later is not 172 * published in DNS. This IPv6 address might be used communications 173 * and thus the resulting ticket useless. 174 * 175 * @param context A kerberos 5 context. 176 * @param auth_context the auth context with the key to encrypt the out_data. 177 * @param ccache credential cache to use 178 * @param flags the flags to control the resulting ticket flags 179 * @param hostname the host to forward the tickets too. 180 * @param in_creds the in client and server ticket names. The client 181 * and server components forwarded to the remote host. 182 * @param out_data the resulting credential. 183 * 184 * @return Return an error code or 0. 185 * 186 * @ingroup krb5_credential 187 */ 188 189 krb5_error_code KRB5_LIB_FUNCTION 190 krb5_get_forwarded_creds (krb5_context context, 191 krb5_auth_context auth_context, 192 krb5_ccache ccache, 193 krb5_flags flags, 194 const char *hostname, 195 krb5_creds *in_creds, 196 krb5_data *out_data) 197 { 198 krb5_error_code ret; 199 krb5_creds *out_creds; 200 krb5_addresses addrs, *paddrs; 201 KRB_CRED cred; 202 KrbCredInfo *krb_cred_info; 203 EncKrbCredPart enc_krb_cred_part; 204 size_t len; 205 unsigned char *buf; 206 size_t buf_size; 207 krb5_kdc_flags kdc_flags; 208 krb5_crypto crypto; 209 struct addrinfo *ai; 210 int save_errno; 211 krb5_creds *ticket; 212 213 paddrs = NULL; 214 addrs.len = 0; 215 addrs.val = NULL; 216 217 ret = krb5_get_credentials(context, 0, ccache, in_creds, &ticket); 218 if(ret == 0) { 219 if (ticket->addresses.len) 220 paddrs = &addrs; 221 krb5_free_creds (context, ticket); 222 } else { 223 krb5_boolean noaddr; 224 krb5_appdefault_boolean(context, NULL, 225 krb5_principal_get_realm(context, 226 in_creds->client), 227 "no-addresses", KRB5_ADDRESSLESS_DEFAULT, 228 &noaddr); 229 if (!noaddr) 230 paddrs = &addrs; 231 } 232 233 /* 234 * If tickets have addresses, get the address of the remote host. 235 */ 236 237 if (paddrs != NULL) { 238 239 ret = getaddrinfo (hostname, NULL, NULL, &ai); 240 if (ret) { 241 save_errno = errno; 242 krb5_set_error_string(context, "resolving %s: %s", 243 hostname, gai_strerror(ret)); 244 return krb5_eai_to_heim_errno(ret, save_errno); 245 } 246 247 ret = add_addrs (context, &addrs, ai); 248 freeaddrinfo (ai); 249 if (ret) 250 return ret; 251 } 252 253 kdc_flags.b = int2KDCOptions(flags); 254 255 ret = krb5_get_kdc_cred (context, 256 ccache, 257 kdc_flags, 258 paddrs, 259 NULL, 260 in_creds, 261 &out_creds); 262 krb5_free_addresses (context, &addrs); 263 if (ret) 264 return ret; 265 266 memset (&cred, 0, sizeof(cred)); 267 cred.pvno = 5; 268 cred.msg_type = krb_cred; 269 ALLOC_SEQ(&cred.tickets, 1); 270 if (cred.tickets.val == NULL) { 271 ret = ENOMEM; 272 krb5_set_error_string(context, "malloc: out of memory"); 273 goto out2; 274 } 275 ret = decode_Ticket(out_creds->ticket.data, 276 out_creds->ticket.length, 277 cred.tickets.val, &len); 278 if (ret) 279 goto out3; 280 281 memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part)); 282 ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1); 283 if (enc_krb_cred_part.ticket_info.val == NULL) { 284 ret = ENOMEM; 285 krb5_set_error_string(context, "malloc: out of memory"); 286 goto out4; 287 } 288 289 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { 290 krb5_timestamp sec; 291 int32_t usec; 292 293 krb5_us_timeofday (context, &sec, &usec); 294 295 ALLOC(enc_krb_cred_part.timestamp, 1); 296 if (enc_krb_cred_part.timestamp == NULL) { 297 ret = ENOMEM; 298 krb5_set_error_string(context, "malloc: out of memory"); 299 goto out4; 300 } 301 *enc_krb_cred_part.timestamp = sec; 302 ALLOC(enc_krb_cred_part.usec, 1); 303 if (enc_krb_cred_part.usec == NULL) { 304 ret = ENOMEM; 305 krb5_set_error_string(context, "malloc: out of memory"); 306 goto out4; 307 } 308 *enc_krb_cred_part.usec = usec; 309 } else { 310 enc_krb_cred_part.timestamp = NULL; 311 enc_krb_cred_part.usec = NULL; 312 } 313 314 if (auth_context->local_address && auth_context->local_port && paddrs) { 315 316 ret = krb5_make_addrport (context, 317 &enc_krb_cred_part.s_address, 318 auth_context->local_address, 319 auth_context->local_port); 320 if (ret) 321 goto out4; 322 } 323 324 if (auth_context->remote_address) { 325 if (auth_context->remote_port) { 326 krb5_boolean noaddr; 327 krb5_const_realm srealm; 328 329 srealm = krb5_principal_get_realm(context, out_creds->server); 330 /* Is this correct, and should we use the paddrs == NULL 331 trick here as well? Having an address-less ticket may 332 indicate that we don't know our own global address, but 333 it does not necessary mean that we don't know the 334 server's. */ 335 krb5_appdefault_boolean(context, NULL, srealm, "no-addresses", 336 FALSE, &noaddr); 337 if (!noaddr) { 338 ret = krb5_make_addrport (context, 339 &enc_krb_cred_part.r_address, 340 auth_context->remote_address, 341 auth_context->remote_port); 342 if (ret) 343 goto out4; 344 } 345 } else { 346 ALLOC(enc_krb_cred_part.r_address, 1); 347 if (enc_krb_cred_part.r_address == NULL) { 348 ret = ENOMEM; 349 krb5_set_error_string(context, "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