1 /* $NetBSD: get_for_creds.c,v 1.1.1.1 2011/04/13 18:15:33 elric Exp $ */ 2 3 /* 4 * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "krb5_locl.h" 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 ret = ENOMEM; 55 krb5_set_error_message(context, ret, N_("malloc: out of memory", "")); 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_message (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_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 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_make_principal(context, 143 &creds.server, 144 client_realm, 145 KRB5_TGS_NAME, 146 client_realm, 147 NULL); 148 if (ret) 149 return ret; 150 151 ret = krb5_get_forwarded_creds (context, 152 auth_context, 153 ccache, 154 flags, 155 hostname, 156 &creds, 157 out_data); 158 return ret; 159 } 160 161 /** 162 * Gets tickets forwarded to hostname. If the tickets that are 163 * forwarded are address-less, the forwarded tickets will also be 164 * address-less. 165 * 166 * If the ticket have any address, hostname will be used for figure 167 * out the address to forward the ticket too. This since this might 168 * use DNS, its insecure and also doesn't represent configured all 169 * addresses of the host. For example, the host might have two 170 * adresses, one IPv4 and one IPv6 address where the later is not 171 * published in DNS. This IPv6 address might be used communications 172 * and thus the resulting ticket useless. 173 * 174 * @param context A kerberos 5 context. 175 * @param auth_context the auth context with the key to encrypt the out_data. 176 * @param ccache credential cache to use 177 * @param flags the flags to control the resulting ticket flags 178 * @param hostname the host to forward the tickets too. 179 * @param in_creds the in client and server ticket names. The client 180 * and server components forwarded to the remote host. 181 * @param out_data the resulting credential. 182 * 183 * @return Return an error code or 0. 184 * 185 * @ingroup krb5_credential 186 */ 187 188 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 189 krb5_get_forwarded_creds (krb5_context context, 190 krb5_auth_context auth_context, 191 krb5_ccache ccache, 192 krb5_flags flags, 193 const char *hostname, 194 krb5_creds *in_creds, 195 krb5_data *out_data) 196 { 197 krb5_error_code ret; 198 krb5_creds *out_creds; 199 krb5_addresses addrs, *paddrs; 200 KRB_CRED cred; 201 KrbCredInfo *krb_cred_info; 202 EncKrbCredPart enc_krb_cred_part; 203 size_t len; 204 unsigned char *buf; 205 size_t buf_size; 206 krb5_kdc_flags kdc_flags; 207 krb5_crypto crypto; 208 struct addrinfo *ai; 209 krb5_creds *ticket; 210 211 paddrs = NULL; 212 addrs.len = 0; 213 addrs.val = NULL; 214 215 ret = krb5_get_credentials(context, 0, ccache, in_creds, &ticket); 216 if(ret == 0) { 217 if (ticket->addresses.len) 218 paddrs = &addrs; 219 krb5_free_creds (context, ticket); 220 } else { 221 krb5_boolean noaddr; 222 krb5_appdefault_boolean(context, NULL, 223 krb5_principal_get_realm(context, 224 in_creds->client), 225 "no-addresses", KRB5_ADDRESSLESS_DEFAULT, 226 &noaddr); 227 if (!noaddr) 228 paddrs = &addrs; 229 } 230 231 /* 232 * If tickets have addresses, get the address of the remote host. 233 */ 234 235 if (paddrs != NULL) { 236 237 ret = getaddrinfo (hostname, NULL, NULL, &ai); 238 if (ret) { 239 krb5_error_code ret2 = krb5_eai_to_heim_errno(ret, errno); 240 krb5_set_error_message(context, ret2, 241 N_("resolving host %s failed: %s", 242 "hostname, error"), 243 hostname, gai_strerror(ret)); 244 return ret2; 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_message(context, ret, N_("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_message(context, ret, N_("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_message(context, ret, N_("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_message(context, ret, N_("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_message(context, ret, 350 N_("malloc: out of memory", "")); 351 goto out4; 352 } 353 354 ret = krb5_copy_address (context, auth_context->remote_address, 355 enc_krb_cred_part.r_address); 356 if (ret) 357 goto out4; 358 } 359 } 360 361 /* fill ticket_info.val[0] */ 362 363 enc_krb_cred_part.ticket_info.len = 1; 364 365 krb_cred_info = enc_krb_cred_part.ticket_info.val; 366 367 copy_EncryptionKey (&out_creds->session, &krb_cred_info->key); 368 ALLOC(krb_cred_info->prealm, 1); 369 copy_Realm (&out_creds->client->realm, krb_cred_info->prealm); 370 ALLOC(krb_cred_info->pname, 1); 371 copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname); 372 ALLOC(krb_cred_info->flags, 1); 373 *krb_cred_info->flags = out_creds->flags.b; 374 ALLOC(krb_cred_info->authtime, 1); 375 *krb_cred_info->authtime = out_creds->times.authtime; 376 ALLOC(krb_cred_info->starttime, 1); 377 *krb_cred_info->starttime = out_creds->times.starttime; 378 ALLOC(krb_cred_info->endtime, 1); 379 *krb_cred_info->endtime = out_creds->times.endtime; 380 ALLOC(krb_cred_info->renew_till, 1); 381 *krb_cred_info->renew_till = out_creds->times.renew_till; 382 ALLOC(krb_cred_info->srealm, 1); 383 copy_Realm (&out_creds->server->realm, krb_cred_info->srealm); 384 ALLOC(krb_cred_info->sname, 1); 385 copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname); 386 ALLOC(krb_cred_info->caddr, 1); 387 copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr); 388 389 krb5_free_creds (context, out_creds); 390 391 /* encode EncKrbCredPart */ 392 393 ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size, 394 &enc_krb_cred_part, &len, ret); 395 free_EncKrbCredPart (&enc_krb_cred_part); 396 if (ret) { 397 free_KRB_CRED(&cred); 398 return ret; 399 } 400 if(buf_size != len) 401 krb5_abortx(context, "internal error in ASN.1 encoder"); 402 403 /** 404 * Some older of the MIT gssapi library used clear-text tickets 405 * (warped inside AP-REQ encryption), use the krb5_auth_context 406 * flag KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED to support those 407 * tickets. The session key is used otherwise to encrypt the 408 * forwarded ticket. 409 */ 410 411 if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) { 412 cred.enc_part.etype = ENCTYPE_NULL; 413 cred.enc_part.kvno = NULL; 414 cred.enc_part.cipher.data = buf; 415 cred.enc_part.cipher.length = buf_size; 416 } else { 417 /* 418 * Here older versions then 0.7.2 of Heimdal used the local or 419 * remote subkey. That is wrong, the session key should be 420 * used. Heimdal 0.7.2 and newer have code to try both in the 421 * receiving end. 422 */ 423 424 ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto); 425 if (ret) { 426 free(buf); 427 free_KRB_CRED(&cred); 428 return ret; 429 } 430 ret = krb5_encrypt_EncryptedData (context, 431 crypto, 432 KRB5_KU_KRB_CRED, 433 buf, 434 len, 435 0, 436 &cred.enc_part); 437 free(buf); 438 krb5_crypto_destroy(context, crypto); 439 if (ret) { 440 free_KRB_CRED(&cred); 441 return ret; 442 } 443 } 444 445 ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret); 446 free_KRB_CRED (&cred); 447 if (ret) 448 return ret; 449 if(buf_size != len) 450 krb5_abortx(context, "internal error in ASN.1 encoder"); 451 out_data->length = len; 452 out_data->data = buf; 453 return 0; 454 out4: 455 free_EncKrbCredPart(&enc_krb_cred_part); 456 out3: 457 free_KRB_CRED(&cred); 458 out2: 459 krb5_free_creds (context, out_creds); 460 return ret; 461 } 462