1 /* $NetBSD: get_for_creds.c,v 1.3 2019/12/15 22:50:50 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1997 - 2004 Kungliga Tekniska Hgskolan 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 = krb5_enomem(context); 55 goto fail; 56 } 57 addr->val = tmp; 58 for (i = addr->len; i < (addr->len + n); ++i) { 59 addr->val[i].addr_type = 0; 60 krb5_data_zero(&addr->val[i].address); 61 } 62 i = addr->len; 63 for (a = ai; a != NULL; a = a->ai_next) { 64 krb5_address ad; 65 66 ret = krb5_sockaddr2address (context, a->ai_addr, &ad); 67 if (ret == 0) { 68 if (krb5_address_search(context, &ad, addr)) 69 krb5_free_address(context, &ad); 70 else 71 addr->val[i++] = ad; 72 } 73 else if (ret == KRB5_PROG_ATYPE_NOSUPP) 74 krb5_clear_error_message (context); 75 else 76 goto fail; 77 addr->len = i; 78 } 79 return 0; 80 fail: 81 krb5_free_addresses (context, addr); 82 return ret; 83 } 84 85 /** 86 * Forward credentials for client to host hostname , making them 87 * forwardable if forwardable, and returning the blob of data to sent 88 * in out_data. If hostname == NULL, pick it from server. 89 * 90 * @param context A kerberos 5 context. 91 * @param auth_context the auth context with the key to encrypt the out_data. 92 * @param hostname the host to forward the tickets too. 93 * @param client the client to delegate from. 94 * @param server the server to delegate the credential too. 95 * @param ccache credential cache to use. 96 * @param forwardable make the forwarded ticket forwabledable. 97 * @param out_data the resulting credential. 98 * 99 * @return Return an error code or 0. 100 * 101 * @ingroup krb5_credential 102 */ 103 104 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 105 krb5_fwd_tgt_creds (krb5_context context, 106 krb5_auth_context auth_context, 107 const char *hostname, 108 krb5_principal client, 109 krb5_principal server, 110 krb5_ccache ccache, 111 int forwardable, 112 krb5_data *out_data) 113 { 114 krb5_flags flags = 0; 115 krb5_creds creds; 116 krb5_error_code ret; 117 krb5_const_realm client_realm; 118 119 flags |= KDC_OPT_FORWARDED; 120 121 if (forwardable) 122 flags |= KDC_OPT_FORWARDABLE; 123 124 if (hostname == NULL && 125 krb5_principal_get_type(context, server) == KRB5_NT_SRV_HST) { 126 const char *inst = krb5_principal_get_comp_string(context, server, 0); 127 const char *host = krb5_principal_get_comp_string(context, server, 1); 128 129 if (inst != NULL && 130 strcmp(inst, "host") == 0 && 131 host != NULL && 132 krb5_principal_get_comp_string(context, server, 2) == NULL) 133 hostname = host; 134 } 135 136 client_realm = krb5_principal_get_realm(context, client); 137 138 memset (&creds, 0, sizeof(creds)); 139 creds.client = client; 140 141 ret = krb5_make_principal(context, 142 &creds.server, 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 */ 186 187 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 188 krb5_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 = krb5_enomem(context); 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 = krb5_enomem(context); 283 goto out4; 284 } 285 286 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { 287 krb5_timestamp sec; 288 int32_t usec; 289 290 krb5_us_timeofday (context, &sec, &usec); 291 292 ALLOC(enc_krb_cred_part.timestamp, 1); 293 if (enc_krb_cred_part.timestamp == NULL) { 294 ret = krb5_enomem(context); 295 goto out4; 296 } 297 *enc_krb_cred_part.timestamp = sec; 298 ALLOC(enc_krb_cred_part.usec, 1); 299 if (enc_krb_cred_part.usec == NULL) { 300 ret = krb5_enomem(context); 301 goto out4; 302 } 303 *enc_krb_cred_part.usec = usec; 304 } else { 305 enc_krb_cred_part.timestamp = NULL; 306 enc_krb_cred_part.usec = NULL; 307 } 308 309 if (auth_context->local_address && auth_context->local_port && paddrs) { 310 311 ret = krb5_make_addrport (context, 312 &enc_krb_cred_part.s_address, 313 auth_context->local_address, 314 auth_context->local_port); 315 if (ret) 316 goto out4; 317 } 318 319 if (auth_context->remote_address) { 320 if (auth_context->remote_port) { 321 krb5_boolean noaddr; 322 krb5_const_realm srealm; 323 324 srealm = krb5_principal_get_realm(context, out_creds->server); 325 /* Is this correct, and should we use the paddrs == NULL 326 trick here as well? Having an address-less ticket may 327 indicate that we don't know our own global address, but 328 it does not necessary mean that we don't know the 329 server's. */ 330 krb5_appdefault_boolean(context, NULL, srealm, "no-addresses", 331 FALSE, &noaddr); 332 if (!noaddr) { 333 ret = krb5_make_addrport (context, 334 &enc_krb_cred_part.r_address, 335 auth_context->remote_address, 336 auth_context->remote_port); 337 if (ret) 338 goto out4; 339 } 340 } else { 341 ALLOC(enc_krb_cred_part.r_address, 1); 342 if (enc_krb_cred_part.r_address == NULL) { 343 ret = krb5_enomem(context); 344 goto out4; 345 } 346 347 ret = krb5_copy_address (context, auth_context->remote_address, 348 enc_krb_cred_part.r_address); 349 if (ret) 350 goto out4; 351 } 352 } 353 354 /* fill ticket_info.val[0] */ 355 356 enc_krb_cred_part.ticket_info.len = 1; 357 358 krb_cred_info = enc_krb_cred_part.ticket_info.val; 359 360 ret = copy_EncryptionKey (&out_creds->session, &krb_cred_info->key); 361 if (ret) 362 goto out4; 363 ALLOC(krb_cred_info->prealm, 1); 364 ret = copy_Realm (&out_creds->client->realm, krb_cred_info->prealm); 365 if (ret) 366 goto out4; 367 ALLOC(krb_cred_info->pname, 1); 368 ret = copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname); 369 if (ret) 370 goto out4; 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 ret = copy_Realm (&out_creds->server->realm, krb_cred_info->srealm); 383 if (ret) 384 goto out4; 385 ALLOC(krb_cred_info->sname, 1); 386 ret = copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname); 387 if (ret) 388 goto out4; 389 ALLOC(krb_cred_info->caddr, 1); 390 ret = copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr); 391 if (ret) 392 goto out4; 393 394 krb5_free_creds (context, out_creds); 395 396 /* encode EncKrbCredPart */ 397 398 ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size, 399 &enc_krb_cred_part, &len, ret); 400 free_EncKrbCredPart (&enc_krb_cred_part); 401 if (ret) { 402 free_KRB_CRED(&cred); 403 return ret; 404 } 405 if(buf_size != len) 406 krb5_abortx(context, "internal error in ASN.1 encoder"); 407 408 /** 409 * Some older of the MIT gssapi library used clear-text tickets 410 * (warped inside AP-REQ encryption), use the krb5_auth_context 411 * flag KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED to support those 412 * tickets. The session key is used otherwise to encrypt the 413 * forwarded ticket. 414 */ 415 416 if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) { 417 cred.enc_part.etype = KRB5_ENCTYPE_NULL; 418 cred.enc_part.kvno = NULL; 419 cred.enc_part.cipher.data = buf; 420 cred.enc_part.cipher.length = buf_size; 421 } else { 422 /* 423 * Here older versions then 0.7.2 of Heimdal used the local or 424 * remote subkey. That is wrong, the session key should be 425 * used. Heimdal 0.7.2 and newer have code to try both in the 426 * receiving end. 427 */ 428 429 ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto); 430 if (ret) { 431 free(buf); 432 free_KRB_CRED(&cred); 433 return ret; 434 } 435 ret = krb5_encrypt_EncryptedData (context, 436 crypto, 437 KRB5_KU_KRB_CRED, 438 buf, 439 len, 440 0, 441 &cred.enc_part); 442 free(buf); 443 krb5_crypto_destroy(context, crypto); 444 if (ret) { 445 free_KRB_CRED(&cred); 446 return ret; 447 } 448 } 449 450 ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret); 451 free_KRB_CRED (&cred); 452 if (ret) 453 return ret; 454 if(buf_size != len) 455 krb5_abortx(context, "internal error in ASN.1 encoder"); 456 out_data->length = len; 457 out_data->data = buf; 458 return 0; 459 out4: 460 free_EncKrbCredPart(&enc_krb_cred_part); 461 out3: 462 free_KRB_CRED(&cred); 463 out2: 464 krb5_free_creds (context, out_creds); 465 return ret; 466 } 467
Indexes created Tue Aug 11 00:25:38 UTC 2026