crypto/external/bsd/heimdal/dist/lib/krb5/get_for_creds.c

   1 /*      $NetBSD: get_for_creds.c,v 1.1.1.2 2014/04/24 12:45:50 pettai 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 }