source4/heimdal/lib/krb5/get_for_creds.c

   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 RCSID("$Id: get_for_creds.c,v 1.47 2006/02/03 11:37:29 lha Exp $");
  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) {
  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`,
  88  * making them forwardable if `forwardable', and returning the
  89  * blob of data to sent in `out_data'.
  90  * If hostname == NULL, pick it from `server'
  91  */
  92
  93 krb5_error_code KRB5_LIB_FUNCTION
  94 krb5_fwd_tgt_creds (krb5_context        context,
  95                     krb5_auth_context   auth_context,
  96                     const char          *hostname,
  97                     krb5_principal      client,
  98                     krb5_principal      server,
  99                     krb5_ccache         ccache,
 100                     int                 forwardable,
 101                     krb5_data           *out_data)
 102 {
 103     krb5_flags flags = 0;
 104     krb5_creds creds;
 105     krb5_error_code ret;
 106     krb5_const_realm client_realm;
 107
 108     flags |= KDC_OPT_FORWARDED;
 109
 110     if (forwardable)
 111         flags |= KDC_OPT_FORWARDABLE;
 112
 113     if (hostname == NULL &&
 114         krb5_principal_get_type(context, server) == KRB5_NT_SRV_HST) {
 115         const char *inst = krb5_principal_get_comp_string(context, server, 0);
 116         const char *host = krb5_principal_get_comp_string(context, server, 1);
 117
 118         if (inst != NULL &&
 119             strcmp(inst, "host") == 0 &&
 120             host != NULL &&
 121             krb5_principal_get_comp_string(context, server, 2) == NULL)
 122             hostname = host;
 123     }
 124
 125     client_realm = krb5_principal_get_realm(context, client);
 126
 127     memset (&creds, 0, sizeof(creds));
 128     creds.client = client;
 129
 130     ret = krb5_build_principal(context,
 131                                &creds.server,
 132                                strlen(client_realm),
 133                                client_realm,
 134                                KRB5_TGS_NAME,
 135                                client_realm,
 136                                NULL);
 137     if (ret)
 138         return ret;
 139
 140     ret = krb5_get_forwarded_creds (context,
 141                                     auth_context,
 142                                     ccache,
 143                                     flags,
 144                                     hostname,
 145                                     &creds,
 146                                     out_data);
 147     return ret;
 148 }
 149
 150 /*
 151  *
 152  */
 153
 154 krb5_error_code KRB5_LIB_FUNCTION
 155 krb5_get_forwarded_creds (krb5_context      context,
 156                           krb5_auth_context auth_context,
 157                           krb5_ccache       ccache,
 158                           krb5_flags        flags,
 159                           const char        *hostname,
 160                           krb5_creds        *in_creds,
 161                           krb5_data         *out_data)
 162 {
 163     krb5_error_code ret;
 164     krb5_creds *out_creds;
 165     krb5_addresses *paddrs = NULL;
 166     krb5_addresses addrs;
 167     KRB_CRED cred;
 168     KrbCredInfo *krb_cred_info;
 169     EncKrbCredPart enc_krb_cred_part;
 170     size_t len;
 171     unsigned char *buf;
 172     size_t buf_size;
 173     krb5_kdc_flags kdc_flags;
 174     krb5_crypto crypto;
 175     int save_errno;
 176     krb5_creds *ticket;
 177     char *realm;
 178     krb5_boolean noaddr_ever;
 179
 180     addrs.len = 0;
 181     addrs.val = NULL;
 182
 183     if (in_creds->client && in_creds->client->realm)
 184         realm = in_creds->client->realm;
 185     else
 186         realm = in_creds->server->realm;
 187
 188     krb5_appdefault_boolean(context, NULL, realm, "no-addresses-ever",
 189                             TRUE, &noaddr_ever);
 190     if (!noaddr_ever) {
 191             struct addrinfo *ai;
 192             paddrs = &addrs;
 193
 194             /*
 195              * If tickets are address-less, forward address-less tickets.
 196              */
 197
 198             ret = _krb5_get_krbtgt (context,
 199                                     ccache,
 200                                     realm,
 201                                     &ticket);
 202             if(ret == 0) {
 203                     if (ticket->addresses.len == 0)
 204                             paddrs = NULL;
 205                     krb5_free_creds (context, ticket);
 206             }
 207
 208             if (paddrs != NULL) {
 209
 210                     ret = getaddrinfo (hostname, NULL, NULL, &ai);
 211                     if (ret) {
 212                             save_errno = errno;
 213                             krb5_set_error_string(context, "resolving %s: %s",
 214                                                   hostname, gai_strerror(ret));
 215                             return krb5_eai_to_heim_errno(ret, save_errno);
 216                     }
 217
 218                     ret = add_addrs (context, &addrs, ai);
 219                     freeaddrinfo (ai);
 220                     if (ret)
 221                             return ret;
 222             }
 223     }
 224
 225     kdc_flags.b = int2KDCOptions(flags);
 226
 227     ret = krb5_get_kdc_cred (context,
 228                              ccache,
 229                              kdc_flags,
 230                              paddrs,
 231                              NULL,
 232                              in_creds,
 233                              &out_creds);
 234     krb5_free_addresses (context, &addrs);
 235     if (ret) {
 236         return ret;
 237     }
 238
 239     memset (&cred, 0, sizeof(cred));
 240     cred.pvno = 5;
 241     cred.msg_type = krb_cred;
 242     ALLOC_SEQ(&cred.tickets, 1);
 243     if (cred.tickets.val == NULL) {
 244         ret = ENOMEM;
 245         krb5_set_error_string(context, "malloc: out of memory");
 246         goto out2;
 247     }
 248     ret = decode_Ticket(out_creds->ticket.data,
 249                         out_creds->ticket.length,
 250                         cred.tickets.val, &len);
 251     if (ret)
 252         goto out3;
 253
 254     memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
 255     ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1);
 256     if (enc_krb_cred_part.ticket_info.val == NULL) {
 257         ret = ENOMEM;
 258         krb5_set_error_string(context, "malloc: out of memory");
 259         goto out4;
 260     }
 261
 262     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
 263         krb5_timestamp sec;
 264         int32_t usec;
 265
 266         krb5_us_timeofday (context, &sec, &usec);
 267
 268         ALLOC(enc_krb_cred_part.timestamp, 1);
 269         if (enc_krb_cred_part.timestamp == NULL) {
 270             ret = ENOMEM;
 271             krb5_set_error_string(context, "malloc: out of memory");
 272             goto out4;
 273         }
 274         *enc_krb_cred_part.timestamp = sec;
 275         ALLOC(enc_krb_cred_part.usec, 1);
 276         if (enc_krb_cred_part.usec == NULL) {
 277             ret = ENOMEM;
 278             krb5_set_error_string(context, "malloc: out of memory");
 279             goto out4;
 280         }
 281         *enc_krb_cred_part.usec      = usec;
 282     } else {
 283         enc_krb_cred_part.timestamp = NULL;
 284         enc_krb_cred_part.usec = NULL;
 285     }
 286
 287     if (auth_context->local_address && auth_context->local_port && paddrs) {
 288
 289         ret = krb5_make_addrport (context,
 290                                   &enc_krb_cred_part.s_address,
 291                                   auth_context->local_address,
 292                                   auth_context->local_port);
 293         if (ret)
 294             goto out4;
 295     }
 296
 297     if (auth_context->remote_address) {
 298         if (auth_context->remote_port) {
 299             krb5_boolean noaddr;
 300             krb5_const_realm srealm;
 301
 302             srealm = krb5_principal_get_realm(context, out_creds->server);
 303             /* Is this correct, and should we use the paddrs == NULL
 304                trick here as well? Having an address-less ticket may
 305                indicate that we don't know our own global address, but
 306                it does not necessary mean that we don't know the
 307                server's. */
 308             krb5_appdefault_boolean(context, NULL, srealm, "no-addresses",
 309                                     FALSE, &noaddr);
 310             if (!noaddr) {
 311                 ret = krb5_make_addrport (context,
 312                                           &enc_krb_cred_part.r_address,
 313                                           auth_context->remote_address,
 314                                           auth_context->remote_port);
 315                 if (ret)
 316                     goto out4;
 317             }
 318         } else {
 319             ALLOC(enc_krb_cred_part.r_address, 1);
 320             if (enc_krb_cred_part.r_address == NULL) {
 321                 ret = ENOMEM;
 322                 krb5_set_error_string(context, "malloc: out of memory");
 323                 goto out4;
 324             }
 325
 326             ret = krb5_copy_address (context, auth_context->remote_address,
 327                                      enc_krb_cred_part.r_address);
 328             if (ret)
 329                 goto out4;
 330         }
 331     }
 332
 333     /* fill ticket_info.val[0] */
 334
 335     enc_krb_cred_part.ticket_info.len = 1;
 336
 337     krb_cred_info = enc_krb_cred_part.ticket_info.val;
 338
 339     copy_EncryptionKey (&out_creds->session, &krb_cred_info->key);
 340     ALLOC(krb_cred_info->prealm, 1);
 341     copy_Realm (&out_creds->client->realm, krb_cred_info->prealm);
 342     ALLOC(krb_cred_info->pname, 1);
 343     copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname);
 344     ALLOC(krb_cred_info->flags, 1);
 345     *krb_cred_info->flags          = out_creds->flags.b;
 346     ALLOC(krb_cred_info->authtime, 1);
 347     *krb_cred_info->authtime       = out_creds->times.authtime;
 348     ALLOC(krb_cred_info->starttime, 1);
 349     *krb_cred_info->starttime      = out_creds->times.starttime;
 350     ALLOC(krb_cred_info->endtime, 1);
 351     *krb_cred_info->endtime        = out_creds->times.endtime;
 352     ALLOC(krb_cred_info->renew_till, 1);
 353     *krb_cred_info->renew_till = out_creds->times.renew_till;
 354     ALLOC(krb_cred_info->srealm, 1);
 355     copy_Realm (&out_creds->server->realm, krb_cred_info->srealm);
 356     ALLOC(krb_cred_info->sname, 1);
 357     copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname);
 358     ALLOC(krb_cred_info->caddr, 1);
 359     copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr);
 360
 361     krb5_free_creds (context, out_creds);
 362
 363     /* encode EncKrbCredPart */
 364
 365     ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size,
 366                        &enc_krb_cred_part, &len, ret);
 367     free_EncKrbCredPart (&enc_krb_cred_part);
 368     if (ret) {
 369         free_KRB_CRED(&cred);
 370         return ret;
 371     }
 372     if(buf_size != len)
 373         krb5_abortx(context, "internal error in ASN.1 encoder");
 374
 375     if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) {
 376         cred.enc_part.etype = ENCTYPE_NULL;
 377         cred.enc_part.kvno = NULL;
 378         cred.enc_part.cipher.data = buf;
 379         cred.enc_part.cipher.length = buf_size;
 380     } else {
 381         /*
 382          * Here older versions then 0.7.2 of Heimdal used the local or
 383          * remote subkey. That is wrong, the session key should be
 384          * used. Heimdal 0.7.2 and newer have code to try both in the
 385          * receiving end.
 386          */
 387
 388         ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto);
 389         if (ret) {
 390             free(buf);
 391             free_KRB_CRED(&cred);
 392             return ret;
 393         }
 394         ret = krb5_encrypt_EncryptedData (context,
 395                                           crypto,
 396                                           KRB5_KU_KRB_CRED,
 397                                           buf,
 398                                           len,
 399                                           0,
 400                                           &cred.enc_part);
 401         free(buf);
 402         krb5_crypto_destroy(context, crypto);
 403         if (ret) {
 404             free_KRB_CRED(&cred);
 405             return ret;
 406         }
 407     }
 408
 409     ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret);
 410     free_KRB_CRED (&cred);
 411     if (ret)
 412         return ret;
 413     if(buf_size != len)
 414         krb5_abortx(context, "internal error in ASN.1 encoder");
 415     out_data->length = len;
 416     out_data->data   = buf;
 417     return 0;
 418  out4:
 419     free_EncKrbCredPart(&enc_krb_cred_part);
 420  out3:
 421     free_KRB_CRED(&cred);
 422  out2:
 423     krb5_free_creds (context, out_creds);
 424     return ret;
 425 }