source/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 17036 2006-04-10 09:28:15Z 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`,
  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 addrs, *paddrs;
 166     KRB_CRED cred;
 167     KrbCredInfo *krb_cred_info;
 168     EncKrbCredPart enc_krb_cred_part;
 169     size_t len;
 170     unsigned char *buf;
 171     size_t buf_size;
 172     krb5_kdc_flags kdc_flags;
 173     krb5_crypto crypto;
 174     struct addrinfo *ai;
 175     int save_errno;
 176     krb5_creds *ticket;
 177     char *realm;
 178
 179     realm = in_creds->client->realm;
 180
 181     addrs.len = 0;
 182     addrs.val = NULL;
 183     paddrs = &addrs;
 184
 185     {
 186         krb5_boolean noaddr;
 187         krb5_appdefault_boolean(context, NULL, realm,
 188                                 "no-addresses", KRB5_ADDRESSLESS_DEFAULT,
 189                                 &noaddr);
 190         if (noaddr)
 191             paddrs = NULL;
 192     }
 193
 194     /*
 195      * If tickets are address-less, forward address-less tickets.
 196      */
 197
 198     if (paddrs) {
 199         ret = _krb5_get_krbtgt (context,
 200                                 ccache,
 201                                 realm,
 202                                 &ticket);
 203         if(ret == 0) {
 204             if (ticket->addresses.len == 0)
 205                 paddrs = NULL;
 206             krb5_free_creds (context, ticket);
 207         }
 208     }
 209
 210     if (paddrs != NULL) {
 211
 212         ret = getaddrinfo (hostname, NULL, NULL, &ai);
 213         if (ret) {
 214             save_errno = errno;
 215             krb5_set_error_string(context, "resolving %s: %s",
 216                                   hostname, gai_strerror(ret));
 217             return krb5_eai_to_heim_errno(ret, save_errno);
 218         }
 219
 220         ret = add_addrs (context, &addrs, ai);
 221         freeaddrinfo (ai);
 222         if (ret)
 223             return ret;
 224     }
 225
 226     kdc_flags.b = int2KDCOptions(flags);
 227
 228     ret = krb5_get_kdc_cred (context,
 229                              ccache,
 230                              kdc_flags,
 231                              paddrs,
 232                              NULL,
 233                              in_creds,
 234                              &out_creds);
 235     krb5_free_addresses (context, &addrs);
 236     if (ret) {
 237         return ret;
 238     }
 239
 240     memset (&cred, 0, sizeof(cred));
 241     cred.pvno = 5;
 242     cred.msg_type = krb_cred;
 243     ALLOC_SEQ(&cred.tickets, 1);
 244     if (cred.tickets.val == NULL) {
 245         ret = ENOMEM;
 246         krb5_set_error_string(context, "malloc: out of memory");
 247         goto out2;
 248     }
 249     ret = decode_Ticket(out_creds->ticket.data,
 250                         out_creds->ticket.length,
 251                         cred.tickets.val, &len);
 252     if (ret)
 253         goto out3;
 254
 255     memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
 256     ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1);
 257     if (enc_krb_cred_part.ticket_info.val == NULL) {
 258         ret = ENOMEM;
 259         krb5_set_error_string(context, "malloc: out of memory");
 260         goto out4;
 261     }
 262
 263     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
 264         krb5_timestamp sec;
 265         int32_t usec;
 266
 267         krb5_us_timeofday (context, &sec, &usec);
 268
 269         ALLOC(enc_krb_cred_part.timestamp, 1);
 270         if (enc_krb_cred_part.timestamp == NULL) {
 271             ret = ENOMEM;
 272             krb5_set_error_string(context, "malloc: out of memory");
 273             goto out4;
 274         }
 275         *enc_krb_cred_part.timestamp = sec;
 276         ALLOC(enc_krb_cred_part.usec, 1);
 277         if (enc_krb_cred_part.usec == NULL) {
 278             ret = ENOMEM;
 279             krb5_set_error_string(context, "malloc: out of memory");
 280             goto out4;
 281         }
 282         *enc_krb_cred_part.usec      = usec;
 283     } else {
 284         enc_krb_cred_part.timestamp = NULL;
 285         enc_krb_cred_part.usec = NULL;
 286     }
 287
 288     if (auth_context->local_address && auth_context->local_port && paddrs) {
 289
 290         ret = krb5_make_addrport (context,
 291                                   &enc_krb_cred_part.s_address,
 292                                   auth_context->local_address,
 293                                   auth_context->local_port);
 294         if (ret)
 295             goto out4;
 296     }
 297
 298     if (auth_context->remote_address) {
 299         if (auth_context->remote_port) {
 300             krb5_boolean noaddr;
 301             krb5_const_realm srealm;
 302
 303             srealm = krb5_principal_get_realm(context, out_creds->server);
 304             /* Is this correct, and should we use the paddrs == NULL
 305                trick here as well? Having an address-less ticket may
 306                indicate that we don't know our own global address, but
 307                it does not necessary mean that we don't know the
 308                server's. */
 309             krb5_appdefault_boolean(context, NULL, srealm, "no-addresses",
 310                                     FALSE, &noaddr);
 311             if (!noaddr) {
 312                 ret = krb5_make_addrport (context,
 313                                           &enc_krb_cred_part.r_address,
 314                                           auth_context->remote_address,
 315                                           auth_context->remote_port);
 316                 if (ret)
 317                     goto out4;
 318             }
 319         } else {
 320             ALLOC(enc_krb_cred_part.r_address, 1);
 321             if (enc_krb_cred_part.r_address == NULL) {
 322                 ret = ENOMEM;
 323                 krb5_set_error_string(context, "malloc: out of memory");
 324                 goto out4;
 325             }
 326
 327             ret = krb5_copy_address (context, auth_context->remote_address,
 328                                      enc_krb_cred_part.r_address);
 329             if (ret)
 330                 goto out4;
 331         }
 332     }
 333
 334     /* fill ticket_info.val[0] */
 335
 336     enc_krb_cred_part.ticket_info.len = 1;
 337
 338     krb_cred_info = enc_krb_cred_part.ticket_info.val;
 339
 340     copy_EncryptionKey (&out_creds->session, &krb_cred_info->key);
 341     ALLOC(krb_cred_info->prealm, 1);
 342     copy_Realm (&out_creds->client->realm, krb_cred_info->prealm);
 343     ALLOC(krb_cred_info->pname, 1);
 344     copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname);
 345     ALLOC(krb_cred_info->flags, 1);
 346     *krb_cred_info->flags          = out_creds->flags.b;
 347     ALLOC(krb_cred_info->authtime, 1);
 348     *krb_cred_info->authtime       = out_creds->times.authtime;
 349     ALLOC(krb_cred_info->starttime, 1);
 350     *krb_cred_info->starttime      = out_creds->times.starttime;
 351     ALLOC(krb_cred_info->endtime, 1);
 352     *krb_cred_info->endtime        = out_creds->times.endtime;
 353     ALLOC(krb_cred_info->renew_till, 1);
 354     *krb_cred_info->renew_till = out_creds->times.renew_till;
 355     ALLOC(krb_cred_info->srealm, 1);
 356     copy_Realm (&out_creds->server->realm, krb_cred_info->srealm);
 357     ALLOC(krb_cred_info->sname, 1);
 358     copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname);
 359     ALLOC(krb_cred_info->caddr, 1);
 360     copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr);
 361
 362     krb5_free_creds (context, out_creds);
 363
 364     /* encode EncKrbCredPart */
 365
 366     ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size,
 367                        &enc_krb_cred_part, &len, ret);
 368     free_EncKrbCredPart (&enc_krb_cred_part);
 369     if (ret) {
 370         free_KRB_CRED(&cred);
 371         return ret;
 372     }
 373     if(buf_size != len)
 374         krb5_abortx(context, "internal error in ASN.1 encoder");
 375
 376     if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) {
 377         cred.enc_part.etype = ENCTYPE_NULL;
 378         cred.enc_part.kvno = NULL;
 379         cred.enc_part.cipher.data = buf;
 380         cred.enc_part.cipher.length = buf_size;
 381     } else {
 382         /*
 383          * Here older versions then 0.7.2 of Heimdal used the local or
 384          * remote subkey. That is wrong, the session key should be
 385          * used. Heimdal 0.7.2 and newer have code to try both in the
 386          * receiving end.
 387          */
 388
 389         ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto);
 390         if (ret) {
 391             free(buf);
 392             free_KRB_CRED(&cred);
 393             return ret;
 394         }
 395         ret = krb5_encrypt_EncryptedData (context,
 396                                           crypto,
 397                                           KRB5_KU_KRB_CRED,
 398                                           buf,
 399                                           len,
 400                                           0,
 401                                           &cred.enc_part);
 402         free(buf);
 403         krb5_crypto_destroy(context, crypto);
 404         if (ret) {
 405             free_KRB_CRED(&cred);
 406             return ret;
 407         }
 408     }
 409
 410     ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret);
 411     free_KRB_CRED (&cred);
 412     if (ret)
 413         return ret;
 414     if(buf_size != len)
 415         krb5_abortx(context, "internal error in ASN.1 encoder");
 416     out_data->length = len;
 417     out_data->data   = buf;
 418     return 0;
 419  out4:
 420     free_EncKrbCredPart(&enc_krb_cred_part);
 421  out3:
 422     free_KRB_CRED(&cred);
 423  out2:
 424     krb5_free_creds (context, out_creds);
 425     return ret;
 426 }