crypto/heimdal-0.6.3/kdc/524.c

   1 /*
   2  * Copyright (c) 1997-2003 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 "kdc_locl.h"
  35
  36 RCSID("$Id: 524.c,v 1.29 2003/03/17 05:35:47 assar Exp $");
  37
  38 #ifndef KRB4
  39 #include <krb5-v4compat.h>
  40 #endif
  41
  42 /*
  43  * fetch the server from `t', returning the name in malloced memory in
  44  * `spn' and the entry itself in `server'
  45  */
  46
  47 static krb5_error_code
  48 fetch_server (const Ticket *t,
  49               char **spn,
  50               hdb_entry **server,
  51               const char *from)
  52 {
  53     krb5_error_code ret;
  54     krb5_principal sprinc;
  55
  56     ret = principalname2krb5_principal(&sprinc, t->sname, t->realm);
  57     if (ret) {
  58         kdc_log(0, "principalname2krb5_principal: %s",
  59                 krb5_get_err_text(context, ret));
  60         return ret;
  61     }
  62     ret = krb5_unparse_name(context, sprinc, spn);
  63     if (ret) {
  64         krb5_free_principal(context, sprinc);
  65         kdc_log(0, "krb5_unparse_name: %s", krb5_get_err_text(context, ret));
  66         return ret;
  67     }
  68     ret = db_fetch(sprinc, server);
  69     krb5_free_principal(context, sprinc);
  70     if (ret) {
  71         kdc_log(0,
  72         "Request to convert ticket from %s for unknown principal %s: %s",
  73                 from, *spn, krb5_get_err_text(context, ret));
  74         if (ret == HDB_ERR_NOENTRY)
  75             ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
  76         return ret;
  77     }
  78     return 0;
  79 }
  80
  81 static krb5_error_code
  82 log_524 (const EncTicketPart *et,
  83          const char *from,
  84          const char *spn)
  85 {
  86     krb5_principal client;
  87     char *cpn;
  88     krb5_error_code ret;
  89
  90     ret = principalname2krb5_principal(&client, et->cname, et->crealm);
  91     if (ret) {
  92         kdc_log(0, "principalname2krb5_principal: %s",
  93                 krb5_get_err_text (context, ret));
  94         return ret;
  95     }
  96     ret = krb5_unparse_name(context, client, &cpn);
  97     if (ret) {
  98         krb5_free_principal(context, client);
  99         kdc_log(0, "krb5_unparse_name: %s",
 100                 krb5_get_err_text (context, ret));
 101         return ret;
 102     }
 103     kdc_log(1, "524-REQ %s from %s for %s", cpn, from, spn);
 104     free(cpn);
 105     krb5_free_principal(context, client);
 106     return 0;
 107 }
 108
 109 static krb5_error_code
 110 verify_flags (const EncTicketPart *et,
 111               const char *spn)
 112 {
 113     if(et->endtime < kdc_time){
 114         kdc_log(0, "Ticket expired (%s)", spn);
 115         return KRB5KRB_AP_ERR_TKT_EXPIRED;
 116     }
 117     if(et->flags.invalid){
 118         kdc_log(0, "Ticket not valid (%s)", spn);
 119         return KRB5KRB_AP_ERR_TKT_NYV;
 120     }
 121     return 0;
 122 }
 123
 124 /*
 125  * set the `et->caddr' to the most appropriate address to use, where
 126  * `addr' is the address the request was received from.
 127  */
 128
 129 static krb5_error_code
 130 set_address (EncTicketPart *et,
 131              struct sockaddr *addr,
 132              const char *from)
 133 {
 134     krb5_error_code ret;
 135     krb5_address *v4_addr;
 136
 137     v4_addr = malloc (sizeof(*v4_addr));
 138     if (v4_addr == NULL)
 139         return ENOMEM;
 140
 141     ret = krb5_sockaddr2address(context, addr, v4_addr);
 142     if(ret) {
 143         free (v4_addr);
 144         kdc_log(0, "Failed to convert address (%s)", from);
 145         return ret;
 146     }
 147
 148     if (et->caddr && !krb5_address_search (context, v4_addr, et->caddr)) {
 149         kdc_log(0, "Incorrect network address (%s)", from);
 150         krb5_free_address(context, v4_addr);
 151         free (v4_addr);
 152         return KRB5KRB_AP_ERR_BADADDR;
 153     }
 154     if(v4_addr->addr_type == KRB5_ADDRESS_INET) {
 155         /* we need to collapse the addresses in the ticket to a
 156            single address; best guess is to use the address the
 157            connection came from */
 158
 159         if (et->caddr != NULL) {
 160             free_HostAddresses(et->caddr);
 161         } else {
 162             et->caddr = malloc (sizeof (*et->caddr));
 163             if (et->caddr == NULL) {
 164                 krb5_free_address(context, v4_addr);
 165                 free(v4_addr);
 166                 return ENOMEM;
 167             }
 168         }
 169         et->caddr->val = v4_addr;
 170         et->caddr->len = 1;
 171     } else {
 172         krb5_free_address(context, v4_addr);
 173         free(v4_addr);
 174     }
 175     return 0;
 176 }
 177
 178
 179 static krb5_error_code
 180 encrypt_v4_ticket(void *buf,
 181                   size_t len,
 182                   krb5_keyblock *skey,
 183                   EncryptedData *reply)
 184 {
 185     krb5_crypto crypto;
 186     krb5_error_code ret;
 187     ret = krb5_crypto_init(context, skey, ETYPE_DES_PCBC_NONE, &crypto);
 188     if (ret) {
 189         free(buf);
 190         kdc_log(0, "krb5_crypto_init failed: %s",
 191                 krb5_get_err_text(context, ret));
 192         return ret;
 193     }
 194
 195     ret = krb5_encrypt_EncryptedData(context,
 196                                      crypto,
 197                                      KRB5_KU_TICKET,
 198                                      buf,
 199                                      len,
 200                                      0,
 201                                      reply);
 202     krb5_crypto_destroy(context, crypto);
 203     if(ret) {
 204         kdc_log(0, "Failed to encrypt data: %s",
 205                 krb5_get_err_text(context, ret));
 206         return ret;
 207     }
 208     return 0;
 209 }
 210
 211 static krb5_error_code
 212 encode_524_response(const char *spn, const EncTicketPart et, const Ticket *t,
 213                     hdb_entry *server, EncryptedData *ticket, int *kvno)
 214 {
 215     krb5_error_code ret;
 216     int use_2b;
 217     size_t len;
 218
 219     use_2b = krb5_config_get_bool(context, NULL, "kdc", "use_2b", spn, NULL);
 220     if(use_2b) {
 221         ASN1_MALLOC_ENCODE(EncryptedData,
 222                            ticket->cipher.data, ticket->cipher.length,
 223                            &t->enc_part, &len, ret);
 224
 225         if (ret) {
 226             kdc_log(0, "Failed to encode v4 (2b) ticket (%s)", spn);
 227             return ret;
 228         }
 229
 230         ticket->etype = 0;
 231         ticket->kvno = NULL;
 232         *kvno = 213; /* 2b's use this magic kvno */
 233     } else {
 234         unsigned char buf[MAX_KTXT_LEN + 4 * 4];
 235         Key *skey;
 236
 237         if (!enable_v4_cross_realm && strcmp (et.crealm, t->realm) != 0) {
 238             kdc_log(0, "524 cross-realm %s -> %s disabled", et.crealm,
 239                     t->realm);
 240             return KRB5KDC_ERR_POLICY;
 241         }
 242
 243         ret = encode_v4_ticket(buf + sizeof(buf) - 1, sizeof(buf),
 244                                &et, &t->sname, &len);
 245         if(ret){
 246             kdc_log(0, "Failed to encode v4 ticket (%s)", spn);
 247             return ret;
 248         }
 249         ret = get_des_key(server, TRUE, FALSE, &skey);
 250         if(ret){
 251             kdc_log(0, "no suitable DES key for server (%s)", spn);
 252             return ret;
 253         }
 254         ret = encrypt_v4_ticket(buf + sizeof(buf) - len, len,
 255                                 &skey->key, ticket);
 256         if(ret){
 257             kdc_log(0, "Failed to encrypt v4 ticket (%s)", spn);
 258             return ret;
 259         }
 260         *kvno = server->kvno;
 261     }
 262
 263     return 0;
 264 }
 265
 266 /*
 267  * process a 5->4 request, based on `t', and received `from, addr',
 268  * returning the reply in `reply'
 269  */
 270
 271 krb5_error_code
 272 do_524(const Ticket *t, krb5_data *reply,
 273        const char *from, struct sockaddr *addr)
 274 {
 275     krb5_error_code ret = 0;
 276     krb5_crypto crypto;
 277     hdb_entry *server = NULL;
 278     Key *skey;
 279     krb5_data et_data;
 280     EncTicketPart et;
 281     EncryptedData ticket;
 282     krb5_storage *sp;
 283     char *spn = NULL;
 284     unsigned char buf[MAX_KTXT_LEN + 4 * 4];
 285     size_t len;
 286     int kvno;
 287
 288     if(!enable_524) {
 289         ret = KRB5KDC_ERR_POLICY;
 290         kdc_log(0, "Rejected ticket conversion request from %s", from);
 291         goto out;
 292     }
 293
 294     ret = fetch_server (t, &spn, &server, from);
 295     if (ret) {
 296         goto out;
 297     }
 298
 299     ret = hdb_enctype2key(context, server, t->enc_part.etype, &skey);
 300     if(ret){
 301         kdc_log(0, "No suitable key found for server (%s) from %s", spn, from);
 302         goto out;
 303     }
 304     ret = krb5_crypto_init(context, &skey->key, 0, &crypto);
 305     if (ret) {
 306         kdc_log(0, "krb5_crypto_init failed: %s",
 307                 krb5_get_err_text(context, ret));
 308         goto out;
 309     }
 310     ret = krb5_decrypt_EncryptedData (context,
 311                                       crypto,
 312                                       KRB5_KU_TICKET,
 313                                       &t->enc_part,
 314                                       &et_data);
 315     krb5_crypto_destroy(context, crypto);
 316     if(ret){
 317         kdc_log(0, "Failed to decrypt ticket from %s for %s", from, spn);
 318         goto out;
 319     }
 320     ret = krb5_decode_EncTicketPart(context, et_data.data, et_data.length,
 321                                     &et, &len);
 322     krb5_data_free(&et_data);
 323     if(ret){
 324         kdc_log(0, "Failed to decode ticket from %s for %s", from, spn);
 325         goto out;
 326     }
 327
 328     ret = log_524 (&et, from, spn);
 329     if (ret) {
 330         free_EncTicketPart(&et);
 331         goto out;
 332     }
 333
 334     ret = verify_flags (&et, spn);
 335     if (ret) {
 336         free_EncTicketPart(&et);
 337         goto out;
 338     }
 339
 340     ret = set_address (&et, addr, from);
 341     if (ret) {
 342         free_EncTicketPart(&et);
 343         goto out;
 344     }
 345
 346     ret = encode_524_response(spn, et, t, server, &ticket, &kvno);
 347     free_EncTicketPart(&et);
 348
 349 out:
 350     /* make reply */
 351     memset(buf, 0, sizeof(buf));
 352     sp = krb5_storage_from_mem(buf, sizeof(buf));
 353     krb5_store_int32(sp, ret);
 354     if(ret == 0){
 355         krb5_store_int32(sp, kvno);
 356         krb5_store_data(sp, ticket.cipher);
 357         /* Aargh! This is coded as a KTEXT_ST. */
 358         krb5_storage_seek(sp, MAX_KTXT_LEN - ticket.cipher.length, SEEK_CUR);
 359         krb5_store_int32(sp, 0); /* mbz */
 360         free_EncryptedData(&ticket);
 361     }
 362     ret = krb5_storage_to_data(sp, reply);
 363     reply->length = krb5_storage_seek(sp, 0, SEEK_CUR);
 364     krb5_storage_free(sp);
 365
 366     if(spn)
 367         free(spn);
 368     if(server)
 369         free_ent (server);
 370     return ret;
 371 }