kdc/524.c

   1 /*
   2  * Copyright (c) 1997-2002 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("$Id$");
  37
  38 #ifdef KRB4
  39
  40 /*
  41  * fetch the server from `t', returning the name in malloced memory in
  42  * `spn' and the entry itself in `server'
  43  */
  44
  45 static krb5_error_code
  46 fetch_server (const Ticket *t,
  47               char **spn,
  48               hdb_entry **server,
  49               const char *from)
  50 {
  51     krb5_error_code ret;
  52     krb5_principal sprinc;
  53
  54     ret = principalname2krb5_principal(&sprinc, t->sname, t->realm);
  55     if (ret) {
  56         kdc_log(0, "principalname2krb5_principal: %s",
  57                 krb5_get_err_text(context, ret));
  58         return ret;
  59     }
  60     ret = krb5_unparse_name(context, sprinc, spn);
  61     if (ret) {
  62         krb5_free_principal(context, sprinc);
  63         kdc_log(0, "krb5_unparse_name: %s", krb5_get_err_text(context, ret));
  64         return ret;
  65     }
  66     ret = db_fetch(sprinc, server);
  67     krb5_free_principal(context, sprinc);
  68     if (ret) {
  69         kdc_log(0,
  70         "Request to convert ticket from %s for unknown principal %s: %s",
  71                 from, *spn, krb5_get_err_text(context, ret));
  72         if (ret == HDB_ERR_NOENTRY)
  73             ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
  74         return ret;
  75     }
  76     return 0;
  77 }
  78
  79 static krb5_error_code
  80 log_524 (const EncTicketPart *et,
  81          const char *from,
  82          const char *spn)
  83 {
  84     krb5_principal client;
  85     char *cpn;
  86     krb5_error_code ret;
  87
  88     ret = principalname2krb5_principal(&client, et->cname, et->crealm);
  89     if (ret) {
  90         kdc_log(0, "principalname2krb5_principal: %s",
  91                 krb5_get_err_text (context, ret));
  92         return ret;
  93     }
  94     ret = krb5_unparse_name(context, client, &cpn);
  95     if (ret) {
  96         krb5_free_principal(context, client);
  97         kdc_log(0, "krb5_unparse_name: %s",
  98                 krb5_get_err_text (context, ret));
  99         return ret;
 100     }
 101     kdc_log(1, "524-REQ %s from %s for %s", cpn, from, spn);
 102     free(cpn);
 103     krb5_free_principal(context, client);
 104     return 0;
 105 }
 106
 107 static krb5_error_code
 108 verify_flags (const EncTicketPart *et,
 109               const char *spn)
 110 {
 111     if(et->endtime < kdc_time){
 112         kdc_log(0, "Ticket expired (%s)", spn);
 113         return KRB5KRB_AP_ERR_TKT_EXPIRED;
 114     }
 115     if(et->flags.invalid){
 116         kdc_log(0, "Ticket not valid (%s)", spn);
 117         return KRB5KRB_AP_ERR_TKT_NYV;
 118     }
 119     return 0;
 120 }
 121
 122 /*
 123  * set the `et->caddr' to the most appropriate address to use, where
 124  * `addr' is the address the request was received from.
 125  */
 126
 127 static krb5_error_code
 128 set_address (EncTicketPart *et,
 129              struct sockaddr *addr,
 130              const char *from)
 131 {
 132     krb5_error_code ret;
 133     krb5_address *v4_addr;
 134
 135     v4_addr = malloc (sizeof(*v4_addr));
 136     if (v4_addr == NULL)
 137         return ENOMEM;
 138
 139     ret = krb5_sockaddr2address(context, addr, v4_addr);
 140     if(ret) {
 141         free (v4_addr);
 142         kdc_log(0, "Failed to convert address (%s)", from);
 143         return ret;
 144     }
 145
 146     if (et->caddr && !krb5_address_search (context, v4_addr, et->caddr)) {
 147         kdc_log(0, "Incorrect network address (%s)", from);
 148         krb5_free_address(context, v4_addr);
 149         free (v4_addr);
 150         return KRB5KRB_AP_ERR_BADADDR;
 151     }
 152     if(v4_addr->addr_type == KRB5_ADDRESS_INET) {
 153         /* we need to collapse the addresses in the ticket to a
 154            single address; best guess is to use the address the
 155            connection came from */
 156
 157         if (et->caddr != NULL) {
 158             free_HostAddresses(et->caddr);
 159         } else {
 160             et->caddr = malloc (sizeof (*et->caddr));
 161             if (et->caddr == NULL) {
 162                 krb5_free_address(context, v4_addr);
 163                 free(v4_addr);
 164                 return ENOMEM;
 165             }
 166         }
 167         et->caddr->val = v4_addr;
 168         et->caddr->len = 1;
 169     } else {
 170         krb5_free_address(context, v4_addr);
 171         free(v4_addr);
 172     }
 173     return 0;
 174 }
 175
 176 /*
 177  * process a 5->4 request, based on `t', and received `from, addr',
 178  * returning the reply in `reply'
 179  */
 180
 181 krb5_error_code
 182 do_524(const Ticket *t, krb5_data *reply,
 183        const char *from, struct sockaddr *addr)
 184 {
 185     krb5_error_code ret = 0;
 186     krb5_crypto crypto;
 187     hdb_entry *server = NULL;
 188     Key *skey;
 189     krb5_data et_data;
 190     EncTicketPart et;
 191     EncryptedData ticket;
 192     krb5_storage *sp;
 193     char *spn = NULL;
 194     unsigned char buf[MAX_KTXT_LEN + 4 * 4];
 195     size_t len;
 196
 197     if(!enable_524) {
 198         ret = KRB5KDC_ERR_POLICY;
 199         kdc_log(0, "Rejected ticket conversion request from %s", from);
 200         goto out;
 201     }
 202
 203     ret = fetch_server (t, &spn, &server, from);
 204     if (ret) {
 205         goto out;
 206     }
 207
 208     ret = hdb_enctype2key(context, server, t->enc_part.etype, &skey);
 209     if(ret){
 210         kdc_log(0, "No suitable key found for server (%s) from %s", spn, from);
 211         goto out;
 212     }
 213     ret = krb5_crypto_init(context, &skey->key, 0, &crypto);
 214     if (ret) {
 215         kdc_log(0, "krb5_crypto_init failed: %s",
 216                 krb5_get_err_text(context, ret));
 217         goto out;
 218     }
 219     ret = krb5_decrypt_EncryptedData (context,
 220                                       crypto,
 221                                       KRB5_KU_TICKET,
 222                                       &t->enc_part,
 223                                       &et_data);
 224     krb5_crypto_destroy(context, crypto);
 225     if(ret){
 226         kdc_log(0, "Failed to decrypt ticket from %s for %s", from, spn);
 227         goto out;
 228     }
 229     ret = krb5_decode_EncTicketPart(context, et_data.data, et_data.length,
 230                                     &et, &len);
 231     krb5_data_free(&et_data);
 232     if(ret){
 233         kdc_log(0, "Failed to decode ticket from %s for %s", from, spn);
 234         goto out;
 235     }
 236
 237     ret = log_524 (&et, from, spn);
 238     if (ret) {
 239         free_EncTicketPart(&et);
 240         goto out;
 241     }
 242
 243     ret = verify_flags (&et, spn);
 244     if (ret) {
 245         free_EncTicketPart(&et);
 246         goto out;
 247     }
 248
 249     ret = set_address (&et, addr, from);
 250     if (ret) {
 251         free_EncTicketPart(&et);
 252         goto out;
 253     }
 254     if (!enable_v4_cross_realm && strcmp (et.crealm, t->realm) != 0) {
 255         kdc_log(0, "524 cross-realm %s -> %s disabled", et.crealm,
 256                 t->realm);
 257         return KRB5KDC_ERR_POLICY;
 258     }
 259
 260     ret = encode_v4_ticket(buf + sizeof(buf) - 1, sizeof(buf),
 261                            &et, &t->sname, &len);
 262     free_EncTicketPart(&et);
 263     if(ret){
 264         kdc_log(0, "Failed to encode v4 ticket (%s)", spn);
 265         goto out;
 266     }
 267     ret = get_des_key(server, TRUE, FALSE, &skey);
 268     if(ret){
 269         kdc_log(0, "no suitable DES key for server (%s)", spn);
 270         goto out;
 271     }
 272     ret = encrypt_v4_ticket(buf + sizeof(buf) - len, len,
 273                             skey->key.keyvalue.data, &ticket);
 274     if(ret){
 275         kdc_log(0, "Failed to encrypt v4 ticket (%s)", spn);
 276         goto out;
 277     }
 278 out:
 279     /* make reply */
 280     memset(buf, 0, sizeof(buf));
 281     sp = krb5_storage_from_mem(buf, sizeof(buf));
 282     krb5_store_int32(sp, ret);
 283     if(ret == 0){
 284         krb5_store_int32(sp, server->kvno); /* is this right? */
 285         krb5_store_data(sp, ticket.cipher);
 286         /* Aargh! This is coded as a KTEXT_ST. */
 287         krb5_storage_seek(sp, MAX_KTXT_LEN - ticket.cipher.length, SEEK_CUR);
 288         krb5_store_int32(sp, 0); /* mbz */
 289         free_EncryptedData(&ticket);
 290     }
 291     ret = krb5_storage_to_data(sp, reply);
 292     reply->length = krb5_storage_seek(sp, 0, SEEK_CUR);
 293     krb5_storage_free(sp);
 294
 295     if(spn)
 296         free(spn);
 297     if(server)
 298         free_ent (server);
 299     return ret;
 300 }
 301
 302 #endif /* KRB4 */