source4/heimdal/kdc/misc.c

   1 /*
   2  * Copyright (c) 1997 - 2001 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 struct timeval _kdc_now;
  37
  38 krb5_error_code
  39 _kdc_db_fetch(krb5_context context,
  40               krb5_kdc_configuration *config,
  41               krb5_const_principal principal,
  42               unsigned flags,
  43               krb5uint32 *kvno_ptr,
  44               HDB **db,
  45               hdb_entry_ex **h)
  46 {
  47     hdb_entry_ex *ent;
  48     krb5_error_code ret = HDB_ERR_NOENTRY;
  49     int i;
  50     unsigned kvno = 0;
  51     krb5_principal enterprise_principal = NULL;
  52     krb5_const_principal princ;
  53
  54     *h = NULL;
  55
  56     if (kvno_ptr) {
  57             kvno = *kvno_ptr;
  58             flags |= HDB_F_KVNO_SPECIFIED;
  59     }
  60
  61     ent = calloc(1, sizeof (*ent));
  62     if (ent == NULL)
  63         return krb5_enomem(context);
  64
  65     if (principal->name.name_type == KRB5_NT_ENTERPRISE_PRINCIPAL) {
  66         if (principal->name.name_string.len != 1) {
  67             ret = KRB5_PARSE_MALFORMED;
  68             krb5_set_error_message(context, ret,
  69                                    "malformed request: "
  70                                    "enterprise name with %d name components",
  71                                    principal->name.name_string.len);
  72             goto out;
  73         }
  74         ret = krb5_parse_name(context, principal->name.name_string.val[0],
  75                               &enterprise_principal);
  76         if (ret)
  77             goto out;
  78     }
  79
  80     for (i = 0; i < config->num_db; i++) {
  81         ret = config->db[i]->hdb_open(context, config->db[i], O_RDONLY, 0);
  82         if (ret) {
  83             const char *msg = krb5_get_error_message(context, ret);
  84             kdc_log(context, config, 0, "Failed to open database: %s", msg);
  85             krb5_free_error_message(context, msg);
  86             continue;
  87         }
  88
  89         princ = principal;
  90         if (!(config->db[i]->hdb_capability_flags & HDB_CAP_F_HANDLE_ENTERPRISE_PRINCIPAL) && enterprise_principal)
  91             princ = enterprise_principal;
  92
  93         ret = config->db[i]->hdb_fetch_kvno(context,
  94                                             config->db[i],
  95                                             princ,
  96                                             flags | HDB_F_DECRYPT,
  97                                             kvno,
  98                                             ent);
  99         config->db[i]->hdb_close(context, config->db[i]);
 100
 101         switch (ret) {
 102         case HDB_ERR_WRONG_REALM:
 103             /*
 104              * the ent->entry.principal just contains hints for the client
 105              * to retry. This is important for enterprise principal routing
 106              * between trusts.
 107              */
 108             /* fall through */
 109         case 0:
 110             if (db)
 111                 *db = config->db[i];
 112             *h = ent;
 113             ent = NULL;
 114             goto out;
 115
 116         case HDB_ERR_NOENTRY:
 117             /* Check the other databases */
 118             continue;
 119
 120         default:
 121             /*
 122              * This is really important, because errors like
 123              * HDB_ERR_NOT_FOUND_HERE (used to indicate to Samba that
 124              * the RODC on which this code is running does not have
 125              * the key we need, and so a proxy to the KDC is required)
 126              * have specific meaning, and need to be propogated up.
 127              */
 128             goto out;
 129         }
 130     }
 131
 132     if (ret == HDB_ERR_NOENTRY) {
 133         krb5_set_error_message(context, ret, "no such entry found in hdb");
 134     }
 135 out:
 136     krb5_free_principal(context, enterprise_principal);
 137     free(ent);
 138     return ret;
 139 }
 140
 141 void
 142 _kdc_free_ent(krb5_context context, hdb_entry_ex *ent)
 143 {
 144     hdb_free_entry (context, ent);
 145     free (ent);
 146 }
 147
 148 /*
 149  * Use the order list of preferred encryption types and sort the
 150  * available keys and return the most preferred key.
 151  */
 152
 153 krb5_error_code
 154 _kdc_get_preferred_key(krb5_context context,
 155                        krb5_kdc_configuration *config,
 156                        hdb_entry_ex *h,
 157                        const char *name,
 158                        krb5_enctype *enctype,
 159                        Key **key)
 160 {
 161     krb5_error_code ret;
 162     int i;
 163
 164     if (config->use_strongest_server_key) {
 165         const krb5_enctype *p = krb5_kerberos_enctypes(context);
 166
 167         for (i = 0; p[i] != ETYPE_NULL; i++) {
 168             if (krb5_enctype_valid(context, p[i]) != 0)
 169                 continue;
 170             ret = hdb_enctype2key(context, &h->entry, p[i], key);
 171             if (ret != 0)
 172                 continue;
 173             if (enctype != NULL)
 174                 *enctype = p[i];
 175             return 0;
 176         }
 177     } else {
 178         *key = NULL;
 179
 180         for (i = 0; i < h->entry.keys.len; i++) {
 181             if (krb5_enctype_valid(context, h->entry.keys.val[i].key.keytype)
 182                 != 0)
 183                 continue;
 184             ret = hdb_enctype2key(context, &h->entry,
 185                 h->entry.keys.val[i].key.keytype, key);
 186             if (ret != 0)
 187                 continue;
 188             if (enctype != NULL)
 189                 *enctype = (*key)->key.keytype;
 190             return 0;
 191         }
 192     }
 193
 194     krb5_set_error_message(context, EINVAL,
 195                            "No valid kerberos key found for %s", name);
 196     return EINVAL; /* XXX */
 197 }
 198