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         if (ret == 0) {
 102             if (db)
 103                 *db = config->db[i];
 104             *h = ent;
 105             ent = NULL;
 106             goto out;
 107         }
 108     }
 109
 110     ret = HDB_ERR_NOENTRY;
 111     krb5_set_error_message(context, ret, "no such entry found in hdb");
 112
 113 out:
 114     krb5_free_principal(context, enterprise_principal);
 115     free(ent);
 116     return ret;
 117 }
 118
 119 void
 120 _kdc_free_ent(krb5_context context, hdb_entry_ex *ent)
 121 {
 122     hdb_free_entry (context, ent);
 123     free (ent);
 124 }
 125
 126 /*
 127  * Use the order list of preferred encryption types and sort the
 128  * available keys and return the most preferred key.
 129  */
 130
 131 krb5_error_code
 132 _kdc_get_preferred_key(krb5_context context,
 133                        krb5_kdc_configuration *config,
 134                        hdb_entry_ex *h,
 135                        const char *name,
 136                        krb5_enctype *enctype,
 137                        Key **key)
 138 {
 139     krb5_error_code ret;
 140     int i;
 141
 142     if (config->use_strongest_server_key) {
 143         const krb5_enctype *p = krb5_kerberos_enctypes(context);
 144
 145         for (i = 0; p[i] != (krb5_enctype)ETYPE_NULL; i++) {
 146             if (krb5_enctype_valid(context, p[i]) != 0 &&
 147                 !_kdc_is_weak_exception(h->entry.principal, p[i]))
 148                 continue;
 149             ret = hdb_enctype2key(context, &h->entry, NULL, p[i], key);
 150             if (ret != 0)
 151                 continue;
 152             if (enctype != NULL)
 153                 *enctype = p[i];
 154             return 0;
 155         }
 156     } else {
 157         *key = NULL;
 158
 159         for (i = 0; i < h->entry.keys.len; i++) {
 160             if (krb5_enctype_valid(context, h->entry.keys.val[i].key.keytype) != 0 &&
 161                 !_kdc_is_weak_exception(h->entry.principal, h->entry.keys.val[i].key.keytype))
 162                 continue;
 163             ret = hdb_enctype2key(context, &h->entry, NULL,
 164                                   h->entry.keys.val[i].key.keytype, key);
 165             if (ret != 0)
 166                 continue;
 167             if (enctype != NULL)
 168                 *enctype = (*key)->key.keytype;
 169             return 0;
 170         }
 171     }
 172
 173     krb5_set_error_message(context, EINVAL,
 174                            "No valid kerberos key found for %s", name);
 175     return EINVAL; /* XXX */
 176 }
 177