lib/krb5/generate_subkey.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 "krb5_locl.h"
  35
  36 /**
  37  * Generate subkey, from keyblock
  38  *
  39  * @param context kerberos context
  40  * @param key session key
  41  * @param etype encryption type of subkey, if ETYPE_NULL, use key's enctype
  42  * @param subkey returned new, free with krb5_free_keyblock().
  43  *
  44  * @return 0 on success or a Kerberos 5 error code
  45  *
  46 * @ingroup krb5_crypto
  47  */
  48
  49 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  50 krb5_generate_subkey_extended(krb5_context context,
  51                               const krb5_keyblock *key,
  52                               krb5_enctype etype,
  53                               krb5_keyblock **subkey)
  54 {
  55     krb5_error_code ret;
  56
  57     ALLOC(*subkey, 1);
  58     if (*subkey == NULL)
  59         return krb5_enomem(context);
  60
  61     if (etype == (krb5_enctype)ETYPE_NULL)
  62         etype = key->keytype; /* use session key etype */
  63
  64     /* XXX should we use the session key as input to the RF? */
  65     ret = krb5_generate_random_keyblock(context, etype, *subkey);
  66     if (ret != 0) {
  67         free(*subkey);
  68         *subkey = NULL;
  69     }
  70
  71     return ret;
  72 }
  73