lib/krb5/mk_priv.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 <krb5_locl.h>
  35
  36 RCSID("$Id$");
  37
  38
  39 krb5_error_code KRB5_LIB_FUNCTION
  40 krb5_mk_priv(krb5_context context,
  41              krb5_auth_context auth_context,
  42              const krb5_data *userdata,
  43              krb5_data *outbuf,
  44              krb5_replay_data *outdata)
  45 {
  46     krb5_error_code ret;
  47     KRB_PRIV s;
  48     EncKrbPrivPart part;
  49     u_char *buf = NULL;
  50     size_t buf_size;
  51     size_t len;
  52     krb5_crypto crypto;
  53     krb5_keyblock *key;
  54     krb5_replay_data rdata;
  55
  56     if ((auth_context->flags &
  57          (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
  58         outdata == NULL)
  59         return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
  60
  61     if (auth_context->local_subkey)
  62         key = auth_context->local_subkey;
  63     else if (auth_context->remote_subkey)
  64         key = auth_context->remote_subkey;
  65     else
  66         key = auth_context->keyblock;
  67
  68     memset(&rdata, 0, sizeof(rdata));
  69
  70     part.user_data = *userdata;
  71
  72     krb5_us_timeofday (context, &rdata.timestamp, &rdata.usec);
  73
  74     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
  75         part.timestamp = &rdata.timestamp;
  76         part.usec      = &rdata.usec;
  77     } else {
  78         part.timestamp = NULL;
  79         part.usec      = NULL;
  80     }
  81
  82     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_TIME) {
  83         outdata->timestamp = rdata.timestamp;
  84         outdata->usec = rdata.usec;
  85     }
  86
  87     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
  88         rdata.seq = auth_context->local_seqnumber;
  89         part.seq_number = &rdata.seq;
  90     } else
  91         part.seq_number = NULL;
  92
  93     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)
  94         outdata->seq = auth_context->local_seqnumber;
  95
  96     part.s_address = auth_context->local_address;
  97     part.r_address = auth_context->remote_address;
  98
  99     krb5_data_zero (&s.enc_part.cipher);
 100
 101     ASN1_MALLOC_ENCODE(EncKrbPrivPart, buf, buf_size, &part, &len, ret);
 102     if (ret)
 103         goto fail;
 104     if (buf_size != len)
 105         krb5_abortx(context, "internal error in ASN.1 encoder");
 106
 107     s.pvno = 5;
 108     s.msg_type = krb_priv;
 109     s.enc_part.etype = key->keytype;
 110     s.enc_part.kvno = NULL;
 111
 112     ret = krb5_crypto_init(context, key, 0, &crypto);
 113     if (ret) {
 114         free (buf);
 115         return ret;
 116     }
 117     ret = krb5_encrypt (context,
 118                         crypto,
 119                         KRB5_KU_KRB_PRIV,
 120                         buf + buf_size - len,
 121                         len,
 122                         &s.enc_part.cipher);
 123     krb5_crypto_destroy(context, crypto);
 124     if (ret) {
 125         free(buf);
 126         return ret;
 127     }
 128     free(buf);
 129
 130
 131     ASN1_MALLOC_ENCODE(KRB_PRIV, buf, buf_size, &s, &len, ret);
 132     if (ret)
 133         goto fail;
 134     if (buf_size != len)
 135         krb5_abortx(context, "internal error in ASN.1 encoder");
 136
 137     krb5_data_free (&s.enc_part.cipher);
 138
 139     ret = krb5_data_copy(outbuf, buf + buf_size - len, len);
 140     if (ret) {
 141         krb5_set_error_string (context, "malloc: out of memory");
 142         free(buf);
 143         return ENOMEM;
 144     }
 145     free (buf);
 146     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
 147         auth_context->local_seqnumber =
 148             (auth_context->local_seqnumber + 1) & 0xFFFFFFFF;
 149     return 0;
 150
 151   fail:
 152     free (buf);
 153     krb5_data_free (&s.enc_part.cipher);
 154     return ret;
 155 }