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 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  37 krb5_mk_priv(krb5_context context,
  38              krb5_auth_context auth_context,
  39              const krb5_data *userdata,
  40              krb5_data *outbuf,
  41              krb5_replay_data *outdata)
  42 {
  43     krb5_error_code ret;
  44     KRB_PRIV s;
  45     EncKrbPrivPart part;
  46     u_char *buf = NULL;
  47     size_t buf_size;
  48     size_t len = 0;
  49     krb5_crypto crypto;
  50     krb5_keyblock *key;
  51     krb5_replay_data rdata;
  52
  53     if ((auth_context->flags &
  54          (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
  55         outdata == NULL)
  56         return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
  57
  58     if (auth_context->local_subkey)
  59         key = auth_context->local_subkey;
  60     else if (auth_context->remote_subkey)
  61         key = auth_context->remote_subkey;
  62     else
  63         key = auth_context->keyblock;
  64
  65     memset(&rdata, 0, sizeof(rdata));
  66
  67     part.user_data = *userdata;
  68
  69     krb5_us_timeofday (context, &rdata.timestamp, &rdata.usec);
  70
  71     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
  72         part.timestamp = &rdata.timestamp;
  73         part.usec      = &rdata.usec;
  74     } else {
  75         part.timestamp = NULL;
  76         part.usec      = NULL;
  77     }
  78
  79     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_TIME) {
  80         outdata->timestamp = rdata.timestamp;
  81         outdata->usec = rdata.usec;
  82     }
  83
  84     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
  85         rdata.seq = auth_context->local_seqnumber;
  86         part.seq_number = &rdata.seq;
  87     } else
  88         part.seq_number = NULL;
  89
  90     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)
  91         outdata->seq = auth_context->local_seqnumber;
  92
  93     part.s_address = auth_context->local_address;
  94     part.r_address = auth_context->remote_address;
  95
  96     krb5_data_zero (&s.enc_part.cipher);
  97
  98     ASN1_MALLOC_ENCODE(EncKrbPrivPart, buf, buf_size, &part, &len, ret);
  99     if (ret)
 100         goto fail;
 101     if (buf_size != len)
 102         krb5_abortx(context, "internal error in ASN.1 encoder");
 103
 104     s.pvno = 5;
 105     s.msg_type = krb_priv;
 106     s.enc_part.etype = key->keytype;
 107     s.enc_part.kvno = NULL;
 108
 109     ret = krb5_crypto_init(context, key, 0, &crypto);
 110     if (ret) {
 111         free (buf);
 112         return ret;
 113     }
 114     ret = krb5_encrypt (context,
 115                         crypto,
 116                         KRB5_KU_KRB_PRIV,
 117                         buf + buf_size - len,
 118                         len,
 119                         &s.enc_part.cipher);
 120     krb5_crypto_destroy(context, crypto);
 121     if (ret) {
 122         free(buf);
 123         return ret;
 124     }
 125     free(buf);
 126
 127
 128     ASN1_MALLOC_ENCODE(KRB_PRIV, buf, buf_size, &s, &len, ret);
 129     if (ret)
 130         goto fail;
 131     if (buf_size != len)
 132         krb5_abortx(context, "internal error in ASN.1 encoder");
 133
 134     krb5_data_free (&s.enc_part.cipher);
 135
 136     ret = krb5_data_copy(outbuf, buf + buf_size - len, len);
 137     if (ret) {
 138         free(buf);
 139         return krb5_enomem(context);
 140     }
 141     free (buf);
 142     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
 143         auth_context->local_seqnumber =
 144             (auth_context->local_seqnumber + 1) & 0xFFFFFFFF;
 145     return 0;
 146
 147   fail:
 148     free (buf);
 149     krb5_data_free (&s.enc_part.cipher);
 150     return ret;
 151 }