crypto/dist/heimdal/lib/krb5/mk_safe.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("$Heimdal: mk_safe.c 13863 2004-05-25 21:46:46Z lha $"
  37         "$NetBSD$");
  38
  39 krb5_error_code KRB5_LIB_FUNCTION
  40 krb5_mk_safe(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_SAFE s;
  48     u_char *buf = NULL;
  49     size_t buf_size;
  50     size_t len;
  51     krb5_crypto crypto;
  52     krb5_keyblock *key;
  53     krb5_replay_data rdata;
  54
  55     if ((auth_context->flags &
  56          (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
  57         outdata == NULL)
  58         return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
  59
  60     if (auth_context->local_subkey)
  61         key = auth_context->local_subkey;
  62     else if (auth_context->remote_subkey)
  63         key = auth_context->remote_subkey;
  64     else
  65         key = auth_context->keyblock;
  66
  67     s.pvno = 5;
  68     s.msg_type = krb_safe;
  69
  70     memset(&rdata, 0, sizeof(rdata));
  71
  72     s.safe_body.user_data = *userdata;
  73
  74     krb5_us_timeofday (context, &rdata.timestamp, &rdata.usec);
  75
  76     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
  77         s.safe_body.timestamp  = &rdata.timestamp;
  78         s.safe_body.usec       = &rdata.usec;
  79     } else {
  80         s.safe_body.timestamp  = NULL;
  81         s.safe_body.usec       = NULL;
  82     }
  83
  84     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_TIME) {
  85         outdata->timestamp = rdata.timestamp;
  86         outdata->usec = rdata.usec;
  87     }
  88
  89     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
  90         rdata.seq = auth_context->local_seqnumber;
  91         s.safe_body.seq_number = &rdata.seq;
  92     } else
  93         s.safe_body.seq_number = NULL;
  94
  95     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)
  96         outdata->seq = auth_context->local_seqnumber;
  97
  98     s.safe_body.s_address = auth_context->local_address;
  99     s.safe_body.r_address = auth_context->remote_address;
 100
 101     s.cksum.cksumtype       = 0;
 102     s.cksum.checksum.data   = NULL;
 103     s.cksum.checksum.length = 0;
 104
 105     ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, &s, &len, ret);
 106     if (ret)
 107         return ret;
 108     if(buf_size != len)
 109         krb5_abortx(context, "internal error in ASN.1 encoder");
 110     ret = krb5_crypto_init(context, key, 0, &crypto);
 111     if (ret) {
 112         free (buf);
 113         return ret;
 114     }
 115     ret = krb5_create_checksum(context,
 116                                crypto,
 117                                KRB5_KU_KRB_SAFE_CKSUM,
 118                                0,
 119                                buf,
 120                                len,
 121                                &s.cksum);
 122     krb5_crypto_destroy(context, crypto);
 123     if (ret) {
 124         free (buf);
 125         return ret;
 126     }
 127
 128     free(buf);
 129     ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, &s, &len, ret);
 130     free_Checksum (&s.cksum);
 131     if(ret)
 132         return ret;
 133     if(buf_size != len)
 134         krb5_abortx(context, "internal error in ASN.1 encoder");
 135
 136     outbuf->length = len;
 137     outbuf->data   = buf;
 138     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
 139         auth_context->local_seqnumber =
 140             (auth_context->local_seqnumber + 1) & 0xFFFFFFFF;
 141     return 0;
 142 }