mk_rep.c revision 72445 
1/*
2 * Copyright (c) 1997 - 2000 Kungliga Tekniska H�gskolan
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
36RCSID("$Id: mk_rep.c,v 1.18 2000/12/06 20:57:23 joda Exp $");
37
38krb5_error_code
39krb5_mk_rep(krb5_context context,
40	    krb5_auth_context auth_context,
41	    krb5_data *outbuf)
42{
43  krb5_error_code ret;
44  AP_REP ap;
45  EncAPRepPart body;
46  u_char *buf = NULL;
47  size_t buf_size;
48  size_t len;
49  krb5_crypto crypto;
50
51  ap.pvno = 5;
52  ap.msg_type = krb_ap_rep;
53
54  memset (&body, 0, sizeof(body));
55
56  body.ctime = auth_context->authenticator->ctime;
57  body.cusec = auth_context->authenticator->cusec;
58  body.subkey = NULL;
59  if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
60    krb5_generate_seq_number (context,
61			      auth_context->keyblock,
62			      &auth_context->local_seqnumber);
63    body.seq_number = malloc (sizeof(*body.seq_number));
64    if (body.seq_number == NULL)
65	return ENOMEM;
66    *(body.seq_number) = auth_context->local_seqnumber;
67  } else
68    body.seq_number = NULL;
69
70  ap.enc_part.etype = auth_context->keyblock->keytype;
71  ap.enc_part.kvno  = NULL;
72
73  buf_size = length_EncAPRepPart(&body);
74  buf = malloc (buf_size);
75  if (buf == NULL) {
76      free_EncAPRepPart (&body);
77      return ENOMEM;
78  }
79
80  ret = krb5_encode_EncAPRepPart (context,
81				  buf + buf_size - 1,
82				  buf_size,
83				  &body,
84				  &len);
85
86  free_EncAPRepPart (&body);
87  ret = krb5_crypto_init(context, auth_context->keyblock,
88			 0 /* ap.enc_part.etype */, &crypto);
89  if (ret) {
90      free (buf);
91      return ret;
92  }
93  ret = krb5_encrypt (context,
94		      crypto,
95		      KRB5_KU_AP_REQ_ENC_PART,
96		      buf + buf_size - len,
97		      len,
98		      &ap.enc_part.cipher);
99  krb5_crypto_destroy(context, crypto);
100  if (ret) {
101      free(buf);
102      return ret;
103  }
104
105  buf_size = length_AP_REP(&ap);
106  buf = realloc(buf, buf_size);
107  if(buf == NULL) {
108      free_AP_REP (&ap);
109      return ENOMEM;
110  }
111  ret = encode_AP_REP (buf + buf_size - 1, buf_size, &ap, &len);
112
113  free_AP_REP (&ap);
114
115  if(len != buf_size)
116      krb5_abortx(context, "krb5_mk_rep: encoded length != calculated length");
117  outbuf->data = buf;
118  outbuf->length = len;
119  return 0;
120}
121