mk_safe.c revision 1.1.1.1.10.1 
1/*	$NetBSD: mk_safe.c,v 1.1.1.1.10.1 2014/08/19 23:45:19 tls Exp $	*/
2
3/*
4 * Copyright (c) 1997 - 2003 Kungliga Tekniska H��gskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include "krb5_locl.h"
37
38KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
39krb5_mk_safe(krb5_context context,
40	     krb5_auth_context auth_context,
41	     const krb5_data *userdata,
42	     krb5_data *outbuf,
43	     krb5_replay_data *outdata)
44{
45    krb5_error_code ret;
46    KRB_SAFE s;
47    u_char *buf = NULL;
48    size_t buf_size;
49    size_t len = 0;
50    krb5_crypto crypto;
51    krb5_keyblock *key;
52    krb5_replay_data rdata;
53
54    if ((auth_context->flags &
55	 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
56	outdata == NULL)
57	return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
58
59    if (auth_context->local_subkey)
60	key = auth_context->local_subkey;
61    else if (auth_context->remote_subkey)
62	key = auth_context->remote_subkey;
63    else
64	key = auth_context->keyblock;
65
66    s.pvno = 5;
67    s.msg_type = krb_safe;
68
69    memset(&rdata, 0, sizeof(rdata));
70
71    s.safe_body.user_data = *userdata;
72
73    krb5_us_timeofday (context, &rdata.timestamp, &rdata.usec);
74
75    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
76	s.safe_body.timestamp  = &rdata.timestamp;
77	s.safe_body.usec       = &rdata.usec;
78    } else {
79	s.safe_body.timestamp  = NULL;
80	s.safe_body.usec       = NULL;
81    }
82
83    if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_TIME) {
84	outdata->timestamp = rdata.timestamp;
85	outdata->usec = rdata.usec;
86    }
87
88    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
89	rdata.seq = auth_context->local_seqnumber;
90	s.safe_body.seq_number = &rdata.seq;
91    } else
92	s.safe_body.seq_number = NULL;
93
94    if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)
95	outdata->seq = auth_context->local_seqnumber;
96
97    s.safe_body.s_address = auth_context->local_address;
98    s.safe_body.r_address = auth_context->remote_address;
99
100    s.cksum.cksumtype       = 0;
101    s.cksum.checksum.data   = NULL;
102    s.cksum.checksum.length = 0;
103
104    ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, &s, &len, ret);
105    if (ret)
106	return ret;
107    if(buf_size != len)
108	krb5_abortx(context, "internal error in ASN.1 encoder");
109    ret = krb5_crypto_init(context, key, 0, &crypto);
110    if (ret) {
111	free (buf);
112	return ret;
113    }
114    ret = krb5_create_checksum(context,
115			       crypto,
116			       KRB5_KU_KRB_SAFE_CKSUM,
117			       0,
118			       buf,
119			       len,
120			       &s.cksum);
121    krb5_crypto_destroy(context, crypto);
122    if (ret) {
123	free (buf);
124	return ret;
125    }
126
127    free(buf);
128    ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, &s, &len, ret);
129    free_Checksum (&s.cksum);
130    if(ret)
131	return ret;
132    if(buf_size != len)
133	krb5_abortx(context, "internal error in ASN.1 encoder");
134
135    outbuf->length = len;
136    outbuf->data   = buf;
137    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
138	auth_context->local_seqnumber =
139	    (auth_context->local_seqnumber + 1) & 0xFFFFFFFF;
140    return 0;
141}
142