1/*
2 * Copyright (c) 1995, 1996, 1997, 1998 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 "sasl_mac_krb_locl.h"
35
36RCSID("$Id: mk_priv.c,v 1.4 2005/01/10 19:10:46 snsimon Exp $");
37
38/* application include files */
39#include "krb-archaeology.h"
40
41/*
42 * krb_mk_priv() constructs an AUTH_MSG_PRIVATE message.  It takes
43 * some user data "in" of "length" bytes and creates a packet in "out"
44 * consisting of the user data, a timestamp, and the sender's network
45 * address.
46 * The packet is encrypted by pcbc_encrypt(), using the given
47 * "key" and "schedule".
48 * The length of the resulting packet "out" is
49 * returned.
50 *
51 * It is similar to krb_mk_safe() except for the additional key
52 * schedule argument "schedule" and the fact that the data is encrypted
53 * rather than appended with a checksum.  The protocol version is
54 * KRB_PROT_VERSION, defined in "krb.h".
55 *
56 * The "out" packet consists of:
57 *
58 * Size			Variable		Field
59 * ----			--------		-----
60 *
61 * 1 byte		KRB_PROT_VERSION	protocol version number
62 * 1 byte		AUTH_MSG_PRIVATE |	message type plus local
63 *			HOST_BYTE_ORDER		byte order in low bit
64 *
65 * 4 bytes		c_length		length of data
66 * we encrypt from here with pcbc_encrypt
67 *
68 * 4 bytes		length			length of user data
69 * length		in			user data
70 * 1 byte		msg_time_5ms		timestamp milliseconds
71 * 4 bytes		sender->sin.addr.s_addr	sender's IP address
72 *
73 * 4 bytes		msg_time_sec or		timestamp seconds with
74 *			-msg_time_sec		direction in sign bit
75 *
76 * 0<=n<=7  bytes	pad to 8 byte multiple	zeroes
77 */
78
79int32_t
80krb_mk_priv(void *in, void *out, u_int32_t length,
81	    struct des_ks_struct *schedule, des_cblock *key,
82	    struct sockaddr_in *sender, struct sockaddr_in *receiver)
83{
84    unsigned char *p = (unsigned char*)out;
85    unsigned char *cipher;
86
87    struct timeval tv;
88    u_int32_t src_addr;
89    u_int32_t len;
90
91    p += krb_put_int(KRB_PROT_VERSION, p, 1, 1);
92    p += krb_put_int(AUTH_MSG_PRIVATE, p, 1, 1);
93
94    len = 4 + length + 1 + 4 + 4;
95    len = (len + 7) & ~7;
96    p += krb_put_int(len, p, 4, 4);
97
98    cipher = p;
99
100    p += krb_put_int(length, p, 4, 4);
101
102    memcpy(p, in, length);
103    p += length;
104
105    krb_kdctimeofday(&tv);
106
107    *p++ =tv.tv_usec / 5000;
108
109    src_addr = sender->sin_addr.s_addr;
110    p += krb_put_address(src_addr, p, 4);
111
112    p += krb_put_int(lsb_time(tv.tv_sec, sender, receiver), p, 4, 4);
113
114    memset(p, 0, 7);
115
116    des_pcbc_encrypt((des_cblock *)cipher, (des_cblock *)cipher,
117		     len, schedule, key, DES_ENCRYPT);
118
119    return  (cipher - (unsigned char*)out) + len;
120}
121