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/*
* Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Kungliga Tekniska
* Högskolan and its contributors.
*
* 4. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb_locl.h"
RCSID("$Id: mk_priv.c,v 1.18 1997/04/01 08:18:37 joda Exp $");
/* application include files */
#include "lsb_addr_comp.h"
/*
* krb_mk_priv() constructs an AUTH_MSG_PRIVATE message. It takes
* some user data "in" of "length" bytes and creates a packet in "out"
* consisting of the user data, a timestamp, and the sender's network
* address.
* The packet is encrypted by pcbc_encrypt(), using the given
* "key" and "schedule".
* The length of the resulting packet "out" is
* returned.
*
* It is similar to krb_mk_safe() except for the additional key
* schedule argument "schedule" and the fact that the data is encrypted
* rather than appended with a checksum. The protocol version is
* KRB_PROT_VERSION, defined in "krb.h".
*
* The "out" packet consists of:
*
* Size Variable Field
* ---- -------- -----
*
* 1 byte KRB_PROT_VERSION protocol version number
* 1 byte AUTH_MSG_PRIVATE | message type plus local
* HOST_BYTE_ORDER byte order in low bit
*
* 4 bytes c_length length of data
* we encrypt from here with pcbc_encrypt
*
* 4 bytes length length of user data
* length in user data
* 1 byte msg_time_5ms timestamp milliseconds
* 4 bytes sender->sin.addr.s_addr sender's IP address
*
* 4 bytes msg_time_sec or timestamp seconds with
* -msg_time_sec direction in sign bit
*
* 0<=n<=7 bytes pad to 8 byte multiple zeroes
*/
int32_t
krb_mk_priv(void *in, void *out, u_int32_t length,
struct des_ks_struct *schedule, des_cblock *key,
struct sockaddr_in *sender, struct sockaddr_in *receiver)
{
unsigned char *p = (unsigned char*)out;
unsigned char *cipher;
struct timeval tv;
u_int32_t src_addr;
u_int32_t len;
p += krb_put_int(KRB_PROT_VERSION, p, 1);
p += krb_put_int(AUTH_MSG_PRIVATE, p, 1);
len = 4 + length + 1 + 4 + 4;
len = (len + 7) & ~7;
p += krb_put_int(len, p, 4);
cipher = p;
p += krb_put_int(length, p, 4);
memcpy(p, in, length);
p += length;
gettimeofday(&tv, NULL);
*p++ =tv.tv_usec / 5000;
src_addr = sender->sin_addr.s_addr;
p += krb_put_address(src_addr, p);
p += krb_put_int(lsb_time(tv.tv_sec, sender, receiver), p, 4);
memset(p, 0, 7);
des_pcbc_encrypt((des_cblock *)cipher, (des_cblock *)cipher,
len, schedule, key, DES_ENCRYPT);
return (cipher - (unsigned char*)out) + len;
}
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