openssh/mpaux.c

45 lines
1.3 KiB
C

/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* This file contains various auxiliary functions related to multiple
* precision integers.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
RCSID("$OpenBSD: mpaux.c,v 1.15 2000/12/19 23:17:57 markus Exp $");
#include <openssl/bn.h>
#include "getput.h"
#include "xmalloc.h"
#include <openssl/md5.h>
void
compute_session_id(u_char session_id[16],
u_char cookie[8],
BIGNUM* host_key_n,
BIGNUM* session_key_n)
{
u_int host_key_bytes = BN_num_bytes(host_key_n);
u_int session_key_bytes = BN_num_bytes(session_key_n);
u_int bytes = host_key_bytes + session_key_bytes;
u_char *buf = xmalloc(bytes);
MD5_CTX md;
BN_bn2bin(host_key_n, buf);
BN_bn2bin(session_key_n, buf + host_key_bytes);
MD5_Init(&md);
MD5_Update(&md, buf, bytes);
MD5_Update(&md, cookie, 8);
MD5_Final(session_id, &md);
memset(buf, 0, bytes);
xfree(buf);
}