1 /*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
5 * This file contains various auxiliary functions related to multiple
6 * precision integers.
7 *
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
13 */
14
15 #include "includes.h"
16 RCSID("$OpenBSD: mpaux.c,v 1.16 2001/02/08 19:30:52 itojun Exp $");
17
18 #pragma ident "%Z%%M% %I% %E% SMI"
19
20 #include <openssl/bn.h>
21 #include "getput.h"
22 #include "xmalloc.h"
23
24 #include <openssl/md5.h>
25
26 #include "mpaux.h"
27
28 void
compute_session_id(u_char session_id[16],u_char cookie[8],BIGNUM * host_key_n,BIGNUM * session_key_n)29 compute_session_id(u_char session_id[16],
30 u_char cookie[8],
31 BIGNUM* host_key_n,
32 BIGNUM* session_key_n)
33 {
34 u_int host_key_bytes = BN_num_bytes(host_key_n);
35 u_int session_key_bytes = BN_num_bytes(session_key_n);
36 u_int bytes = host_key_bytes + session_key_bytes;
37 u_char *buf = xmalloc(bytes);
38 MD5_CTX md;
39
40 BN_bn2bin(host_key_n, buf);
41 BN_bn2bin(session_key_n, buf + host_key_bytes);
42 MD5_Init(&md);
43 MD5_Update(&md, buf, bytes);
44 MD5_Update(&md, cookie, 8);
45 MD5_Final(session_id, &md);
46 memset(buf, 0, bytes);
47 xfree(buf);
48 }
49