1 /*
2 * Copyright 2006 Kai Blin
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
17 *
18 * This file implements RFC 2104 (HMAC) for the MD5 provider.
19 * It is needed for NTLM2 signing and sealing.
20 */
21
22 #include "hmac_md5.h"
23
HMACMD5Init(HMAC_MD5_CTX * ctx,const unsigned char * key,unsigned int key_len)24 void HMACMD5Init(HMAC_MD5_CTX *ctx, const unsigned char *key, unsigned int key_len)
25 {
26 int i;
27 unsigned char inner_padding[64];
28 unsigned char temp_key[16];
29
30 if(key_len > 64)
31 {
32 MD5_CTX temp_ctx;
33
34 MD5Init(&temp_ctx);
35 MD5Update(&temp_ctx, key, key_len);
36 MD5Final(&temp_ctx);
37 memcpy(temp_key, temp_ctx.digest, 16);
38
39 key = temp_key;
40 key_len = 16;
41 }
42
43 memset(inner_padding, 0, 64);
44 memset(ctx->outer_padding, 0, 64);
45 memcpy(inner_padding, key, key_len);
46 memcpy(ctx->outer_padding, key, key_len);
47
48 for(i = 0; i < 64; ++i)
49 {
50 inner_padding[i] ^= 0x36;
51 ctx->outer_padding[i] ^= 0x5c;
52 }
53
54 MD5Init(&(ctx->ctx));
55 MD5Update(&(ctx->ctx), inner_padding, 64);
56 }
57
HMACMD5Update(HMAC_MD5_CTX * ctx,const unsigned char * data,unsigned int data_len)58 void HMACMD5Update(HMAC_MD5_CTX *ctx, const unsigned char *data, unsigned int data_len)
59 {
60 MD5Update(&(ctx->ctx), data, data_len);
61 }
62
HMACMD5Final(HMAC_MD5_CTX * ctx,unsigned char * digest)63 void HMACMD5Final(HMAC_MD5_CTX *ctx, unsigned char *digest)
64 {
65 MD5_CTX outer_ctx;
66 unsigned char inner_digest[16];
67
68 MD5Final(&(ctx->ctx));
69 memcpy(inner_digest, ctx->ctx.digest, 16);
70
71 MD5Init(&outer_ctx);
72 MD5Update(&outer_ctx, ctx->outer_padding, 64);
73 MD5Update(&outer_ctx, inner_digest, 16);
74 MD5Final(&outer_ctx);
75
76 memcpy(digest, outer_ctx.digest, 16);
77 }
78