www.pudn.com > IPsec_Src_Instal.rar > HMAC.C
#include "precomp.h"
#include "hmac.h"
/*
Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
rights reserved.
License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD5 Message-Digest
Algorithm" in all material mentioning or referencing this software
or this function.
License is also granted to make and use derivative works provided
that such works are identified as "derived from the RSA Data
Security, Inc. MD5 Message-Digest Algorithm" in all material
mentioning or referencing the derived work.
RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.
These notices must be retained in any copies of any part of this
documentation and/or software.
*/
/*
Following work is derived from "derived from the RSA Data
Security, Inc. MD5 Message-Digest Algorithm"
*/
static void MD5Transform(UINT4 [4], unsigned char [64]);
static void Encode(unsigned char *, UINT4 *, unsigned int);
static void Decode(UINT4 *, unsigned char *, unsigned int);
static void MD5_memcpy (POINTER, POINTER, unsigned int);
static void MD5_memset (POINTER, int, unsigned int);
/*
MD5 initialization. Begins an MD5 operation, writing a new context.
*/
void MD5Init(
MD5_CTX *context
)
{
context->count[0] = context->count[1] = 0;
//
// Load magic initialization constants.
//
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}
/*
MD5 block update operation. Continues an MD5 message-digest
operation, processing another message block, and updating the
context.
*/
void MD5Update(
MD5_CTX *context, // context
unsigned char *input, // input block
unsigned int inputLen // length of input block
)
{
unsigned int i, index, partLen;
//
// Compute number of bytes mod 64
//
index = (unsigned int)((context->count[0] >> 3) & 0x3F);
//
// Update number of bits
//
if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
{
context->count[1]++;
}
context->count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - index;
//
// Transform as many times as possible.
//
if (inputLen >= partLen)
{
MD5_memcpy((POINTER)&context->buffer[index], (POINTER)input, partLen);
MD5Transform (context->state, context->buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
{
MD5Transform (context->state, &input[i]);
}
index = 0;
}
else
{
i = 0;
}
//
// Buffer remaining input
//
MD5_memcpy((POINTER)&context->buffer[index], (POINTER)&input[i], inputLen-i);
}
/*
MD5 finalization. Ends an MD5 message-digest operation, writing the
the message digest and zeroizing the context.
*/
void MD5Final (
unsigned char digest[16], // message digest
MD5_CTX *context // context
)
{
unsigned char bits[8];
unsigned int index, padLen;
//
// Save number of bits
//
Encode (bits, context->count, 8);
//
// Pad out to 56 mod 64.
//
index = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD5Update (context, PADDING, padLen);
//
// Append length (before padding)
//
MD5Update (context, bits, 8);
//
// Store state in digest
//
Encode (digest, context->state, 16);
//
// Zeroize sensitive information.
//
MD5_memset ((POINTER)context, 0, sizeof (*context));
}
/*
MD5 basic transformation. Transforms state based on block.
*/
static void MD5Transform(
UINT4 state[4],
unsigned char block[64]
)
{
UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
Decode (x, block, 64);
// Round 1
FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
/* Round 2 */
GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
/* Round 3 */
HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
/* Round 4 */
II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
// Zeroize sensitive information.
MD5_memset ((POINTER)x, 0, sizeof (x));
}
/*
Encodes input (UINT4) into output (unsigned char). Assumes len is
a multiple of 4.
*/
static void Encode(
unsigned char *output,
UINT4 *input,
unsigned int len
)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
{
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}
/*
Decodes input (unsigned char) into output (UINT4). Assumes len is
a multiple of 4.
*/
static void Decode (
UINT4 *output,
unsigned char *input,
unsigned int len
)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
{
output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
(((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}
}
static void MD5_memcpy (
POINTER output,
POINTER input,
unsigned int len
)
{
unsigned int i;
for (i = 0; i < len; i++)
{
output[i] = input[i];
}
}
static void MD5_memset (
POINTER output,
int value,
unsigned int len
)
{
unsigned int i;
for (i = 0; i < len; i++)
{
((char *)output)[i] = (char)value;
}
}
/*
Digests a string and prints the result.
*/
static void MDString (
char *string
)
{
MD5_CTX context;
unsigned char digest[16];
unsigned int len = strlen (string);
MD5Init (&context);
MD5Update (&context, string, len);
MD5Final (digest, &context);
}
/*
Function: hmac_md5
*/
void hmac_md5(
unsigned char* text, // pointer to data stream
int text_len, // length of data stream
unsigned char* key, // pointer to authentication key
int key_len, // length of authentication key
unsigned char* digest // caller digest to be filled in
)
{
MD5_CTX context;
unsigned char k_ipad[65]; // inner padding - key XORd with ipad
unsigned char k_opad[65]; // outer padding - key XORd with opad
unsigned char tk[16];
int i;
//
// if key is longer than 64 bytes reset it to key=MD5(key)
//
if (key_len > 64)
{
MD5_CTX tctx;
MD5Init(&tctx);
MD5Update(&tctx, key, key_len);
MD5Final(tk, &tctx);
key = tk;
key_len = 16;
}
/*
the HMAC_MD5 transform looks like:
MD5(K XOR opad, MD5(K XOR ipad, text))
where K is an n byte key
ipad is the byte 0x36 repeated 64 times
opad is the byte 0x5c repeated 64 times
and text is the data being protected
*/
//
// start out by storing key in pads
//
for(i=0;i<65;i++)
{
k_ipad[i]=k_opad[i]=0;
}
for(i=0;i