mirror of
https://codeberg.org/anoncontributorxmr/monero.git
synced 2024-11-22 23:42:24 +00:00
560 lines
17 KiB
C++
560 lines
17 KiB
C++
/*
|
|
* libEtPan! -- a mail stuff library
|
|
*
|
|
* Copyright (C) 2001, 2005 - DINH Viet Hoa
|
|
* 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. Neither the name of the libEtPan! project 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 AUTHORS 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 AUTHORS 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.
|
|
*/
|
|
|
|
/*
|
|
* $Id: md5.c,v 1.1.1.1 2005/03/18 20:17:27 zautrix Exp $
|
|
*/
|
|
|
|
/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
|
|
*/
|
|
|
|
/* 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.
|
|
*/
|
|
|
|
#ifdef _WIN32
|
|
# include <winsock2.h>
|
|
#else
|
|
# include <arpa/inet.h>
|
|
#endif
|
|
#include "md5global.h"
|
|
#include "md5_l.h"
|
|
#include "hmac-md5.h"
|
|
|
|
namespace md5
|
|
{
|
|
/* Constants for MD5Transform routine.
|
|
*/
|
|
|
|
#define S11 7
|
|
#define S12 12
|
|
#define S13 17
|
|
#define S14 22
|
|
#define S21 5
|
|
#define S22 9
|
|
#define S23 14
|
|
#define S24 20
|
|
#define S31 4
|
|
#define S32 11
|
|
#define S33 16
|
|
#define S34 23
|
|
#define S41 6
|
|
#define S42 10
|
|
#define S43 15
|
|
#define S44 21
|
|
|
|
/*
|
|
static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
|
|
static void Encode PROTO_LIST
|
|
((unsigned char *, UINT4 *, unsigned int));
|
|
static void Decode PROTO_LIST
|
|
((UINT4 *, unsigned char *, unsigned int));
|
|
static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
|
|
static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));
|
|
*/
|
|
|
|
static void MD5_memcpy (POINTER output, POINTER input, unsigned int len)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < len; i++)
|
|
output[i] = input[i];
|
|
}
|
|
|
|
/* Note: Replace "for loop" with standard memset if possible.
|
|
*/
|
|
|
|
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;
|
|
}
|
|
|
|
static void MD5Transform (UINT4 state[4], unsigned char block[64]);
|
|
|
|
static unsigned char* PADDING()
|
|
{
|
|
static unsigned char local_PADDING[64] = {
|
|
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
|
|
};
|
|
|
|
return local_PADDING;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* F, G, H and I are basic MD5 functions.
|
|
|
|
*/
|
|
#ifdef I
|
|
/* This might be defined via NANA */
|
|
#undef I
|
|
#endif
|
|
|
|
#define MD5_M_F(x, y, z) (((x) & (y)) | ((~x) & (z)))
|
|
#define MD5_M_G(x, y, z) (((x) & (z)) | ((y) & (~z)))
|
|
#define MD5_M_H(x, y, z) ((x) ^ (y) ^ (z))
|
|
#define MD5_M_I(x, y, z) ((y) ^ ((x) | (~z)))
|
|
|
|
/* ROTATE_LEFT rotates x left n bits.
|
|
|
|
*/
|
|
|
|
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
|
|
|
|
/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
|
|
Rotation is separate from addition to prevent recomputation.
|
|
*/
|
|
|
|
#define FF(a, b, c, d, x, s, ac) { (a) += MD5_M_F ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
|
|
#define GG(a, b, c, d, x, s, ac) { (a) += MD5_M_G ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
|
|
#define HH(a, b, c, d, x, s, ac) { (a) += MD5_M_H ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
|
|
#define II(a, b, c, d, x, s, ac) { (a) += MD5_M_I ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }
|
|
|
|
/* MD5 initialization. Begins an MD5 operation, writing a new context.
|
|
*/
|
|
|
|
static 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.
|
|
*/
|
|
|
|
static void MD5Update( MD5_CTX *context, const unsigned char *input, unsigned int inputLen )
|
|
{
|
|
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, (unsigned char*)&input[i]);
|
|
|
|
index = 0;
|
|
}
|
|
else
|
|
i = 0;
|
|
|
|
/* Buffer remaining input */
|
|
MD5_memcpy( (POINTER)&context->buffer[index], (POINTER)&input[i], inputLen-i );
|
|
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/* MD5 finalization. Ends an MD5 message-digest operation, writing the
|
|
the message digest and zeroizing the context.
|
|
|
|
*/
|
|
|
|
static void MD5Final ( unsigned char digest[16], MD5_CTX *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.
|
|
|
|
*/
|
|
memwipe ((POINTER)context, 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.
|
|
*/
|
|
memwipe ((POINTER)x, sizeof (x));
|
|
}
|
|
|
|
/* Note: Replace "for loop" with standard memcpy if possible.
|
|
|
|
*/
|
|
inline
|
|
void hmac_md5_init(HMAC_MD5_CTX *hmac,
|
|
const unsigned char *key,
|
|
int key_len)
|
|
{
|
|
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 */
|
|
MD5_memset(k_ipad, '\0', sizeof k_ipad);
|
|
MD5_memset(k_opad, '\0', sizeof k_opad);
|
|
MD5_memcpy( k_ipad, (POINTER)key, key_len);
|
|
MD5_memcpy( k_opad, (POINTER)key, key_len);
|
|
|
|
/* XOR key with ipad and opad values */
|
|
for (i=0; i<64; i++) {
|
|
k_ipad[i] ^= 0x36;
|
|
k_opad[i] ^= 0x5c;
|
|
}
|
|
|
|
MD5Init(&hmac->ictx); /* init inner context */
|
|
MD5Update(&hmac->ictx, k_ipad, 64); /* apply inner pad */
|
|
|
|
MD5Init(&hmac->octx); /* init outer context */
|
|
MD5Update(&hmac->octx, k_opad, 64); /* apply outer pad */
|
|
|
|
/* scrub the pads and key context (if used) */
|
|
memwipe( (POINTER)&k_ipad, sizeof(k_ipad));
|
|
memwipe( (POINTER)&k_opad, sizeof(k_opad));
|
|
memwipe( (POINTER)&tk, sizeof(tk));
|
|
|
|
/* and we're done. */
|
|
}
|
|
|
|
/* The precalc and import routines here rely on the fact that we pad
|
|
* the key out to 64 bytes and use that to initialize the md5
|
|
* contexts, and that updating an md5 context with 64 bytes of data
|
|
* leaves nothing left over; all of the interesting state is contained
|
|
* in the state field, and none of it is left over in the count and
|
|
* buffer fields. So all we have to do is save the state field; we
|
|
* can zero the others when we reload it. Which is why the decision
|
|
* was made to pad the key out to 64 bytes in the first place. */
|
|
inline
|
|
void hmac_md5_precalc(HMAC_MD5_STATE *state,
|
|
const unsigned char *key,
|
|
int key_len)
|
|
{
|
|
HMAC_MD5_CTX hmac;
|
|
unsigned lupe;
|
|
|
|
hmac_md5_init(&hmac, key, key_len);
|
|
for (lupe = 0; lupe < 4; lupe++) {
|
|
state->istate[lupe] = htonl(hmac.ictx.state[lupe]);
|
|
state->ostate[lupe] = htonl(hmac.octx.state[lupe]);
|
|
}
|
|
memwipe( (POINTER)&hmac, sizeof(hmac));
|
|
}
|
|
|
|
|
|
inline
|
|
void hmac_md5_import(HMAC_MD5_CTX *hmac,
|
|
HMAC_MD5_STATE *state)
|
|
{
|
|
unsigned lupe;
|
|
MD5_memset( (POINTER)hmac, 0, sizeof(HMAC_MD5_CTX));
|
|
for (lupe = 0; lupe < 4; lupe++) {
|
|
hmac->ictx.state[lupe] = ntohl(state->istate[lupe]);
|
|
hmac->octx.state[lupe] = ntohl(state->ostate[lupe]);
|
|
}
|
|
/* Init the counts to account for our having applied
|
|
* 64 bytes of key; this works out to 0x200 (64 << 3; see
|
|
* MD5Update above...) */
|
|
hmac->ictx.count[0] = hmac->octx.count[0] = 0x200;
|
|
}
|
|
|
|
inline
|
|
void hmac_md5_final(unsigned char digest[HMAC_MD5_SIZE],
|
|
HMAC_MD5_CTX *hmac)
|
|
{
|
|
MD5Final(digest, &hmac->ictx); /* Finalize inner md5 */
|
|
MD5Update(&hmac->octx, digest, 16); /* Update outer ctx */
|
|
MD5Final(digest, &hmac->octx); /* Finalize outer md5 */
|
|
}
|
|
|
|
|
|
void hmac_md5(const unsigned char* text, int text_len, const unsigned char* key, int key_len, unsigned char *digest)
|
|
{
|
|
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 */
|
|
MD5_memset(k_ipad, '\0', sizeof k_ipad);
|
|
MD5_memset(k_opad, '\0', sizeof k_opad);
|
|
MD5_memcpy( k_ipad, (POINTER)key, key_len);
|
|
MD5_memcpy( k_opad, (POINTER)key, key_len);
|
|
|
|
/* XOR key with ipad and opad values */
|
|
for (i=0; i<64; i++) {
|
|
k_ipad[i] ^= 0x36;
|
|
k_opad[i] ^= 0x5c;
|
|
}
|
|
/*
|
|
* perform inner MD5
|
|
*/
|
|
|
|
MD5Init(&context); /* init context for 1st
|
|
* pass */
|
|
MD5Update(&context, k_ipad, 64); /* start with inner pad */
|
|
MD5Update(&context, text, text_len); /* then text of datagram */
|
|
MD5Final(digest, &context); /* finish up 1st pass */
|
|
|
|
/*
|
|
* perform outer MD5
|
|
*/
|
|
MD5Init(&context); /* init context for 2nd
|
|
* pass */
|
|
MD5Update(&context, k_opad, 64); /* start with outer pad */
|
|
MD5Update(&context, digest, 16); /* then results of 1st
|
|
* hash */
|
|
MD5Final(digest, &context); /* finish up 2nd pass */
|
|
|
|
}
|
|
}
|