/*!
	@file RuCrypto_MD5.cpp

	Copyright (c) 2004-2007 All rights reserved
*/

#include "../../Core/Crypto/RuCrypto_MD5.h"

#pragma managed(push, off)

// ************************************************************************************************************************************************************

struct MD5_CTX
{
	UINT32				state[4];							// state (ABCD)
	UINT32				count[2];							// number of bits, modulo 2^64 (lsb first)
	UINT8				buffer[64];							// input buffer
};

// ************************************************************************************************************************************************************
//	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(UINT32 *state, const UINT8 *block);
static void Encode(UINT8 *output, const UINT32 *input, UINT32 len);
static void Decode(UINT32 *output, const UINT8 *input, UINT32 len);

static UINT8 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
};

// F, G, H and I are basic MD5 functions.
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define 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 re-computation.
#define FF(a, b, c, d, x, s, ac) { \
 (a) += F ((b), (c), (d)) + (x) + (UINT32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) { \
 (a) += G ((b), (c), (d)) + (x) + (UINT32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
 (a) += H ((b), (c), (d)) + (x) + (UINT32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
 (a) += I ((b), (c), (d)) + (x) + (UINT32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

/*
	MD5 initialization. Begins an MD5 operation, writing a new context.

	MD5_CTX *context;                         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.

	MD5_CTX *context;                         context
	unsigned char *input;                     input block
	unsigned int inputLen;                    length of input block
*/
void MD5Update(MD5_CTX *context, const UINT8 *input, UINT32 inputLen)
{
	UINT32 i, index, partLen;

	// Compute number of bytes mod 64
	index = (UINT32) ((context->count[0] >> 3) & 0x3F);

	// Update number of bits 
	if((context->count[0] += ((UINT32) inputLen << 3)) < ((UINT32) inputLen << 3))
		context->count[1]++;

	context->count[1] += ((UINT32) inputLen >> 29);

	partLen = 64 - index;

	// Transform as many times as possible.
	if(inputLen >= partLen)
	{
		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 
	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.

	unsigned char digest[16];                      message digest
	MD5_CTX *context;                              context
*/
void MD5Final(UINT8 *digest, MD5_CTX *context)
{
	UINT8 bits[8];
	UINT32 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.
	memset((POINTER)context, 0, sizeof (*context));
}

/*
	MD5 basic transformation. Transforms state based on block.
*/
static void MD5Transform(UINT32 *state, const UINT8 *block)
{
	UINT32 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.
	memset((POINTER) x, 0, sizeof(x));
}

/*
	Encodes input (UINT32) into output (unsigned char). Assumes len is a multiple of 4.
*/
static void Encode(UINT8 *output, const UINT32 *input, UINT32 len)
{
	UINT32 i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
	{
		output[j] = (UINT8)(input[i] & 0xff);
		output[j+1] = (UINT8)((input[i] >> 8) & 0xff);
		output[j+2] = (UINT8)((input[i] >> 16) & 0xff);
		output[j+3] = (UINT8)((input[i] >> 24) & 0xff);
	}
}

/*
	Decodes input (unsigned char) into output (UINT32). Assumes len is
	a multiple of 4.
*/
static void Decode(UINT32 *output, const UINT8 *input, UINT32 len)
{
	UINT32 i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
		output[i] = ((UINT32)input[j]) | (((UINT32)input[j+1]) << 8) | (((UINT32)input[j+2]) << 16) | (((UINT32)input[j+3]) << 24);
}

// ************************************************************************************************************************************************************

char *CRuCrypto_MD5::CalculateMD5Digest(const char *text)
{
/*
	// Initialize MD5 context
	MD5_CTX context;
	MD5Init(&context); 

	// Calculate digest
	UINT8 digest[16];
	MD5Update(&context, reinterpret_cast<const UINT8 *>(text), strlen(text));
	MD5Final(digest, &context);

	// Allocate memory for digest output
	char *digestString = ruNEW char [33];
	memset(digestString, 0, 33);

	// Make a string version of the numeric digest value
	for(int i = 0, p = 0; i < 16; ++i, p += 2)
	{
		sprintf(&digestString[p], "%02x", digest[i]);
	}

	return digestString;
*/
	return CalculateMD5Digest(reinterpret_cast<const BYTE *>(text), strlen(text));
}

char *CRuCrypto_MD5::CalculateMD5Digest(const BYTE *text, INT32 textLen)
{
	// Initialize MD5 context
	MD5_CTX context;
	MD5Init(&context); 

	// Calculate digest
	UINT8 digest[16];
	MD5Update(&context, reinterpret_cast<const UINT8 *>(text), textLen);
	MD5Final(digest, &context);

	// Allocate memory for digest output
	char *digestString = ruNEW char [33];
	memset(digestString, 0, 33);

	// Make a string version of the numeric digest value
	for(int i = 0, p = 0; i < 16; ++i, p += 2)
	{
		sprintf(&digestString[p], "%02x", digest[i]);
	}

	return digestString;
}

// ************************************************************************************************************************************************************

#pragma managed(pop)
