#ifndef __LC_MD5_H__
#define __LC_MD5_H__

#include <string.h>

#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))
#define MD5STEP(f, w, x, y, z, data, s) \
	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

#define ByteReverse(buf, longs)

class CLCMD5
{
	unsigned int		m_buf[4];
	unsigned int		m_bits[2];
	unsigned char		m_in[64];
	unsigned char		m_digest[16];
	unsigned int		m_digest_num[4];

public:
	CLCMD5();
	void Init();
	void Update(const void* pBuf, unsigned int nLen);
	const unsigned int* Final();

private:
	void Transform(unsigned int buf[4], unsigned int in[4]);
}; // class CLCMD5

inline CLCMD5::CLCMD5()
{
	Init();
}

inline void CLCMD5::Init()
{
	m_buf[0] = 0x67452301;
	m_buf[1] = 0xefcdab89;
	m_buf[2] = 0x98badcfe;
	m_buf[3] = 0x10325476;

	m_bits[0] = 0;
	m_bits[1] = 0;
}

inline void CLCMD5::Update(const void* pBuf, unsigned int nLen)
{
	unsigned int t;

	unsigned char* pbBuf = (unsigned char*)pBuf;

	t = m_bits[0];
	if ((m_bits[0] = t + ((unsigned int) nLen << 3)) < t)
		m_bits[1]++;
	m_bits[1] += nLen >> 29;

	t = (t >> 3) & 0x3f;

	if (t)
	{
		unsigned char *p = (unsigned char *) m_in + t;

		t = 64 - t;
		if (nLen < t)
		{
			memcpy(p, pbBuf, nLen);
			return;
		}
		memcpy(p, pbBuf, t);
		ByteReverse(m_in, 16);
		Transform(m_buf, (unsigned int *) m_in);
		pbBuf += t;
		nLen -= t;
	}

	while (nLen >= 64)
	{
		memcpy(m_in, pbBuf, 64);
		ByteReverse(m_in, 16);
		Transform(m_buf, (unsigned int *) m_in);
		pbBuf += 64;
		nLen -= 64;
	}

	memcpy(m_in, pbBuf, nLen);
}

inline const unsigned int* CLCMD5::Final()
{
	unsigned int	nCount;
	unsigned char*	p;

	nCount = (m_bits[0] >> 3) & 0x3F;

	p = m_in + nCount;
	*p++ = 0x80;

	nCount = 64 - 1 - nCount;

	if (nCount < 8)
	{
		memset(p, 0, nCount);
		ByteReverse(m_in, 16);
		Transform(m_buf, (unsigned int*)m_in);

		memset(m_in, 0, 56);
	}
	else
	{
		memset(p, 0, nCount - 8);
	}
	ByteReverse(m_in, 14);

	((unsigned int*)m_in)[14] = m_bits[0];
	((unsigned int*)m_in)[15] = m_bits[1];

	Transform(m_buf, (unsigned int*)m_in);
	ByteReverse((unsigned char *)m_buf, 4);
	memcpy(m_digest, m_buf, 16);
	memcpy(m_digest_num, m_digest, 16);

	memset(m_buf, 0, sizeof(m_buf));
	memset(m_bits, 0, sizeof(m_bits));
	memset(m_in, 0, sizeof(m_in));

	return (const unsigned int*)m_digest_num;
}

inline void CLCMD5::Transform(unsigned int buf[4], unsigned int in[4])
{
	register unsigned int a, b, c, d;

	a = buf[0];
	b = buf[1];
	c = buf[2];
	d = buf[3];

	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);

	buf[0] += a;
	buf[1] += b;
	buf[2] += c;
	buf[3] += d;
}

#undef F1
#undef F2
#undef F3
#undef F4
#undef MD5STEP
#undef ByteReverse

#endif // __LC_MD5_H__
//
