HashUtil.h

/**
 * HashUtil (MD5 hashing)
 *
 * 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. 
 *
 * @author  RSA Data Security, Inc. (http://www.rsasecurity.com)
 * @date  21/08/04
 * @see RFC1321
 */

#ifndef _HASHUTIL_H_
#define _HASHUTIL_H_

class HashUtil {
private:
	static const unsigned int S11 = 7;
	static const unsigned int S12 = 12;
	static const unsigned int S13 = 17;
	static const unsigned int S14 = 22;
	static const unsigned int S21 = 5;
	static const unsigned int S22 = 9;
	static const unsigned int S23 = 14;
	static const unsigned int S24 = 20;
	static const unsigned int S31 = 4;
	static const unsigned int S32 = 11;
	static const unsigned int S33 = 16;
	static const unsigned int S34 = 23;
	static const unsigned int S41 = 6;
	static const unsigned int S42 = 10;
	static const unsigned int S43 = 15;
	static const unsigned int S44 = 21;

	// F, G, H and I are basic MD5 functions.
	static inline unsigned int F(unsigned int x, unsigned int y, unsigned int z)
	{
		return (((x) & (y)) | ((~x) & (z)));
	}
	static inline unsigned int G(unsigned int x, unsigned int y, unsigned int z)
	{
		return (((x) & (z)) | ((y) & (~z)));
	}
	static inline unsigned int H(unsigned int x, unsigned int y, unsigned int z)
	{
		return ((x) ^ (y) ^ (z));
	}
	static inline unsigned int I(unsigned int x, unsigned int y, unsigned int z)
	{
		return ((y) ^ ((x) | (~z)));
	}
	static inline unsigned int ROTATE_LEFT(unsigned int x, unsigned int n)
	{
		return (((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.
	static inline void FF(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
	{
		a += F(b, c, d) + x + ac;
		a = ROTATE_LEFT(a, s);
		a += b;
	}
	static inline void GG(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
	{
		a += G(b, c, d) + x + ac;
		a = ROTATE_LEFT(a, s);
		a += b;
	}
	static inline void HH(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
	{
		a += H(b, c, d) + x + ac;
		a = ROTATE_LEFT(a, s);
		a += b;
	}
	static inline void II(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
	{
		a += I(b, c, d) + x + ac;
		a = ROTATE_LEFT(a, s);
		a += b;
	}

	typedef struct {
		unsigned int state[4];
		unsigned int count[2];
		unsigned char buffer[64];
	} MD5_CTX;

	static unsigned char m_PADDING[64];

	static void MD5Init(MD5_CTX* context);
	static void MD5Update(MD5_CTX* context, unsigned char* input, unsigned int inputLen);
	static void MD5Final(unsigned char digest[16], MD5_CTX* context);

	static void MD5Transform(unsigned int state[4], unsigned char block[64]);
	static void MD5_Encode(unsigned char*, unsigned int*, unsigned int);
	static void MD5_Decode(unsigned int*, unsigned char*, unsigned int);
	static void MD5_memcpy(unsigned char*, unsigned char*, unsigned int);
	static void MD5_memset(unsigned char*, int, unsigned int);

public:
	static unsigned char* getMD5Sum(unsigned char* pData, int size);
};

#endif