#ifndef MD5_H

#define MD5_H

#include <string>

#include <fstream>

/* Type define */

typedef unsigned char byte;

typedef unsigned int uint32;

using std::string;

using std::ifstream;

/* MD5 declaration. */

class MD5 {

public:

    MD5();

    MD5(const void* input, size_t length);

    MD5(const string& str);

    MD5(ifstream& in);

    void update(const void* input, size_t length);

    void update(const string& str);

    void update(ifstream& in);

    const byte* digest();

    string toString();

    void reset();

private:

    void update(const byte* input, size_t length);

    void final();

    void transform(const byte block[]);

    void encode(const uint32* input, byte* output, size_t length);

    void decode(const byte* input, uint32* output, size_t length);

    string bytesToHexString(const byte* input, size_t length);

    /* class uncopyable */

    MD5(const MD5&);

    MD5& operator=(const MD5&);

private:

    uint32 _state[];    /* state (ABCD) */

    uint32 _count[];    /* number of bits, modulo 2^64 (low-order word first) */

    byte _buffer[];    /* input buffer */

    byte _digest[];    /* message digest */

    bool _finished;        /* calculate finished ? */

    static const byte PADDING[];    /* padding for calculate */

    static const char HEX[];

    enum { BUFFER_SIZE =  };

};

#endif /*MD5_H*/

#include "md5.h"

#include <string.h>

using namespace std;

/* 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

/* 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 recomputation.

*/

#define FF(a, b, c, d, x, s, ac) { \

    (a) += F ((b), (c), (d)) + (x) + ac; \

    (a) = ROTATE_LEFT ((a), (s)); \

    (a) += (b); \

}

#define GG(a, b, c, d, x, s, ac) { \

    (a) += G ((b), (c), (d)) + (x) + ac; \

    (a) = ROTATE_LEFT ((a), (s)); \

    (a) += (b); \

}

#define HH(a, b, c, d, x, s, ac) { \

    (a) += H ((b), (c), (d)) + (x) + ac; \

    (a) = ROTATE_LEFT ((a), (s)); \

    (a) += (b); \

}

#define II(a, b, c, d, x, s, ac) { \

    (a) += I ((b), (c), (d)) + (x) + ac; \

    (a) = ROTATE_LEFT ((a), (s)); \

    (a) += (b); \

}

const byte MD5::PADDING[] = { 0x80 };

const char MD5::HEX[] = {

    '', '', '', '',

    '', '', '', '',

    '', '', 'a', 'b',

    'c', 'd', 'e', 'f'

};

/* Default construct. */

MD5::MD5() {

    reset();

}

/* Construct a MD5 object with a input buffer. */

MD5::MD5(const void* input, size_t length) {

    reset();

    update(input, length);

}

/* Construct a MD5 object with a string. */

MD5::MD5(const string& str) {

    reset();

    update(str);

}

/* Construct a MD5 object with a file. */

MD5::MD5(ifstream& in) {

    reset();

    update(in);

}

/* Return the message-digest */

const byte* MD5::digest() {

    if (!_finished) {

        _finished = true;

        final();

    }

    return _digest;

}

/* Reset the calculate state */

void MD5::reset() {

    _finished = false;

    /* reset number of bits. */

    _count[] = _count[] = ;

    /* Load magic initialization constants. */

    _state[] = 0x67452301;

    _state[] = 0xefcdab89;

    _state[] = 0x98badcfe;

    _state[] = 0x10325476;

}

/* Updating the context with a input buffer. */

void MD5::update(const void* input, size_t length) {

    update((const byte*)input, length);

}

/* Updating the context with a string. */

void MD5::update(const string& str) {

    update((const byte*)str.c_str(), str.length());

}

/* Updating the context with a file. */

void MD5::update(ifstream& in) {

    if (!in) {

        return;

    }

    std::streamsize length;

    char buffer[BUFFER_SIZE];

    while (!in.eof()) {

        in.read(buffer, BUFFER_SIZE);

        length = in.gcount();

        if (length > ) {

            update(buffer, length);

        }

    }

    in.close();

}

/* MD5 block update operation. Continues an MD5 message-digest

operation, processing another message block, and updating the

context.

*/

void MD5::update(const byte* input, size_t length) {

    uint32 i, index, partLen;

    _finished = false;

    /* Compute number of bytes mod 64 */

    index = (uint32)((_count[] >> ) & 0x3f);

    /* update number of bits */

    if ((_count[] += ((uint32)length << )) < ((uint32)length << )) {

        ++_count[];

    }

    _count[] += ((uint32)length >> );

    partLen =  - index;

    /* transform as many times as possible. */

    if (length >= partLen) {

        memcpy(&_buffer[index], input, partLen);

        transform(_buffer);

        for (i = partLen; i +  < length; i += ) {

            transform(&input[i]);

        }

        index = ;

    } else {

        i = ;

    }

    /* Buffer remaining input */

    memcpy(&_buffer[index], &input[i], length - i);

}

/* MD5 finalization. Ends an MD5 message-_digest operation, writing the

the message _digest and zeroizing the context.

*/

void MD5::final() {

    byte bits[];

    uint32 oldState[];

    uint32 oldCount[];

    uint32 index, padLen;

    /* Save current state and count. */

    memcpy(oldState, _state, );

    memcpy(oldCount, _count, );

    /* Save number of bits */

    encode(_count, bits, );

    /* Pad out to 56 mod 64. */

    index = (uint32)((_count[] >> ) & 0x3f);

    padLen = (index < ) ? ( - index) : ( - index);

    update(PADDING, padLen);

    /* Append length (before padding) */

    update(bits, );

    /* Store state in digest */

    encode(_state, _digest, );

    /* Restore current state and count. */

    memcpy(_state, oldState, );

    memcpy(_count, oldCount, );

}

/* MD5 basic transformation. Transforms _state based on block. */

void MD5::transform(const byte block[]) {

    uint32 a = _state[], b = _state[], c = _state[], d = _state[], x[];

    decode(block, x, );

    /* Round 1 */

    FF (a, b, c, d, x[ ], S11, 0xd76aa478); /* 1 */

    FF (d, a, b, c, x[ ], S12, 0xe8c7b756); /* 2 */

    FF (c, d, a, b, x[ ], S13, 0x242070db); /* 3 */

    FF (b, c, d, a, x[ ], S14, 0xc1bdceee); /* 4 */

    FF (a, b, c, d, x[ ], S11, 0xf57c0faf); /* 5 */

    FF (d, a, b, c, x[ ], S12, 0x4787c62a); /* 6 */

    FF (c, d, a, b, x[ ], S13, 0xa8304613); /* 7 */

    FF (b, c, d, a, x[ ], S14, 0xfd469501); /* 8 */

    FF (a, b, c, d, x[ ], S11, 0x698098d8); /* 9 */

    FF (d, a, b, c, x[ ], S12, 0x8b44f7af); /* 10 */

    FF (c, d, a, b, x[], S13, 0xffff5bb1); /* 11 */

    FF (b, c, d, a, x[], S14, 0x895cd7be); /* 12 */

    FF (a, b, c, d, x[], S11, 0x6b901122); /* 13 */

    FF (d, a, b, c, x[], S12, 0xfd987193); /* 14 */

    FF (c, d, a, b, x[], S13, 0xa679438e); /* 15 */

    FF (b, c, d, a, x[], S14, 0x49b40821); /* 16 */

    /* Round 2 */

    GG (a, b, c, d, x[ ], S21, 0xf61e2562); /* 17 */

    GG (d, a, b, c, x[ ], S22, 0xc040b340); /* 18 */

    GG (c, d, a, b, x[], S23, 0x265e5a51); /* 19 */

    GG (b, c, d, a, x[ ], S24, 0xe9b6c7aa); /* 20 */

    GG (a, b, c, d, x[ ], S21, 0xd62f105d); /* 21 */

    GG (d, a, b, c, x[], S22,  0x2441453); /* 22 */

    GG (c, d, a, b, x[], S23, 0xd8a1e681); /* 23 */

    GG (b, c, d, a, x[ ], S24, 0xe7d3fbc8); /* 24 */

    GG (a, b, c, d, x[ ], S21, 0x21e1cde6); /* 25 */

    GG (d, a, b, c, x[], S22, 0xc33707d6); /* 26 */

    GG (c, d, a, b, x[ ], S23, 0xf4d50d87); /* 27 */

    GG (b, c, d, a, x[ ], S24, 0x455a14ed); /* 28 */

    GG (a, b, c, d, x[], S21, 0xa9e3e905); /* 29 */

    GG (d, a, b, c, x[ ], S22, 0xfcefa3f8); /* 30 */

    GG (c, d, a, b, x[ ], S23, 0x676f02d9); /* 31 */

    GG (b, c, d, a, x[], S24, 0x8d2a4c8a); /* 32 */

    /* Round 3 */

    HH (a, b, c, d, x[ ], S31, 0xfffa3942); /* 33 */

    HH (d, a, b, c, x[ ], S32, 0x8771f681); /* 34 */

    HH (c, d, a, b, x[], S33, 0x6d9d6122); /* 35 */

    HH (b, c, d, a, x[], S34, 0xfde5380c); /* 36 */

    HH (a, b, c, d, x[ ], S31, 0xa4beea44); /* 37 */

    HH (d, a, b, c, x[ ], S32, 0x4bdecfa9); /* 38 */

    HH (c, d, a, b, x[ ], S33, 0xf6bb4b60); /* 39 */

    HH (b, c, d, a, x[], S34, 0xbebfbc70); /* 40 */

    HH (a, b, c, d, x[], S31, 0x289b7ec6); /* 41 */

    HH (d, a, b, c, x[ ], S32, 0xeaa127fa); /* 42 */

    HH (c, d, a, b, x[ ], S33, 0xd4ef3085); /* 43 */

    HH (b, c, d, a, x[ ], S34,  0x4881d05); /* 44 */

    HH (a, b, c, d, x[ ], S31, 0xd9d4d039); /* 45 */

    HH (d, a, b, c, x[], S32, 0xe6db99e5); /* 46 */

    HH (c, d, a, b, x[], S33, 0x1fa27cf8); /* 47 */

    HH (b, c, d, a, x[ ], S34, 0xc4ac5665); /* 48 */

    /* Round 4 */

    II (a, b, c, d, x[ ], S41, 0xf4292244); /* 49 */

    II (d, a, b, c, x[ ], S42, 0x432aff97); /* 50 */

    II (c, d, a, b, x[], S43, 0xab9423a7); /* 51 */

    II (b, c, d, a, x[ ], S44, 0xfc93a039); /* 52 */

    II (a, b, c, d, x[], S41, 0x655b59c3); /* 53 */

    II (d, a, b, c, x[ ], S42, 0x8f0ccc92); /* 54 */

    II (c, d, a, b, x[], S43, 0xffeff47d); /* 55 */

    II (b, c, d, a, x[ ], S44, 0x85845dd1); /* 56 */

    II (a, b, c, d, x[ ], S41, 0x6fa87e4f); /* 57 */

    II (d, a, b, c, x[], S42, 0xfe2ce6e0); /* 58 */

    II (c, d, a, b, x[ ], S43, 0xa3014314); /* 59 */

    II (b, c, d, a, x[], S44, 0x4e0811a1); /* 60 */

    II (a, b, c, d, x[ ], S41, 0xf7537e82); /* 61 */

    II (d, a, b, c, x[], S42, 0xbd3af235); /* 62 */

    II (c, d, a, b, x[ ], S43, 0x2ad7d2bb); /* 63 */

    II (b, c, d, a, x[ ], S44, 0xeb86d391); /* 64 */

    _state[] += a;

    _state[] += b;

    _state[] += c;

    _state[] += d;

}

/* Encodes input (ulong) into output (byte). Assumes length is

a multiple of 4.

*/

void MD5::encode(const uint32* input, byte* output, size_t length) {

    for (size_t i = , j = ; j < length; ++i, j += ) {

        output[j]= (byte)(input[i] & 0xff);

        output[j + ] = (byte)((input[i] >> ) & 0xff);

        output[j + ] = (byte)((input[i] >> ) & 0xff);

        output[j + ] = (byte)((input[i] >> ) & 0xff);

    }

}

/* Decodes input (byte) into output (ulong). Assumes length is

a multiple of 4.

*/

void MD5::decode(const byte* input, uint32* output, size_t length) {

    for (size_t i = , j = ; j < length; ++i, j += ) {

        output[i] = ((uint32)input[j]) | (((uint32)input[j + ]) << ) |

        (((uint32)input[j + ]) << ) | (((uint32)input[j + ]) << );

    }

}

/* Convert byte array to hex string. */

string MD5::bytesToHexString(const byte* input, size_t length) {

    string str;

    str.reserve(length << );

    for (size_t i = ; i < length; ++i) {

        int t = input[i];

        int a = t / ;

        int b = t % ;

        str.append(, HEX[a]);

        str.append(, HEX[b]);

    }

    return str;

}

/* Convert digest to string value */

string MD5::toString() {

    return bytesToHexString(digest(), );

}