// MD5.cpp: implementation of the CMD5 class.
//
//////////////////////////////////////////////////////////////////////

/*
	MD5计算类
	
 
	Rewriter: multiget@gmail.com
	Create Date:	2001/07/26
	Last Revision:	2001/07/26
	Version: 0.01
*/

#include <string.h>  //memcpy,memset
#include <stdio.h>
#include "MD5.h"

#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

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CMD5::CMD5()
{
    MD5Init ( &m_context );
}

CMD5::~CMD5()
{
}


/*
static void MD5Transform PROTO_LIST ((unsigned int [4], unsigned char [64]));
static void Encode PROTO_LIST
((unsigned char *, unsigned int *, unsigned int));
static void Decode PROTO_LIST
((unsigned int *, unsigned char *, unsigned int));
static void MD5_memcpy PROTO_LIST ((unsigned char*, unsigned char*, unsigned int));
static void MD5_memset PROTO_LIST ((unsigned char*, int, unsigned int));
*/
static unsigned char 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 recomputation.
*/
#define FF(a, b, c, d, x, s, ac) { \
	(a) += F ((b), (c), (d)) + (x) + (unsigned int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define GG(a, b, c, d, x, s, ac) { \
	(a) += G ((b), (c), (d)) + (x) + (unsigned int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define HH(a, b, c, d, x, s, ac) { \
	(a) += H ((b), (c), (d)) + (x) + (unsigned int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define II(a, b, c, d, x, s, ac) { \
	(a) += I ((b), (c), (d)) + (x) + (unsigned int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}

/* MD5 initialization. Begins an MD5 operation, writing a new context.
*/
void CMD5::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.
*/
void CMD5::MD5Update ( MD5_CTX* context, 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 ] += ( ( unsigned int ) inputLen << 3 ) )

            < ( ( unsigned int ) inputLen << 3 ) )
        context->count[ 1 ] ++;

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

    partLen = 64 - index;

    /* Transform as many times as possible.
    */
    if ( inputLen >= partLen )
    {
        MD5_memcpy
        ( ( unsigned char* ) & context->buffer[ index ], ( unsigned char* ) 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 */
    MD5_memcpy
    ( ( unsigned char* ) & context->buffer[ index ], ( unsigned char* ) & input[ i ],
      inputLen - i );
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
the message digest and zeroizing the context.
*/
void CMD5::MD5Final ( unsigned char *digest, MD5_CTX* context )
//unsigned char digest[16];                         /* message digest */
//MD5_CTX *context;                                       /* 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.
    */
    MD5_memset ( ( unsigned char* ) context, 0, sizeof ( *context ) );
}

/* MD5 basic transformation. Transforms state based on block.
*/
void CMD5::MD5Transform ( unsigned int state[ 4 ], unsigned char block[ 64 ] )
{
    unsigned int a = state[ 0 ], b = state[ 1 ], c = state[ 2 ], d = state[ 3 ], x[ 16 ];

    Decode ( ( unsigned int* ) ( &x[ 0 ] ), 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.
    */
    MD5_memset ( ( unsigned char* ) x, 0, sizeof ( x ) );
}

/* Encodes input (unsigned int) into output (unsigned char). Assumes len is
a multiple of 4.
*/
void CMD5::Encode ( unsigned char* output, unsigned int* 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 (unsigned int). Assumes len is
a multiple of 4.
*/
void CMD5::Decode ( unsigned int* output, unsigned char* input, unsigned int len )
{
    unsigned int i, j;

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

/* Note: Replace "for loop" with standard memcpy if possible.
*/

void CMD5::MD5_memcpy ( unsigned char* output, unsigned char* input, unsigned int len )
{
    memcpy( output, input, len );
    /*
    	unsigned int i;
    	
    	for (i = 0; i < len; i++)
    		output[i] = input[i];
    	*/
}

/* Note: Replace "for loop" with standard memset if possible.
*/
void CMD5::MD5_memset ( unsigned char* output, int value, unsigned int len )
{

    memset( output, ( char ) value, len );
    /*
    	unsigned int i;
    	for (i = 0; i < len; i++)
    		((char *)output)[i] = (char)value;
    	*/
}

void CMD5::InitData()
{
    MD5Init ( &m_context );
}

void CMD5::AddData( unsigned char* data, unsigned int dlen )
{
    MD5Update( &m_context, data, dlen );
}

void CMD5::EndData()
{
    MD5Final ( m_Digest, &m_context );
}

//one time
unsigned char* CMD5::Encrypt( unsigned char* data, unsigned int dlen )
{

    MD5Init ( &m_context );
    MD5Update ( &m_context, data, dlen );
    MD5Final ( m_Digest, &m_context );
    return m_Digest;
}

std::string CMD5::GetDigestStr()
{
    char temp[ 35 ] = {0};

    for ( int i = 0;i < 16;i++ )
    {
        char dig[ 5 ];
        sprintf( dig, "%02x", m_Digest[ i ] );
        strcat( temp, dig );
    }

    return std::string( temp );
}

