#include "Stdafx.h"
#include "WHMD5CheckSum.h"

/////////////////////////////////////////////////////////////////////////////////////////////////////
//构造函数
CWHMD5Checksum::CWHMD5Checksum()
{
    //初始成员
    memset(m_lpszBuffer, 0, 64);
    m_nCount[0] = m_nCount[1] = 0;

    //初始变量
    m_lMD5[0] = MD5_INIT_STATE_0;
    m_lMD5[1] = MD5_INIT_STATE_1;
    m_lMD5[2] = MD5_INIT_STATE_2;
    m_lMD5[3] = MD5_INIT_STATE_3;
}

//析构函数
CWHMD5Checksum::~CWHMD5Checksum()
{
}

//获取校验和
CString CWHMD5Checksum::GetMD5(const CString& strFilePath)
{
    //打开文件
    CFile File;
    if (File.Open(strFilePath, CFile::modeRead | CFile::shareDenyNone) == false)
    {
        return TEXT("");
    }

    //返回校验和
    return GetMD5(File);
}

//获取校验和
CString CWHMD5Checksum::GetMD5(CFile& File)
{
    try
    {
        //变量定义
        CWHMD5Checksum MD5Checksum;
        int nLength = 0;
        const int nBufferSize = 1024;
        BYTE Buffer[nBufferSize];

        //校验文件
        while ((nLength = File.Read(Buffer, nBufferSize)) > 0)
        {
            MD5Checksum.Update(Buffer, nLength);
        }

        //完成校验
        return MD5Checksum.Final();
    }
    catch (CFileException* e)
    {
        TRACE0("CWHMD5Checksum::GetMD5: CFileException caught");
        throw e;
    }
}

//获取校验和
CString CWHMD5Checksum::GetMD5(BYTE* pBuf, UINT nLength)
{
    AfxIsValidAddress(pBuf, nLength, FALSE);

    //变量定义
    CWHMD5Checksum MD5Checksum;

    //计算校验和
    MD5Checksum.Update(pBuf, nLength);

    //完成校验
    return MD5Checksum.Final();
}

//
CString CWHMD5Checksum::Final()
{
    //变量定义
    BYTE Bits[8];
    DWordToByte(Bits, m_nCount, 8);

    //变量定义
    UINT nIndex = (UINT)((m_nCount[0] >> 3) & 0x3f);
    UINT nPadLen = (nIndex < 56) ? (56 - nIndex) : (120 - nIndex);
    Update(PADDING, nPadLen);

    //更新数据
    Update(Bits, 8);

    //变量定义
    const int nMD5Size = 16;
    unsigned char lpszMD5[nMD5Size];
    DWordToByte(lpszMD5, m_lMD5, nMD5Size);

    //转换类型
    CString strMD5;
    for (int i = 0; i < nMD5Size; i++)
    {
        CString Str;
        if (lpszMD5[i] == 0)
        {
            Str = CString("00");
        }
        else if (lpszMD5[i] <= 15)
        {
            Str.Format(TEXT("0%x"), lpszMD5[i]);
        }
        else
        {
            Str.Format(TEXT("%x"), lpszMD5[i]);
        }

        ASSERT(Str.GetLength() == 2);
        strMD5 += Str;
    }

    //结果校验
    ASSERT(strMD5.GetLength() == 32);
    return strMD5;
}

//转换数据
VOID CWHMD5Checksum::Transform(BYTE Block[64])
{
    //变量定义
    ULONG a = m_lMD5[0];
    ULONG b = m_lMD5[1];
    ULONG c = m_lMD5[2];
    ULONG d = m_lMD5[3];

    //变量定义
    ULONG X[16];

    //数据转换
    ByteToDWord(X, Block, 64);

    //1轮转换
    FF(a, b, c, d, X[0], MD5_S11, MD5_T01);
    FF(d, a, b, c, X[1], MD5_S12, MD5_T02);
    FF(c, d, a, b, X[2], MD5_S13, MD5_T03);
    FF(b, c, d, a, X[3], MD5_S14, MD5_T04);
    FF(a, b, c, d, X[4], MD5_S11, MD5_T05);
    FF(d, a, b, c, X[5], MD5_S12, MD5_T06);
    FF(c, d, a, b, X[6], MD5_S13, MD5_T07);
    FF(b, c, d, a, X[7], MD5_S14, MD5_T08);
    FF(a, b, c, d, X[8], MD5_S11, MD5_T09);
    FF(d, a, b, c, X[9], MD5_S12, MD5_T10);
    FF(c, d, a, b, X[10], MD5_S13, MD5_T11);
    FF(b, c, d, a, X[11], MD5_S14, MD5_T12);
    FF(a, b, c, d, X[12], MD5_S11, MD5_T13);
    FF(d, a, b, c, X[13], MD5_S12, MD5_T14);
    FF(c, d, a, b, X[14], MD5_S13, MD5_T15);
    FF(b, c, d, a, X[15], MD5_S14, MD5_T16);

    //2轮转换
    GG(a, b, c, d, X[1], MD5_S21, MD5_T17);
    GG(d, a, b, c, X[6], MD5_S22, MD5_T18);
    GG(c, d, a, b, X[11], MD5_S23, MD5_T19);
    GG(b, c, d, a, X[0], MD5_S24, MD5_T20);
    GG(a, b, c, d, X[5], MD5_S21, MD5_T21);
    GG(d, a, b, c, X[10], MD5_S22, MD5_T22);
    GG(c, d, a, b, X[15], MD5_S23, MD5_T23);
    GG(b, c, d, a, X[4], MD5_S24, MD5_T24);
    GG(a, b, c, d, X[9], MD5_S21, MD5_T25);
    GG(d, a, b, c, X[14], MD5_S22, MD5_T26);
    GG(c, d, a, b, X[3], MD5_S23, MD5_T27);
    GG(b, c, d, a, X[8], MD5_S24, MD5_T28);
    GG(a, b, c, d, X[13], MD5_S21, MD5_T29);
    GG(d, a, b, c, X[2], MD5_S22, MD5_T30);
    GG(c, d, a, b, X[7], MD5_S23, MD5_T31);
    GG(b, c, d, a, X[12], MD5_S24, MD5_T32);

    //3轮转换
    HH(a, b, c, d, X[5], MD5_S31, MD5_T33);
    HH(d, a, b, c, X[8], MD5_S32, MD5_T34);
    HH(c, d, a, b, X[11], MD5_S33, MD5_T35);
    HH(b, c, d, a, X[14], MD5_S34, MD5_T36);
    HH(a, b, c, d, X[1], MD5_S31, MD5_T37);
    HH(d, a, b, c, X[4], MD5_S32, MD5_T38);
    HH(c, d, a, b, X[7], MD5_S33, MD5_T39);
    HH(b, c, d, a, X[10], MD5_S34, MD5_T40);
    HH(a, b, c, d, X[13], MD5_S31, MD5_T41);
    HH(d, a, b, c, X[0], MD5_S32, MD5_T42);
    HH(c, d, a, b, X[3], MD5_S33, MD5_T43);
    HH(b, c, d, a, X[6], MD5_S34, MD5_T44);
    HH(a, b, c, d, X[9], MD5_S31, MD5_T45);
    HH(d, a, b, c, X[12], MD5_S32, MD5_T46);
    HH(c, d, a, b, X[15], MD5_S33, MD5_T47);
    HH(b, c, d, a, X[2], MD5_S34, MD5_T48);

    //4轮转换
    II(a, b, c, d, X[0], MD5_S41, MD5_T49);
    II(d, a, b, c, X[7], MD5_S42, MD5_T50);
    II(c, d, a, b, X[14], MD5_S43, MD5_T51);
    II(b, c, d, a, X[5], MD5_S44, MD5_T52);
    II(a, b, c, d, X[12], MD5_S41, MD5_T53);
    II(d, a, b, c, X[3], MD5_S42, MD5_T54);
    II(c, d, a, b, X[10], MD5_S43, MD5_T55);
    II(b, c, d, a, X[1], MD5_S44, MD5_T56);
    II(a, b, c, d, X[8], MD5_S41, MD5_T57);
    II(d, a, b, c, X[15], MD5_S42, MD5_T58);
    II(c, d, a, b, X[6], MD5_S43, MD5_T59);
    II(b, c, d, a, X[13], MD5_S44, MD5_T60);
    II(a, b, c, d, X[4], MD5_S41, MD5_T61);
    II(d, a, b, c, X[11], MD5_S42, MD5_T62);
    II(c, d, a, b, X[2], MD5_S43, MD5_T63);
    II(b, c, d, a, X[9], MD5_S44, MD5_T64);

    //设置校验和
    m_lMD5[0] += a;
    m_lMD5[1] += b;
    m_lMD5[2] += c;
    m_lMD5[3] += d;
}

//更新数据
VOID CWHMD5Checksum::Update(BYTE* Input, ULONG nInputLen)
{
    //变量定义
    UINT nIndex = (UINT)((m_nCount[0] >> 3) & 0x3F);

    //更新位数
    if ((m_nCount[0] += nInputLen << 3) < (nInputLen << 3))
    {
        m_nCount[1]++;
    }

    //设置变量
    m_nCount[1] += (nInputLen >> 29);

    //重复转换
    UINT i = 0;
    UINT nPartLen = 64 - nIndex;
    if (nInputLen >= nPartLen)
    {
        memcpy(&m_lpszBuffer[nIndex], Input, nPartLen);
        Transform(m_lpszBuffer);
        for (i = nPartLen; i + 63 < nInputLen; i += 64)
        {
            Transform(&Input[i]);
        }
        nIndex = 0;
    }
    else
    {
        i = 0;
    }

    //拷贝缓冲
    memcpy(&m_lpszBuffer[nIndex], &Input[i], nInputLen - i);
}

//类型转换
VOID CWHMD5Checksum::ByteToDWord(DWORD* Output, BYTE* Input, UINT nLength)
{
    //参数校验
    ASSERT(nLength % 4 == 0);
    ASSERT(AfxIsValidAddress(Output, nLength / 4, TRUE));
    ASSERT(AfxIsValidAddress(Input, nLength, FALSE));

    //变量定义
    UINT nOutIndex = 0;
    UINT nLoopIndex = 0;

    //转换拷贝
    for (; nLoopIndex < nLength; nOutIndex++, nLoopIndex += 4)
    {
        Output[nOutIndex] = (ULONG)Input[nLoopIndex] |
            (ULONG)Input[nLoopIndex + 1] << 8 |
            (ULONG)Input[nLoopIndex + 2] << 16 |
            (ULONG)Input[nLoopIndex + 3] << 24;
    }

    return;
}

//类型转换
VOID CWHMD5Checksum::DWordToByte(BYTE* Output, DWORD* Input, UINT nLength)
{
    //校验变量
    ASSERT(nLength % 4 == 0);
    ASSERT(AfxIsValidAddress(Output, nLength, TRUE));
    ASSERT(AfxIsValidAddress(Input, nLength / 4, FALSE));

    //转换拷贝
    UINT nInIndex = 0;
    UINT nLoopIndex = 0;
    for (; nLoopIndex < nLength; nInIndex++, nLoopIndex += 4)
    {
        Output[nLoopIndex] = (UCHAR)(Input[nInIndex] & 0xff);
        Output[nLoopIndex + 1] = (UCHAR)((Input[nInIndex] >> 8) & 0xff);
        Output[nLoopIndex + 2] = (UCHAR)((Input[nInIndex] >> 16) & 0xff);
        Output[nLoopIndex + 3] = (UCHAR)((Input[nInIndex] >> 24) & 0xff);
    }

    return;
}

//
DWORD CWHMD5Checksum::RotateLeft(DWORD x, int n)
{
    //参数校验
    ASSERT(sizeof(x) == 4);

    //返回结果
    return (x << n) | (x >> (32 - n));
}


VOID CWHMD5Checksum::FF(DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{
    DWORD F = (B & C) | (~B & D);
    A += F + X + T;
    A = RotateLeft(A, S);
    A += B;
}

VOID CWHMD5Checksum::GG(DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{
    DWORD G = (B & D) | (C & ~D);
    A += G + X + T;
    A = RotateLeft(A, S);
    A += B;
}

VOID CWHMD5Checksum::HH(DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{
    DWORD H = (B ^ C ^ D);
    A += H + X + T;
    A = RotateLeft(A, S);
    A += B;
}

VOID CWHMD5Checksum::II(DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{
    DWORD I = (C ^ (B | ~D));
    A += I + X + T;
    A = RotateLeft(A, S);
    A += B;
}

/////////////////////////////////////////////////////////////////////////////////////////////////////