//Password.h文件
CString Base64Encode(LPCTSTR lpszSrc);//加密
CString Base64Decode(LPCTSTR lpszSrc);//解密

CString Base64Encode(LPCTSTR lpszSrc)
{
    ASSERT(lpszSrc != NULL && AfxIsValidString(lpszSrc));
    const char BASE64_ENCODE_TABLE[64] = {
        65, 66, 67, 68, 69, 70, 71, 72,  // 00 - 07
        73, 74, 75, 76, 77, 78, 79, 80,  // 08 - 15
        81, 82, 83, 84, 85, 86, 87, 88,  // 16 - 23
        89, 90, 97, 98, 99, 100, 101, 102,  // 24 - 31
        103, 104, 105, 106, 107, 108, 109, 110,  // 32 - 39
        111, 112, 113, 114, 115, 116, 117, 118,  // 40 - 47
        119, 120, 121, 122, 48, 49, 50, 51,  // 48 - 55
        52, 53, 54, 55, 56, 57, 43, 47 };// 56 - 63

    unsigned int iTest;

    LPCTSTR pInBuffer = lpszSrc;

    int nSize = (int)_tcslen(lpszSrc);
    char* pOutBuffer = new char[nSize / 3 * 4 + 5];
    ZeroMemory(pOutBuffer, nSize / 3 * 4 + 5);

    for (int i = 0; i < nSize / 3; i++)
    {
        iTest = (unsigned char)*pInBuffer++;
        iTest = iTest << 8;

        iTest = iTest | (unsigned char)*pInBuffer++;
        iTest = iTest << 8;

        iTest = iTest | (unsigned char)*pInBuffer++;

        //以4 byte倒序?qū)懭胼敵鼍彌_
        pOutBuffer[3] = BASE64_ENCODE_TABLE[iTest & 0x3F];
        iTest = iTest >> 6;
        pOutBuffer[2] = BASE64_ENCODE_TABLE[iTest & 0x3F];
        iTest = iTest >> 6;
        pOutBuffer[1] = BASE64_ENCODE_TABLE[iTest & 0x3F];
        iTest = iTest >> 6;
        pOutBuffer[0] = BASE64_ENCODE_TABLE[iTest];
        pOutBuffer += 4;
    }

    //設(shè)置尾部
    switch (_tcslen(lpszSrc) % 3)
    {
    case 0:
        break;
    case 1:
        iTest = (unsigned char)*pInBuffer;
        iTest = iTest << 4;
        pOutBuffer[1] = BASE64_ENCODE_TABLE[iTest & 0x3F];
        iTest = iTest >> 6;
        pOutBuffer[0] = BASE64_ENCODE_TABLE[iTest];
        pOutBuffer[2] = '='; //用'='也就是64碼填充剩余部分
        pOutBuffer[3] = '=';
        break;
    case 2:
        iTest = (unsigned char)*pInBuffer++;
        iTest = iTest << 8;
        iTest = iTest | (unsigned char)*pInBuffer;
        iTest = iTest << 2;
        pOutBuffer[2] = BASE64_ENCODE_TABLE[iTest & 0x3F];
        iTest = iTest >> 6;
        pOutBuffer[1] = BASE64_ENCODE_TABLE[iTest & 0x3F];
        iTest = iTest >> 6;
        pOutBuffer[0] = BASE64_ENCODE_TABLE[iTest];
        pOutBuffer[3] = '='; // Fill remaining byte.
        break;
    }
    pOutBuffer -= nSize / 3 * 4;
    CString strEncode(pOutBuffer);
    delete[] pOutBuffer;
    pOutBuffer = NULL;
    return strEncode;
}


CString Base64Decode(LPCTSTR lpszSrc)
{
    ASSERT(lpszSrc != NULL && AfxIsValidString(lpszSrc));
    const unsigned int BASE64_DECODE_TABLE[256] = {
        255, 255, 255, 255, 255, 255, 255, 255, //  00 -  07
        255, 255, 255, 255, 255, 255, 255, 255, //  08 -  15
        255, 255, 255, 255, 255, 255, 255, 255, //  16 -  23
        255, 255, 255, 255, 255, 255, 255, 255, //  24 -  31
        255, 255, 255, 255, 255, 255, 255, 255, //  32 -  39
        255, 255, 255, 62, 255, 255, 255, 63, //  40 -  47
        52, 53, 54, 55, 56, 57, 58, 59, //  48 -  55
        60, 61, 255, 255, 255, 255, 255, 255, //  56 -  63
        255, 0, 1, 2, 3, 4, 5, 6, //  64 -  71
        7, 8, 9, 10, 11, 12, 13, 14, //  72 -  79
        15, 16, 17, 18, 19, 20, 21, 22, //  80 -  87
        23, 24, 25, 255, 255, 255, 255, 255, //  88 -  95
        255, 26, 27, 28, 29, 30, 31, 32, //  96 - 103
        33, 34, 35, 36, 37, 38, 39, 40, // 104 - 111
        41, 42, 43, 44, 45, 46, 47, 48, // 112 - 119
        49, 50, 51, 255, 255, 255, 255, 255, // 120 - 127
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255 };


    const int nSrcCount = (int)_tcslen(lpszSrc);
    int nSize = nSrcCount / 4 * 3;
    if (lpszSrc[nSrcCount - 1] == '=')
        nSize--;
    if (lpszSrc[nSrcCount - 2] == '=')
        nSize--;
    char* pOutBuffer = new char[nSize + 3];
    ZeroMemory(pOutBuffer, nSize + 3);
    LPCTSTR pInBuffer = lpszSrc;
    UINT iTest, iPack;
    for (int i = 0; i < nSize / 3; i++)
    {
        for (int j = 0; j < 4; j++)
        {
            iTest = BASE64_DECODE_TABLE[*pInBuffer++]; // Read from InputBuffer.
            //InPtr++;
            if (iTest == 0xFF)
            {
                j--;
                continue; //讀到255非法字符
            }
            iPack = iPack << 6;
            iPack = iPack | iTest;
        }
        pOutBuffer[2] = iPack;
        iPack = iPack >> 8;
        pOutBuffer[1] = iPack;
        iPack = iPack >> 8;
        pOutBuffer[0] = iPack;
        //準(zhǔn)備寫入后3位
        pOutBuffer += 3; iPack = 0;

    }
    switch (nSize % 3)
    {
    case 1:
        iTest = BASE64_DECODE_TABLE[*pInBuffer++]; // Read from InputBuffer.
        if (iTest != 0xFF)
        {
            iPack = iPack << 6;
            iPack = iPack | iTest;
        }
        iTest = BASE64_DECODE_TABLE[*pInBuffer++]; // Read from InputBuffer.
        if (iTest != 0xFF)
        {
            iPack = iPack << 6;
            iPack = iPack | iTest;
        }
        iPack = iPack >> 4;
        pOutBuffer[0] = iPack;
        pOutBuffer++;
        break;
    case 2:
        iTest = BASE64_DECODE_TABLE[*pInBuffer++]; // Read from InputBuffer.
        if (iTest != 0xFF)
        {
            iPack = iPack << 6;
            iPack = iPack | iTest;
        }
        iTest = BASE64_DECODE_TABLE[*pInBuffer++]; // Read from InputBuffer.
        if (iTest != 0xFF)
        {
            iPack = iPack << 6;
            iPack = iPack | iTest;
        }
        iTest = BASE64_DECODE_TABLE[*pInBuffer++]; // Read from InputBuffer.
        if (iTest != 0xFF)
        {
            iPack = iPack << 6;
            iPack = iPack | iTest;
        }
        iPack = iPack >> 2;
        pOutBuffer[1] = iPack;
        iPack = iPack >> 8;
        pOutBuffer[0] = iPack;
        pOutBuffer += 2;
        break;
    default:
        break;
    }
    pOutBuffer -= nSize;
    CString strDecode(pOutBuffer);
    delete pOutBuffer;
    return strDecode;
}