C++简单加解密

来源：互联网发布：中国银联工作知乎编辑：程序博客网时间：2024/06/05 23:01

最近做个C++小项目，其中的用户名、密码要求加密，要求原字母、数字不会重现就行。

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

//Password.cpp文件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倒序写入输出缓冲        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;    }    //设置尾部    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码填充剩余部分        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; //读到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;        //准备写入后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;}

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