//加密 cbc zeropadding 自己实现

std::string des_cbc_zero_encrypt(const std::string &clearText, const std::string &key)

{

    static unsigned char cbc_iv[] = {'j', 'k', 't', '', '', '', '', ''};

    //初始化IV向量

    std::string strCipherText;

    DES_cblock keyEncrypt, ivec;

    memset(keyEncrypt, , );  

    if (key.length() <= )

        memcpy(keyEncrypt, key.c_str(), key.length());

    else

        memcpy(keyEncrypt, key.c_str(), );  

    DES_key_schedule keySchedule;  //密钥表

    DES_set_key_unchecked(&keyEncrypt, &keySchedule);   //设置密钥，且不检测密钥奇偶性  

    memcpy(ivec, cbc_iv, sizeof(cbc_iv));  

     // 循环加密，每8字节一次

    const_DES_cblock inputText;

    DES_cblock outputText;

    std::vector<unsigned char> vecCiphertext;

    unsigned char tmp[];  

    for (int i = ; i < clearText.length() / ; i++)

    {

        memcpy(inputText, clearText.c_str() + i * , );

        DES_ncbc_encrypt(inputText, outputText, , &keySchedule, &ivec, DES_ENCRYPT);  //加密

        memcpy(tmp, outputText, );  

        for (int j = ; j < ; j++)

            vecCiphertext.push_back(tmp[j]);

        //重置ivec

        memcpy(ivec, outputText, );

    }

    if (clearText.length() %  != )

    {

        int tmp1 = clearText.length() /  * ;

        int tmp2 = clearText.length() - tmp1;

        memset(inputText, , );

        memcpy(inputText, clearText.c_str() + tmp1, tmp2);

        // 加密函数

        DES_ncbc_encrypt(inputText, outputText, , &keySchedule, &ivec, DES_ENCRYPT);  //加密

        memcpy(tmp, outputText, );  

        for (int j = ; j < ; j++)

            vecCiphertext.push_back(tmp[j]);

    }  

    strCipherText.clear();

    strCipherText.assign(vecCiphertext.begin(), vecCiphertext.end());

    return strCipherText;

}

//加密 cbc pkcs5padding 自己实现  //pkcs7padding 跟 pkcs5padding是一样的

std::string des_cbc_pkcs5_encrypt(const std::string &clearText, const std::string &key)

{

    static unsigned char cbc_iv[] = {'j', 'k', 't', '', '', '', '', ''};

    //初始化IV向量

    std::string strCipherText;

    DES_cblock keyEncrypt, ivec;

    memset(keyEncrypt, , );  

    if (key.length() <= )

        memcpy(keyEncrypt, key.c_str(), key.length());

    else

        memcpy(keyEncrypt, key.c_str(), );  

    DES_key_schedule keySchedule;  //密钥表

    DES_set_key_unchecked(&keyEncrypt, &keySchedule);   //设置密钥，且不检测密钥奇偶性  

    memcpy(ivec, cbc_iv, sizeof(cbc_iv));  

     // 循环加密，每8字节一次

    const_DES_cblock inputText;

    DES_cblock outputText;

    std::vector<unsigned char> vecCiphertext;

    unsigned char tmp[];  

    for (int i = ; i < clearText.length() / ; i++)

    {

        memcpy(inputText, clearText.c_str() + i * , );

        DES_ncbc_encrypt(inputText, outputText, , &keySchedule, &ivec, DES_ENCRYPT);  //加密

        memcpy(tmp, outputText, );  

        for (int j = ; j < ; j++)

            vecCiphertext.push_back(tmp[j]);

        //重置ivec

        memcpy(ivec, outputText, );

    }

    if (clearText.length() %  != )

    {

        int tmp1 = clearText.length() /  * ;

        int tmp2 = clearText.length() - tmp1;

        memset(inputText,(-tmp2), );

        memcpy(inputText, clearText.c_str() + tmp1, tmp2);

    }

    else

    {

        memset(inputText,, );

    }

    // 加密函数

    DES_ncbc_encrypt(inputText, outputText, , &keySchedule, &ivec, DES_ENCRYPT);  //加密

    memcpy(tmp, outputText, );

    for (int j = ; j < ; j++)

        vecCiphertext.push_back(tmp[j]);

    strCipherText.clear();

    strCipherText.assign(vecCiphertext.begin(), vecCiphertext.end());

    return strCipherText;

}

//解密 cbc pkcs5padding 自己实现  //zeropadding / pkcs7padding 跟 pkcs5padding是一样的

std::string des_cbc_pkcs5_decrypt(const std::string &cipherText, const std::string &key)

{

    static unsigned char cbc_iv[] = {'j', 'k', 't', '', '', '', '', ''};

    //初始化IV向量

    std::string clearText;

    DES_cblock keyEncrypt, ivec;

    memset(keyEncrypt, , );  

    if (key.length() <= )

        memcpy(keyEncrypt, key.c_str(), key.length());

    else

        memcpy(keyEncrypt, key.c_str(), );  

    DES_key_schedule keySchedule;  //密钥表

    DES_set_key_unchecked(&keyEncrypt, &keySchedule);   //设置密钥，且不检测密钥奇偶性  

    memcpy(ivec, cbc_iv, sizeof(cbc_iv));  

     // 循环解密，每8字节一次

    const_DES_cblock inputText;

    DES_cblock outputText;

    std::vector<unsigned char> vecCleartext;

    unsigned char tmp[];  

    for (int i = ; i < cipherText.length() / ; i++)

    {

        memcpy(inputText, cipherText.c_str() + i * , );

        DES_ncbc_encrypt(inputText, outputText, , &keySchedule, &ivec, DES_DECRYPT);  //解密

        memcpy(tmp, outputText, );  

        for (int j = ; j < ; j++)

            vecCleartext.push_back(tmp[j]);

        //重置ivec

        //memcpy(ivec, outputText, 8);  //解密过程不需要用前一块的结果作为下一块的IV

    }

    if (clearText.length() %  != )

    {

        int tmp1 = clearText.length() /  * ;

        int tmp2 = clearText.length() - tmp1;

        memset(inputText,, tmp2);

        memcpy(inputText, cipherText.c_str() + tmp1, tmp2);

        DES_ncbc_encrypt(inputText, outputText, tmp2, &keySchedule, &ivec, DES_DECRYPT);  //解密

        memcpy(tmp, outputText, tmp2);

        for (int j = ; j < ; j++)

            vecCleartext.push_back(tmp[j]);

    }

    clearText.clear();

    clearText.assign(vecCleartext.begin(), vecCleartext.end());

    return clearText;

}