将AES密文作为参数传递

Pass AES ciphertext as parameter

本文关键字：参数传递 密文 AES      更新时间：2023-10-16

我正在尝试编写两个不同的函数，以在cryptopp中使用AES加密和解密数据。我想把密文作为参数传递给解密函数。然而在解密函数上，它接收到一些特殊的符号作为密文&因此不能正确解密。请帮忙。

// -- AES encryption function ----------
void Security_packetAgent::encryption(char out[])
{ 
    std::string plaintext = out;
    std::string ciphertext = "";
    CryptoPP::AES::Encryption aesEncryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
    CryptoPP::CBC_Mode_ExternalCipher::Encryption cbcEncryption( aesEncryption, iv );
    CryptoPP::StreamTransformationFilter stfEncryptor(cbcEncryption, new CryptoPP::StringSink( ciphertext ) );
    stfEncryptor.Put( reinterpret_cast<const unsigned char*>( plaintext.c_str() ), plaintext.length() + 1 );
    stfEncryptor.MessageEnd();
    std::cout << "Cipher Text (" << ciphertext.size() << " bytes)" << std::endl;
    for( int i = 0; i < ciphertext.size(); i++ )
    {
        std::cout << "0x" << std::hex << (0xFF & static_cast<byte>(ciphertext[i])) << " ";
    }
    std::cout<<"nMessage encrypted ...";
    std::cout << std::endl << std::endl;
    sprintf(out, "%s", ciphertext.c_str());
    printf("Final Data: %s : %s ", out, reinterpret_cast<const unsigned char*>(ciphertext.c_str()));
}
// ---- AES decryption  ------------------
void Security_packetAgent::decryption(char out[])
{ 
    cout<<"nCipher recieved: "<<out;
    std::cout<<"nEntered decryption ..";
    std::string ciphertext = out;
    std::string decryptedtext;
    cout<<"nCipher recieved: "<<reinterpret_cast<const unsigned char*>( ciphertext.c_str());
    CryptoPP::AES::Decryption aesDecryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
    CryptoPP::CBC_Mode_ExternalCipher::Decryption cbcDecryption( aesDecryption, iv );
    CryptoPP::StreamTransformationFilter stfDecryptor(cbcDecryption, new CryptoPP::StringSink( decryptedtext ) );
    stfDecryptor.Put( reinterpret_cast<const unsigned char*>( ciphertext.c_str() ), ciphertext.size() );
    stfDecryptor.MessageEnd();
    std::cout << "Decrypted Text: " << std::endl;
    std::cout << decryptedtext;
    std::cout << std::endl << std::endl;    
}

如果char*指向的不是文本字符串，例如加密数据，则不应该从char*构造std::string。

std::string ciphertext = out;

一旦ciphertext的结构达到0字节，它就会停止从out进行复制。相反，您还需要传入加密数据的长度，并使用std::string(const char* data, size_t size)构造函数。

std::string ciphertext(out, outSize);

或者，您也可以使用带有开始和结束迭代器的构造函数。

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