encryption - 使用 Crypto++ 的 AES 示例

Question

我一直在互联网上搜索好的c++ AES 代码示例/教程，它教授加密技术的基础知识和库的使用，但到目前为止，我还没有获得像样的材料。

好：易于理解（只是随时随地学习的基础知识）。

Answer 1

Crypto++ AES的官方文档是一个好的开始。从我的档案中，AES 的基本实现如下：

更多解释请参考这里，我建议您先了解算法，然后尝试逐步了解每一行。

#include <iostream>
#include <iomanip>

#include "modes.h"
#include "aes.h"
#include "filters.h"

int main(int argc, char* argv[]) {

    //Key and IV setup
    //AES encryption uses a secret key of a variable length (128-bit, 196-bit or 256-   
    //bit). This key is secretly exchanged between two parties before communication   
    //begins. DEFAULT_KEYLENGTH= 16 bytes
    CryptoPP::byte key[ CryptoPP::AES::DEFAULT_KEYLENGTH ], iv[ CryptoPP::AES::BLOCKSIZE ];
    memset( key, 0x00, CryptoPP::AES::DEFAULT_KEYLENGTH );
    memset( iv, 0x00, CryptoPP::AES::BLOCKSIZE );

    //
    // String and Sink setup
    //
    std::string plaintext = "Now is the time for all good men to come to the aide...";
    std::string ciphertext;
    std::string decryptedtext;

    //
    // Dump Plain Text
    //
    std::cout << "Plain Text (" << plaintext.size() << " bytes)" << std::endl;
    std::cout << plaintext;
    std::cout << std::endl << std::endl;

    //
    // Create Cipher Text
    //
    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() );
    stfEncryptor.MessageEnd();

    //
    // Dump Cipher Text
    //
    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<CryptoPP::byte>(ciphertext[i])) << " ";
    }

    std::cout << std::endl << std::endl;

    //
    // Decrypt
    //
    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();

    //
    // Dump Decrypted Text
    //
    std::cout << "Decrypted Text: " << std::endl;
    std::cout << decryptedtext;
    std::cout << std::endl << std::endl;

    return 0;
}

安装细节：

• 如何在 Visual Studio 2010 Windows 7 中安装 Crypto++？
• *nix 环境
• 对于 Ubuntu，我做了：

sudo apt-get install libcrypto++-dev libcrypto++-doc libcrypto++-utils