利用crypto++庫實現AES加密算法

利用crypto++庫實現AES加/解密字符串，文件

MyAES.h:

/*
 * MyAES.h
 *
 *  Created on: 2013-3-6
 *      Author: hust
 */

#ifndef MYAES_H_
#define MYAES_H_

#include <cryptopp/aes.h>
#include <cryptopp/default.h>
#include <cryptopp/filters.h>
#include <cryptopp/files.h>
#include <cryptopp/osrng.h>

#include <stdlib.h>
#include <string>
#include <iostream>

using namespace CryptoPP;
using namespace std;

class MyAES
{
public:
    byte * key;
    byte * iv;
    int key_length;

    MyAES();
    MyAES(byte * key, byte *iv, int length);
    ~MyAES();

    //use the key to encrypt the plainText and return the cipher
    string Encrypt(const string &plainText);
    //use the same key to decrypt the cipher and return the recover
    string Decrypt(const string &cipher);
    //use the key to encrypt the file
    bool EncryptFile(const string & inFilename, const string & outFilename);
    //use the key to decyrpt the file
    bool DecryptFile(const string & DecFilename,
            const string & recoverFilename);
    void GenerateKey();
    void SetKey(byte * key, byte * iv, int length);
};

#endif /* MYAES_H_ */

MyAES.cpp:

//============================================================================
// Name        : MyAES.cpp
// Author      : hust
// Version     :
// Copyright   : 1.0
// Description : 本類將AES的加密，解密函數封裝，直接調用即可對string進行加密or解密
//               另外，構造MyAES類的時候，傳入參數key, iv, key_length
//               待解決：編寫一個生成密鑰的函數，即需要 KeyGenerate(Random random);
// reference   : http://www.codeproject.com/Articles/21877/Applied-Crypto-Block-Ciphers
//============================================================================

#include "MyAES.h"
#include <time.h>
MyAES::MyAES()
{

}

MyAES::MyAES(byte * key1, byte * iv1, int key_length1)
{
    SetKey(key1, iv1, key_length1);
}

MyAES::~MyAES()
{

}

void MyAES::GenerateKey()
{
    AutoSeededRandomPool rnd;
    byte key1[AES::DEFAULT_KEYLENGTH];
    rnd.GenerateBlock(key1, AES::DEFAULT_KEYLENGTH);

    // Generate a random IV
    byte iv1[AES::BLOCKSIZE];
    rnd.GenerateBlock(iv1, AES::BLOCKSIZE);

    SetKey(key1, iv1, 16);
}

void MyAES::SetKey(byte * key1, byte * iv1, int length1)
{
    this->key = key1;
    this->iv = iv1;
    this->key_length = length1;
}

/*
 * Description: use key to encrypt 'plainText', return the cipher
 * Input:
 *  plainText: the string need to be encrypted
 * OutPUt:
 *  return the cipher
 */
string MyAES::Encrypt(const string &plainText)
{
    string cipher;
    CBC_Mode<AES>::Encryption aesEncryptor(key, key_length, iv);
//  AESEncryption aesEncryptor; //加密器
//  aesEncryptor.SetKey( key, key_length );  //設定加密密鑰
    StringSource(plainText, true,
            new StreamTransformationFilter(aesEncryptor,
                    new StringSink(cipher)));
    return cipher;
}

/*
 * Description: use the same key to decrypt "cipher" and return the plainText
 * Input:
 *  cipher: the string to be decrypted
 * Output:
 *  return the recover
 */
string MyAES::Decrypt(const string & cipher)
{
    string recover;
    CBC_Mode<AES>::Decryption aesDecryptor(key, key_length, iv);
    //AESDecryption aesDecryptor; //解密器
    //aesDecryptor.SetKey( key, key_length );  //設定加密密鑰
    StringSource(cipher, true,
            new StreamTransformationFilter(aesDecryptor,
                    new StringSink(recover)));
    return recover;
}

/*
 * Description: use the key to encrypt the 'inFilename' and store the cipher in 'outFilname'
 * Input:
 *  inFilename: the file need to be encrypted!
 *  outFilename: the encrypted file
 * OutPut:
 *  if encrypt success, return true, or return false
 * Others: the function should delete the file : 'inFilename', however I note it
 */
bool MyAES::EncryptFile(const string & inFilename, const string & outFilename)
{
    // check if the file 'inFilename' exists.
    if (access(inFilename.c_str(), 0) == -1)
    {
        cout << "The file " << inFilename << " is not exist! " << endl;
        return false;
    }
    // file exists, the encrypt the file
    CBC_Mode<AES>::Encryption aesEncryptor(key, key_length, iv);

    FileSource(inFilename.c_str(), true,
            new StreamTransformationFilter(aesEncryptor,
                    new FileSink(outFilename.c_str())));
    // remove the file 'inFilename'
    // if(remove(inFilename) == 0) cout << "remove file succeed! " << endl;
    //      else cout << "fail to remove the file " << inFilname << endl;
    // use function remove(), you have to add #include <cstdio> in the .h file
    return true;
}

/*
 * Description: use the same key to decrypt the 'decFilename' and create recoverFile
 * Input:
 *  decFilename: the encrypted file name
 *  recoverFilename: the decrypted file name
 * OutPut:
 *  if decrypted the file successful, return true, else return false
 * Others: we should also delete the file 'decFilename'
 */
bool MyAES::DecryptFile(const string & decFilename,
        const string & recoverFilename)
{
    // check if the file 'decFilename' exists!
    if (access(decFilename.c_str(), 0) == -1)
    {
        cout << "The file " << decFilename << " is not exist! " << endl;
        return false;
    }
    // exist , then decrypt the file
    CBC_Mode<AES>::Decryption aesDecryptor(key, key_length, iv);
    FileSource(decFilename.c_str(), true,
            new StreamTransformationFilter(aesDecryptor,
                    new FileSink(recoverFilename.c_str())));
    return true;
}



 int main() {

     // byte key[]  = {0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08, 0x01,0x02, 0x03,0x04,0x05,0x06,0x07,0x08};
     // //AES::DEFAULT_KEYLENGTH
     // byte iv[]   = {0x01,0x02,0x03,0x03,0x03,0x03,0x03,0x03, 0x03,0x03, 0x01,0x02,0x03,0x03,0x03,0x03};
     // int keysize = 16;


     // generate the key
     AutoSeededRandomPool rnd;
     byte key[AES::DEFAULT_KEYLENGTH];
     rnd.GenerateBlock( key, AES::DEFAULT_KEYLENGTH);

     // Generate a random IV
     byte iv[AES::BLOCKSIZE];
     rnd.GenerateBlock(iv, AES::BLOCKSIZE);

     int keysize = 16;

     string plainText = "Hello World!";

     clock_t start , finish;
     double duration;
     start = clock();

     MyAES aes(key, iv, keysize);

     cout << "AES parameters: " << endl;
     cout << "The algorithm name is : " << AES::StaticAlgorithmName() << endl;
     cout << "The iv is : " << aes.iv << endl;
     cout << "The key is : " << aes.key << endl;
     cout << "The key length is : " << aes.key_length << endl;

     string cipher = aes.Encrypt(plainText);
     cout << "The cipher is : " << cipher << endl;

     string recover = aes.Decrypt(cipher);
     cout << "The recover is : " << recover << endl;

     cout << "=====================" << endl;

     // encrypt the file and decrypt it
     string inFilename = "aesTest";
     string outFilename = "aesEncrypt";
     string recoverFilename = "aesRecover";

     if(aes.EncryptFile(inFilename, outFilename)){
     cout << "*__*" << endl << "Encrypt succeed!" << endl;
     if(aes.DecryptFile(outFilename, recoverFilename)){
     cout << "*__*" << endl << "Recover succeed!" << endl;
     } else
     cout << ")__(" << endl << "Recover failed!" << endl;
     } else
     cout << ")__(" << endl << "Encrypt failed!" << endl;



     finish = clock();
     duration = (double)(finish - start) / CLOCKS_PER_SEC;
     cout << "the cost is : " << duration << endl;

     return 0;
 }

在linux系統中編譯命令為：

g++ MyAES.cpp -o test -lpthread -lcryptopp