利用crypto++库实现AES加密算法

/*
 * 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_ */

//============================================================================
// Name        : MyAES.cpp
// Author      : hust
// Version     :
// Copyright   : 1.0
// Description : 本类将AES的加密，解密函数封装，直接调用即可对string进行加密or解密
//				 另外，构造MyAES类的时候，传入参数key, iv, key_length
//				 待解决：编写一个生成密钥的函数，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 );  //设定加密密钥
	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 );  //设定加密密钥
	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;
 }

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