如何用Crypto++实现DES

发布网友发布时间：2022-04-29 13:36

共1个回答

热心网友时间：2022-06-29 00:38

代码如下：
[cpp] view plain copy
#include <QtCore/QCoreApplication>

#include <crypto++/des.h>

#include <stdio.h>

// keyString 是一个密钥，必须保证长度要超过 16
// block 是要处理的数据，处理后的数据也同时存放在 block 里，必须保证它的长度为 8 的整倍数
// length 是 block 的长度，必须保证它为 8 的整倍数
// direction 是表示是否是加密还是解密，若是加密，则用 CryptoPP::ENCRYPTION, 解密用 CryptoPP::DECRYPTION
void DES_Process(const char *keyString, byte *block, size_t length, CryptoPP::CipherDir direction){
using namespace CryptoPP;

byte key[DES_EDE2::KEYLENGTH];
memcpy(key, keyString, DES_EDE2::KEYLENGTH);
BlockTransformation *t = NULL;

if(direction == ENCRYPTION)
t = new DES_EDE2_Encryption(key, DES_EDE2::KEYLENGTH);
else
t = new DES_EDE2_Decryption(key, DES_EDE2::KEYLENGTH);

int steps = length / t->BlockSize();
for(int i=0; i<steps; i++){
int offset = i * t->BlockSize();
t->ProcessBlock(block + offset);
}

delete t;
}

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

byte block[1024] = "++++++++--------********////////";

const char *key = "http://qsanguosha.org/forum";

printf("original text: %s\n", block);

DES_Process(key, block, 16, CryptoPP::ENCRYPTION);

printf("Encrypt: %s\n", block);

DES_Process(key, block, 16, CryptoPP::DECRYPTION);

printf("Decrypt: %s\n", block);

return a.exec();
}