我正在尝试在 C++ 中使用 crypto++ 实现 2 键三重 DES。
我的实现基于位于此处的 crypto++ wiki 中的代码。
wiki 上的代码正确构建；当我运行示例程序时，我可以看到它正在正确加密和解密。
对于我的实现，我正在尝试执行以下操作：
用户可以运行“desimp.exe encrypt test.txt”。该程序将对 test.txt 进行加密，然后输出一个名为 test.txt.des 的加密文件。这似乎工作正常。
用户可以运行“desimp.exe decrypt test.txt.des”，程序将解密 test.txt.des 并将解密后的文本输出到文件“decrypted.txt”我无法让它工作。我得到的错误是“ StreamTransformationFilter: invalid PKCS #7 block padding found ”
我相信我可能还需要在加密时将 iv 中的数据保存到文件中。它是否正确？我已经尝试过这样做，并且我认为我能够将 iv 正确保存到文件中 - 但我认为为了读取 iv 以用于解密，它需要作为数组读取8 个字节。当我尝试保存 iv 时 test.txt.iv 的文件大小为 21 个字节。如果这是正确的方法，我不确定如何进行。如果这是错误的方法，我想知道我需要做些什么不同的事情。这是代码：
#ifndef CRYPTOPP_DLL_ONLY
#define CRYPTOPP_DEFAULT_NO_DLL
#endif
#include "dll.h"
#include "rc6.h"
#include <stdio.h>
#include <string.h>
#include <fstream>
#include <stdlib.h>
#include <string>
#include <streambuf>
USING_NAMESPACE(CryptoPP)
USING_NAMESPACE(std)
#ifdef CRYPTOPP_IMPORTS
static PNew s_pNew = NULL;
static PDelete s_pDelete = NULL;
#endif
#ifdef CRYPTOPP_DLL_ONLY
int __cdecl main(int argc, char *argv[])
{
AutoSeededRandomPool prng;
SecByteBlock key(DES_EDE2::DEFAULT_KEYLENGTH);
prng.GenerateBlock(key, key.size());
byte iv[DES_EDE2::BLOCKSIZE];
prng.GenerateBlock(iv, sizeof(iv));
string plain = "CBC Mode Test";
string cipher, encoded, recovered;
char *fileName = argv[1];
char *runMode = argv[2];
char *ivFile = argv[3];
cout << "ARGUMENT 1: " << fileName << endl;
cout << "ARGUMENT 2: " << runMode << endl;
string fileNameString(fileName);
string encryptedFileNameString = fileNameString + ".des";//add .des to the filename of the encrypted file once it's generated
string ivString = fileNameString + ".iv";//iv file
string runModeString(runMode);
if (runModeString == "encrypt")
{
ifstream t(fileName);
string str((std::istreambuf_iterator<char>(t)),
istreambuf_iterator<char>());
try
{
cout << "plain text: " << str << endl;
CBC_Mode< DES_EDE2 >::Encryption e;
e.SetKeyWithIV(key, key.size(), iv);
// The StreamTransformationFilter adds padding
// as required. ECB and CBC Mode must be padded
// to the block size of the cipher.
StringSource ss1(str, true,
new StreamTransformationFilter(e,
new StringSink(cipher)
) // StreamTransformationFilter
); // StringSource
}
catch(const CryptoPP::Exception& e)
{
cerr << e.what() << endl;
exit(1);
}
// Pretty print
StringSource ss2(cipher, true,
new HexEncoder(
new StringSink(encoded)
) // HexEncoder
); // StringSource
cout << "cipher text: " << encoded << endl;//"encoded" is just the pretty print version of the ciphertext.
ofstream fout(encryptedFileNameString);
fout << cipher;
fout.close();//outputs/saves the encrypted file
cout << "Encrypted file was saved to local path as " << encryptedFileNameString << endl;
ofstream fout2(ivString);
fout2 << iv;
fout2.close();
cout << "iv was saved to local path as " << ivString << endl;
}
if (runModeString == "decrypt")// USER WANTS TO DECRYPT A FILE
{
ifstream t2(fileName);
string str2((istreambuf_iterator<char>(t2)),istreambuf_iterator<char>());
cipher = str2;
try
{
CBC_Mode< DES_EDE2 >::Decryption d;
d.SetKeyWithIV(key, key.size(), iv);
// The StreamTransformationFilter removes
// padding as required.
StringSource ss3(cipher, true,
new StreamTransformationFilter(d,
new StringSink(recovered)
) // StreamTransformationFilter
); // StringSource
cout << "recovered text: " << recovered << endl;
}
catch(const CryptoPP::Exception& e)
{
cerr << e.what() << endl;
exit(1);
}
}
return 0;
}//end main
extern "C" __declspec(dllexport) void __cdecl SetNewAndDeleteFromCryptoPP(PNew pNew, PDelete pDelete, PSetNewHandler pSetNewHandler)
{
s_pNew = pNew;
s_pDelete = pDelete;
}
void * __cdecl operator new (size_t size)
{
return s_pNew(size);
}
void __cdecl operator delete (void * p)
{
s_pDelete(p);
}
#endif