代码之家 › 专栏 › 技术社区 › EinderJam

使用文件源加密内容后无法删除文件

crypto++ encryption windows c++

1

EinderJam · 技术社区 · 8 年前

我正在尝试使用AES EAX模式和CryptoPP库加密文件。以下是主要()内容:

SecByteBlock key(AES::MAX_KEYLENGTH);
rnd.GenerateBlock(key, key.size());
ArraySource as(key.begin(), key.size(), true, new FileSink("key.bin"));

SecByteBlock iv(AES::BLOCKSIZE);
rnd.GenerateBlock(iv, AES::BLOCKSIZE);

EAX<AES>::Encryption encryptor;
encryptor.SetKeyWithIV(key, key.size(), iv, iv.size());

FileSink file("image.jpg.enc");

ArraySource write_iv(iv, iv.size(), true, new Redirector(file));

FileSource write_ciphertext("image.jpg", true, new AuthenticatedEncryptionFilter(encryptor, new Redirector(file)));

const int delete_file = std::remove("image.jpg");
std::cout << delete_file << std::endl;
std::cout << "Error code is:" << GetLastError();

return 0;

加密部分成功结束,但删除原始文件(image.jpg)失败。我得到的输出是:

Error code is:32

这是一个 ERROR_SHARING_VIOLATION ,这意味着“该进程无法访问该文件,因为它正被另一个进程使用。” 我的问题是:我怎样才能在 Filesource 行,可以删除文件后?用经典的 ifstream file.close() ,但如何使用Crypto++?

1 回复 | 直到 8 年前

1

2

Dai 8 年前

我不熟悉 crypto++ 但如果他们遵循RAII模式,那么触发 ~FileSource

在C++中,您将使用匿名作用域来定义自动变量的生存期。匿名作用域是使用不带任何关键字的大括号定义的:

using namespace std;
...
encryptor.SetKeyWithIV(key, key.size(), iv, iv.size());

// begin an anonymous scope:
{

    FileSink    file             ( "image.jpg.enc" );
    ArraySource write_iv         ( iv, iv.size(), true, new Redirector( file ) );
    FileSource  write_ciphertext ( "image.jpg", true, new AuthenticatedEncryptionFilter( encryptor, new Redirector( file ) ) );        
}
// end the scope, causing all objects declared within to have their destructors called

const int delete_file = remove("image.jpg");
cout << delete_file << endl;
cout << "Error code is:" << GetLastError();
...

new delete .我相信你可以让这些论点对象也自动产生,比如:

using namespace std;
...
encryptor.SetKeyWithIV(key, key.size(), iv, iv.size());

// begin an anonymous scope:
{       
    FileSink                      file            ( "image.jpg.enc" );
    Redirector                    write_redir     ( file );
    ArraySource                   write_iv        ( iv, iv.size(), true, &write_redir );
    AuthenticatedEncryptionFilter filter          ( encryptor, &write_redir )
    FileSource                    write_ciphertext( "image.jpg", true, &filter );
}
// end the scope, causing all objects declared within to have their destructors called

const int delete_file = remove("image.jpg");
cout << delete_file << endl;
cout << "Error code is:" << GetLastError();
...