encfs/encfs/CipherFileIO.h
2016-04-24 23:15:43 -07:00

98 lines
2.7 KiB
C++

/*****************************************************************************
* Author: Valient Gough <vgough@pobox.com>
*
*****************************************************************************
* Copyright (c) 2004, Valient Gough
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _CipherFileIO_incl_
#define _CipherFileIO_incl_
#include <inttypes.h>
#include <memory>
#include <stdint.h>
#include <sys/types.h>
#include "BlockFileIO.h"
#include "CipherKey.h"
#include "FSConfig.h"
#include "FileUtils.h"
#include "Interface.h"
namespace encfs {
class Cipher;
class FileIO;
struct IORequest;
/*
Implement the FileIO interface encrypting data in blocks.
Uses BlockFileIO to handle the block scatter / gather issues.
*/
class CipherFileIO : public BlockFileIO {
public:
CipherFileIO(const std::shared_ptr<FileIO> &base, const FSConfigPtr &cfg);
virtual ~CipherFileIO();
virtual Interface interface() const;
virtual void setFileName(const char *fileName);
virtual const char *getFileName() const;
virtual bool setIV(uint64_t iv);
virtual int open(int flags);
virtual int getAttr(struct stat *stbuf) const;
virtual off_t getSize() const;
virtual int truncate(off_t size);
virtual bool isWritable() const;
private:
virtual ssize_t readOneBlock(const IORequest &req) const;
virtual bool writeOneBlock(const IORequest &req);
virtual void generateReverseHeader(unsigned char *data);
void initHeader();
bool writeHeader();
bool blockRead(unsigned char *buf, int size, uint64_t iv64) const;
bool streamRead(unsigned char *buf, int size, uint64_t iv64) const;
bool blockWrite(unsigned char *buf, int size, uint64_t iv64) const;
bool streamWrite(unsigned char *buf, int size, uint64_t iv64) const;
ssize_t read(const IORequest &req) const;
std::shared_ptr<FileIO> base;
FSConfigPtr fsConfig;
// if haveHeader is true, then we have a transparent file header which
// contains a 64 bit initialization vector.
bool haveHeader;
uint64_t externalIV;
uint64_t fileIV;
int lastFlags;
std::shared_ptr<Cipher> cipher;
CipherKey key;
};
} // namespace encfs
#endif