encfs/fs/NameIO.h
2013-01-29 03:07:54 +00:00

143 lines
4.4 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 _NameIO_incl_
#define _NameIO_incl_
#include <string>
#include <list>
#include <inttypes.h>
#include "base/Interface.h"
#include "cipher/CipherKey.h"
class Cipher;
class NameIO
{
public:
typedef shared_ptr<NameIO> (*Constructor)( const Interface &iface,
const shared_ptr<Cipher> &cipher, const CipherKey &key);
struct Algorithm
{
std::string name;
std::string description;
Interface iface;
bool needsStreamMode;
};
typedef std::list<Algorithm> AlgorithmList;
static AlgorithmList GetAlgorithmList( bool includeHidden = false );
static shared_ptr<NameIO> New( const Interface &iface,
const shared_ptr<Cipher> &cipher, const CipherKey &key);
static shared_ptr<NameIO> New( const std::string &name,
const shared_ptr<Cipher> &cipher, const CipherKey &key);
static bool Register( const char *name, const char *description,
const Interface &iface, Constructor constructor,
bool needsStreamMode,
bool hidden = false);
NameIO();
virtual ~NameIO();
virtual Interface interface() const =0;
void setChainedNameIV( bool enable );
bool getChainedNameIV() const;
void setReverseEncryption( bool enable );
bool getReverseEncryption() const;
std::string encodePath( const char *plaintextPath ) const;
std::string decodePath( const char *encodedPath ) const;
std::string encodePath( const char *plaintextPath, uint64_t *iv ) const;
std::string decodePath( const char *encodedPath, uint64_t *iv ) const;
virtual int maxEncodedNameLen( int plaintextNameLen ) const =0;
virtual int maxDecodedNameLen( int encodedNameLen ) const =0;
std::string encodeName( const char *plaintextName, int length ) const;
std::string decodeName( const char *encodedName, int length ) const;
protected:
virtual int encodeName( const char *plaintextName, int length,
char *encodedName ) const;
virtual int decodeName( const char *encodedName, int length,
char *plaintextName ) const;
virtual int encodeName( const char *plaintextName, int length,
uint64_t *iv, char *encodedName ) const =0;
virtual int decodeName( const char *encodedName, int length,
uint64_t *iv, char *plaintextName ) const =0;
private:
std::string recodePath( const char *path,
int (NameIO::*codingLen)(int) const,
int (NameIO::*codingFunc)(const char *, int,
uint64_t *, char *) const,
uint64_t *iv ) const;
std::string _encodePath( const char *plaintextPath, uint64_t *iv ) const;
std::string _decodePath( const char *encodedPath, uint64_t *iv ) const;
std::string _encodeName( const char *plaintextName, int length ) const;
std::string _decodeName( const char *encodedName, int length ) const;
bool chainedNameIV;
bool reverseEncryption;
};
/*
Helper macros for creating temporary buffers with an optimization that
below a given size (OptimizedSize) is allocated on the stack, and when a
larger size is requested it is allocated on the heap.
BUFFER_RESET should be called for the same name as BUFFER_INIT
*/
#define BUFFER_INIT( Name, OptimizedSize, Size ) \
char Name ## _Raw [ OptimizedSize ]; \
char *Name = Name ## _Raw; \
if( sizeof(Name ## _Raw) < Size ) \
{ \
Name = new char[ Size ];\
} \
memset( Name, 0, Size )
#define BUFFER_RESET( Name ) \
do { \
if( Name != Name ## _Raw ) \
{ \
delete[] Name; \
Name = Name ## _Raw; \
} \
} while(0)
#endif