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//========================================================================
//
// Decrypt.h
//
// Copyright 1996-2003 Glyph & Cog, LLC
//
//========================================================================
//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2008 Julien Rebetez <julien@fhtagn.net>
// Copyright (C) 2009 David Benjamin <davidben@mit.edu>
// Copyright (C) 2012 Fabio D'Urso <fabiodurso@hotmail.it>
// Copyright (C) 2013 Adrian Johnson <ajohnson@redneon.com>
// Copyright (C) 2013 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2013 Thomas Freitag <Thomas.Freitag@alfa.de>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================
#ifndef DECRYPT_H
#define DECRYPT_H
#ifdef USE_GCC_PRAGMAS
#pragma interface
#endif
#include "goo/gtypes.h"
#include "goo/GooString.h"
#include "Object.h"
#include "Stream.h"
//------------------------------------------------------------------------
// Decrypt
//------------------------------------------------------------------------
class Decrypt {
public:
// Generate a file key. The <fileKey> buffer must have space for at
// least 16 bytes. Checks <ownerPassword> and then <userPassword>
// and returns true if either is correct. Sets <ownerPasswordOk> if
// the owner password was correct. Either or both of the passwords
// may be NULL, which is treated as an empty string.
static GBool makeFileKey(int encVersion, int encRevision, int keyLength,
GooString *ownerKey, GooString *userKey,
GooString *ownerEnc, GooString *userEnc,
int permissions, GooString *fileID,
GooString *ownerPassword, GooString *userPassword,
Guchar *fileKey, GBool encryptMetadata,
GBool *ownerPasswordOk);
private:
static GBool makeFileKey2(int encVersion, int encRevision, int keyLength,
GooString *ownerKey, GooString *userKey,
int permissions, GooString *fileID,
GooString *userPassword, Guchar *fileKey,
GBool encryptMetadata);
};
//------------------------------------------------------------------------
// Helper classes
//------------------------------------------------------------------------
/* DecryptRC4State, DecryptAESState, DecryptAES256State are named like this for
* historical reasons, but they're used for encryption too.
* In case of decryption, the cbc field in AES and AES-256 contains the previous
* input block or the CBC initialization vector (IV) if the stream has just been
* reset). In case of encryption, it always contains the IV, whereas the
* previous output is kept in buf. The paddingReached field is only used in
* case of encryption. */
struct DecryptRC4State {
Guchar state[256];
Guchar x, y;
};
struct DecryptAESState {
Guint w[44];
Guchar state[16];
Guchar cbc[16];
Guchar buf[16];
GBool paddingReached; // encryption only
int bufIdx;
};
struct DecryptAES256State {
Guint w[60];
Guchar state[16];
Guchar cbc[16];
Guchar buf[16];
GBool paddingReached; // encryption only
int bufIdx;
};
class BaseCryptStream : public FilterStream {
public:
BaseCryptStream(Stream *strA, Guchar *fileKey, CryptAlgorithm algoA,
int keyLength, int objNum, int objGen);
virtual ~BaseCryptStream();
virtual StreamKind getKind() { return strCrypt; }
virtual void reset();
virtual int getChar();
virtual int lookChar() = 0;
virtual Goffset getPos();
virtual GBool isBinary(GBool last);
virtual Stream *getUndecodedStream() { return this; }
void setAutoDelete(GBool val);
protected:
CryptAlgorithm algo;
int objKeyLength;
Guchar objKey[32];
Goffset charactersRead; // so that getPos() can be correct
int nextCharBuff; // EOF means not read yet
GBool autoDelete;
union {
DecryptRC4State rc4;
DecryptAESState aes;
DecryptAES256State aes256;
} state;
};
//------------------------------------------------------------------------
// EncryptStream / DecryptStream
//------------------------------------------------------------------------
class EncryptStream : public BaseCryptStream {
public:
EncryptStream(Stream *strA, Guchar *fileKey, CryptAlgorithm algoA,
int keyLength, int objNum, int objGen);
~EncryptStream();
virtual void reset();
virtual int lookChar();
};
class DecryptStream : public BaseCryptStream {
public:
DecryptStream(Stream *strA, Guchar *fileKey, CryptAlgorithm algoA,
int keyLength, int objNum, int objGen);
~DecryptStream();
virtual void reset();
virtual int lookChar();
};
//------------------------------------------------------------------------
extern void md5(Guchar *msg, int msgLen, Guchar *digest);
#endif
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