Decrypt.h

//========================================================================
//
// Decrypt.h
//
// Copyright 1996-2002 Glyph & Cog, LLC
//
//========================================================================
 
#ifndef DECRYPT_H
#define DECRYPT_H
 
#include <aconf.h>
 
#ifdef USE_GCC_PRAGMAS
#pragma interface
#endif
 
#include "gtypes.h"
#include "GString.h"
 
//------------------------------------------------------------------------
// Decrypt
//------------------------------------------------------------------------
 
class Decrypt {
public:
 
  // Initialize the decryptor object.
  Decrypt(Guchar *fileKey, int keyLength, int objNum, int objGen);
 
  // Reset decryption.
  void reset();
 
  // Decrypt one byte.
  Guchar decryptByte(Guchar c);
 
  // 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,
               GString *ownerKey, GString *userKey,
               int permissions, GString *fileID,
               GString *ownerPassword, GString *userPassword,
               Guchar *fileKey, GBool *ownerPasswordOk);
 
private:
 
  static GBool makeFileKey2(int encVersion, int encRevision, int keyLength,
                GString *ownerKey, GString *userKey,
                int permissions, GString *fileID,
                GString *userPassword, Guchar *fileKey);
 
  int objKeyLength;
  Guchar objKey[21];
  Guchar state[256];
  Guchar x, y;
};
 
#endif