pdftops/Decrypt.h

   1 //========================================================================
   2 //
   3 // Decrypt.h
   4 //
   5 // Copyright 1996-2003 Glyph & Cog, LLC
   6 //
   7 //========================================================================
   8
   9 #ifndef DECRYPT_H
  10 #define DECRYPT_H
  11
  12 #include <config.h>
  13
  14 #ifdef USE_GCC_PRAGMAS
  15 #pragma interface
  16 #endif
  17
  18 #include "gtypes.h"
  19 #include "GString.h"
  20
  21 //------------------------------------------------------------------------
  22 // Decrypt
  23 //------------------------------------------------------------------------
  24
  25 class Decrypt {
  26 public:
  27
  28   // Initialize the decryptor object.
  29   Decrypt(Guchar *fileKey, int keyLength, int objNum, int objGen);
  30
  31   // Reset decryption.
  32   void reset();
  33
  34   // Decrypt one byte.
  35   Guchar decryptByte(Guchar c);
  36
  37   // Generate a file key.  The <fileKey> buffer must have space for at
  38   // least 16 bytes.  Checks <ownerPassword> and then <userPassword>
  39   // and returns true if either is correct.  Sets <ownerPasswordOk> if
  40   // the owner password was correct.  Either or both of the passwords
  41   // may be NULL, which is treated as an empty string.
  42   static GBool makeFileKey(int encVersion, int encRevision, int keyLength,
  43                            GString *ownerKey, GString *userKey,
  44                            int permissions, GString *fileID,
  45                            GString *ownerPassword, GString *userPassword,
  46                            Guchar *fileKey, GBool encryptMetadata,
  47                            GBool *ownerPasswordOk);
  48
  49 private:
  50
  51   static GBool makeFileKey2(int encVersion, int encRevision, int keyLength,
  52                             GString *ownerKey, GString *userKey,
  53                             int permissions, GString *fileID,
  54                             GString *userPassword, Guchar *fileKey,
  55                             GBool encryptMetadata);
  56
  57   int objKeyLength;
  58   Guchar objKey[21];
  59   Guchar state[256];
  60   Guchar x, y;
  61 };
  62
  63 #endif