pdf2swf/xpdf/Decrypt.h

   1 //========================================================================
   2 //
   3 // Decrypt.h
   4 //
   5 // Copyright 1996-2002 Glyph & Cog, LLC
   6 //
   7 //========================================================================
   8
   9 #ifndef DECRYPT_H
  10 #define DECRYPT_H
  11
  12 #ifdef __GNUC__
  13 #pragma interface
  14 #endif
  15
  16 #include "gtypes.h"
  17 #include "GString.h"
  18
  19 //------------------------------------------------------------------------
  20 // Decrypt
  21 //------------------------------------------------------------------------
  22
  23 class Decrypt {
  24 public:
  25
  26   // Initialize the decryptor object.
  27   Decrypt(Guchar *fileKey, int keyLength, int objNum, int objGen);
  28
  29   // Reset decryption.
  30   void reset();
  31
  32   // Decrypt one byte.
  33   Guchar decryptByte(Guchar c);
  34
  35   // Generate a file key.  The <fileKey> buffer must have space for at
  36   // least 16 bytes.  Checks <ownerPassword> and then <userPassword>
  37   // and returns true if either is correct.  Sets <ownerPasswordOk> if
  38   // the owner password was correct.  Either or both of the passwords
  39   // may be NULL, which is treated as an empty string.
  40   static GBool makeFileKey(int encVersion, int encRevision, int keyLength,
  41                            GString *ownerKey, GString *userKey,
  42                            int permissions, GString *fileID,
  43                            GString *ownerPassword, GString *userPassword,
  44                            Guchar *fileKey, GBool *ownerPasswordOk);
  45
  46 private:
  47
  48   static GBool makeFileKey2(int encVersion, int encRevision, int keyLength,
  49                             GString *ownerKey, GString *userKey,
  50                             int permissions, GString *fileID,
  51                             GString *userPassword, Guchar *fileKey);
  52
  53   int objKeyLength;
  54   Guchar objKey[21];
  55   Guchar state[256];
  56   Guchar x, y;
  57 };
  58
  59 #endif