source/libs/poppler/poppler-0.37.0/poppler/Decrypt.h

   1 //========================================================================
   2 //
   3 // Decrypt.h
   4 //
   5 // Copyright 1996-2003 Glyph & Cog, LLC
   6 //
   7 //========================================================================
   8
   9 //========================================================================
  10 //
  11 // Modified under the Poppler project - http://poppler.freedesktop.org
  12 //
  13 // All changes made under the Poppler project to this file are licensed
  14 // under GPL version 2 or later
  15 //
  16 // Copyright (C) 2008 Julien Rebetez <julien@fhtagn.net>
  17 // Copyright (C) 2009 David Benjamin <davidben@mit.edu>
  18 // Copyright (C) 2012 Fabio D'Urso <fabiodurso@hotmail.it>
  19 // Copyright (C) 2013 Adrian Johnson <ajohnson@redneon.com>
  20 // Copyright (C) 2013 Albert Astals Cid <aacid@kde.org>
  21 // Copyright (C) 2013 Thomas Freitag <Thomas.Freitag@alfa.de>
  22 //
  23 // To see a description of the changes please see the Changelog file that
  24 // came with your tarball or type make ChangeLog if you are building from git
  25 //
  26 //========================================================================
  27
  28 #ifndef DECRYPT_H
  29 #define DECRYPT_H
  30
  31 #ifdef USE_GCC_PRAGMAS
  32 #pragma interface
  33 #endif
  34
  35 #include "goo/gtypes.h"
  36 #include "goo/GooString.h"
  37 #include "Object.h"
  38 #include "Stream.h"
  39
  40 //------------------------------------------------------------------------
  41 // Decrypt
  42 //------------------------------------------------------------------------
  43
  44 class Decrypt {
  45 public:
  46
  47   // Generate a file key.  The <fileKey> buffer must have space for at
  48   // least 16 bytes.  Checks <ownerPassword> and then <userPassword>
  49   // and returns true if either is correct.  Sets <ownerPasswordOk> if
  50   // the owner password was correct.  Either or both of the passwords
  51   // may be NULL, which is treated as an empty string.
  52   static GBool makeFileKey(int encVersion, int encRevision, int keyLength,
  53                            GooString *ownerKey, GooString *userKey,
  54                            GooString *ownerEnc, GooString *userEnc,
  55                            int permissions, GooString *fileID,
  56                            GooString *ownerPassword, GooString *userPassword,
  57                            Guchar *fileKey, GBool encryptMetadata,
  58                            GBool *ownerPasswordOk);
  59
  60 private:
  61
  62   static GBool makeFileKey2(int encVersion, int encRevision, int keyLength,
  63                             GooString *ownerKey, GooString *userKey,
  64                             int permissions, GooString *fileID,
  65                             GooString *userPassword, Guchar *fileKey,
  66                             GBool encryptMetadata);
  67 };
  68
  69 //------------------------------------------------------------------------
  70 // Helper classes
  71 //------------------------------------------------------------------------
  72
  73 /* DecryptRC4State, DecryptAESState, DecryptAES256State are named like this for
  74  * historical reasons, but they're used for encryption too.
  75  * In case of decryption, the cbc field in AES and AES-256 contains the previous
  76  * input block or the CBC initialization vector (IV) if the stream has just been
  77  * reset). In case of encryption, it always contains the IV, whereas the
  78  * previous output is kept in buf. The paddingReached field is only used in
  79  * case of encryption. */
  80 struct DecryptRC4State {
  81   Guchar state[256];
  82   Guchar x, y;
  83 };
  84
  85 struct DecryptAESState {
  86   Guint w[44];
  87   Guchar state[16];
  88   Guchar cbc[16];
  89   Guchar buf[16];
  90   GBool paddingReached; // encryption only
  91   int bufIdx;
  92 };
  93
  94 struct DecryptAES256State {
  95   Guint w[60];
  96   Guchar state[16];
  97   Guchar cbc[16];
  98   Guchar buf[16];
  99   GBool paddingReached; // encryption only
 100   int bufIdx;
 101 };
 102
 103 class BaseCryptStream : public FilterStream {
 104 public:
 105
 106   BaseCryptStream(Stream *strA, Guchar *fileKey, CryptAlgorithm algoA,
 107                   int keyLength, int objNum, int objGen);
 108   virtual ~BaseCryptStream();
 109   virtual StreamKind getKind() { return strCrypt; }
 110   virtual void reset();
 111   virtual int getChar();
 112   virtual int lookChar() = 0;
 113   virtual Goffset getPos();
 114   virtual GBool isBinary(GBool last);
 115   virtual Stream *getUndecodedStream() { return this; }
 116   void setAutoDelete(GBool val);
 117
 118 protected:
 119   CryptAlgorithm algo;
 120   int objKeyLength;
 121   Guchar objKey[32];
 122   Goffset charactersRead; // so that getPos() can be correct
 123   int nextCharBuff;   // EOF means not read yet
 124   GBool autoDelete;
 125
 126   union {
 127     DecryptRC4State rc4;
 128     DecryptAESState aes;
 129     DecryptAES256State aes256;
 130   } state;
 131 };
 132
 133 //------------------------------------------------------------------------
 134 // EncryptStream / DecryptStream
 135 //------------------------------------------------------------------------
 136
 137 class EncryptStream : public BaseCryptStream {
 138 public:
 139
 140   EncryptStream(Stream *strA, Guchar *fileKey, CryptAlgorithm algoA,
 141                 int keyLength, int objNum, int objGen);
 142   ~EncryptStream();
 143   virtual void reset();
 144   virtual int lookChar();
 145 };
 146
 147 class DecryptStream : public BaseCryptStream {
 148 public:
 149
 150   DecryptStream(Stream *strA, Guchar *fileKey, CryptAlgorithm algoA,
 151                 int keyLength, int objNum, int objGen);
 152   ~DecryptStream();
 153   virtual void reset();
 154   virtual int lookChar();
 155 };
 156
 157 //------------------------------------------------------------------------
 158
 159 extern void md5(Guchar *msg, int msgLen, Guchar *digest);
 160
 161 #endif