1 files changed, 133 insertions, 0 deletions
diff --git a/xpdf/Decrypt.h b/xpdf/Decrypt.h
new file mode 100644
index 0000000..2b10abd
--- /dev/null
+++ b/xpdf/Decrypt.h
@@ -0,0 +1,133 @@
+//========================================================================
+//
+// Decrypt.h
+//
+// Copyright 1996-2003 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"
+#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,
+			   GString *ownerKey, GString *userKey,
+			   GString *ownerEnc, GString *userEnc,
+			   int permissions, GString *fileID,
+			   GString *ownerPassword, GString *userPassword,
+			   Guchar *fileKey, GBool encryptMetadata,
+			   GBool *ownerPasswordOk);
+
+private:
+
+  static void r6Hash(Guchar *key, int keyLen, const char *pwd, int pwdLen,
+		     char *userKey);
+  static GBool makeFileKey2(int encVersion, int encRevision, int keyLength,
+			    GString *ownerKey, GString *userKey,
+			    int permissions, GString *fileID,
+			    GString *userPassword, Guchar *fileKey,
+			    GBool encryptMetadata);
+};
+
+//------------------------------------------------------------------------
+// DecryptStream
+//------------------------------------------------------------------------
+
+struct DecryptRC4State {
+  Guchar state[256];
+  Guchar x, y;
+  int buf;
+};
+
+struct DecryptAESState {
+  Guint w[44];
+  Guchar state[16];
+  Guchar cbc[16];
+  Guchar buf[16];
+  int bufIdx;
+};
+
+struct DecryptAES256State {
+  Guint w[60];
+  Guchar state[16];
+  Guchar cbc[16];
+  Guchar buf[16];
+  int bufIdx;
+};
+
+class DecryptStream: public FilterStream {
+public:
+
+  DecryptStream(Stream *strA, Guchar *fileKeyA,
+		CryptAlgorithm algoA, int keyLengthA,
+		int objNumA, int objGenA);
+  virtual ~DecryptStream();
+  virtual Stream *copy();
+  virtual StreamKind getKind() { return strWeird; }
+  virtual void reset();
+  virtual int getChar();
+  virtual int lookChar();
+  virtual GBool isBinary(GBool last);
+  virtual Stream *getUndecodedStream() { return this; }
+
+private:
+
+  Guchar fileKey[32];
+  CryptAlgorithm algo;
+  int keyLength;
+  int objNum, objGen;
+  int objKeyLength;
+  Guchar objKey[32];
+
+  union {
+    DecryptRC4State rc4;
+    DecryptAESState aes;
+    DecryptAES256State aes256;
+  } state;
+};
+
+//------------------------------------------------------------------------
+
+struct MD5State {
+  Gulong a, b, c, d;
+  Guchar buf[64];
+  int bufLen;
+  int msgLen;
+  Guchar digest[16];
+};
+
+extern void rc4InitKey(Guchar *key, int keyLen, Guchar *state);
+extern Guchar rc4DecryptByte(Guchar *state, Guchar *x, Guchar *y, Guchar c);
+void md5Start(MD5State *state);
+void md5Append(MD5State *state, Guchar *data, int dataLen);
+void md5Finish(MD5State *state);
+extern void md5(Guchar *msg, int msgLen, Guchar *digest);
+extern void aesKeyExpansion(DecryptAESState *s,
+			    Guchar *objKey, int objKeyLen,
+			    GBool decrypt);
+extern void aesEncryptBlock(DecryptAESState *s, Guchar *in);
+extern void aesDecryptBlock(DecryptAESState *s, Guchar *in, GBool last);
+
+#endif