From 7ffce028d04a6b13ef762e2b89c34b688e8ca59d Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@idrix.fr>
Date: Sat, 31 May 2014 18:44:53 +0200
Subject: Add TrueCrypt 7.1a MacOSX/Linux specific source files.

---
 src/Volume/EncryptionModeLRW.cpp | 195 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 195 insertions(+)
 create mode 100644 src/Volume/EncryptionModeLRW.cpp

(limited to 'src/Volume/EncryptionModeLRW.cpp')

diff --git a/src/Volume/EncryptionModeLRW.cpp b/src/Volume/EncryptionModeLRW.cpp
new file mode 100644
index 00000000..38731d5d
--- /dev/null
+++ b/src/Volume/EncryptionModeLRW.cpp
@@ -0,0 +1,195 @@
+/*
+ Copyright (c) 2008 TrueCrypt Developers Association. All rights reserved.
+
+ Governed by the TrueCrypt License 3.0 the full text of which is contained in
+ the file License.txt included in TrueCrypt binary and source code distribution
+ packages.
+*/
+
+#include "EncryptionModeLRW.h"
+#include "Common/GfMul.h"
+
+namespace TrueCrypt
+{
+	void EncryptionModeLRW::Decrypt (byte *data, uint64 length) const
+	{
+		if_debug (ValidateState ());
+		DecryptBuffer (data, length, 1);
+	}
+
+	void EncryptionModeLRW::DecryptBuffer (byte *data, uint64 length, uint64 blockIndex) const
+	{
+		size_t blockSize = Ciphers.front()->GetBlockSize();
+		if (blockSize != 8 && blockSize != 16)
+			throw ParameterIncorrect (SRC_POS);
+
+		byte i[8];
+		*(uint64 *)i = Endian::Big (blockIndex);
+
+		byte t[Cipher::MaxBlockSize];
+
+		for (unsigned int b = 0; b < length / blockSize; b++)
+		{
+			if (blockSize == 8)
+			{
+				Gf64MulTab (i, t, (GfCtx *) (GfContext.Ptr()));
+				Xor64 ((uint64 *)data, (uint64 *)t);
+			}
+			else
+			{
+				Gf128MulBy64Tab (i, t, (GfCtx *) (GfContext.Ptr()));
+				Xor128 ((uint64 *)data, (uint64 *)t);
+			}
+
+			for (CipherList::const_reverse_iterator iCipherList = Ciphers.rbegin();
+				iCipherList != Ciphers.rend();
+				++iCipherList)
+			{
+				const Cipher &c = **iCipherList;
+
+				if (c.GetBlockSize () != blockSize)
+					throw ParameterIncorrect (SRC_POS);
+
+				c.DecryptBlock (data);
+			}
+
+			if (blockSize == 8)
+				Xor64 ((uint64 *)data, (uint64 *)t);
+			else
+				Xor128 ((uint64 *)data, (uint64 *)t);
+
+			data += blockSize;
+			IncrementBlockIndex (i);
+		}
+
+		Memory::Erase (t, sizeof (t));
+	}
+
+	void EncryptionModeLRW::DecryptSectorsCurrentThread (byte *data, uint64 sectorIndex, uint64 sectorCount, size_t sectorSize) const
+	{
+		if_debug (ValidateState ());
+		if_debug (ValidateParameters (data, sectorCount, sectorSize));
+
+		DecryptBuffer (data,
+			sectorCount * sectorSize,
+			SectorToBlockIndex (sectorIndex));
+	}
+
+	void EncryptionModeLRW::Encrypt (byte *data, uint64 length) const
+	{
+		ValidateState ();
+		EncryptBuffer (data, length, 1);
+	}
+
+	void EncryptionModeLRW::EncryptBuffer (byte *data, uint64 length, uint64 blockIndex) const
+	{
+		size_t blockSize = Ciphers.front()->GetBlockSize();
+		if (blockSize != 8 && blockSize != 16)
+			throw ParameterIncorrect (SRC_POS);
+
+		byte i[8];
+		*(uint64 *)i = Endian::Big (blockIndex);
+
+		byte t[Cipher::MaxBlockSize];
+
+		for (unsigned int b = 0; b < length / blockSize; b++)
+		{
+			if (blockSize == 8)
+			{
+				Gf64MulTab (i, t, (GfCtx *) (GfContext.Ptr()));
+				Xor64 ((uint64 *)data, (uint64 *)t);
+			}
+			else
+			{
+				Gf128MulBy64Tab (i, t, (GfCtx *) (GfContext.Ptr()));
+				Xor128 ((uint64 *)data, (uint64 *)t);
+			}
+
+			for (CipherList::const_iterator iCipherList = Ciphers.begin();
+				iCipherList != Ciphers.end();
+				++iCipherList)
+			{
+				const Cipher &c = **iCipherList;
+
+				if (c.GetBlockSize () != blockSize)
+					throw ParameterIncorrect (SRC_POS);
+
+				c.EncryptBlock (data);
+			}
+
+			if (blockSize == 8)
+				Xor64 ((uint64 *)data, (uint64 *)t);
+			else
+				Xor128 ((uint64 *)data, (uint64 *)t);
+
+			data += blockSize;
+			IncrementBlockIndex (i);
+		}
+
+		Memory::Erase (t, sizeof (t));
+	}
+
+	void EncryptionModeLRW::EncryptSectorsCurrentThread (byte *data, uint64 sectorIndex, uint64 sectorCount, size_t sectorSize) const
+	{
+		if_debug (ValidateState ());
+		if_debug (ValidateParameters (data, sectorCount, sectorSize));
+
+		EncryptBuffer (data,
+			sectorCount * sectorSize,
+			SectorToBlockIndex (sectorIndex));
+	}
+
+	void EncryptionModeLRW::IncrementBlockIndex (byte *index) const
+	{
+		if (index[7] != 0xff)
+			index[7]++;
+		else
+			*(uint64 *)index = Endian::Big ( Endian::Big (*(uint64 *)index) + 1 );
+	}
+
+	uint64 EncryptionModeLRW::SectorToBlockIndex (uint64 sectorIndex) const
+	{
+		sectorIndex -= SectorOffset;
+
+		switch (Ciphers.front()->GetBlockSize())
+		{
+		case 8:
+			return (sectorIndex << 6) | 1;
+
+		case 16:
+			return (sectorIndex << 5) | 1;
+		
+		default:
+			throw ParameterIncorrect (SRC_POS);
+		}
+	}
+
+	void EncryptionModeLRW::SetKey (const ConstBufferPtr &key)
+	{
+		if (key.Size() != 16)
+			throw ParameterIncorrect (SRC_POS);
+
+		if (!KeySet)
+			GfContext.Allocate (sizeof (GfCtx));
+
+		if (!Gf64TabInit ((unsigned char *) key.Get(), (GfCtx *) (GfContext.Ptr())))
+			throw bad_alloc();
+
+		if (!Gf128Tab64Init ((unsigned char *) key.Get(), (GfCtx *) (GfContext.Ptr())))
+			throw bad_alloc();
+
+		Key.CopyFrom (key);
+		KeySet = true;
+	}
+
+	void EncryptionModeLRW::Xor64 (uint64 *a, const uint64 *b) const
+	{
+		*a ^= *b;
+	}
+
+	void EncryptionModeLRW::Xor128 (uint64 *a, const uint64 *b) const
+	{
+		*a++ ^= *b++;
+		*a ^= *b;
+	}
+}
-- 
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