From 7ffce028d04a6b13ef762e2b89c34b688e8ca59d Mon Sep 17 00:00:00 2001 From: Mounir IDRASSI Date: Sat, 31 May 2014 18:44:53 +0200 Subject: Add TrueCrypt 7.1a MacOSX/Linux specific source files. --- src/Volume/EncryptionModeXTS.cpp | 374 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 374 insertions(+) create mode 100644 src/Volume/EncryptionModeXTS.cpp (limited to 'src/Volume/EncryptionModeXTS.cpp') diff --git a/src/Volume/EncryptionModeXTS.cpp b/src/Volume/EncryptionModeXTS.cpp new file mode 100644 index 00000000..8073f3ca --- /dev/null +++ b/src/Volume/EncryptionModeXTS.cpp @@ -0,0 +1,374 @@ +/* + Copyright (c) 2008-2010 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 "EncryptionModeXTS.h" +#include "Common/Crypto.h" + +namespace TrueCrypt +{ + void EncryptionModeXTS::Encrypt (byte *data, uint64 length) const + { + EncryptBuffer (data, length, 0); + } + + void EncryptionModeXTS::EncryptBuffer (byte *data, uint64 length, uint64 startDataUnitNo) const + { + if_debug (ValidateState()); + + CipherList::const_iterator iSecondaryCipher = SecondaryCiphers.begin(); + + for (CipherList::const_iterator iCipher = Ciphers.begin(); iCipher != Ciphers.end(); ++iCipher) + { + EncryptBufferXTS (**iCipher, **iSecondaryCipher, data, length, startDataUnitNo, 0); + ++iSecondaryCipher; + } + + assert (iSecondaryCipher == SecondaryCiphers.end()); + } + + void EncryptionModeXTS::EncryptBufferXTS (const Cipher &cipher, const Cipher &secondaryCipher, byte *buffer, uint64 length, uint64 startDataUnitNo, unsigned int startCipherBlockNo) const + { + byte finalCarry; + byte whiteningValues [ENCRYPTION_DATA_UNIT_SIZE]; + byte whiteningValue [BYTES_PER_XTS_BLOCK]; + byte byteBufUnitNo [BYTES_PER_XTS_BLOCK]; + uint64 *whiteningValuesPtr64 = (uint64 *) whiteningValues; + uint64 *whiteningValuePtr64 = (uint64 *) whiteningValue; + uint64 *bufPtr = (uint64 *) buffer; + uint64 *dataUnitBufPtr; + unsigned int startBlock = startCipherBlockNo, endBlock, block; + uint64 *const finalInt64WhiteningValuesPtr = whiteningValuesPtr64 + sizeof (whiteningValues) / sizeof (*whiteningValuesPtr64) - 1; + uint64 blockCount, dataUnitNo; + + startDataUnitNo += SectorOffset; + + /* The encrypted data unit number (i.e. the resultant ciphertext block) is to be multiplied in the + finite field GF(2^128) by j-th power of n, where j is the sequential plaintext/ciphertext block + number and n is 2, a primitive element of GF(2^128). This can be (and is) simplified and implemented + as a left shift of the preceding whitening value by one bit (with carry propagating). In addition, if + the shift of the highest byte results in a carry, 135 is XORed into the lowest byte. The value 135 is + derived from the modulus of the Galois Field (x^128+x^7+x^2+x+1). */ + + // Convert the 64-bit data unit number into a little-endian 16-byte array. + // Note that as we are converting a 64-bit number into a 16-byte array we can always zero the last 8 bytes. + dataUnitNo = startDataUnitNo; + *((uint64 *) byteBufUnitNo) = Endian::Little (dataUnitNo); + *((uint64 *) byteBufUnitNo + 1) = 0; + + if (length % BYTES_PER_XTS_BLOCK) + TC_THROW_FATAL_EXCEPTION; + + blockCount = length / BYTES_PER_XTS_BLOCK; + + // Process all blocks in the buffer + while (blockCount > 0) + { + if (blockCount < BLOCKS_PER_XTS_DATA_UNIT) + endBlock = startBlock + (unsigned int) blockCount; + else + endBlock = BLOCKS_PER_XTS_DATA_UNIT; + + whiteningValuesPtr64 = finalInt64WhiteningValuesPtr; + whiteningValuePtr64 = (uint64 *) whiteningValue; + + // Encrypt the data unit number using the secondary key (in order to generate the first + // whitening value for this data unit) + *whiteningValuePtr64 = *((uint64 *) byteBufUnitNo); + *(whiteningValuePtr64 + 1) = 0; + secondaryCipher.EncryptBlock (whiteningValue); + + // Generate subsequent whitening values for blocks in this data unit. Note that all generated 128-bit + // whitening values are stored in memory as a sequence of 64-bit integers in reverse order. + for (block = 0; block < endBlock; block++) + { + if (block >= startBlock) + { + *whiteningValuesPtr64-- = *whiteningValuePtr64++; + *whiteningValuesPtr64-- = *whiteningValuePtr64; + } + else + whiteningValuePtr64++; + + // Derive the next whitening value + +#if BYTE_ORDER == LITTLE_ENDIAN + + // Little-endian platforms + + finalCarry = + (*whiteningValuePtr64 & 0x8000000000000000ULL) ? + 135 : 0; + + *whiteningValuePtr64-- <<= 1; + + if (*whiteningValuePtr64 & 0x8000000000000000ULL) + *(whiteningValuePtr64 + 1) |= 1; + + *whiteningValuePtr64 <<= 1; +#else + + // Big-endian platforms + + finalCarry = + (*whiteningValuePtr64 & 0x80) ? + 135 : 0; + + *whiteningValuePtr64 = Endian::Little (Endian::Little (*whiteningValuePtr64) << 1); + + whiteningValuePtr64--; + + if (*whiteningValuePtr64 & 0x80) + *(whiteningValuePtr64 + 1) |= 0x0100000000000000ULL; + + *whiteningValuePtr64 = Endian::Little (Endian::Little (*whiteningValuePtr64) << 1); +#endif + + whiteningValue[0] ^= finalCarry; + } + + dataUnitBufPtr = bufPtr; + whiteningValuesPtr64 = finalInt64WhiteningValuesPtr; + + // Encrypt all blocks in this data unit + + for (block = startBlock; block < endBlock; block++) + { + // Pre-whitening + *bufPtr++ ^= *whiteningValuesPtr64--; + *bufPtr++ ^= *whiteningValuesPtr64--; + } + + // Actual encryption + cipher.EncryptBlocks ((byte *) dataUnitBufPtr, endBlock - startBlock); + + bufPtr = dataUnitBufPtr; + whiteningValuesPtr64 = finalInt64WhiteningValuesPtr; + + for (block = startBlock; block < endBlock; block++) + { + // Post-whitening + *bufPtr++ ^= *whiteningValuesPtr64--; + *bufPtr++ ^= *whiteningValuesPtr64--; + } + + blockCount -= endBlock - startBlock; + startBlock = 0; + dataUnitNo++; + *((uint64 *) byteBufUnitNo) = Endian::Little (dataUnitNo); + } + + FAST_ERASE64 (whiteningValue, sizeof (whiteningValue)); + FAST_ERASE64 (whiteningValues, sizeof (whiteningValues)); + } + + void EncryptionModeXTS::EncryptSectorsCurrentThread (byte *data, uint64 sectorIndex, uint64 sectorCount, size_t sectorSize) const + { + EncryptBuffer (data, sectorCount * sectorSize, sectorIndex * sectorSize / ENCRYPTION_DATA_UNIT_SIZE); + } + + size_t EncryptionModeXTS::GetKeySize () const + { + if (Ciphers.empty()) + throw NotInitialized (SRC_POS); + + size_t keySize = 0; + foreach_ref (const Cipher &cipher, SecondaryCiphers) + { + keySize += cipher.GetKeySize(); + } + + return keySize; + } + + void EncryptionModeXTS::Decrypt (byte *data, uint64 length) const + { + DecryptBuffer (data, length, 0); + } + + void EncryptionModeXTS::DecryptBuffer (byte *data, uint64 length, uint64 startDataUnitNo) const + { + if_debug (ValidateState()); + + CipherList::const_iterator iSecondaryCipher = SecondaryCiphers.end(); + + for (CipherList::const_reverse_iterator iCipher = Ciphers.rbegin(); iCipher != Ciphers.rend(); ++iCipher) + { + --iSecondaryCipher; + DecryptBufferXTS (**iCipher, **iSecondaryCipher, data, length, startDataUnitNo, 0); + } + + assert (iSecondaryCipher == SecondaryCiphers.begin()); + } + + void EncryptionModeXTS::DecryptBufferXTS (const Cipher &cipher, const Cipher &secondaryCipher, byte *buffer, uint64 length, uint64 startDataUnitNo, unsigned int startCipherBlockNo) const + { + byte finalCarry; + byte whiteningValues [ENCRYPTION_DATA_UNIT_SIZE]; + byte whiteningValue [BYTES_PER_XTS_BLOCK]; + byte byteBufUnitNo [BYTES_PER_XTS_BLOCK]; + uint64 *whiteningValuesPtr64 = (uint64 *) whiteningValues; + uint64 *whiteningValuePtr64 = (uint64 *) whiteningValue; + uint64 *bufPtr = (uint64 *) buffer; + uint64 *dataUnitBufPtr; + unsigned int startBlock = startCipherBlockNo, endBlock, block; + uint64 *const finalInt64WhiteningValuesPtr = whiteningValuesPtr64 + sizeof (whiteningValues) / sizeof (*whiteningValuesPtr64) - 1; + uint64 blockCount, dataUnitNo; + + startDataUnitNo += SectorOffset; + + // Convert the 64-bit data unit number into a little-endian 16-byte array. + // Note that as we are converting a 64-bit number into a 16-byte array we can always zero the last 8 bytes. + dataUnitNo = startDataUnitNo; + *((uint64 *) byteBufUnitNo) = Endian::Little (dataUnitNo); + *((uint64 *) byteBufUnitNo + 1) = 0; + + if (length % BYTES_PER_XTS_BLOCK) + TC_THROW_FATAL_EXCEPTION; + + blockCount = length / BYTES_PER_XTS_BLOCK; + + // Process all blocks in the buffer + while (blockCount > 0) + { + if (blockCount < BLOCKS_PER_XTS_DATA_UNIT) + endBlock = startBlock + (unsigned int) blockCount; + else + endBlock = BLOCKS_PER_XTS_DATA_UNIT; + + whiteningValuesPtr64 = finalInt64WhiteningValuesPtr; + whiteningValuePtr64 = (uint64 *) whiteningValue; + + // Encrypt the data unit number using the secondary key (in order to generate the first + // whitening value for this data unit) + *whiteningValuePtr64 = *((uint64 *) byteBufUnitNo); + *(whiteningValuePtr64 + 1) = 0; + secondaryCipher.EncryptBlock (whiteningValue); + + // Generate subsequent whitening values for blocks in this data unit. Note that all generated 128-bit + // whitening values are stored in memory as a sequence of 64-bit integers in reverse order. + for (block = 0; block < endBlock; block++) + { + if (block >= startBlock) + { + *whiteningValuesPtr64-- = *whiteningValuePtr64++; + *whiteningValuesPtr64-- = *whiteningValuePtr64; + } + else + whiteningValuePtr64++; + + // Derive the next whitening value + +#if BYTE_ORDER == LITTLE_ENDIAN + + // Little-endian platforms + + finalCarry = + (*whiteningValuePtr64 & 0x8000000000000000ULL) ? + 135 : 0; + + *whiteningValuePtr64-- <<= 1; + + if (*whiteningValuePtr64 & 0x8000000000000000ULL) + *(whiteningValuePtr64 + 1) |= 1; + + *whiteningValuePtr64 <<= 1; + +#else + // Big-endian platforms + + finalCarry = + (*whiteningValuePtr64 & 0x80) ? + 135 : 0; + + *whiteningValuePtr64 = Endian::Little (Endian::Little (*whiteningValuePtr64) << 1); + + whiteningValuePtr64--; + + if (*whiteningValuePtr64 & 0x80) + *(whiteningValuePtr64 + 1) |= 0x0100000000000000ULL; + + *whiteningValuePtr64 = Endian::Little (Endian::Little (*whiteningValuePtr64) << 1); +#endif + + whiteningValue[0] ^= finalCarry; + } + + dataUnitBufPtr = bufPtr; + whiteningValuesPtr64 = finalInt64WhiteningValuesPtr; + + // Decrypt blocks in this data unit + + for (block = startBlock; block < endBlock; block++) + { + *bufPtr++ ^= *whiteningValuesPtr64--; + *bufPtr++ ^= *whiteningValuesPtr64--; + } + + cipher.DecryptBlocks ((byte *) dataUnitBufPtr, endBlock - startBlock); + + bufPtr = dataUnitBufPtr; + whiteningValuesPtr64 = finalInt64WhiteningValuesPtr; + + for (block = startBlock; block < endBlock; block++) + { + *bufPtr++ ^= *whiteningValuesPtr64--; + *bufPtr++ ^= *whiteningValuesPtr64--; + } + + blockCount -= endBlock - startBlock; + startBlock = 0; + dataUnitNo++; + + *((uint64 *) byteBufUnitNo) = Endian::Little (dataUnitNo); + } + + FAST_ERASE64 (whiteningValue, sizeof (whiteningValue)); + FAST_ERASE64 (whiteningValues, sizeof (whiteningValues)); + } + + void EncryptionModeXTS::DecryptSectorsCurrentThread (byte *data, uint64 sectorIndex, uint64 sectorCount, size_t sectorSize) const + { + DecryptBuffer (data, sectorCount * sectorSize, sectorIndex * sectorSize / ENCRYPTION_DATA_UNIT_SIZE); + } + + void EncryptionModeXTS::SetCiphers (const CipherList &ciphers) + { + EncryptionMode::SetCiphers (ciphers); + + SecondaryCiphers.clear(); + + foreach_ref (const Cipher &cipher, ciphers) + { + SecondaryCiphers.push_back (cipher.GetNew()); + } + + if (SecondaryKey.Size() > 0) + SetSecondaryCipherKeys(); + } + + void EncryptionModeXTS::SetKey (const ConstBufferPtr &key) + { + SecondaryKey.Allocate (key.Size()); + SecondaryKey.CopyFrom (key); + + if (!SecondaryCiphers.empty()) + SetSecondaryCipherKeys(); + } + + void EncryptionModeXTS::SetSecondaryCipherKeys () + { + size_t keyOffset = 0; + foreach_ref (Cipher &cipher, SecondaryCiphers) + { + cipher.SetKey (SecondaryKey.GetRange (keyOffset, cipher.GetKeySize())); + keyOffset += cipher.GetKeySize(); + } + + KeySet = true; + } +} -- cgit v1.2.3