--- truecrypt/boot/windows/bootencryptedio.cpp	2018/04/24 16:49:04	1.1
+++ truecrypt/boot/windows/bootencryptedio.cpp	2018/04/24 17:03:46	1.1.1.5
@@ -1,16 +1,16 @@
 /*
  Copyright (c) 2008 TrueCrypt Foundation. All rights reserved.
 
- Governed by the TrueCrypt License 2.4 the full text of which is contained
+ Governed by the TrueCrypt License 2.7 the full text of which is contained
  in the file License.txt included in TrueCrypt binary and source code
  distribution packages.
 */
 
 #include "Crypto.h"
 #include "Platform.h"
-#include "Bios.h"
 #include "BootConfig.h"
 #include "BootDebug.h"
+#include "BootDefs.h"
 #include "BootDiskIo.h"
 #include "BootEncryptedIo.h"
 
@@ -18,24 +18,54 @@
 BiosResult ReadEncryptedSectors (uint16 destSegment, uint16 destOffset, byte drive, uint64 sector, uint16 sectorCount)
 {
 	BiosResult result;
-	byte sectorBuf[TC_LB_SIZE];
+	bool decrypt = true;
 
-	while (sectorCount-- > 0)
+	if (BootCryptoInfo->hiddenVolume)
 	{
-		result = ReadSectors (sectorBuf, drive, sector, 1);
-
-		if (result != BiosResultSuccess)
-			return result;
+		if (ReadWritePartiallyCoversEncryptedArea (sector, sectorCount))
+			return BiosResultInvalidFunction;
 
-		if (drive == EncryptedVirtualPartition.Drive && sector >= EncryptedVirtualPartition.StartSector && sector <= EncryptedVirtualPartition.EndSector)
+		if (sector >= EncryptedVirtualPartition.StartSector && sector <= EncryptedVirtualPartition.EndSector)
 		{
-			DecryptDataUnits (sectorBuf, &sector, 1, BootCryptoInfo);
+			// Remap the request to the hidden volume
+			sector -= EncryptedVirtualPartition.StartSector;
+			sector += HiddenVolumeStartSector;
 		}
+		else
+			decrypt = false;
+	}
 
-		CopyMemory (sectorBuf, destSegment, destOffset, sizeof (sectorBuf));
+	result = ReadSectors (destSegment, destOffset, drive, sector, sectorCount);
 
-		++sector;
-		destOffset += sizeof (sectorBuf);
+	if (result != BiosResultSuccess || !decrypt)
+		return result;
+
+	if (BootCryptoInfo->hiddenVolume)
+	{
+		// Convert sector number to data unit number of the hidden volume
+		sector -= HiddenVolumeStartSector;
+		sector += HiddenVolumeStartUnitNo;
+	}
+
+	if (drive == EncryptedVirtualPartition.Drive)
+	{
+		while (sectorCount-- > 0)
+		{
+			if (BootCryptoInfo->hiddenVolume
+				|| (sector >= EncryptedVirtualPartition.StartSector && sector <= EncryptedVirtualPartition.EndSector))
+			{
+				AcquireSectorBuffer();
+				CopyMemory (destSegment, destOffset, SectorBuffer, TC_LB_SIZE);
+
+				DecryptDataUnits (SectorBuffer, &sector, 1, BootCryptoInfo);
+
+				CopyMemory (SectorBuffer, destSegment, destOffset, TC_LB_SIZE);
+				ReleaseSectorBuffer();
+			}
+
+			++sector;
+			destOffset += TC_LB_SIZE;
+		}
 	}
 
 	return result;
@@ -45,25 +75,54 @@ BiosResult ReadEncryptedSectors (uint16
 BiosResult WriteEncryptedSectors (uint16 sourceSegment, uint16 sourceOffset, byte drive, uint64 sector, uint16 sectorCount)
 {
 	BiosResult result;
-	byte sectorBuf[TC_LB_SIZE];
+	AcquireSectorBuffer();
+	uint64 dataUnitNo;
+	uint64 writeOffset;
+
+	dataUnitNo = sector;
+	writeOffset.HighPart = 0;
+	writeOffset.LowPart = 0;
+
+	if (BootCryptoInfo->hiddenVolume)
+	{
+		if (ReadWritePartiallyCoversEncryptedArea (sector, sectorCount))
+			return BiosResultInvalidFunction;
+
+		// Remap the request to the hidden volume
+		writeOffset = HiddenVolumeStartSector;
+		writeOffset -= EncryptedVirtualPartition.StartSector;
+		dataUnitNo -= EncryptedVirtualPartition.StartSector;
+		dataUnitNo += HiddenVolumeStartUnitNo;
+	}
 
 	while (sectorCount-- > 0)
 	{
-		CopyMemory (sourceSegment, sourceOffset, sectorBuf, sizeof (sectorBuf));
+		CopyMemory (sourceSegment, sourceOffset, SectorBuffer, TC_LB_SIZE);
 
 		if (drive == EncryptedVirtualPartition.Drive && sector >= EncryptedVirtualPartition.StartSector && sector <= EncryptedVirtualPartition.EndSector)
 		{
-			EncryptDataUnits (sectorBuf, &sector, 1, BootCryptoInfo);
+			EncryptDataUnits (SectorBuffer, &dataUnitNo, 1, BootCryptoInfo);
 		}
 
-		result = WriteSectors (sectorBuf, drive, sector, 1);
+		result = WriteSectors (SectorBuffer, drive, sector + writeOffset, 1);
 
 		if (result != BiosResultSuccess)
-			return result;
+			break;
 
 		++sector;
-		sourceOffset += sizeof (sectorBuf);
+		++dataUnitNo;
+		sourceOffset += TC_LB_SIZE;
 	}
 
+	ReleaseSectorBuffer();
 	return result;
 }
+
+
+static bool ReadWritePartiallyCoversEncryptedArea (const uint64 &sector, uint16 sectorCount)
+{
+	uint64 readWriteEnd = sector + --sectorCount;
+
+	return ((sector < EncryptedVirtualPartition.StartSector && readWriteEnd >= EncryptedVirtualPartition.StartSector)
+		|| (sector >= EncryptedVirtualPartition.StartSector && readWriteEnd > EncryptedVirtualPartition.EndSector));
+}