From f5606a44a6331715e9a8a43d6f4441f0cd89cb3a Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@idrix.fr>
Date: Thu, 14 Apr 2016 08:52:06 +0200
Subject: Windows: Finalize implementation of the new volume ID mechanism. Use
 SHA-256 instead of SHA-512 to compute volume ID to reduce string size and
 make more convenient to use.

---
 src/Driver/Ntdriver.c | 14 +++++++-------
 src/Driver/Ntdriver.h |  2 +-
 src/Driver/Ntvol.c    |  2 +-
 3 files changed, 9 insertions(+), 9 deletions(-)

(limited to 'src/Driver')

diff --git a/src/Driver/Ntdriver.c b/src/Driver/Ntdriver.c
index cd3309d2..eeea7815 100644
--- a/src/Driver/Ntdriver.c
+++ b/src/Driver/Ntdriver.c
@@ -1049,7 +1049,7 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
 						if (opentest->bMatchVolumeID)
 						{
 							int volumeType;
-							BYTE volumeID[SHA512_DIGEST_SIZE];
+							BYTE volumeID[VOLUME_ID_SIZE];
 
 							// Go through all volume types (e.g., normal, hidden)
 							for (volumeType = TC_VOLUME_TYPE_NORMAL;
@@ -1069,7 +1069,7 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
 									break;
 								}
 
-								ntStatus = ZwReadFile (Extension->hDeviceFile,
+								ntStatus = ZwReadFile (NtFileHandle,
 								NULL,
 								NULL,
 								NULL,
@@ -1081,10 +1081,10 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
 
 								if (NT_SUCCESS (ntStatus))
 								{
-									/* compute the ID of this volume: SHA-512 of the effective header */
-									sha512 (volumeID, readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE);
+									/* compute the ID of this volume: SHA-256 of the effective header */
+									sha256 (volumeID, readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE);
 
-									if (0 == memcmp (volumeID, opentest->volumeID, SHA512_DIGEST_SIZE))
+									if (0 == memcmp (volumeID, opentest->volumeID, VOLUME_ID_SIZE))
 									{
 										opentest->VolumeIDMatched = TRUE;
 										break;
@@ -1265,7 +1265,7 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
 					list->ulMountedDrives |= (1 << ListExtension->nDosDriveNo);
 					RtlStringCbCopyW (list->wszVolume[ListExtension->nDosDriveNo], sizeof(list->wszVolume[ListExtension->nDosDriveNo]),ListExtension->wszVolume);
 					RtlStringCbCopyW (list->wszLabel[ListExtension->nDosDriveNo], sizeof(list->wszLabel[ListExtension->nDosDriveNo]),ListExtension->wszLabel);
-					memcpy (list->volumeID[ListExtension->nDosDriveNo], ListExtension->volumeID, SHA512_DIGEST_SIZE);
+					memcpy (list->volumeID[ListExtension->nDosDriveNo], ListExtension->volumeID, VOLUME_ID_SIZE);
 					list->diskLength[ListExtension->nDosDriveNo] = ListExtension->DiskLength;
 					list->ea[ListExtension->nDosDriveNo] = ListExtension->cryptoInfo->ea;
 					if (ListExtension->cryptoInfo->hiddenVolume)
@@ -1317,7 +1317,7 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
 					prop->uniqueId = ListExtension->UniqueVolumeId;
 					RtlStringCbCopyW (prop->wszVolume, sizeof(prop->wszVolume),ListExtension->wszVolume);
 					RtlStringCbCopyW (prop->wszLabel, sizeof(prop->wszLabel),ListExtension->wszLabel);
-					memcpy (prop->volumeID, ListExtension->volumeID, SHA512_DIGEST_SIZE);
+					memcpy (prop->volumeID, ListExtension->volumeID, VOLUME_ID_SIZE);
 					prop->bDriverSetLabel = ListExtension->bDriverSetLabel;
 					prop->diskLength = ListExtension->DiskLength;
 					prop->ea = ListExtension->cryptoInfo->ea;
diff --git a/src/Driver/Ntdriver.h b/src/Driver/Ntdriver.h
index ae91f3af..59634760 100644
--- a/src/Driver/Ntdriver.h
+++ b/src/Driver/Ntdriver.h
@@ -81,7 +81,7 @@ typedef struct EXTENSION
 	BOOL bIsNTFS;
 	BOOL bDriverSetLabel;
 
-	unsigned char volumeID[SHA512_DIGESTSIZE];
+	unsigned char volumeID[VOLUME_ID_SIZE];
 
 	LARGE_INTEGER fileCreationTime;
 	LARGE_INTEGER fileLastAccessTime;
diff --git a/src/Driver/Ntvol.c b/src/Driver/Ntvol.c
index 317e3653..4f35323b 100644
--- a/src/Driver/Ntvol.c
+++ b/src/Driver/Ntvol.c
@@ -518,7 +518,7 @@ NTSTATUS TCOpenVolume (PDEVICE_OBJECT DeviceObject,
 			Extension->cryptoInfo->bPartitionInInactiveSysEncScope = mount->bPartitionInInactiveSysEncScope;
 
 			/* compute the ID of this volume: SHA-512 of the effective header */
-			sha512 (Extension->volumeID, readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE);
+			sha256 (Extension->volumeID, readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE);
 
 			if (volumeType == TC_VOLUME_TYPE_NORMAL)
 			{
-- 
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