/*
 Legal Notice: Some portions of the source code contained in this file were
 derived from the source code of Encryption for the Masses 2.02a, which is
 Copyright (c) 1998-2000 Paul Le Roux and which is governed by the 'License
 Agreement for Encryption for the Masses'. Modifications and additions to
 the original source code (contained in this file) and all other portions of
 this file are Copyright (c) 2003-2008 TrueCrypt Foundation and are governed
 by the TrueCrypt License 2.5 the full text of which is contained in the
 file License.txt included in TrueCrypt binary and source code distribution
 packages. */

#include "Tcdefs.h"

#ifndef TC_WINDOWS_BOOT
#include <fcntl.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include "EncryptionThreadPool.h"
#endif

#include <io.h>
#include "Random.h"

#include "Crc.h"
#include "Crypto.h"
#include "Common/Endian.h"
#include "Volumes.h"
#include "Pkcs5.h"


/* Volume header v4 structure: */
//
// Offset	Length	Description
// ------------------------------------------
// Unencrypted:
// 0		64		Salt
// Encrypted:
// 64		4		ASCII string 'TRUE'
// 68		2		Header version
// 70		2		Required program version
// 72		4		CRC-32 checksum of the (decrypted) bytes 256-511
// 76		8		Reserved (set to zero)
// 84		8		Reserved (set to zero)
// 92		8		Size of hidden volume in bytes (0 = normal volume)
// 100		8		Size of the volume in bytes (identical with field 92 for hidden volumes)
// 108		8		Byte offset of the start of the master key scope
// 116		8		Size of the encrypted area within the master key scope
// 124		4		Flags: bit 0 set = system encryption; bits 1-31 are reserved
// 128		124		Reserved (set to zero)
// 252		4		CRC-32 checksum of the (decrypted) bytes 64-251
// 256		256		Concatenated primary master key(s) and secondary master key(s) (XTS mode)
// 512		65024	Reserved


/* Volume header v3 structure (used by TrueCrypt 5.x): */
//
// Offset	Length	Description
// ------------------------------------------
// Unencrypted:
// 0		64		Salt
// Encrypted:
// 64		4		ASCII string 'TRUE'
// 68		2		Header version
// 70		2		Required program version
// 72		4		CRC-32 checksum of the (decrypted) bytes 256-511
// 76		8		Volume creation time
// 84		8		Header creation time
// 92		8		Size of hidden volume in bytes (0 = normal volume)
// 100		8		Size of the volume in bytes (identical with field 92 for hidden volumes)
// 108		8		Start byte offset of the encrypted area of the volume
// 116		8		Size of the encrypted area of the volume in bytes
// 124		132		Reserved (set to zero)
// 256		256		Concatenated primary master key(s) and secondary master key(s) (XTS mode)


/* Deprecated/legacy volume header v2 structure (used before TrueCrypt 5.0): */
//
// Offset	Length	Description
// ------------------------------------------
// Unencrypted:
// 0		64		Salt
// Encrypted:
// 64		4		ASCII string 'TRUE'
// 68		2		Header version
// 70		2		Required program version
// 72		4		CRC-32 checksum of the (decrypted) bytes 256-511
// 76		8		Volume creation time
// 84		8		Header creation time
// 92		8		Size of hidden volume in bytes (0 = normal volume)
// 100		156		Reserved (set to zero)
// 256		32		For LRW (deprecated/legacy), secondary key
//					For CBC (deprecated/legacy), data used to generate IV and whitening values
// 288		224		Master key(s)



uint16 GetHeaderField16 (byte *header, size_t offset)
{
	return BE16 (*(uint16 *) (header + offset));
}


uint32 GetHeaderField32 (byte *header, size_t offset)
{
	return BE32 (*(uint32 *) (header + offset));
}


UINT64_STRUCT GetHeaderField64 (byte *header, size_t offset)
{
	UINT64_STRUCT uint64Struct;

#ifndef TC_NO_COMPILER_INT64
	uint64Struct.Value = BE64 (*(uint64 *) (header + offset));
#else
	uint64Struct.HighPart = BE32 (*(uint32 *) (header + offset));
	uint64Struct.LowPart = BE32 (*(uint32 *) (header + offset + 4));
#endif
	return uint64Struct;
}


#ifndef TC_WINDOWS_BOOT

typedef struct
{
	char DerivedKey[MASTER_KEYDATA_SIZE];
	BOOL Free;
	LONG KeyReady;
	int Pkcs5Prf;
} KeyDerivationWorkItem;


int VolumeReadHeader (BOOL bBoot, char *encryptedHeader, Password *password, PCRYPTO_INFO *retInfo, CRYPTO_INFO *retHeaderCryptoInfo)
{
	char header[TC_VOLUME_HEADER_EFFECTIVE_SIZE];
	KEY_INFO keyInfo;
	PCRYPTO_INFO cryptoInfo;
	char dk[MASTER_KEYDATA_SIZE];
	int enqPkcs5Prf, pkcs5_prf;
	int headerVersion;
	int status;
	int primaryKeyOffset;

	TC_EVENT keyDerivationCompletedEvent;
	TC_EVENT noOutstandingWorkItemEvent;
	KeyDerivationWorkItem *keyDerivationWorkItems;
	KeyDerivationWorkItem *item;
	int pkcs5PrfCount = LAST_PRF_ID - FIRST_PRF_ID + 1;
	int encryptionThreadCount = GetEncryptionThreadCount();
	int queuedWorkItems = 0;
	LONG outstandingWorkItemCount = 0;
	int i;

	if (retHeaderCryptoInfo != NULL)
	{
		cryptoInfo = retHeaderCryptoInfo;
	}
	else
	{
		cryptoInfo = *retInfo = crypto_open ();
		if (cryptoInfo == NULL)
			return ERR_OUTOFMEMORY;
	}

	if (encryptionThreadCount > 1)
	{
		keyDerivationWorkItems = TCalloc (sizeof (KeyDerivationWorkItem) * pkcs5PrfCount);
		if (!keyDerivationWorkItems)
			return ERR_OUTOFMEMORY;

		for (i = 0; i < pkcs5PrfCount; ++i)
			keyDerivationWorkItems[i].Free = TRUE;

#ifdef DEVICE_DRIVER
		KeInitializeEvent (&keyDerivationCompletedEvent, SynchronizationEvent, FALSE);
		KeInitializeEvent (&noOutstandingWorkItemEvent, SynchronizationEvent, TRUE);
#else
		keyDerivationCompletedEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
		if (!keyDerivationCompletedEvent)
		{
			TCfree (keyDerivationWorkItems);
			return ERR_OUTOFMEMORY;
		}

		noOutstandingWorkItemEvent = CreateEvent (NULL, FALSE, TRUE, NULL);
		if (!noOutstandingWorkItemEvent)
		{
			CloseHandle (keyDerivationCompletedEvent);
			TCfree (keyDerivationWorkItems);
			return ERR_OUTOFMEMORY;
		}
#endif
	}
		
#ifndef DEVICE_DRIVER
	VirtualLock (&keyInfo, sizeof (keyInfo));
	VirtualLock (&dk, sizeof (dk));
#endif

	crypto_loadkey (&keyInfo, password->Text, (int) password->Length);

	// PKCS5 is used to derive the primary header key(s) and secondary header key(s) (XTS mode) from the password
	memcpy (keyInfo.salt, encryptedHeader + HEADER_SALT_OFFSET, PKCS5_SALT_SIZE);

	// Test all available PKCS5 PRFs
	for (enqPkcs5Prf = FIRST_PRF_ID; enqPkcs5Prf <= LAST_PRF_ID || queuedWorkItems > 0; ++enqPkcs5Prf)
	{
		BOOL lrw64InitDone = FALSE;		// Deprecated/legacy
		BOOL lrw128InitDone = FALSE;	// Deprecated/legacy

		if (encryptionThreadCount > 1)
		{
			// Enqueue key derivation on thread pool
			if (queuedWorkItems < encryptionThreadCount && enqPkcs5Prf <= LAST_PRF_ID)
			{
				for (i = 0; i < pkcs5PrfCount; ++i)
				{
					item = &keyDerivationWorkItems[i];
					if (item->Free)
					{
						item->Free = FALSE;
						item->KeyReady = FALSE;
						item->Pkcs5Prf = enqPkcs5Prf;

						EncryptionThreadPoolBeginKeyDerivation (&keyDerivationCompletedEvent, &noOutstandingWorkItemEvent,
							&item->KeyReady, &outstandingWorkItemCount, enqPkcs5Prf, keyInfo.userKey,
							keyInfo.keyLength, keyInfo.salt, get_pkcs5_iteration_count (enqPkcs5Prf, bBoot), item->DerivedKey);
						
						++queuedWorkItems;
						break;
					}
				}

				if (enqPkcs5Prf < LAST_PRF_ID)
					continue;
			}
			else
				--enqPkcs5Prf;

			// Wait for completion of a key derivation
			while (queuedWorkItems > 0)
			{
				for (i = 0; i < pkcs5PrfCount; ++i)
				{
					item = &keyDerivationWorkItems[i];
					if (!item->Free && InterlockedExchangeAdd (&item->KeyReady, 0) == TRUE)
					{
						pkcs5_prf = item->Pkcs5Prf;
						keyInfo.noIterations = get_pkcs5_iteration_count (pkcs5_prf, bBoot);
						memcpy (dk, item->DerivedKey, sizeof (dk));

						item->Free = TRUE;
						--queuedWorkItems;
						goto KeyReady;
					}
				}

				if (queuedWorkItems > 0)
					TC_WAIT_EVENT (keyDerivationCompletedEvent);
			}
			continue;
KeyReady:	;
		}
		else
		{
			pkcs5_prf = enqPkcs5Prf;
			keyInfo.noIterations = get_pkcs5_iteration_count (enqPkcs5Prf, bBoot);

			switch (pkcs5_prf)
			{
			case RIPEMD160:
				derive_key_ripemd160 (keyInfo.userKey, keyInfo.keyLength, keyInfo.salt,
					PKCS5_SALT_SIZE, keyInfo.noIterations, dk, GetMaxPkcs5OutSize());
				break;

			case SHA512:
				derive_key_sha512 (keyInfo.userKey, keyInfo.keyLength, keyInfo.salt,
					PKCS5_SALT_SIZE, keyInfo.noIterations, dk, GetMaxPkcs5OutSize());
				break;

			case SHA1:
				// Deprecated/legacy
				derive_key_sha1 (keyInfo.userKey, keyInfo.keyLength, keyInfo.salt,
					PKCS5_SALT_SIZE, keyInfo.noIterations, dk, GetMaxPkcs5OutSize());
				break;

			case WHIRLPOOL:
				derive_key_whirlpool (keyInfo.userKey, keyInfo.keyLength, keyInfo.salt,
					PKCS5_SALT_SIZE, keyInfo.noIterations, dk, GetMaxPkcs5OutSize());
				break;

			default:		
				// Unknown/wrong ID
				TC_THROW_FATAL_EXCEPTION;
			} 
		}

		// Test all available modes of operation
		for (cryptoInfo->mode = FIRST_MODE_OF_OPERATION_ID;
			cryptoInfo->mode <= LAST_MODE_OF_OPERATION;
			cryptoInfo->mode++)
		{
			switch (cryptoInfo->mode)
			{
			case LRW:
			case CBC:
			case INNER_CBC:
			case OUTER_CBC:

				// For LRW (deprecated/legacy), copy the tweak key 
				// For CBC (deprecated/legacy), copy the IV/whitening seed 
				memcpy (cryptoInfo->k2, dk, LEGACY_VOL_IV_SIZE);
				primaryKeyOffset = LEGACY_VOL_IV_SIZE;
				break;

			default:
				primaryKeyOffset = 0;
			}

			// Test all available encryption algorithms
			for (cryptoInfo->ea = EAGetFirst ();
				cryptoInfo->ea != 0;
				cryptoInfo->ea = EAGetNext (cryptoInfo->ea))
			{
				int blockSize;

				if (!EAIsModeSupported (cryptoInfo->ea, cryptoInfo->mode))
					continue;	// This encryption algorithm has never been available with this mode of operation

				blockSize = CipherGetBlockSize (EAGetFirstCipher (cryptoInfo->ea));

				status = EAInit (cryptoInfo->ea, dk + primaryKeyOffset, cryptoInfo->ks);
				if (status == ERR_CIPHER_INIT_FAILURE)
					goto err;

				// Init objects related to the mode of operation

				if (cryptoInfo->mode == XTS)
				{
					// Copy the secondary key (if cascade, multiple concatenated)
					memcpy (cryptoInfo->k2, dk + EAGetKeySize (cryptoInfo->ea), EAGetKeySize (cryptoInfo->ea));

					// Secondary key schedule
					if (!EAInitMode (cryptoInfo))
					{
						status = ERR_MODE_INIT_FAILED;
						goto err;
					}
				}
				else if (cryptoInfo->mode == LRW
					&& (blockSize == 8 && !lrw64InitDone || blockSize == 16 && !lrw128InitDone))
				{
					// Deprecated/legacy

					if (!EAInitMode (cryptoInfo))
					{
						status = ERR_MODE_INIT_FAILED;
						goto err;
					}

					if (blockSize == 8)
						lrw64InitDone = TRUE;
					else if (blockSize == 16)
						lrw128InitDone = TRUE;
				}

				// Copy the header for decryption
				memcpy (header, encryptedHeader, sizeof (header));

				// Try to decrypt header 

				DecryptBuffer (header + HEADER_ENCRYPTED_DATA_OFFSET, HEADER_ENCRYPTED_DATA_SIZE, cryptoInfo);

				// Magic 'TRUE'
				if (GetHeaderField32 (header, TC_HEADER_OFFSET_MAGIC) != 0x54525545)
					continue;

				// Header version
				headerVersion = GetHeaderField16 (header, TC_HEADER_OFFSET_VERSION);
				
				// Check CRC of the header fields
				if (headerVersion >= 4 && GetHeaderField32 (header, TC_HEADER_OFFSET_HEADER_CRC) != GetCrc32 (header + TC_HEADER_OFFSET_MAGIC, TC_HEADER_OFFSET_HEADER_CRC - TC_HEADER_OFFSET_MAGIC))
					continue;

				// Required program version
				cryptoInfo->RequiredProgramVersion = GetHeaderField16 (header, TC_HEADER_OFFSET_REQUIRED_VERSION);
				cryptoInfo->LegacyVolume = cryptoInfo->RequiredProgramVersion < 0x600;

				// Check CRC of the key set
				if (GetHeaderField32 (header, TC_HEADER_OFFSET_KEY_AREA_CRC) != GetCrc32 (header + HEADER_MASTER_KEYDATA_OFFSET, MASTER_KEYDATA_SIZE))
					continue;

				// Now we have the correct password, cipher, hash algorithm, and volume type

				// Check the version required to handle this volume
				if (cryptoInfo->RequiredProgramVersion > VERSION_NUM)
				{
					status = ERR_NEW_VERSION_REQUIRED;
					goto err;
				}

				// Volume creation time (legacy)
				cryptoInfo->volume_creation_time = GetHeaderField64 (header, TC_HEADER_OFFSET_VOLUME_CREATION_TIME).Value;

				// Header creation time (legacy)
				cryptoInfo->header_creation_time = GetHeaderField64 (header, TC_HEADER_OFFSET_MODIFICATION_TIME).Value;

				// Hidden volume size (if any)
				cryptoInfo->hiddenVolumeSize = GetHeaderField64 (header, TC_HEADER_OFFSET_HIDDEN_VOLUME_SIZE).Value;

				// Hidden volume status
				cryptoInfo->hiddenVolume = (cryptoInfo->hiddenVolumeSize != 0);

				// Volume size
				cryptoInfo->VolumeSize = GetHeaderField64 (header, TC_HEADER_OFFSET_VOLUME_SIZE);
				
				// Encrypted area size and length
				cryptoInfo->EncryptedAreaStart = GetHeaderField64 (header, TC_HEADER_OFFSET_ENCRYPTED_AREA_START);
				cryptoInfo->EncryptedAreaLength = GetHeaderField64 (header, TC_HEADER_OFFSET_ENCRYPTED_AREA_LENGTH);

				// Flags
				cryptoInfo->HeaderFlags = GetHeaderField32 (header, TC_HEADER_OFFSET_FLAGS);

				// Preserve scheduled header keys if requested			
				if (retHeaderCryptoInfo)
				{
					if (retInfo == NULL)
					{
						cryptoInfo->pkcs5 = pkcs5_prf;
						cryptoInfo->noIterations = keyInfo.noIterations;
						goto ret;
					}

					cryptoInfo = *retInfo = crypto_open ();
					if (cryptoInfo == NULL)
					{
						status = ERR_OUTOFMEMORY;
						goto err;
					}

					memcpy (cryptoInfo, retHeaderCryptoInfo, sizeof (*cryptoInfo));
				}

				// Master key data
				memcpy (keyInfo.master_keydata, header + HEADER_MASTER_KEYDATA_OFFSET, MASTER_KEYDATA_SIZE);
				memcpy (cryptoInfo->master_keydata, keyInfo.master_keydata, MASTER_KEYDATA_SIZE);

				// PKCS #5
				memcpy (cryptoInfo->salt, keyInfo.salt, PKCS5_SALT_SIZE);
				cryptoInfo->pkcs5 = pkcs5_prf;
				cryptoInfo->noIterations = keyInfo.noIterations;

				// Init the encryption algorithm with the decrypted master key
				status = EAInit (cryptoInfo->ea, keyInfo.master_keydata + primaryKeyOffset, cryptoInfo->ks);
				if (status == ERR_CIPHER_INIT_FAILURE)
					goto err;

				switch (cryptoInfo->mode)
				{
				case LRW:
				case CBC:
				case INNER_CBC:
				case OUTER_CBC: