// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// Implementation of compression and encryption

// 

//

/**

 @file

*/

#include "sbencrypt.h"

#include "sbecompressionandencryption.h"

#include "sbtypes.h"

#include <arc4.h>

#include <ezcompressor.h>

#include <ezdecompressor.h>

// Uncomment the next line if you want to turn off compression & encryption, ignore the warnings.

//#define TURN_OFF_COMPRESSION_AND_ENCRYPTION

namespace conn

	{

#ifndef TURN_OFF_COMPRESSION_AND_ENCRYPTION

	const TInt KJavaVirtualMachineSecureId = 0x102033e6;

	const TInt KMaxHeapSize = KMaxTInt / 2;

#endif

	/** Compression block size

	*/

	const TInt KCompressionBlockSize = 1024 * 64; // 64K

	/** Compression growth size

	This is calculated as the size of the block we want to compress * 1.01. As defined by the ZLib library.

	*/

	const TInt CSBECompressAndEncrypt::iCompressionGrowthSize = static_cast<TInt>(KCompressionBlockSize * 0.01) + 12 + sizeof(TCompressionHeader);

	template <class T> void ReadL(T& aT, TPtr8& aBuffer, TInt aStartAt = 0, TInt aToCopy = sizeof(T))

	/** Reads data from any given type into aBuffer

	@param aT type to put in buffer

	@param aBuffer the buffer

	@param aStartAt offset of the data

	@param aToCopy the amount of data to copy

	*/

		{

		TUint8* inData = const_cast<TUint8*>(aBuffer.Ptr());

		TUint8* outData = (reinterpret_cast<TUint8*>(&aT)) + aStartAt;

		for (TInt x = 0; x < aToCopy; x++)

			{

			*(outData++) = *(inData++);

			} // for

		}

	template<class T> void WriteL(T& aT, TPtr8& aBuffer, TInt aStartAt = 0, TInt aToCopy = sizeof(T))

	/** Writes data from aBuffer into any given type

	@param aT type to read in from buffer

	@param aBuffer the buffer

	@param aStartAt offset of the data

	@param aToCopy the amount of data to copy

	*/

		{

		TUint8* inData = reinterpret_cast<TUint8*>(&aT);

		TUint8* outData = (const_cast<TUint8*>(aBuffer.Ptr())) + aStartAt;

		for (TInt x = 0; x < aToCopy; x++)

			{

			*(outData++) = *(inData++);

			} // for

		aBuffer.SetLength(aBuffer.Length() + sizeof(T));

		}

	CSBECompressAndEncrypt* CSBECompressAndEncrypt::NewLC(CSBGenericTransferType*& apTransferType, TPtr8& aInputData)

	/** Standard Symbian constructor

	@param apTransferType transfer type of data.

	@param aInputData data block to be used. Start point will be changed to allow for compression.

	*/

		{

		CSBECompressAndEncrypt* self = new(ELeave) CSBECompressAndEncrypt();

		CleanupStack::PushL(self);

		self->ConstructL(apTransferType, aInputData);

		return self;

		}

	CSBECompressAndEncrypt::CSBECompressAndEncrypt() :

		iActualStart(NULL, 0), iCipher(NULL), iIsFreed(EFalse)

	/** Standard C++ Constructor

	*/

		{

		}

	CSBECompressAndEncrypt::~CSBECompressAndEncrypt()

	/** Standard C++ Destructor

	*/

		{

#ifndef TURN_OFF_COMPRESSION_AND_ENCRYPTION	

		if( ! iIsFreed )

			iOffsetStart->Set(iActualStart);	// free reserved space when leave occurs.

#endif

		delete iCipher;

		}

	void CSBECompressAndEncrypt::ConstructL(CSBGenericTransferType*& apTransferType, TPtr8& aOutputData)

	/**

		Standard Symbian second phase constructor

	@param apTransferType transfer type of data.

	@param aInputData data block to be used. Start point will be changed to allow for compression.

	*/

		{

#ifndef TURN_OFF_COMPRESSION_AND_ENCRYPTION		

		// Do we need a key source and cipher?

		TSBDerivedType derivedType = apTransferType->DerivedTypeL();

		TInt extraToReserve = 0;

		if ((derivedType == ESIDTransferDerivedType) || (derivedType == EJavaTransferDerivedType))

			{

		 	TSecureId secureId;

		 	TDriveNumber driveNumber;

		 	if (derivedType == ESIDTransferDerivedType)

		 		{

	    		// Need the Sid transfertype

				CSBSIDTransferType* pSIDTransferType = CSBSIDTransferType::NewL(apTransferType);

				CleanupStack::PushL(pSIDTransferType);

		 		secureId = pSIDTransferType->SecureIdL();

		 		driveNumber = pSIDTransferType->DriveNumberL();

		 		CleanupStack::PopAndDestroy(pSIDTransferType);

		 		} // if

		 	else

		 		{

		 		// Java

		 		secureId.iId = KJavaVirtualMachineSecureId;

		 		driveNumber = apTransferType->DriveNumberL();

		 		} // else

		 	// We will be doing encryption. Get the key

		 	CSecureBUREncryptKeySource* keySource = CSecureBUREncryptKeySource::NewL();

		 	CleanupStack::PushL(keySource);

		 	// Get the key and the buffer?

		 	keySource->GetBackupKeyL(driveNumber, secureId,

		 							 iDoEncrypt, iKey, iGotBuffer, iBuffer);

			if (!iGotBuffer)

				{

				// See if there is a default buffer

				keySource->GetDefaultBufferForBackupL(driveNumber, iGotBuffer, iBuffer);

				} // if

		 	CleanupStack::PopAndDestroy(keySource);

		 	// Create the cipher, if needed.

		 	if (iDoEncrypt)

		 		{

			 	iCipher = CARC4::NewL(iKey);

			 	} // if

			extraToReserve = sizeof(TEncryptionHeader) + iBuffer.Size();

		 	} // if

		// Reserve the space required

		TInt numberBlocks = (aOutputData.MaxSize() / KCompressionBlockSize) + (((aOutputData.MaxSize() % KCompressionBlockSize) == 0) ? 0 : 1);

		TInt reservedSpace = (numberBlocks * iCompressionGrowthSize) + extraToReserve;

		// Keep a copy of the acutual data block

		iActualStart.Set(const_cast<TUint8*>(aOutputData.Ptr()), 0, aOutputData.MaxSize());

		// Reserve the space in the input data

		if (reservedSpace > aOutputData.MaxSize())

			{

			User::Leave(KErrOverflow);

			}

		aOutputData.Set((const_cast<TUint8*>(aOutputData.Ptr()) + reservedSpace), 0, aOutputData.MaxSize() - reservedSpace);

		iOffsetStart = &aOutputData;

#endif		 	

		}

	void CSBECompressAndEncrypt::PackL(TPtr8& aOutputData)

	/** Performs the compression and encryption

	@param aOutputData the compressed data

	*/

		{

#ifndef TURN_OFF_COMPRESSION_AND_ENCRYPTION		

		// Add the encryption header

		TEncryptionHeader encryptionHeader;

		encryptionHeader.iEncrypted = iDoEncrypt;

		encryptionHeader.iBufferSize = iBuffer.Size();

		encryptionHeader.iTotalSize = sizeof(TEncryptionHeader) + encryptionHeader.iBufferSize;

		// Move along

		TPtr8 encryptionOffset(const_cast<TUint8*>(iActualStart.Ptr()), 0, sizeof(TEncryptionHeader));

		iActualStart.SetLength(sizeof(TEncryptionHeader));

		// Add the encryption buffer

		if (encryptionHeader.iBufferSize > 0)

			{

			iActualStart.Append(reinterpret_cast<TUint8*>(const_cast<TUint16*>(iBuffer.Ptr())), iBuffer.Size());

			} // if

		// Temp buffers used for compression & encryption

		HBufC8* compressionBuffer = HBufC8::NewLC(KCompressionBlockSize + iCompressionGrowthSize);

		HBufC8* encryptionBuffer = NULL;

		if (iDoEncrypt)

			{

			encryptionBuffer = HBufC8::NewLC(KCompressionBlockSize + iCompressionGrowthSize);

			} // if

		// Do compression and encryption

		TInt location = 0;

		while (location < iOffsetStart->Size())

			{

			// Size of data to compress

			TInt toCompressSize = KCompressionBlockSize; 

			if ((iOffsetStart->Size() - location) < KCompressionBlockSize)

				{

				toCompressSize = iOffsetStart->Size() - location;

				}

			// Compress the data

			TPtr8 toCompress((const_cast<TUint8*>(iOffsetStart->Ptr()) + location), toCompressSize, toCompressSize);

			TPtr8 compress = compressionBuffer->Des();

			CEZCompressor::CompressL(compress, toCompress, Z_BEST_COMPRESSION);

			// Add the header information

			TCompressionHeader compressionHeader;

			compressionHeader.iCompressedSize = compressionBuffer->Size();

			compressionHeader.iUncompressedSize = toCompressSize;

			if (iDoEncrypt)

				{

				encryptionBuffer->Des().Append(reinterpret_cast<TUint8*>(&compressionHeader), sizeof(TCompressionHeader));

				encryptionBuffer->Des().Append(compressionBuffer->Des());

				iCipher->Process(encryptionBuffer->Des(), iActualStart);

				} // if

			else

				{

				iActualStart.Append(reinterpret_cast<TUint8*>(&compressionHeader), sizeof(TCompressionHeader));

				iActualStart.Append(compressionBuffer->Des());

				} // else

			if (encryptionBuffer)

				{

				encryptionBuffer->Des().SetLength(0);

				}

			compressionBuffer->Des().SetLength(0);

			location += toCompressSize;

			encryptionHeader.iTotalSize += sizeof(TCompressionHeader) + compressionHeader.iCompressedSize;

			} // while

		// Add the encryption buffer

		WriteL(encryptionHeader, encryptionOffset, 0, sizeof(TEncryptionHeader));

		// Cleanup

		if (encryptionBuffer)

			{

			CleanupStack::PopAndDestroy(encryptionBuffer);

			} // if

		CleanupStack::PopAndDestroy(compressionBuffer);

		aOutputData.Set(iActualStart);

		iIsFreed = ETrue;

#endif		

		}

	void CSBECompressAndEncrypt::FreeReservedSpace(TPtr8& aOutputData)

		/*

		Free space researved in ConstructL if no data to be compressed.

		@param aOutputData the compressed data

		*/

		{

#ifndef TURN_OFF_COMPRESSION_AND_ENCRYPTION	

		aOutputData.Set(iActualStart);

		iIsFreed = ETrue;

#endif

		}

	CSBEDecompressAndEncrypt* CSBEDecompressAndEncrypt::NewL()

	/** Standard Symbian constructor

	*/

		{

		CSBEDecompressAndEncrypt* self = CSBEDecompressAndEncrypt::NewLC();

		CleanupStack::Pop(self);

		return self;

		}

	CSBEDecompressAndEncrypt* CSBEDecompressAndEncrypt::NewLC()

	/** Standard Symbian constructor

	*/

		{

		CSBEDecompressAndEncrypt* self = new(ELeave) CSBEDecompressAndEncrypt();

		CleanupStack::PushL(self);

		return self;

		}

	CSBEDecompressAndEncrypt::CSBEDecompressAndEncrypt() :

		iType(ENotSet), iCurrentPtr(NULL, 0), iCount(0), iJavaHash(NULL), iCipher(NULL)

		/** Stanard C++ Constructor

		*/

		{

		Reset();

		}

	CSBEDecompressAndEncrypt::~CSBEDecompressAndEncrypt()

	/** Standard C++ Destructor 

	*/

		{

		delete iCipher;

		delete iJavaHash;

		delete iBuffer;

		}

	void CSBEDecompressAndEncrypt::SetBuffer(TDesC8& aOutputData)

		{

		iCurrentPtr.Set(const_cast<TUint8*>(aOutputData.Ptr()), aOutputData.Size(), aOutputData.Size());

		}

	void CSBEDecompressAndEncrypt::SetGenericTransferTypeL(CSBGenericTransferType*& apTransferType)

		{

#ifndef TURN_OFF_COMPRESSION_AND_ENCRYPTION

		TSBDerivedType derivedType = apTransferType->DerivedTypeL();

		if (derivedType == ESIDTransferDerivedType)

			{

			// Need the Sid transfertype

			CSBSIDTransferType* pSIDTransferType = CSBSIDTransferType::NewL(apTransferType);

			CleanupStack::PushL(pSIDTransferType);

			// Do we need to perform a reset

			if ((iType != ESid) ||

				(iDriveNumber != pSIDTransferType->DriveNumberL()) ||

			    (iSecureId != pSIDTransferType->SecureIdL()))

				{

				Reset();

				iDriveNumber = pSIDTransferType->DriveNumberL();

				iSecureId = pSIDTransferType->SecureIdL();

				iType = ESid;

				} // if

				CleanupStack::PopAndDestroy(pSIDTransferType);

			} // if

		else if (derivedType == EJavaTransferDerivedType)

			{

	 		// Java

			CSBJavaTransferType* pJavaTransferType = CSBJavaTransferType::NewL(apTransferType);

			CleanupStack::PushL(pJavaTransferType);

			// Do we need to perform a reset

			const TDesC& javahash = pJavaTransferType->SuiteHashL();

			if ((iType != EJava) ||

			    (iDriveNumber != pJavaTransferType->DriveNumberL()) ||

			    (iJavaHash->Des() != javahash))

				{

				Reset();

		 		// Store java hash

		 		delete iJavaHash;

		 		iJavaHash = NULL;

		 		iJavaHash = HBufC::NewL(javahash.Size());

		 		iJavaHash->Des().Append(javahash);

		 		iSecureId.iId = KJavaVirtualMachineSecureId;

		 		iDriveNumber = apTransferType->DriveNumberL();

		 		iType = EJava;

				}

	 		CleanupStack::PopAndDestroy(pJavaTransferType);

			} // else if

		else if (derivedType == EPackageTransferDerivedType)

			{

			// Package

			CSBPackageTransferType* pPackageTransferType = CSBPackageTransferType::NewL(apTransferType);

			CleanupStack::PushL(pPackageTransferType);

			// Do we need to perform a reset

			if ((iType != EPackage) ||

			    (iPackageId != pPackageTransferType->PackageIdL()))

				{

				Reset();

				iPackageId = pPackageTransferType->PackageIdL();

				iType = EPackage;

				}

			CleanupStack::PopAndDestroy(pPackageTransferType);

			} // else if

		else

			{

			User::Leave(KErrNotSupported);

			} // else

#endif

		}

	void CSBEDecompressAndEncrypt::Reset()

	/** Resets the data 

	*/

		{

		iCount = 0;

		iType = ENotSet;

		iDoDecrypt = EFalse;

		iCurrentPtr.Set(NULL, 0, 0);

		iGotCompressionHeader = EFalse;

		iCompressionSizeRead = 0;

		iEncryptionSizeRead = 0;

		iDoneDecompression = EFalse;

		iGotCipher = EFalse;

		delete iBuffer;

  		iBuffer = NULL;

		}

	void CSBEDecompressAndEncrypt::MoveAlongL(TPtr8& aPtr, TInt aAmount)

	/** Move a pointer along a given amount

	@param aPtr pointer to move

	@param aAmount amount to move

	*/

		{

		TInt newSize = aPtr.Size() - aAmount;

		// Check

		if (newSize < 0)

			{

			User::Leave(KErrOverflow);

			}

		aPtr.Set(const_cast<TUint8*>(aPtr.Ptr()) + aAmount, newSize, newSize);			

		}

	TBool CSBEDecompressAndEncrypt::NextLC(HBufC8*& apOutput, TBool& aMoreData)

	/** Decompress a block of the data

	@param apOutput on return the next block of uncompressed data. This must be deleted by the caller.

	@param aMoreData is there more data left in the compressed block.

	*/

		{

#ifndef TURN_OFF_COMPRESSION_AND_ENCRYPTION

		if (!iGotCipher)

			{

			iGotCipher = CreateCipherL();