/*

 * Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of the License "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: 

 *

 */

 #include "pkcs12macdata.h"

 using namespace PKCS12;

 CDecPkcs12MacData::CDecPkcs12MacData()

 	{

 	}

 EXPORT_C CDecPkcs12MacData* CDecPkcs12MacData::NewL(const TDesC8& aMacData, const TDesC8& aAuthSafeData)

 	{

 	CDecPkcs12MacData* self = new(ELeave) CDecPkcs12MacData();

 	CleanupStack::PushL(self);

 	self->ConstructL(aMacData, aAuthSafeData);

 	CleanupStack::Pop(self);

 	return self;

 	}

 CDecPkcs12MacData::~CDecPkcs12MacData()

 	{

 	delete iDigestInfo;

 	}

 void CDecPkcs12MacData::ConstructL(const TDesC8& aMacData, const TDesC8& aAuthSafeData)

 	{

 	iAuthSafeDataPtr.Set(aAuthSafeData);

 	// MacData is a Sequence

 	TASN1DecGeneric seqGen(aMacData);

 	seqGen.InitL();

 	if (seqGen.Tag() != EASN1Sequence || seqGen.Class() != EUniversal)

 		{

 		User::Leave(KErrArgument);

 		}

 	// Decode the MacData Sequence

 	TASN1DecSequence seq;

 	CArrayPtr<TASN1DecGeneric>* macDataSequence = seq.DecodeDERLC(seqGen);

 	TInt macDataCount = macDataSequence->Count();

 	// Check if Mac, MacSalt and Iteration Count are present

 	// Iteration Count is 1 by default

 	if (macDataCount < 2 || macDataCount > 3)

 		{

 		User::Leave(KErrArgument);

 		}

 	// DigestInfo

 	const TASN1DecGeneric* macDataSequenceAt0 = macDataSequence->At(0);

 	// DigestInfo is a Sequence

 	if (macDataSequenceAt0->Tag() != EASN1Sequence || macDataSequenceAt0->Class() != EUniversal)

 		{

 		User::Leave(KErrArgument);

 		}

 	iDigestInfo = CPKCS7DigestInfo::NewL(macDataSequenceAt0->Encoding());

 	// MacSalt

 	const TASN1DecGeneric* macDataSequenceAt1 = macDataSequence->At(1);

 	// MacSalt is an OctetString

 	if (macDataSequenceAt1->Tag() != EASN1OctetString || macDataSequenceAt1->Class() != EUniversal)

 		{

 		User::Leave(KErrArgument);

 		}  

     iMacSalt.Set(macDataSequenceAt1->GetContentDER());

     // Iteration Count

 	if(macDataSequence->Count() == 3)

 		{

 		// Check for IterationCount

 		const TASN1DecGeneric* macDataSequenceAt2 = macDataSequence->At(2);

 		if (macDataSequenceAt2->Tag() != EASN1Integer || macDataSequenceAt2->Class() != EUniversal)

 			{

 			User::Leave(KErrArgument);

 			}

 		TASN1DecInteger intDecoder;

 		iIterationCount = intDecoder.DecodeDERShortL(*macDataSequenceAt2);

 		if(iIterationCount <= 0)

 			{

 			User::Leave(KErrArgument);

 			}

 		}

     // Assign the Default value as 1 if Iteration Count is not present.

 	else

 		{

 		iIterationCount = KDefaultIterationCount;

 		}	

 	CleanupStack::PopAndDestroy(macDataSequence);

     }

 EXPORT_C const CPKCS7DigestInfo& CDecPkcs12MacData::DigestInfo() const

 	{

 	return *iDigestInfo;

 	}

 EXPORT_C const TDesC8& CDecPkcs12MacData::MacSalt() const

 	{

 	return iMacSalt;	

 	}

 EXPORT_C TInt CDecPkcs12MacData::IterationCount() const

 	{

 	return iIterationCount;	

 	}

 EXPORT_C TBool CDecPkcs12MacData::VerifyIntegrityL(const TDesC& aPassword) const

 	{	

 	__UHEAP_MARK;

 	HBufC8* encryptKey = HBufC8::NewMaxLC(KSha1HmacKeyLength);

 	TPtr8 encryptedKey(encryptKey->Des());

 	// Convert the supplied string to a byte string. Each character is converted to a big 

 	// endian two-byte value, and a terminating NULL character is appended to the end.

 	HBufC8* password = PKCS12KDF::GeneratePasswordLC(aPassword);

 	PKCS12KDF::DeriveKeyL(encryptedKey, PKCS12KDF::EIDByteMACKey, *password ,MacSalt(), IterationCount());

 	CMessageDigest* digest1 = NULL;

 	TAlgorithmId algorithmId = DigestInfo().Algorithm();

 	if (algorithmId != ESHA1)

 		{

 		User::Leave(KErrNotSupported);

 		}

 	digest1 = CSHA1::NewL();

 	CleanupStack::PushL( digest1 );

 	CHMAC* hmac1 = CHMAC::NewL( encryptedKey, digest1);

 	CleanupStack::PushL( hmac1 );

 	TPtrC8 tmpHash = hmac1->Final(iAuthSafeDataPtr);

 	TInt ret = tmpHash.Compare(DigestInfo().Digest());

 	TBool result;

 	if(ret)

 		{

 		result = EFalse;

 		}

 	else

 		{

 		result = ETrue;

 		}

 	CleanupStack::PopAndDestroy(hmac1);

 	CleanupStack::Pop(digest1);

 	CleanupStack::PopAndDestroy(2,encryptKey); // encryptKey, password

 	__UHEAP_MARKEND;

 	return result;	

 	}