sl@0: /*
sl@0: * Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of the License "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: * This file contains the object implementing the Bitstring ASN1 object.
sl@0: * There is no handling for constructed form of Bitstring right now.
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: #include "asn1dec.h"
sl@0: 
sl@0: EXPORT_C TASN1DecBitString::TASN1DecBitString(void)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: EXPORT_C HBufC8* TASN1DecBitString::DecodeDERL(const TDesC8& /*aSource*/,TInt& /*aPos*/)
sl@0: 	{
sl@0: 	User::Leave(KErrNotSupported);
sl@0: 	return NULL;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C HBufC8* TASN1DecBitString::DecodeDERL(const TASN1DecGeneric& /*aSource*/)
sl@0: 	{
sl@0: 	User::Leave(KErrNotSupported);
sl@0: 	return NULL;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C HBufC8* TASN1DecBitString::ExtractOctetStringL(const TDesC8& aSource,TInt& aPos)
sl@0: 	{
sl@0: 	TASN1DecGeneric gen(aSource.Right(aSource.Length() - aPos));
sl@0: 	gen.InitL();
sl@0: 	HBufC8* res = ExtractOctetStringL(gen);
sl@0: 	aPos+=gen.LengthDER();
sl@0: 	return res;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C HBufC8* TASN1DecBitString::ExtractOctetStringL(const TASN1DecGeneric& aSource)
sl@0: 	{
sl@0: 	TPtrC8 encoding = aSource.GetContentDER();
sl@0: 	
sl@0: 	// Special case. The empty bit string. (No padding length octet)
sl@0: 	if (encoding.Length() == 0 )
sl@0: 		{
sl@0: 		return encoding.AllocL();				
sl@0: 		}
sl@0: 	
sl@0: 	// Length must either be 0 for the empty string or >= 2 because
sl@0: 	// of the padding length octet.
sl@0: 	if (encoding.Length() == 1)
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 		
sl@0: 	TUint8 paddingLength = encoding[0];
sl@0: 	if (paddingLength > 7)
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 	TPtrC8 pEncoding = encoding.Right(encoding.Length()-1);
sl@0: 	HBufC8* octetStr = pEncoding.AllocL();
sl@0: 	TPtr8 pEncKey = octetStr->Des();
sl@0: 
sl@0: 	//stop stupid compiler warning
sl@0: 	TUint8 mask =(TUint8)(255 << paddingLength);
sl@0: 	//stop stupid compiler warning
sl@0: 	pEncKey[pEncKey.Length()-1] = (TUint8) ((pEncKey[pEncKey.Length()-1]) & mask);
sl@0: 	return octetStr;
sl@0: 	}