/*

 * Copyright (c) 2001-2009 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: 

 * Implementation for TASN1EncBase128 class.

 *

 */

 #include "base128enc.h"

 TASN1EncBase128DER::TASN1EncBase128DER(TUint aInt) : iInt(aInt), iLengthDER(0)

 	{

 	CalculateLengthDER();

 	}

 TUint TASN1EncBase128DER::LengthDER() const

 	{

 	return iLengthDER;

 	}

 void TASN1EncBase128DER::CalculateLengthDER()

 	{

 	iLengthDER = 1;

 	TUint working = iInt;

 	while (working >>= 7)

 		{

 		++iLengthDER;

 		}

 	}

 void TASN1EncBase128DER::WriteDERL(TDes8& aBuf, TUint& aPos) const

 	{

 	__ASSERT_DEBUG(aBuf.Length() - aPos >= STATIC_CAST(TUint8, iLengthDER), 

 		User::Leave(KErrBadDescriptor));

 	TInt last = aPos + iLengthDER - 1;

 	TUint working = iInt;

 	for (TUint cursor = last; cursor >= aPos; --cursor)

 		{

 		// Cast takes least significant 8 bits only (actually, we only need 7)

 		aBuf[cursor] = STATIC_CAST(TUint8, working);

 		aBuf[cursor] |= 0x80; // Top bit always set to 1...

 		working >>= 7;

 		}

 	// ...except top bit on last byte is 0

 	aBuf[last] &= 0x7F;

 	aPos += iLengthDER;

 	}