/*

* Copyright (c) 1998-2009 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: 

* This file contains the implementation of the ASN1 integer class.

* As noted in Notes.txt there are two approaches to the storage of data by

* this class, it can either hold a copy of the data or a pointer to something

* else which holds a copy of the data.

* The object contained within this file encapsulates the ASN1 integer object

* as described in X208 section 14 and the encoding described in X209 section

* 8. 

*

*/

#include "asn1dec.h"

#include <bigint.h>

EXPORT_C TASN1DecInteger::TASN1DecInteger()

	{

	}

EXPORT_C TInt TASN1DecInteger::DecodeDERShortL(const TDesC8& aSource,TInt& aPos)

	{

	TPtrC8 Source=aSource.Mid(aPos);

	TASN1DecGeneric gen(Source);

	gen.InitL();

	TInt res = DecodeDERShortL(gen);

	aPos+=gen.LengthDER();

	return res;

	}

EXPORT_C TInt TASN1DecInteger::DecodeDERShortL(const TASN1DecGeneric& aSource)

	{

	TInt res = 0;

	TPtrC8 ptr(aSource.GetContentDER());

	//stop stupid compiler warning

	TUint length = (TUint)(ptr.Length());

	if (length == 0) // DEF055722 

		{

		User::Leave(KErrArgument);

		}

	if (length > sizeof(TInt))

		{

		User::Leave(KErrTooBig);

		}

	TInt8 i;

	if (ptr[0]&128)

		{

		res = -1;

		}

	for (i=0;i<ptr.Length();i++)

		{

		res<<=8;

		res+=ptr[i];

		}

	return res;

	}

EXPORT_C RInteger TASN1DecInteger::DecodeDERLongL(const TDesC8& aSource,TInt& aPos)

	{

	TPtrC8 Source=aSource.Right(aSource.Length() - aPos);

	TASN1DecGeneric gen(Source);

	gen.InitL();

	RInteger res = DecodeDERLongL(gen);

	aPos+=gen.LengthDER();

	return res;

	}

EXPORT_C RInteger TASN1DecInteger::DecodeDERLongL(const TASN1DecGeneric& aSource)

	{

	const TDesC8& data = aSource.GetContentDER();

//	JCS 14/03/2003: Changed call to NewL from NewSignedL() because current

//	problem in RInteger for signed code means this sometimes returns incorrect

//	results causing failure in certstore testcode.  However, making this change

//	does cause problems in TASN1 now (posted defect DEF021796).

	RInteger res = RInteger::NewL(data);//aSource.GetContentDER());

	return (res);

	}