1 /*

     2 * Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of the License "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 * This file contains the object implementing the Bitstring ASN1 object.

    16 * There is no handling for constructed form of Bitstring right now.

    17 *

    18 */

    19 

    20 

    21 #include "asn1dec.h"

    22 

    23 EXPORT_C TASN1DecBitString::TASN1DecBitString(void)

    24 	{

    25 	}

    26 

    27 EXPORT_C HBufC8* TASN1DecBitString::DecodeDERL(const TDesC8& /*aSource*/,TInt& /*aPos*/)

    28 	{

    29 	User::Leave(KErrNotSupported);

    30 	return NULL;

    31 	}

    32 

    33 EXPORT_C HBufC8* TASN1DecBitString::DecodeDERL(const TASN1DecGeneric& /*aSource*/)

    34 	{

    35 	User::Leave(KErrNotSupported);

    36 	return NULL;

    37 	}

    38 

    39 EXPORT_C HBufC8* TASN1DecBitString::ExtractOctetStringL(const TDesC8& aSource,TInt& aPos)

    40 	{

    41 	TASN1DecGeneric gen(aSource.Right(aSource.Length() - aPos));

    42 	gen.InitL();

    43 	HBufC8* res = ExtractOctetStringL(gen);

    44 	aPos+=gen.LengthDER();

    45 	return res;

    46 	}

    47 

    48 EXPORT_C HBufC8* TASN1DecBitString::ExtractOctetStringL(const TASN1DecGeneric& aSource)

    49 	{

    50 	TPtrC8 encoding = aSource.GetContentDER();

    51 	

    52 	// Special case. The empty bit string. (No padding length octet)

    53 	if (encoding.Length() == 0 )

    54 		{

    55 		return encoding.AllocL();				

    56 		}

    57 	

    58 	// Length must either be 0 for the empty string or >= 2 because

    59 	// of the padding length octet.

    60 	if (encoding.Length() == 1)

    61 		{

    62 		User::Leave(KErrArgument);

    63 		}

    64 		

    65 	TUint8 paddingLength = encoding[0];

    66 	if (paddingLength > 7)

    67 		{

    68 		User::Leave(KErrArgument);

    69 		}

    70 	TPtrC8 pEncoding = encoding.Right(encoding.Length()-1);

    71 	HBufC8* octetStr = pEncoding.AllocL();

    72 	TPtr8 pEncKey = octetStr->Des();

    73 

    74 	//stop stupid compiler warning

    75 	TUint8 mask =(TUint8)(255 << paddingLength);

    76 	//stop stupid compiler warning

    77 	pEncKey[pEncKey.Length()-1] = (TUint8) ((pEncKey[pEncKey.Length()-1]) & mask);

    78 	return octetStr;

    79 	}