1 /*

     2 * Copyright (c) 2001-2009 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 * Implementation for class encoding TInt in ASN1 DER

    16 *

    17 */

    18 

    19 

    20 #include <asn1enc.h>

    21 

    22 EXPORT_C CASN1EncInt* CASN1EncInt::NewLC(const TInt aInt)

    23 	{

    24 	CASN1EncInt* self = new (ELeave) CASN1EncInt(aInt);

    25 	CleanupStack::PushL(self);

    26 	self->ConstructL();

    27 	return self;

    28 	}

    29 

    30 EXPORT_C CASN1EncInt* CASN1EncInt::NewL(const TInt aInt)

    31 	{

    32 	CASN1EncInt* self = NewLC(aInt);

    33 	CleanupStack::Pop(self);

    34 	return self;

    35 	}

    36 

    37 CASN1EncInt::CASN1EncInt(const TInt aInt)

    38 : CASN1EncPrimitive(EASN1Integer), iInt(aInt)

    39 	{

    40 	}

    41 

    42 void CASN1EncInt::CalculateContentsLengthDER()

    43 	{

    44 	iContentsLengthDER = 1;

    45 

    46 	// Flip bits in -ve numbers

    47 	TUint working = iInt < 0 ? ~iInt : iInt;

    48 	TUint last = working;

    49 	while (working >>= 8)

    50 		{

    51 		last = working;

    52 		++iContentsLengthDER;

    53 		}

    54 	

    55 	// If most sig non-zero byte had a 1 top bit, we'll need the next byte too

    56 	// (applies to both +ve and -ve cases)

    57 	if (last & 0x80)

    58 		{

    59 		++iContentsLengthDER;

    60 		}

    61 	}

    62 

    63 

    64 void CASN1EncInt::WriteContentsDERL(TDes8& aBuf) const

    65 	{

    66 	// Unsigned, so operator>>= works sensibly

    67 	TUint working = iInt;

    68 	TUint position = iContentsLengthDER;

    69 	while (position)

    70 		{

    71 		// Cast takes least sig 8 bits

    72 		aBuf[--position] = STATIC_CAST(TUint8, working);

    73 		working >>= 8;

    74 		}

    75 	}