/*

* 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 UTC time ASN1 object.

* At this moment in time this class will only deal with Zulu times and 

* doesn't have any kind of handling for time offsets. This is not going to be 

* a problem for certificate implementations as the PKIX (RFC2459) profile

* defines that certificate validity periods are specified as Zulu times.

* Points that need updating if handling for offsets are marked with __OFFSET__

*

*/

#include <asn1dec.h>

EXPORT_C TASN1DecUTCTime::TASN1DecUTCTime()

	{

	}

TTime TASN1DecUTCTime::GetTimeL(const TDesC8& aSource)

	{

	// __OFFSET__ Extract corrected time to include offset too.

	// Did this checking ought to be done on creation rather than when we attempt to get the result?

	// YES!

	// I guess we ought to check that the contents we've got are long enough to contain a time!

	if (aSource.Length()<11)

		{

		User::Leave(KErrArgument);

		}

	// Check all digits the main bit of time are valid - this doesn't check the seconds or offset

	TInt i;

	for (i=0;i<10;i++)

		{

		TUint8 j;

		j=(TUint8)(aSource[i]-'0');

		if (j>=10)

			{

			User::Leave(KErrArgument);

			}

		}

	// Uh-oh, looks like we're going to have to pull each bit manually and pop it in a TDateTime thing

	TInt Year,Month,Day,Hour,Minute,Second=0;		// Only set seconds to zero 'cos they are optional, everything else is going to be set

	Year=(aSource[0]-'0')*10+aSource[1]-'0';

	Year+=(Year<50)?2000:1900;						//  collection to fit with PKIX UTC/Generalised time rollover at 2049/2050

	Month=(aSource[2]-'0')*10+aSource[3]-'0';

	Month--;										// Because the enum for months starts at 0 not 1

	Day=((aSource[4]-'0')*10+aSource[5]-'0') -1;//added -1 for offset from zero(!)

	Hour=(aSource[6]-'0')*10+aSource[7]-'0';

	Minute=(aSource[8]-'0')*10+aSource[9]-'0';

	TInt Pos=10;

	if (aSource.Length()>11)

		{

		if ((aSource[Pos]>='0')&&(aSource[Pos]<='9'))

			{

			// seconds

			Second=(aSource[Pos++]-'0')*10;

			Second += aSource[Pos++]-'0';

			}

		}

	if (aSource.Length()>Pos)

		{

		switch (aSource[Pos])

			{

		case 'Z':

			// Zulu - nothing more to do

			break;

		case '+':

		case '-':

			// __OFFSET__ Extract corrected time to include offset too.

		    User::Leave(KErrNotSupported);

		    break;

		default:

			// Error!

			User::Leave(KErrArgument);

			break;

			}

		}

	else

		{

		User::Leave(KErrArgument);

		}

	if (Month<EJanuary || Month>EDecember)

		{

		User::Leave(KErrArgument);

		}

	TMonth month = (TMonth)Month;

	if (	(Day<0 || Day>=Time::DaysInMonth(Year,month))	||

			(Hour<0 || Hour>=24)	||

			(Minute<0 || Minute>=60)	||

			(Second<0 || Second>=60)	)

		{

		User::Leave(KErrArgument);

		}

	TDateTime D(Year,month,Day,Hour,Minute,Second,0);

	TTime T(D);

	return T;

	}

// __OFFSET__ Add GetOffset() method

EXPORT_C TTime TASN1DecUTCTime::DecodeDERL(const TDesC8& aSource,TInt& aPos)

	{

	TPtrC8 Source=aSource.Mid(aPos);

	TASN1DecGeneric gen(Source);

	gen.InitL();

	TTime t = GetTimeL(gen.GetContentDER());

	aPos+=gen.LengthDER();

	return t;

	}

EXPORT_C TTime TASN1DecUTCTime::DecodeDERL(const TASN1DecGeneric& aGen)

	{

	return GetTimeL(aGen.GetContentDER());

	}