sl@0: /*
sl@0: * Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of the License "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: #include <e32base.h>
sl@0: #include <padding.h>
sl@0: #include <securityerr.h>
sl@0: #include <cryptopanic.h>
sl@0: 
sl@0: #include "paddingshim.h"
sl@0: 
sl@0: /* CPaddingPKCS7 */
sl@0: EXPORT_C CPaddingPKCS7* CPaddingPKCS7::NewL(TInt aBlockBytes)
sl@0: 	{
sl@0: 	__ASSERT_ALWAYS(aBlockBytes > 0, User::Leave(KErrArgument));
sl@0: 	return CPaddingPKCS7Shim::NewL(aBlockBytes);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C CPaddingPKCS7* CPaddingPKCS7::NewLC(TInt aBlockBytes)
sl@0: 	{
sl@0: 	CPaddingPKCS7* self = CPaddingPKCS7::NewL(aBlockBytes);
sl@0: 	CleanupStack::PushL(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C CPaddingPKCS7::CPaddingPKCS7(TInt aBlockBytes):CPadding(aBlockBytes)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: void CPaddingPKCS7::DoPadL(const TDesC8& aInput,TDes8& aOutput)
sl@0: 	{
sl@0: 	TInt paddingBytes = BlockSize()-(aInput.Length()%BlockSize());		
sl@0: 	aOutput.Append(aInput);
sl@0: 	aOutput.SetLength(aOutput.Length()+paddingBytes);
sl@0: 	for (TInt i=1;i<=paddingBytes;i++)
sl@0: 		{
sl@0: 		aOutput[aOutput.Length()-i]=(TUint8)(paddingBytes);
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: void CPaddingPKCS7::UnPadL(const TDesC8& aInput,TDes8& aOutput)
sl@0: 	{
sl@0: 	TUint inputLen = aInput.Length();
sl@0:  	TUint paddingLen = (TUint)(aInput[inputLen - 1]);
sl@0: 
sl@0: 	if (paddingLen > inputLen)
sl@0:  		{
sl@0:  		User::Leave(KErrInvalidPadding);
sl@0:  		}
sl@0:    
sl@0: 	TInt outlen = aInput.Length() - paddingLen;
sl@0: 
sl@0: 	__ASSERT_DEBUG(aOutput.MaxLength() >= outlen, User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow));
sl@0: 
sl@0: 	aOutput.Append(aInput.Left(outlen));
sl@0: 	for (TInt i=outlen;i<inputLen;i++)
sl@0: 		{
sl@0: 		//All padding bytes must equal the length of padding expected
sl@0: 		if (aInput[i]!=paddingLen)
sl@0: 			{
sl@0: 			User::Leave(KErrInvalidPadding);
sl@0: 			}
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: TInt CPaddingPKCS7::MinPaddingLength(void) const
sl@0: 	{
sl@0: 	//if aInputBytes is 1 less than the blocksize then we get 1 byte of padding
sl@0: 	return 1;
sl@0: 	}
sl@0: 
sl@0: TInt CPaddingPKCS7::MaxPaddedLength(TInt aInputBytes) const
sl@0: 	{
sl@0: 	TUint padBytes = BlockSize() - (aInputBytes % BlockSize());
sl@0: 	return padBytes + aInputBytes;
sl@0: 	}
sl@0: