crypto/weakcryptospi/source/padding/pkcs7.cpp
changeset 17 cd501b96611d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/weakcryptospi/source/padding/pkcs7.cpp	Fri Nov 06 13:21:00 2009 +0200
@@ -0,0 +1,91 @@
+/*
+* Copyright (c) 2003-2009 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: 
+*
+*/
+
+
+#include <e32base.h>
+#include <padding.h>
+#include <securityerr.h>
+#include <cryptopanic.h>
+
+#include "paddingshim.h"
+
+/* CPaddingPKCS7 */
+EXPORT_C CPaddingPKCS7* CPaddingPKCS7::NewL(TInt aBlockBytes)
+	{
+	__ASSERT_ALWAYS(aBlockBytes > 0, User::Leave(KErrArgument));
+	return CPaddingPKCS7Shim::NewL(aBlockBytes);
+	}
+
+EXPORT_C CPaddingPKCS7* CPaddingPKCS7::NewLC(TInt aBlockBytes)
+	{
+	CPaddingPKCS7* self = CPaddingPKCS7::NewL(aBlockBytes);
+	CleanupStack::PushL(self);
+	return self;
+	}
+
+EXPORT_C CPaddingPKCS7::CPaddingPKCS7(TInt aBlockBytes):CPadding(aBlockBytes)
+	{
+	}
+
+void CPaddingPKCS7::DoPadL(const TDesC8& aInput,TDes8& aOutput)
+	{
+	TInt paddingBytes = BlockSize()-(aInput.Length()%BlockSize());		
+	aOutput.Append(aInput);
+	aOutput.SetLength(aOutput.Length()+paddingBytes);
+	for (TInt i=1;i<=paddingBytes;i++)
+		{
+		aOutput[aOutput.Length()-i]=(TUint8)(paddingBytes);
+		}
+	}
+
+void CPaddingPKCS7::UnPadL(const TDesC8& aInput,TDes8& aOutput)
+	{
+	TUint inputLen = aInput.Length();
+ 	TUint paddingLen = (TUint)(aInput[inputLen - 1]);
+
+	if (paddingLen > inputLen)
+ 		{
+ 		User::Leave(KErrInvalidPadding);
+ 		}
+   
+	TInt outlen = aInput.Length() - paddingLen;
+
+	__ASSERT_DEBUG(aOutput.MaxLength() >= outlen, User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow));
+
+	aOutput.Append(aInput.Left(outlen));
+	for (TInt i=outlen;i<inputLen;i++)
+		{
+		//All padding bytes must equal the length of padding expected
+		if (aInput[i]!=paddingLen)
+			{
+			User::Leave(KErrInvalidPadding);
+			}
+		}
+	}
+
+TInt CPaddingPKCS7::MinPaddingLength(void) const
+	{
+	//if aInputBytes is 1 less than the blocksize then we get 1 byte of padding
+	return 1;
+	}
+
+TInt CPaddingPKCS7::MaxPaddedLength(TInt aInputBytes) const
+	{
+	TUint padBytes = BlockSize() - (aInputBytes % BlockSize());
+	return padBytes + aInputBytes;
+	}
+