--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cryptoservices/certificateandkeymgmt/asn1/baseenc.cpp	Wed Jul 08 11:25:26 2009 +0100
@@ -0,0 +1,207 @@
+/*
+* Copyright (c) 2001-2009 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: 
+* Define methods for asn1-encoding base class
+*
+*/
+
+
+#include "base128enc.h"
+#include "panic.h"
+
+#include <asn1enc.h>
+
+const TUint KMaxLowNumberFormTag = 30;
+const TUint KMaxShortFormLength = 127;
+
+
+EXPORT_C CASN1EncBase::CASN1EncBase(const TTagType aType, const TASN1Class aClass)
+: iType(aType), iClass(aClass)
+	{
+	CalculateTagLengthDER();
+	}
+
+
+EXPORT_C CASN1EncBase::~CASN1EncBase()
+	{
+	}
+
+
+EXPORT_C void CASN1EncBase::ConstructL()
+	{
+	ContentsLengthChanged();
+	}
+
+
+void CASN1EncBase::ContentsLengthChanged()
+	{
+	CalculateContentsLengthDER();
+	CalculateLengthLengthDER();
+
+	if (iParent)
+		{
+		iParent->ContentsLengthChanged();
+		}
+	}
+
+
+// Set tagging scheme/tag/class
+EXPORT_C void CASN1EncBase::SetTag(const TTagType aType, const TASN1Class aClass)
+	{
+	iType = aType;
+	iClass = aClass;
+
+	CalculateTagLengthDER();
+	}
+
+
+// Gives total number of octets in the DER encoding of this object
+EXPORT_C TUint CASN1EncBase::LengthDER() const
+	{
+	return iTagLengthDER + iLengthLengthDER + iContentsLengthDER;
+	}
+	
+
+// Writes entire DER encoding of this object into the given buffer
+EXPORT_C void CASN1EncBase::WriteDERL(TDes8& aBuf, TUint& aPos) const
+	{
+	__ASSERT_ALWAYS(aBuf.Length() - STATIC_CAST(TInt, aPos) >= STATIC_CAST(TInt, LengthDER()),
+		Panic(KErrDescriptorTooShort));
+
+	WriteHelperL(aBuf, aPos, iTagLengthDER,      &CASN1EncBase::WriteTagDERL);
+	WriteHelperL(aBuf, aPos, iLengthLengthDER,   &CASN1EncBase::WriteLengthDER);
+	WriteHelperL(aBuf, aPos, iContentsLengthDER, &CASN1EncBase::WriteContentsDERL);
+	}
+
+
+// Internal helper method, used for efficiency
+void CASN1EncBase::WriteHelperL(TDes8& aBuf, TUint& aPos, const TUint aLength,
+									WriteFunc aWriteFunc) const
+	{
+	if (aLength)
+		{
+		// Get the middle bit of buffer we should be using
+		TPtr8 ptr(&aBuf[aPos], aLength, aLength);
+		
+		// Call the function to actually write the data
+		(this->*aWriteFunc)(ptr);
+		
+		aPos += aLength;
+		}
+	}
+
+
+// Give number of octets in tag section
+void CASN1EncBase::CalculateTagLengthDER()
+	{
+	if (iType <= KMaxLowNumberFormTag)
+		{
+		// Low tag number form
+		iTagLengthDER = 1;
+		}
+	else
+		{
+		// High tag number form
+		TASN1EncBase128DER encoder(iType);
+		iTagLengthDER = encoder.LengthDER() + 1;
+		}
+	}
+
+
+// Give number of octets in length section
+// Only called after contents length is worked out
+void CASN1EncBase::CalculateLengthLengthDER()
+	{
+	iLengthLengthDER = 1;
+	if (iContentsLengthDER > KMaxShortFormLength)
+		{
+		// Long form - need number of octets in base256 representation
+		// of length, plus 1.
+
+		TUint working = iContentsLengthDER;
+		do
+			{
+			++iLengthLengthDER;
+			}
+		while (working >>= 8);
+		}
+	}
+
+
+// Writes the tag section into the given buffer
+void CASN1EncBase::WriteTagDERL(TDes8& aBuf) const
+	{
+	// Write class - bits 7-8
+	aBuf[0] = STATIC_CAST(TUint8, iClass << 6);
+
+	// Write constructed/primitive flag in bit 6
+	if (IsConstructed())
+		{
+		aBuf[0] |= 0x20;
+		}
+
+	// Write length
+	if (iType <= KMaxLowNumberFormTag)
+		{
+		aBuf[0] |= iType;
+		}
+	else
+		{
+		// First byte signals more to come
+		aBuf[0] |= 0x1F;
+
+		// The rest we delegate
+		TASN1EncBase128DER encoder(iType);
+		TUint offset = 1;
+		encoder.WriteDERL(aBuf, offset);
+		}
+	}
+
+
+// Writes the length section into the given buffer
+void CASN1EncBase::WriteLengthDER(TDes8& aBuf) const
+	{
+	if (iContentsLengthDER > KMaxShortFormLength)
+		{
+		// First byte is the number of other bytes, with top bit also set
+		TUint octets = iLengthLengthDER - 1;
+
+		// Cast takes 8 least sig bits
+		aBuf[0] = STATIC_CAST(TUint8, octets);
+		aBuf[0] |= 0x80;
+
+		// Other bytes are base 256 representation of length, most significant first
+		TUint working = iContentsLengthDER;
+		do
+			{
+			// Cast to TUint8 takes 8 least sig bits
+			aBuf[octets] = STATIC_CAST(TUint8, working);
+			working >>= 8;
+			}
+		while (--octets);
+		}
+	else
+		{
+		// Short form, nice and easy - take least sig 8 bits with a cast
+		aBuf[0] = STATIC_CAST(TUint8, iContentsLengthDER);
+		}
+	}
+
+
+// Sets the parent (can only do this once)
+void CASN1EncBase::SetParent(CASN1EncBase* aParent)
+	{
+	__ASSERT_ALWAYS(iParent == 0, Panic(KErrAlreadyHasParent));
+	iParent = aParent;
+	}