sl@0: // Copyright (c) 1998-2009 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 "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: #include "UE_STD.H"
sl@0: 
sl@0: #include <pbe.h>
sl@0: 
sl@0: #define UNUSED_VAR(a) a = a
sl@0: 
sl@0: TSecureFilter::TSecureFilter()
sl@0: 	{}
sl@0: 
sl@0: void TSecureFilter::Set(MStreamBuf* aHost,TInt aMode)
sl@0: //
sl@0: // Set this filter up for encryption.
sl@0: //
sl@0: 	{
sl@0: 	TStreamFilter::Set(aHost,aMode);
sl@0: 	iIn.Zero();
sl@0: //	Make sure any header added by the en/de-cryption goes
sl@0: //	straight into the output buffer 
sl@0:     TPtr8 buf(iBuf,sizeof(iBuf));
sl@0:     TRAPD(r, CryptL(buf,iIn));
sl@0:     UNUSED_VAR(r);
sl@0:     iOut.Set(buf);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TSecureFilter::Capacity(TInt aMaxLength)
sl@0: //
sl@0: // Return the maximum guaranteed input used for aMaxLength output.
sl@0: // If we can fulfil the request from the output buffer, consume nothing,
sl@0: // otherwise return the space left in the input buffer
sl@0: //
sl@0: 	{
sl@0: 	return aMaxLength<=iOut.Length() ? 0 : KEncryptionFilterBufSize-iIn.Length();
sl@0: 	}
sl@0: 
sl@0: LOCAL_C TInt transfer(TDes8& aTarg,TPtrC8& aSrc)
sl@0: 	{
sl@0: 	TInt avail=aTarg.MaxLength()-aTarg.Length();
sl@0: 	TInt len=Min(aSrc.Length(),avail);
sl@0: 	if (len)
sl@0: 		{
sl@0: 		aTarg.Append(aSrc.Left(len));
sl@0: 		aSrc.Set(aSrc.Mid(len));
sl@0: 		}
sl@0: 	return avail-len;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TSecureFilter::FilterL(TAny* aPtr,TInt aMaxLength,const TUint8*& aFrom,const TUint8* anEnd)
sl@0: //
sl@0: // Encrypt the input buffer.
sl@0: //
sl@0: // This must consume all its input - when called during reading, it's asserted
sl@0: // that aFrom == anEnd after calling this
sl@0: //
sl@0: 	{
sl@0: 	TPtr8 dest((TUint8*)aPtr,aMaxLength);
sl@0: 	TPtrC8 src(aFrom,anEnd-aFrom);
sl@0: 
sl@0:     // Copy as much as possible from the output buffer to the destination
sl@0: 	TInt req=transfer(dest,iOut);
sl@0: 
sl@0:     // If there's input in src, copy as much as possible to the input buffer
sl@0:     // iIn.  If the input buffer is full, the output buffer is empty, and there
sl@0:     // is space in the destination buffer, process data
sl@0: 	if ((src.Length()==0 || transfer(iIn,src)==0) && req)
sl@0: 		{	// process input buffer to generate more output
sl@0: 		do
sl@0: 			{
sl@0:             TPtr8 buf(iBuf,sizeof(iBuf));
sl@0: 			CryptL(buf,iIn);
sl@0: 			iOut.Set(buf);
sl@0:             iIn.Zero();
sl@0: 
sl@0:             // Copy as much data as possible from the output buffer to the final
sl@0:             // destination (updating iOut to point to the remainder), and as
sl@0:             // much as possible from the source to the input buffer.  If we have
sl@0:             // completely emptied the output buffer and filled the input buffer,
sl@0:             // and there is space in the destination buffer, go round again.
sl@0: 			} while (transfer(dest,iOut) && transfer(iIn,src)==0);
sl@0: 		}
sl@0: 
sl@0:     // Update client's src pointer to reflect what we've consumed
sl@0: 	aFrom=src.Ptr();
sl@0: 
sl@0:     // Return the number of bytes output
sl@0: 	return dest.Length();	
sl@0: }
sl@0: 
sl@0: TInt TSecureFilter::EmitL(const TDesC8& aDes)
sl@0: 	{
sl@0: 	TInt len=aDes.Length();
sl@0: 	if (len)
sl@0: 		TStreamFilter::EmitL(aDes.Ptr(),len);
sl@0: 	return len;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TSecureFilter::DoSynchL()
sl@0: //
sl@0: // Pad out remaining input if necessary, encrypt and emit.
sl@0: //
sl@0: 	{
sl@0: 	if (IsCommitted())
sl@0: 		return;
sl@0: //
sl@0: 	EmitL(iOut);
sl@0: 	iOut.Set(NULL,0);
sl@0: 	TPtr8 buf(iBuf,sizeof(iBuf));
sl@0: 	CompleteL(buf,iIn);
sl@0: 	TStreamFilter::DoSynchL();
sl@0: 	Committed();
sl@0: 	}
sl@0: 
sl@0: 
sl@0: EXPORT_C TEncryptFilter::TEncryptFilter():
sl@0: 	iKey(NULL)
sl@0: /** Constructs an empty encrypting filter object.
sl@0: 
sl@0: The encrypting filter must be set up before use.
sl@0: 
sl@0: @see Set() */
sl@0: 	{}
sl@0: 
sl@0: 
sl@0: EXPORT_C void TEncryptFilter::SetL(MStreamBuf* aHost,CPBEncryptor* aKey,TInt aMode)
sl@0: /*
sl@0: Set this filter up for encryption using a Password Based Encryption object.
sl@0: @publishedPartner
sl@0: @leave KErrNoMemory. If a leave occurs, ownership of aKey is retained by the caller, 
sl@0: which should thus keep aKey on the cleanup stack when calling this function.
sl@0: @param aHost The stream buffer that is the target for encrypted data.
sl@0: @param aKey A Password Based Encryption handling object. 
sl@0: Ownership is transferred from the caller to this object as long as no allocation leave occurs.
sl@0: @param aMode The mode in which the stream buffer is to be used. 
sl@0: By default, this is write mode as represented by EWrite.
sl@0: */
sl@0: 	{
sl@0:     __ASSERT_ALWAYS(aKey!=NULL,Panic(ECryptNoKey));
sl@0:     iKey=aKey;
sl@0: 	TSecureFilter::Set(aHost,aMode);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TEncryptFilter::CryptL(TDes8& aTarget,const TDesC8& aSource)
sl@0: 	{
sl@0:     iKey->Process(aSource,aTarget);
sl@0:     return aSource.Length();
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TEncryptFilter::CompleteL(TDes8& aTarget,const TDesC8& aSource)
sl@0: 	{
sl@0: // Encrypt and send remaining input buffer
sl@0:     if (aSource.Length() > 0)
sl@0:         {
sl@0:         CryptL(aTarget, aSource);
sl@0:         EmitL(aTarget);
sl@0:         aTarget.Zero();
sl@0:         }
sl@0: 
sl@0: 	TPtrC8 ptr;
sl@0: 	ptr.Set(NULL,0);
sl@0:     iKey->ProcessFinalL(ptr, aTarget);
sl@0: 	EmitL(aTarget);	
sl@0: }
sl@0: 
sl@0: EXPORT_C void TEncryptFilter::DoRelease()
sl@0: 	{
sl@0: 	delete iKey;
sl@0: 	iKey=NULL;
sl@0: 	TSecureFilter::DoRelease();
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TDecryptFilter::TDecryptFilter():
sl@0: 	iKey(NULL)
sl@0: /** Constructs an empty decrypting filter object.
sl@0: 
sl@0: The decrypting filter must be set up before use.
sl@0: 
sl@0: @see Set() */
sl@0: 	{}
sl@0: 
sl@0: 
sl@0: EXPORT_C void TDecryptFilter::SetL(MStreamBuf* aHost,CPBDecryptor* aKey,TInt aMode)
sl@0: /*
sl@0: Set this filter up for decryption using a Password Based Encryption object.
sl@0: @publishedPartner
sl@0: @leave KErrNoMemory. If a leave occurs, ownership of aKey is retained by the caller, 
sl@0: which should thus keep aKey on the cleanup stack when calling this function.
sl@0: @param aHost The stream buffer that is the source of encrypted data.
sl@0: @param aKey A Password Based Encryption decryption object. 
sl@0: Ownership is transferred from the caller to this object as long as no allocation leave occurs.
sl@0: @param aMode The mode in which the stream buffer is to be used. 
sl@0: By default, this is write mode as represented by ERead.
sl@0: */
sl@0: 	{
sl@0: 	__ASSERT_ALWAYS(aKey!=NULL,Panic(ECryptNoKey));
sl@0: 	iKey=aKey;
sl@0: 	TSecureFilter::Set(aHost,aMode);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TDecryptFilter::CryptL(TDes8& aTarget,const TDesC8& aSource)
sl@0: 	{
sl@0:     iKey->Process(aSource,aTarget);
sl@0:     return aSource.Length();
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TDecryptFilter::CompleteL(TDes8& /*aTarget*/,const TDesC8& aSource)
sl@0: 	{
sl@0: 	if (aSource.Length()!=0)
sl@0: 		User::Leave(KErrCorrupt);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TDecryptFilter::DoRelease()
sl@0: 	{
sl@0: 	delete iKey;
sl@0: 	iKey=NULL;
sl@0: 	TSecureFilter::DoRelease();
sl@0: 	}
sl@0: 
sl@0: void HEncryptFilter::DoRelease()
sl@0: //
sl@0: // Finished with this filter.
sl@0: //
sl@0: 	{
sl@0: 	delete this;
sl@0: 	}
sl@0: 
sl@0: void HDecryptFilter::DoRelease()
sl@0: //
sl@0: // Finished with this filter.
sl@0: //
sl@0: 	{
sl@0: 	delete this;
sl@0: 	}
sl@0: