/*

* Copyright (c) 2006-2009 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: 

*

*/

/**

 @file

 @internalTechnology 

*/

#ifndef __PKCS12RECOG_H__

#include <apmrec.h>

/**

 A recogniser that recognises the following MIME types:

 application/x-pkcs12

 */

class CPkcs12Recognizer : public CApaDataRecognizerType

	{

	/** PKCS#12 recognizer panic codes */

	enum TPkcs12RecogPanic 

		{

		/** Data type index does not correspond to a mime-type */

		EPanicInvalidDataType

		};

public:

	/**

	Constructor

	*/

	CPkcs12Recognizer();

public: 

	/**

	Returns the preferred buffer size for PKCS#12 recognition

	@return preferred buffer size in bytes

	*/

	TUint PreferredBufSize();

	/**

	Allows a client to enumerate the supported mime-types.

	@param aIndex index of the mimetype to return

	@return mime-type corresponding to aIndex

	*/

	TDataType SupportedDataTypeL(TInt aIndex) const;

	static CApaDataRecognizerType* CreateRecognizerL();

private:

	// Implementation CApaDataRecognizerType::DoRecognizeL

	void DoRecognizeL(const TDesC& aName, const TDesC8& aBuffer);

	/**

	Checks whether the file name has a known PKCS#12 extension

	@param aName the file name to examine

	@return ETrue if the file extension looks is .pfx or .p12;

		    otherwise, EFalse is returned.

	*/

	TBool HasPkcs12Extension(const TDesC& aName);

	/**	

	Checks whether the buffer contains a valid PKCS#12 header.

	aBuffer buffer to recognise

	Expected ASN.1 sequence

	SEQ

		INTEGER  	// Version = 3

		SEQ		 	// authSafe - PKCS#7 ContentInfo

			OID		// ContentType (data or signed data)

	It is not practical to check further than this because the content

	field within the ContentInfo objects is optional and could be absent.

	@param aBuffer the buffer to check

	@return ETrue if the buffer contains a PKCS#12 header; 

			otherwise, EFalse is returned.	

	*/

	TBool DoRecognizeBufferL(const TDesC8& aBuffer);

	// There is no need to validate the lengths because the recogniser

	// checks the buffer size is at least as large as the minimum header

	// size	

	/**

	Checks that the data at the specified offset is a DER sequence tag

	and advances past the tag and it's length.

	@param aBuffer the buffer containing the DER sequence to validate

	@param aOffset the offset of the current byte within the buffer. This

	               is undefined if an error occurs.

	@return ETrue if a valid sequence tag & length is encountered;

			otherwise, EFalse is returned.

	*/

	TBool ConsumeSequenceL(const TDesC8& aBuffer, TUint& aOffset) const;

	/**

	Decodes a DER encoded integer at the specified offset and advances

	to the next element.

	Signed integers greater than 32 bits in length are not supported.	

	@param aBuffer the buffer containing the DER intger to decode

	@param aOffset the offset of the current byte within the buffer. This

	               is undefined if an error occurs.

	@param aIntVal the decoded integer value. This is undefined if an error occurs.

	@return ETrue if a valid integer is encountered; 

			otherwise, EFalse is returned.

	*/	

	TBool ConsumeIntegerL(const TDesC8& aBuffer, TUint& aOffset, TInt& aIntVal) const;

	/**

	Decodes a DER encoded length at the specified offset and advances

	to the start of the value.

	Lengths greater than 32 bits in length are not supported.

	@param aBuffer the buffer containing the length to decode.

	@param aOffset the offset of the current byte within the buffer. This

	               is undefined if an error occurs.

	@param aLength the decoded length value in octets. This is undefined if an error occurs.

	@return ETrue if the length is valid; otherwise, EFalse is returned.

	*/			

	TBool ConsumeLengthL(const TDesC8& aBuffer, TUint& aOffset, TInt& aLengthOctets) const;

	/**

	Decodes base256 encoded integer up to 4 bytes in length and advances

	past the data.

	Signed integers greater than 32 bits in length are not supported.

	@param aBuffer the buffer containing the octets to decode.

	@param aOffset the offset of the current byte within the buffer. This

	               is undefined if an error occurs.

	@param aLength the number of octets to decode (must be <= 4)

	@param aIntVal the decoded integer. This is undefined if an error occurs.

	*/		

	TBool ConsumeBase256L(const TDesC8& aBuffer, TUint& aOffset, TInt aLengthOctets, TInt& aIntVal) const;

	/**

	Calls panic with PKCS#12 recognizer category with the supplied panic code.

	@param aReason the panic code

	*/

	void Panic(TPkcs12RecogPanic aReason) const;

	};

#endif