/*

 * 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