/*

 * 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: 

 * Declares all classes used to decode ASN.1 data, including the 

 * base interface.

 *

 */

 /**

  @file

  @publishedAll

  @released

 */

 #ifndef __ASN1ENC_H__

 #define __ASN1ENC_H__

 #include <e32base.h>

 #include <asn1cons.h>

 class CASN1EncBase;

 class TASN1EncBase128DER;

 class TInteger;

 typedef void (CASN1EncBase::* WriteFunc)(TDes8& aBuf) const;

 /**

  * Base class for all ASN.1 types that we can encode.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncBase : public CBase

 	{

 public:

 	/**

 	 * Gives total number of octets in the DER encoding of this 

 	 * object.

 	 * @return Number of octets in DER encoding of this object.

 	 */

 	IMPORT_C TUint LengthDER() const;

 	/**

 	 * Writes entire DER encoding of this object into the given 

 	 * buffer.

 	 * @param aBuf Buffer receiving the encoding.

 	 * @param aPos Position to start writing at.

 	 */

 	IMPORT_C void WriteDERL(TDes8& aBuf, TUint& aPos) const;

 	/**

 	 * Sets tag type/class of the encoding object

 	 * @param aType Tag type to set

 	 * @param aClass Tag class to set.

 	 */

 	IMPORT_C void SetTag(const TTagType aType,

 		const TASN1Class aClass = EContextSpecific);

 	IMPORT_C ~CASN1EncBase();

 	/**

 	 * @internalComponent

 	 * 

 	 * Sets parent for the object

 	 * @param aParent Pointer to an ASN.1 object that becomes this 

 	 *     object's parent.

 	 */

 	void SetParent(CASN1EncBase* aParent);

 protected:

 	/**

 	 * Protected constructor

 	 * @param aType Tag type of the new object

 	 * @param aClass Tag class of the new object.

 	 */

 	IMPORT_C CASN1EncBase(const TTagType aType, const TASN1Class aClass);

 	/** 

 	 * Must call this version from derived classes in their 

 	 * ConstructL, but only once they're ready to have 

 	 * CalculateContentsLengthDER called on them.

 	 */

 	IMPORT_C virtual void ConstructL();

 	/**

 	 * @internalComponent

 	 *

 	 * Derived classes must call this if the length of their 

 	 * contents changes after construction.

 	 */

 	void ContentsLengthChanged();

 protected:

 	/** 

 	 * @internalComponent

 	 * 

 	 * Calculates number of octets in DER length encoding. Must set 

 	 * value of the appropriate data member. Made protected because it is 

 	 * needed by CASN1EncEncoding class.

 	 */

 	void CalculateLengthLengthDER();

 private:

 	/** 

 	 * Calculates number of octets in DER tag encoding. Must set 

 	 * value of the appropriate data member.

 	 */

 	void CalculateTagLengthDER();

 	/** 

 	 * Calculates number of octets in DER content encoding. Must set 

 	 * value of the appropriate data member.

 	 */

 	virtual void CalculateContentsLengthDER() = 0;

 	virtual TBool IsConstructed() const = 0;

 	// Write the octet data in each section

 	// Note that buffer *will* be big enough: these are called only 

 	// after checking.

 	/** 

 	 * Writes DER tag encoding into supplied buffer, which is 

 	 * already verified to be big enough.

 	 * @param aBuf Buffer to write to.

 	 */

 	void WriteTagDERL(TDes8& aBuf) const;

 	/** 

 	 * Writes DER length encoding into supplied buffer, which is 

 	 * already verified to be big enough.

 	 * @param aBuf Buffer to write to.

 	 */

 	virtual void WriteLengthDER(TDes8& aBuf) const;

 	/** 

 	 * Writes DER content encoding into supplied buffer, which is 

 	 * already verified to be big enough. Must be implemented by 

 	 * derived classes.

 	 * @param aBuf Buffer to write to.

 	 */

 	virtual void WriteContentsDERL(TDes8& aBuf) const = 0;

 	/** 

 	 * Helper function, used for efficiency

 	 * @param aBuf Buffer to write to

 	 * @param aPos Position in the buffer to start writing at 

 	 *     (updated on exit)

 	 * @param aLength Length of data to write

 	 * @param aWriteFunc Points to the function used to perform 

 	 *     the actual write operation.

 	 */

 	void WriteHelperL(TDes8& aBuf, TUint& aPos, const TUint aLength,

 		WriteFunc aWriteFunc) const;

 protected:

 	// Cached length data - data set from the CalculateXxxx methods above

 	TUint iTagLengthDER; ///< Length of DER encoded tag

 	TUint iLengthLengthDER; ///< Length of DER encoded length

 	TUint iContentsLengthDER; ///< Length of DER encoded content

 private:

 	/** 

 	 * The object owning this one (if we're held in a sequence, 

 	 * for example).

 	 */

 	CASN1EncBase* iParent;

 	// Tag data

 	TTagType iType; ///< Tag type of this object

 	TASN1Class iClass; ///< Tag class of this object

 	};

 /** 

  * Base class for all ASN1 constructed-type objects.  Most of these 

  * are container classes, but another type is the explicit-tagging 

  * wrapper object.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncConstructed : public CASN1EncBase

 	{

 protected:

 	/** 

 	 * @internalComponent

 	 * 

 	 * Protected constructor

 	 * @param aType Tag type for the new object

 	 * @param aClass Tag class for the new object.

 	 */

 	CASN1EncConstructed(const TTagType aType, const TASN1Class aClass);

 private:

 	virtual const CASN1EncBase& Child(const TUint aIndex) const = 0;

 	virtual TUint NumChildren() const = 0;

 private:

 	// From CASN1EncBase

 	void CalculateContentsLengthDER();

 	TBool IsConstructed() const;

 	void WriteContentsDERL(TDes8& aBuf) const;

 	};

 /** 

  * Class used to wrap other encoding objects in order to give 

  * them an explicit tag.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncExplicitTag : public CASN1EncConstructed

 	{

 public:

 	/** 

 	 * Takes ownership of the encoder, *including* the case when

 	 * this method leaves.

 	 * @param aEncoder ASN.1 encoding object to wrap

 	 * @param aType Tag type to assign

 	 * @param aClass Tag class to assign

 	 * @return Wrapped encoding object pushed on the cleanup stack.

 	 */

 	IMPORT_C static CASN1EncExplicitTag* NewLC(CASN1EncBase* aEncoder,

 		const TTagType aType, const TASN1Class aClass = EContextSpecific);

 	/** 

 	 * Takes ownership of the encoder, *including* the case when

 	 * this method leaves.

 	 * @param aEncoder ASN.1 encoding object to wrap

 	 * @param aType Tag type to assign

 	 * @param aClass Tag class to assign

 	 * @return Wrapped encoding object.

 	 */

 	IMPORT_C static CASN1EncExplicitTag* NewL(CASN1EncBase* aEncoder,

 		const TTagType aType, const TASN1Class aClass = EContextSpecific);

 	IMPORT_C ~CASN1EncExplicitTag(); // virtual from base

 private:

 	CASN1EncExplicitTag(CASN1EncBase* aEncoder, const TTagType aType, 

 		const TASN1Class aClass);

 	// From CASN1EncConstructed

 	TUint NumChildren() const;

 	const CASN1EncBase& Child(const TUint aIndex) const;

 private:

 	CASN1EncBase* iEncoder;  // Inner encoding object

 	};

 /** 

  * Base class for all ASN1 container types - sequences, 

  * sets, etc.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncContainer : public CASN1EncConstructed

 	{

 public:

 	/** 

 	 * Call this to add a child object to the container.

 	 * Takes ownership if and only if it doesn't Leave.

 	 * Checks for null input, calls AddChildInt, calls 

 	 * ContentsLengthChanged().

 	 * @param aChild Child ASN1 encoding object to add.

 	 */

 	IMPORT_C void AddChildL(CASN1EncBase* aChild);

 	/** 

 	 * Call this to add a child object to the container.

 	 * Takes ownership if and only if it doesn't Leave.

 	 * Checks for null input, calls AddChildInt, calls 

 	 * ContentsLengthChanged(). Pops added child object 

 	 * off the cleanup stack.

 	 * @param aChild Child ASN1 encoding object to add.

 	 */

 	IMPORT_C void AddAndPopChildL(CASN1EncBase* aChild);

 protected:

 	/** @internalComponent */

 	CASN1EncContainer(const TTagType aType);

 private:

 	/** 

 	 * Internal method, derived classes implement to add a child.

 	 * No need to check for null input or call 

 	 * ContentsLengthChanged(). Takes ownership, but only if you 

 	 * don't leave.

 	 * @param aChild Child encoding object to add.

 	 */

 	virtual void AddChildIntL(const CASN1EncBase* aChild) = 0;

 	};

 /** 

  * Class for encoding SEQUENCE and SEQUENCE-OF data types.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncSequence : public CASN1EncContainer

 	{

 public:

 	IMPORT_C static CASN1EncSequence* NewL();

 	IMPORT_C static CASN1EncSequence* NewLC();

 	IMPORT_C ~CASN1EncSequence(); // virtual from base

 protected:

 	/** @internalComponent */ 

 	CASN1EncSequence();

 private:

 	// From CASN1EncContainer

 	const CASN1EncBase& Child(const TUint aIndex) const;

 	void AddChildIntL(const CASN1EncBase* aChild);

 	TUint NumChildren() const;

 private:

 	RPointerArray<CASN1EncBase> iChildren;

 	};

 /** 

  * Class for encoding SET and SET-OF data types.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncSet : public CASN1EncContainer

 	{

 public:

 	/**

 	Creates an ASN.1 Set encoder.

 	@return The fully constructed object.

 	*/

 	IMPORT_C static CASN1EncSet* NewL();

 	/**

 	Creates an ASN.1 Set encoder, and puts it onto the cleanup stack.

 	@return The fully constructed object.

 	*/

 	IMPORT_C static CASN1EncSet* NewLC();

 	/**

 	Destructor.

 	*/

 	IMPORT_C ~CASN1EncSet(); // virtual from base

 protected:

 	/**

 	 * @internalComponent

 	 * 

 	 * Constructor

 	 */

 	CASN1EncSet();

 private:

 	// From CASN1EncContainer

 	const CASN1EncBase& Child(const TUint aIndex) const;

 	void AddChildIntL(const CASN1EncBase* aChild);

 	TUint NumChildren() const;

 private:

 	RPointerArray<CASN1EncBase> iChildren;

 	};

 /**

  * All ASN1 primitive type encoding classes derive from here.

  *

  * @publishedAll

  * @released

  */

 class CASN1EncPrimitive : public CASN1EncBase

 	{

 protected:

 	IMPORT_C CASN1EncPrimitive(const TTagType aType);

 private:

 	TBool IsConstructed() const; ///< Inherited from CASN1EncBase

 	};

 /** 

  * Class for encoding NULLs.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncNull : public CASN1EncPrimitive

 	{

 public:

 	IMPORT_C static CASN1EncNull* NewL();

 	IMPORT_C static CASN1EncNull* NewLC();

 private:

 	CASN1EncNull();

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER() ;

 	void WriteContentsDERL(TDes8& aBuf) const;

 	};

 /** 

  * Class for encoding Boolean values.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncBoolean : public CASN1EncPrimitive

 	{

 public:

 	IMPORT_C static CASN1EncBoolean* NewLC(const TBool aBool);

 	IMPORT_C static CASN1EncBoolean* NewL(const TBool aBool);

 private:

 	CASN1EncBoolean(const TBool aBool);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER() ;

 	void WriteContentsDERL(TDes8& aBuf) const;

 	const TBool iBool;

 	};

 /** 

  * Class for encoding TInts only. Use CASN1EncBigInt for encoding 

  * Big Integer objects.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncInt : public CASN1EncPrimitive

 	{

 public:

 	IMPORT_C static CASN1EncInt* NewLC(const TInt aInt);

 	IMPORT_C static CASN1EncInt* NewL(const TInt aInt);

 private:

 	CASN1EncInt(const TInt aInt);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER() ;

 	void WriteContentsDERL(TDes8& aBuf) const;

 private:

 	const TInt iInt;

 	};

 /** 

  * Class for encoding Big Integer objects only - use CASN1EncInt 

  * for TInts.

  *

  * @publishedAll

  * @released

  */

 class CASN1EncBigInt : public CASN1EncPrimitive

 	{

 public:

 	// Takes a deep copy

 	IMPORT_C static CASN1EncBigInt* NewLC(const TInteger& aInteger);

 	IMPORT_C static CASN1EncBigInt* NewL(const TInteger& aInteger);

 	IMPORT_C ~CASN1EncBigInt(); // virtual from base

 private:

 	CASN1EncBigInt();

 	void ConstructL(const TInteger& aInteger);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER();

 	void WriteContentsDERL(TDes8& aBuf) const;

 private:

 	HBufC8* iContents;

 	TPtrC8 iWriteContents;

 	};

 /** 

  * Class for encoding octet strings.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncOctetString : public CASN1EncPrimitive

 	{

 public:

 	// Takes a deep copy

 	IMPORT_C static CASN1EncOctetString* NewLC(const TDesC8& aStr);

 	IMPORT_C static CASN1EncOctetString* NewL(const TDesC8& aStr);

 	IMPORT_C ~CASN1EncOctetString(); // virtual from base

 private:

 	CASN1EncOctetString();

 	void ConstructL(const TDesC8& aStr);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER();

 	void WriteContentsDERL(TDes8& aBuf) const;

 private:

 	HBufC8* iContents;

 	};

 /** 

  * Class for encoding printable strings.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncPrintableString : public CASN1EncPrimitive

 	{

 public:

 	/**

 	Creates an ASN.1 Printable String encoder, and puts it onto the cleanup stack.

 	@return The fully constructed object.

 	*/

 	IMPORT_C static CASN1EncPrintableString* NewLC(const TDesC8& aStr);

 	/**

 	Creates an ASN.1 Printable String encoder.

 	@return The fully constructed object.

 	*/

 	IMPORT_C static CASN1EncPrintableString* NewL(const TDesC8& aStr);

 	/**

 	Destructor.

 	*/

 	IMPORT_C ~CASN1EncPrintableString(); // virtual from base

 private:

 	CASN1EncPrintableString();

 	void ConstructL(const TDesC8& aStr);

 	TInt CheckValid(const TDesC8& aStr);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER();

 	void WriteContentsDERL(TDes8& aBuf) const;

 private:

 	HBufC8* iContents;

 	};

 /**

  * Class for encoding bit strings (keys, for example).

  *

  * @publishedAll

  * @released

  */

 class CASN1EncBitString : public CASN1EncPrimitive

 	{

 public:

 	/** 

 	 * Constructs a new DER bit string encoder from a bit string that 

 	 * does not have unused bits at the end, i.e. is octet-aligned. 

 	 * The passed string must be in big-endian format. 

 	 * @param aBitStr	Octet-aligned bit string.

 	 * @return			A new DER bit string encoder object, 

 	 *					which is left on the cleanup stack.

 	 */

 	IMPORT_C static CASN1EncBitString* NewLC(const TDesC8& aBitStr);

 	/** 

 	 * Constructs a new DER bit string encoder from a bit string that 

 	 * does not have unused bits at the end, i.e. is octet-aligned. 

 	 * The passed string must be in big-endian format. 

 	 * @param aBitStr	Octet-aligned bit string.

 	 * @return			A new DER bit string encoder object.

 	 */

 	IMPORT_C static CASN1EncBitString* NewL(const TDesC8& aBitStr);

 	/** 

 	 * Constructs a new DER bit string encoder from a bit string that 

 	 * is not octet-aligned, which means it has unused bits in its last 

 	 * octet. The passed string must be in big-endian format.

 	 * @param aBitStr		Bit string.

 	 * @param aLengthBits	Length in bits of the passed bit string. 

 	 *     					The function will panic if aLengthBits is greater than 

 	 *     					the actual bit length of aBitString, or the difference 

 	 *     					is more that 7 bits.

 	 * @return				A new DER bit string encoder object which is left on the 

 	 *						cleanup stack.

 	 */

 	IMPORT_C static CASN1EncBitString* NewLC(const TDesC8& aBitStr, TUint aLengthBits);

 	/** 

 	 * Constructs a new DER bit string encoder from a bit string that 

 	 * is not octet-aligned, which means it has unused bits in its last 

 	 * octet. The passed string must be in big-endian format.

 	 * @param aBitStr		Bit string.

 	 * @param aLengthBits	Length in bits of the passed bit string. 

 	 *     					The function will panic if aLengthBits is greater than 

 	 *     					the actual bit length of aBitString, or the difference 

 	 *     					is more that 7 bits.

 	 * @return				A new DER bit string encoder object.

 	 */

 	IMPORT_C static CASN1EncBitString* NewL(const TDesC8& aBitStr, TUint aLengthBits);

 	/**

 	 * Wraps the passed encoding object into a bit string.

 	 * @param aAsnObj	Encoding object to wrap.

 	 * @return			A new bit string containing the passed encoding object.

 	 */

 	IMPORT_C static CASN1EncBitString* NewL(const CASN1EncBase& aAsnObj);

 	/**

 	 * Wraps the passed encoding object into a bit string.

 	 * @param aAsnObj	Encoding object to wrap.

 	 * @return			A new bit string containing the passed encoding object

 	 *     				on the cleanup stack.

 	 */

 	IMPORT_C static CASN1EncBitString* NewLC(const CASN1EncBase& aAsnObj);

 	IMPORT_C ~CASN1EncBitString(); // virtual from base

 private:

 	CASN1EncBitString();

 	void ConstructL(const TDesC8& aBitStr);

 	void ConstructL(const TDesC8& aBitStr, TUint aLengthBits);

 	void ConstructL(const CASN1EncBase& aAsnObj);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER();

 	void WriteContentsDERL(TDes8& aBuf) const;

 private:

 	HBufC8* iContents;

 	TUint8 iPadding;

 	};

 /**

  * Class for encoding object identifiers.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncObjectIdentifier : public CASN1EncPrimitive

 	{

 public:

 	/** 

 	 * Takes ints in a string, delimited by '.' characters in 

 	 * between (not at ends). Takes a deep copy of the info.

 	 * @param aStr	OID string.

 	 * @return		New ASN.1 OID object on the cleanup stack.

 	 */

 	IMPORT_C static CASN1EncObjectIdentifier* NewLC(const TDesC& aStr);

 	/** 

 	 * Takes ints in a string, delimited by '.' characters in 

 	 * between (not at ends). Takes a deep copy of the info.

 	 * @param aStr	OID string.

 	 * @return		New ASN.1 OID object.

 	 */

 	IMPORT_C static CASN1EncObjectIdentifier* NewL(const TDesC& aStr);

 	/** Destructor */

 	IMPORT_C ~CASN1EncObjectIdentifier(); // virtual from base

 private:

 	CASN1EncObjectIdentifier();

 	void ConstructL(const TDesC& aStr);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER();

 	void WriteContentsDERL(TDes8& aBuf) const;

 private:

 	// Data to encode

 	RArray<TASN1EncBase128DER> iData;

 	TUint8 iFirstOctet;

 	};

 /** 

  * Class for encoding GeneralisedTime objects. 

  *

  * Doesn't support fractions of seconds or regional time zone offsets.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncGeneralizedTime : public CASN1EncPrimitive

 	{

 public:

 	IMPORT_C static CASN1EncGeneralizedTime* NewLC(const TTime& aTime);

 	IMPORT_C static CASN1EncGeneralizedTime* NewL(const TTime& aTime);

 private:

 	CASN1EncGeneralizedTime(const TTime& aTime);

 	// Methods from CASN1EncBase

 	void CalculateContentsLengthDER();

 	void WriteContentsDERL(TDes8& aBuf) const;

 private:

 	TDateTime iDateTime;

 	};

 /** 

  * Class for encapsulation of already encoded data. 

  *

  * Wraps it so that the data could be used in the ASN.1 hierarchy. 

  * It reverse-engineers and stores the encoded data, providing whatever 

  * information is needed to override pure virtual methods of the base 

  * class and write out the DER encoding in its initial form.

  * 

  * @publishedAll

  * @released

  */

 class CASN1EncEncoding : public CASN1EncBase

 	{

 public:

 	/** 

 	 * Creates a new object from raw DER encoding and places it on the 

 	 * cleanup stack.

 	 * @param aEncoding	Raw DER encoding.

 	 * @return			New wrapper object placed on the cleanup stack.

 	 */

 	IMPORT_C static CASN1EncEncoding* NewLC(const TDesC8& aEncoding);

 	/** 

 	 * Creates a new object from raw DER encoding.

 	 * @param aEncoding	Raw DER encoding.

 	 * @return			New wrapper object.

 	 */

 	IMPORT_C static CASN1EncEncoding* NewL(const TDesC8& aEncoding);

 	IMPORT_C static CASN1EncEncoding* NewLC(const TDesC8& aEncoding, TTagType aType, TASN1Class aClass);

 	IMPORT_C ~CASN1EncEncoding();

 protected:

 	/** 

 	 * Protected constructor.

 	 * <!--

 	 * @param aType		Tag type of the new object

 	 * @param aClass	Tag class of the new object.

 	 * -->

 	 */

 	IMPORT_C CASN1EncEncoding();

 private:

 	/** 

 	 * Constructs the wrapper around the passed raw DER encoding. 

 	 * Calculates element sizes. Decodes it to get type and length.

 	 * @param aEncoding Raw DER encoding.

 	 */

 	void ConstructL(const TDesC8& aEncoding);

 	void ConstructL(const TDesC8& aEncoding, TTagType aType, TASN1Class aClass);

 	virtual TBool IsConstructed() const;

 	/** 

 	 * Writes DER content encoding into supplied buffer, which is 

 	 * already verified to be big enough.

 	 * @param aBuf	Buffer to write to.

 	 */

 	virtual void WriteContentsDERL(TDes8& aBuf) const;

 	/** 

 	 * Calculates number of octets in DER content encoding. Sets 

 	 * value of the appropriate data member.

 	 */

 	virtual void CalculateContentsLengthDER();

 private:

 	HBufC8* iContents; ///< Copy of the supplied DER encoded data (contents only).

 	TASN1Class iClass; ///< ASN.1 class of the encoded object.

 	TTagType iTag; ///< ASN.1 tag of the encoding.

 	};

 #endif // __ASN1ENC_H__