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+// cryptlib.h - written and placed in the public domain by Wei Dai
+/*! \file
+ 	This file contains the declarations for the abstract base
+	classes that provide a uniform interface to this library.
+*/
+
+/*!	\mainpage Crypto++ Library 5.6.0 API Reference
+<dl>
+<dt>Abstract Base Classes<dd>
+	cryptlib.h
+<dt>Authenticated Encryption<dd>
+	AuthenticatedSymmetricCipherDocumentation
+<dt>Symmetric Ciphers<dd>
+	SymmetricCipherDocumentation
+<dt>Hash Functions<dd>
+	SHA1, SHA224, SHA256, SHA384, SHA512, Tiger, Whirlpool, RIPEMD160, RIPEMD320, RIPEMD128, RIPEMD256, Weak1::MD2, Weak1::MD4, Weak1::MD5
+<dt>Non-Cryptographic Checksums<dd>
+	CRC32, Adler32
+<dt>Message Authentication Codes<dd>
+	VMAC, HMAC, CBC_MAC, CMAC, DMAC, TTMAC, GCM (GMAC)
+<dt>Random Number Generators<dd>
+	NullRNG(), LC_RNG, RandomPool, BlockingRng, NonblockingRng, AutoSeededRandomPool, AutoSeededX917RNG, DefaultAutoSeededRNG
+<dt>Password-based Cryptography<dd>
+	PasswordBasedKeyDerivationFunction
+<dt>Public Key Cryptosystems<dd>
+	DLIES, ECIES, LUCES, RSAES, RabinES, LUC_IES
+<dt>Public Key Signature Schemes<dd>
+	DSA, GDSA, ECDSA, NR, ECNR, LUCSS, RSASS, RSASS_ISO, RabinSS, RWSS, ESIGN
+<dt>Key Agreement<dd>
+	#DH, DH2, #MQV, ECDH, ECMQV, XTR_DH
+<dt>Algebraic Structures<dd>
+	Integer, PolynomialMod2, PolynomialOver, RingOfPolynomialsOver,
+	ModularArithmetic, MontgomeryRepresentation, GFP2_ONB,
+	GF2NP, GF256, GF2_32, EC2N, ECP
+<dt>Secret Sharing and Information Dispersal<dd>
+	SecretSharing, SecretRecovery, InformationDispersal, InformationRecovery
+<dt>Compression<dd>
+	Deflator, Inflator, Gzip, Gunzip, ZlibCompressor, ZlibDecompressor
+<dt>Input Source Classes<dd>
+	StringSource, ArraySource, FileSource, SocketSource, WindowsPipeSource, RandomNumberSource
+<dt>Output Sink Classes<dd>
+	StringSinkTemplate, ArraySink, FileSink, SocketSink, WindowsPipeSink, RandomNumberSink
+<dt>Filter Wrappers<dd>
+	StreamTransformationFilter, HashFilter, HashVerificationFilter, SignerFilter, SignatureVerificationFilter
+<dt>Binary to Text Encoders and Decoders<dd>
+	HexEncoder, HexDecoder, Base64Encoder, Base64Decoder, Base32Encoder, Base32Decoder
+<dt>Wrappers for OS features<dd>
+	Timer, Socket, WindowsHandle, ThreadLocalStorage, ThreadUserTimer
+<dt>FIPS 140 related<dd>
+	fips140.h
+</dl>
+
+In the FIPS 140-2 validated DLL version of Crypto++, only the following implementation class are available.
+<dl>
+<dt>Block Ciphers<dd>
+	AES, DES_EDE2, DES_EDE3, SKIPJACK
+<dt>Cipher Modes (replace template parameter BC with one of the block ciphers above)<dd>
+	ECB_Mode\<BC\>, CTR_Mode\<BC\>, CBC_Mode\<BC\>, CFB_FIPS_Mode\<BC\>, OFB_Mode\<BC\>
+<dt>Hash Functions<dd>
+	SHA1, SHA224, SHA256, SHA384, SHA512
+<dt>Public Key Signature Schemes (replace template parameter H with one of the hash functions above)<dd>
+	RSASS\<PKCS1v15, H\>, RSASS\<PSS, H\>, RSASS_ISO\<H\>, RWSS\<P1363_EMSA2, H\>, DSA, ECDSA\<ECP, H\>, ECDSA\<EC2N, H\>
+<dt>Message Authentication Codes (replace template parameter H with one of the hash functions above)<dd>
+	HMAC\<H\>, CBC_MAC\<DES_EDE2\>, CBC_MAC\<DES_EDE3\>
+<dt>Random Number Generators<dd>
+	DefaultAutoSeededRNG (AutoSeededX917RNG\<AES\>)
+<dt>Key Agreement<dd>
+	#DH
+<dt>Public Key Cryptosystems<dd>
+	RSAES\<OAEP\<SHA1\> \>
+</dl>
+
+<p>This reference manual is a work in progress. Some classes are still lacking detailed descriptions.
+<p>Click <a href="CryptoPPRef.zip">here</a> to download a zip archive containing this manual.
+<p>Thanks to Ryan Phillips for providing the Doxygen configuration file
+and getting me started with this manual.
+*/
+
+#ifndef CRYPTOPP_CRYPTLIB_H
+#define CRYPTOPP_CRYPTLIB_H
+
+#include "config.h"
+#include "stdcpp.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+// forward declarations
+class Integer;
+class RandomNumberGenerator;
+class BufferedTransformation;
+
+//! used to specify a direction for a cipher to operate in (encrypt or decrypt)
+enum CipherDir {ENCRYPTION, DECRYPTION};
+
+//! used to represent infinite time
+const unsigned long INFINITE_TIME = ULONG_MAX;
+
+// VC60 workaround: using enums as template parameters causes problems
+template <typename ENUM_TYPE, int VALUE>
+struct EnumToType
+{
+	static ENUM_TYPE ToEnum() {return (ENUM_TYPE)VALUE;}
+};
+
+enum ByteOrder {LITTLE_ENDIAN_ORDER = 0, BIG_ENDIAN_ORDER = 1};
+typedef EnumToType<ByteOrder, LITTLE_ENDIAN_ORDER> LittleEndian;
+typedef EnumToType<ByteOrder, BIG_ENDIAN_ORDER> BigEndian;
+
+//! base class for all exceptions thrown by Crypto++
+class CRYPTOPP_DLL Exception : public std::exception
+{
+public:
+	//! error types
+	enum ErrorType {
+		//! a method is not implemented
+		NOT_IMPLEMENTED,
+		//! invalid function argument
+		INVALID_ARGUMENT,
+		//! BufferedTransformation received a Flush(true) signal but can't flush buffers
+		CANNOT_FLUSH,
+		//! data integerity check (such as CRC or MAC) failed
+		DATA_INTEGRITY_CHECK_FAILED,
+		//! received input data that doesn't conform to expected format
+		INVALID_DATA_FORMAT,
+		//! error reading from input device or writing to output device
+		IO_ERROR,
+		//! some error not belong to any of the above categories
+		OTHER_ERROR
+	};
+
+	explicit Exception(ErrorType errorType, const std::string &s) : m_errorType(errorType), m_what(s) {}
+	virtual ~Exception() throw() {}
+	const char *what() const throw() {return (m_what.c_str());}
+	const std::string &GetWhat() const {return m_what;}
+	void SetWhat(const std::string &s) {m_what = s;}
+	ErrorType GetErrorType() const {return m_errorType;}
+	void SetErrorType(ErrorType errorType) {m_errorType = errorType;}
+
+private:
+	ErrorType m_errorType;
+	std::string m_what;
+};
+
+//! exception thrown when an invalid argument is detected
+class CRYPTOPP_DLL InvalidArgument : public Exception
+{
+public:
+	explicit InvalidArgument(const std::string &s) : Exception(INVALID_ARGUMENT, s) {}
+};
+
+//! exception thrown when input data is received that doesn't conform to expected format
+class CRYPTOPP_DLL InvalidDataFormat : public Exception
+{
+public:
+	explicit InvalidDataFormat(const std::string &s) : Exception(INVALID_DATA_FORMAT, s) {}
+};
+
+//! exception thrown by decryption filters when trying to decrypt an invalid ciphertext
+class CRYPTOPP_DLL InvalidCiphertext : public InvalidDataFormat
+{
+public:
+	explicit InvalidCiphertext(const std::string &s) : InvalidDataFormat(s) {}
+};
+
+//! exception thrown by a class if a non-implemented method is called
+class CRYPTOPP_DLL NotImplemented : public Exception
+{
+public:
+	explicit NotImplemented(const std::string &s) : Exception(NOT_IMPLEMENTED, s) {}
+};
+
+//! exception thrown by a class when Flush(true) is called but it can't completely flush its buffers
+class CRYPTOPP_DLL CannotFlush : public Exception
+{
+public:
+	explicit CannotFlush(const std::string &s) : Exception(CANNOT_FLUSH, s) {}
+};
+
+//! error reported by the operating system
+class CRYPTOPP_DLL OS_Error : public Exception
+{
+public:
+	OS_Error(ErrorType errorType, const std::string &s, const std::string& operation, int errorCode)
+		: Exception(errorType, s), m_operation(operation), m_errorCode(errorCode) {}
+	~OS_Error() throw() {}
+
+	// the operating system API that reported the error
+	const std::string & GetOperation() const {return m_operation;}
+	// the error code return by the operating system
+	int GetErrorCode() const {return m_errorCode;}
+
+protected:
+	std::string m_operation;
+	int m_errorCode;
+};
+
+//! used to return decoding results
+struct CRYPTOPP_DLL DecodingResult
+{
+	explicit DecodingResult() : isValidCoding(false), messageLength(0) {}
+	explicit DecodingResult(size_t len) : isValidCoding(true), messageLength(len) {}
+
+	bool operator==(const DecodingResult &rhs) const {return isValidCoding == rhs.isValidCoding && messageLength == rhs.messageLength;}
+	bool operator!=(const DecodingResult &rhs) const {return !operator==(rhs);}
+
+	bool isValidCoding;
+	size_t messageLength;
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+	operator size_t() const {return isValidCoding ? messageLength : 0;}
+#endif
+};
+
+//! interface for retrieving values given their names
+/*! \note This class is used to safely pass a variable number of arbitrarily typed arguments to functions
+	and to read values from keys and crypto parameters.
+	\note To obtain an object that implements NameValuePairs for the purpose of parameter
+	passing, use the MakeParameters() function.
+	\note To get a value from NameValuePairs, you need to know the name and the type of the value. 
+	Call GetValueNames() on a NameValuePairs object to obtain a list of value names that it supports.
+	Then look at the Name namespace documentation to see what the type of each value is, or
+	alternatively, call GetIntValue() with the value name, and if the type is not int, a
+	ValueTypeMismatch exception will be thrown and you can get the actual type from the exception object.
+*/
+class CRYPTOPP_NO_VTABLE NameValuePairs
+{
+public:
+	virtual ~NameValuePairs() {}
+
+	//! exception thrown when trying to retrieve a value using a different type than expected
+	class CRYPTOPP_DLL ValueTypeMismatch : public InvalidArgument
+	{
+	public:
+		ValueTypeMismatch(const std::string &name, const std::type_info &stored, const std::type_info &retrieving)
+			: InvalidArgument("NameValuePairs: type mismatch for '" + name + "', stored '" + stored.name() + "', trying to retrieve '" + retrieving.name() + "'")
+			, m_stored(stored), m_retrieving(retrieving) {}
+
+		const std::type_info & GetStoredTypeInfo() const {return m_stored;}
+		const std::type_info & GetRetrievingTypeInfo() const {return m_retrieving;}
+
+	private:
+		const std::type_info &m_stored;
+		const std::type_info &m_retrieving;
+	};
+
+	//! get a copy of this object or a subobject of it
+	template <class T>
+	bool GetThisObject(T &object) const
+	{
+		return GetValue((std::string("ThisObject:")+typeid(T).name()).c_str(), object);
+	}
+
+	//! get a pointer to this object, as a pointer to T
+	template <class T>
+	bool GetThisPointer(T *&p) const
+	{
+		return GetValue((std::string("ThisPointer:")+typeid(T).name()).c_str(), p);
+	}
+
+	//! get a named value, returns true if the name exists
+	template <class T>
+	bool GetValue(const char *name, T &value) const
+	{
+		return GetVoidValue(name, typeid(T), &value);
+	}
+
+	//! get a named value, returns the default if the name doesn't exist
+	template <class T>
+	T GetValueWithDefault(const char *name, T defaultValue) const
+	{
+		GetValue(name, defaultValue);
+		return defaultValue;
+	}
+
+	//! get a list of value names that can be retrieved
+	CRYPTOPP_DLL std::string GetValueNames() const
+		{std::string result; GetValue("ValueNames", result); return result;}
+
+	//! get a named value with type int
+	/*! used to ensure we don't accidentally try to get an unsigned int
+		or some other type when we mean int (which is the most common case) */
+	CRYPTOPP_DLL bool GetIntValue(const char *name, int &value) const
+		{return GetValue(name, value);}
+
+	//! get a named value with type int, with default
+	CRYPTOPP_DLL int GetIntValueWithDefault(const char *name, int defaultValue) const
+		{return GetValueWithDefault(name, defaultValue);}
+
+	//! used by derived classes to check for type mismatch
+	CRYPTOPP_DLL static void CRYPTOPP_API ThrowIfTypeMismatch(const char *name, const std::type_info &stored, const std::type_info &retrieving)
+		{if (stored != retrieving) throw ValueTypeMismatch(name, stored, retrieving);}
+
+	template <class T>
+	void GetRequiredParameter(const char *className, const char *name, T &value) const
+	{
+		if (!GetValue(name, value))
+			throw InvalidArgument(std::string(className) + ": missing required parameter '" + name + "'");
+	}
+
+	CRYPTOPP_DLL void GetRequiredIntParameter(const char *className, const char *name, int &value) const
+	{
+		if (!GetIntValue(name, value))
+			throw InvalidArgument(std::string(className) + ": missing required parameter '" + name + "'");
+	}
+
+	//! to be implemented by derived classes, users should use one of the above functions instead
+	CRYPTOPP_DLL virtual bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const =0;
+};
+
+//! namespace containing value name definitions
+/*!	value names, types and semantics:
+
+	ThisObject:ClassName (ClassName, copy of this object or a subobject)
+	ThisPointer:ClassName (const ClassName *, pointer to this object or a subobject)
+*/
+DOCUMENTED_NAMESPACE_BEGIN(Name)
+// more names defined in argnames.h
+DOCUMENTED_NAMESPACE_END
+
+//! empty set of name-value pairs
+class CRYPTOPP_DLL NullNameValuePairs : public NameValuePairs
+{
+public:
+	bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const {return false;}
+};
+
+//! _
+extern CRYPTOPP_DLL const NullNameValuePairs g_nullNameValuePairs;
+
+// ********************************************************
+
+//! interface for cloning objects, this is not implemented by most classes yet
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE Clonable
+{
+public:
+	virtual ~Clonable() {}
+	//! this is not implemented by most classes yet
+	virtual Clonable* Clone() const {throw NotImplemented("Clone() is not implemented yet.");}	// TODO: make this =0
+};
+
+//! interface for all crypto algorithms
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE Algorithm : public Clonable
+{
+public:
+	/*! When FIPS 140-2 compliance is enabled and checkSelfTestStatus == true,
+		this constructor throws SelfTestFailure if the self test hasn't been run or fails. */
+	Algorithm(bool checkSelfTestStatus = true);
+	//! returns name of this algorithm, not universally implemented yet
+	virtual std::string AlgorithmName() const {return "unknown";}
+};
+
+//! keying interface for crypto algorithms that take byte strings as keys
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE SimpleKeyingInterface
+{
+public:
+	virtual ~SimpleKeyingInterface() {}
+
+	//! returns smallest valid key length in bytes */
+	virtual size_t MinKeyLength() const =0;
+	//! returns largest valid key length in bytes */
+	virtual size_t MaxKeyLength() const =0;
+	//! returns default (recommended) key length in bytes */
+	virtual size_t DefaultKeyLength() const =0;
+
+	//! returns the smallest valid key length in bytes that is >= min(n, GetMaxKeyLength())
+	virtual size_t GetValidKeyLength(size_t n) const =0;
+
+	//! returns whether n is a valid key length
+	virtual bool IsValidKeyLength(size_t n) const
+		{return n == GetValidKeyLength(n);}
+
+	//! set or reset the key of this object
+	/*! \param params is used to specify Rounds, BlockSize, etc. */
+	virtual void SetKey(const byte *key, size_t length, const NameValuePairs &params = g_nullNameValuePairs);
+
+	//! calls SetKey() with an NameValuePairs object that just specifies "Rounds"
+	void SetKeyWithRounds(const byte *key, size_t length, int rounds);
+
+	//! calls SetKey() with an NameValuePairs object that just specifies "IV"
+	void SetKeyWithIV(const byte *key, size_t length, const byte *iv, size_t ivLength);
+
+	//! calls SetKey() with an NameValuePairs object that just specifies "IV"
+	void SetKeyWithIV(const byte *key, size_t length, const byte *iv)
+		{SetKeyWithIV(key, length, iv, IVSize());}
+
+	enum IV_Requirement {UNIQUE_IV = 0, RANDOM_IV, UNPREDICTABLE_RANDOM_IV, INTERNALLY_GENERATED_IV, NOT_RESYNCHRONIZABLE};
+	//! returns the minimal requirement for secure IVs
+	virtual IV_Requirement IVRequirement() const =0;
+
+	//! returns whether this object can be resynchronized (i.e. supports initialization vectors)
+	/*! If this function returns true, and no IV is passed to SetKey() and CanUseStructuredIVs()==true, an IV of all 0's will be assumed. */
+	bool IsResynchronizable() const {return IVRequirement() < NOT_RESYNCHRONIZABLE;}
+	//! returns whether this object can use random IVs (in addition to ones returned by GetNextIV)
+	bool CanUseRandomIVs() const {return IVRequirement() <= UNPREDICTABLE_RANDOM_IV;}
+	//! returns whether this object can use random but possibly predictable IVs (in addition to ones returned by GetNextIV)
+	bool CanUsePredictableIVs() const {return IVRequirement() <= RANDOM_IV;}
+	//! returns whether this object can use structured IVs, for example a counter (in addition to ones returned by GetNextIV)
+	bool CanUseStructuredIVs() const {return IVRequirement() <= UNIQUE_IV;}
+
+	virtual unsigned int IVSize() const {throw NotImplemented(GetAlgorithm().AlgorithmName() + ": this object doesn't support resynchronization");}
+	//! returns default length of IVs accepted by this object
+	unsigned int DefaultIVLength() const {return IVSize();}
+	//! returns minimal length of IVs accepted by this object
+	virtual unsigned int MinIVLength() const {return IVSize();}
+	//! returns maximal length of IVs accepted by this object
+	virtual unsigned int MaxIVLength() const {return IVSize();}
+	//! resynchronize with an IV. ivLength=-1 means use IVSize()
+	virtual void Resynchronize(const byte *iv, int ivLength=-1) {throw NotImplemented(GetAlgorithm().AlgorithmName() + ": this object doesn't support resynchronization");}
+	//! get a secure IV for the next message
+	/*! This method should be called after you finish encrypting one message and are ready to start the next one.
+		After calling it, you must call SetKey() or Resynchronize() before using this object again. 
+		This method is not implemented on decryption objects. */
+	virtual void GetNextIV(RandomNumberGenerator &rng, byte *IV);
+
+protected:
+	virtual const Algorithm & GetAlgorithm() const =0;
+	virtual void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params) =0;
+
+	void ThrowIfInvalidKeyLength(size_t length);
+	void ThrowIfResynchronizable();			// to be called when no IV is passed
+	void ThrowIfInvalidIV(const byte *iv);	// check for NULL IV if it can't be used
+	size_t ThrowIfInvalidIVLength(int size);
+	const byte * GetIVAndThrowIfInvalid(const NameValuePairs &params, size_t &size);
+	inline void AssertValidKeyLength(size_t length) const
+		{assert(IsValidKeyLength(length));}
+};
+
+//! interface for the data processing part of block ciphers
+
+/*! Classes derived from BlockTransformation are block ciphers
+	in ECB mode (for example the DES::Encryption class), which are stateless.
+	These classes should not be used directly, but only in combination with
+	a mode class (see CipherModeDocumentation in modes.h).
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE BlockTransformation : public Algorithm
+{
+public:
+	//! encrypt or decrypt inBlock, xor with xorBlock, and write to outBlock
+	virtual void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const =0;
+
+	//! encrypt or decrypt one block
+	/*! \pre size of inBlock and outBlock == BlockSize() */
+	void ProcessBlock(const byte *inBlock, byte *outBlock) const
+		{ProcessAndXorBlock(inBlock, NULL, outBlock);}
+
+	//! encrypt or decrypt one block in place
+	void ProcessBlock(byte *inoutBlock) const
+		{ProcessAndXorBlock(inoutBlock, NULL, inoutBlock);}
+
+	//! block size of the cipher in bytes
+	virtual unsigned int BlockSize() const =0;
+
+	//! returns how inputs and outputs should be aligned for optimal performance
+	virtual unsigned int OptimalDataAlignment() const;
+
+	//! returns true if this is a permutation (i.e. there is an inverse transformation)
+	virtual bool IsPermutation() const {return true;}
+
+	//! returns true if this is an encryption object
+	virtual bool IsForwardTransformation() const =0;
+
+	//! return number of blocks that can be processed in parallel, for bit-slicing implementations
+	virtual unsigned int OptimalNumberOfParallelBlocks() const {return 1;}
+
+	enum {BT_InBlockIsCounter=1, BT_DontIncrementInOutPointers=2, BT_XorInput=4, BT_ReverseDirection=8} FlagsForAdvancedProcessBlocks;
+
+	//! encrypt and xor blocks according to flags (see FlagsForAdvancedProcessBlocks)
+	/*! /note If BT_InBlockIsCounter is set, last byte of inBlocks may be modified. */
+	virtual size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
+
+	inline CipherDir GetCipherDirection() const {return IsForwardTransformation() ? ENCRYPTION : DECRYPTION;}
+};
+
+//! interface for the data processing part of stream ciphers
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE StreamTransformation : public Algorithm
+{
+public:
+	//! return a reference to this object, 
+	/*! This function is useful for passing a temporary StreamTransformation object to a 
+		function that takes a non-const reference. */
+	StreamTransformation& Ref() {return *this;}
+
+	//! returns block size, if input must be processed in blocks, otherwise 1
+	virtual unsigned int MandatoryBlockSize() const {return 1;}
+
+	//! returns the input block size that is most efficient for this cipher
+	/*! \note optimal input length is n * OptimalBlockSize() - GetOptimalBlockSizeUsed() for any n > 0 */
+	virtual unsigned int OptimalBlockSize() const {return MandatoryBlockSize();}
+	//! returns how much of the current block is used up
+	virtual unsigned int GetOptimalBlockSizeUsed() const {return 0;}
+
+	//! returns how input should be aligned for optimal performance
+	virtual unsigned int OptimalDataAlignment() const;
+
+	//! encrypt or decrypt an array of bytes of specified length
+	/*! \note either inString == outString, or they don't overlap */
+	virtual void ProcessData(byte *outString, const byte *inString, size_t length) =0;
+
+	//! for ciphers where the last block of data is special, encrypt or decrypt the last block of data
+	/*! For now the only use of this function is for CBC-CTS mode. */
+	virtual void ProcessLastBlock(byte *outString, const byte *inString, size_t length);
+	//! returns the minimum size of the last block, 0 indicating the last block is not special
+	virtual unsigned int MinLastBlockSize() const {return 0;}
+
+	//! same as ProcessData(inoutString, inoutString, length)
+	inline void ProcessString(byte *inoutString, size_t length)
+		{ProcessData(inoutString, inoutString, length);}
+	//! same as ProcessData(outString, inString, length)
+	inline void ProcessString(byte *outString, const byte *inString, size_t length)
+		{ProcessData(outString, inString, length);}
+	//! implemented as {ProcessData(&input, &input, 1); return input;}
+	inline byte ProcessByte(byte input)
+		{ProcessData(&input, &input, 1); return input;}
+
+	//! returns whether this cipher supports random access
+	virtual bool IsRandomAccess() const =0;
+	//! for random access ciphers, seek to an absolute position
+	virtual void Seek(lword n)
+	{
+		assert(!IsRandomAccess());
+		throw NotImplemented("StreamTransformation: this object doesn't support random access");
+	}
+
+	//! returns whether this transformation is self-inverting (e.g. xor with a keystream)
+	virtual bool IsSelfInverting() const =0;
+	//! returns whether this is an encryption object
+	virtual bool IsForwardTransformation() const =0;
+};
+
+//! interface for hash functions and data processing part of MACs
+
+/*! HashTransformation objects are stateful.  They are created in an initial state,
+	change state as Update() is called, and return to the initial
+	state when Final() is called.  This interface allows a large message to
+	be hashed in pieces by calling Update() on each piece followed by
+	calling Final().
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE HashTransformation : public Algorithm
+{
+public:
+	//! return a reference to this object, 
+	/*! This function is useful for passing a temporary HashTransformation object to a 
+		function that takes a non-const reference. */
+	HashTransformation& Ref() {return *this;}
+
+	//! process more input
+	virtual void Update(const byte *input, size_t length) =0;
+
+	//! request space to write input into
+	virtual byte * CreateUpdateSpace(size_t &size) {size=0; return NULL;}
+
+	//! compute hash for current message, then restart for a new message
+	/*!	\pre size of digest == DigestSize(). */
+	virtual void Final(byte *digest)
+		{TruncatedFinal(digest, DigestSize());}
+
+	//! discard the current state, and restart with a new message
+	virtual void Restart()
+		{TruncatedFinal(NULL, 0);}
+
+	//! size of the hash/digest/MAC returned by Final()
+	virtual unsigned int DigestSize() const =0;
+
+	//! same as DigestSize()
+	unsigned int TagSize() const {return DigestSize();}
+
+
+	//! block size of underlying compression function, or 0 if not block based
+	virtual unsigned int BlockSize() const {return 0;}
+
+	//! input to Update() should have length a multiple of this for optimal speed
+	virtual unsigned int OptimalBlockSize() const {return 1;}
+
+	//! returns how input should be aligned for optimal performance
+	virtual unsigned int OptimalDataAlignment() const;
+
+	//! use this if your input is in one piece and you don't want to call Update() and Final() separately
+	virtual void CalculateDigest(byte *digest, const byte *input, size_t length)
+		{Update(input, length); Final(digest);}
+
+	//! verify that digest is a valid digest for the current message, then reinitialize the object
+	/*! Default implementation is to call Final() and do a bitwise comparison
+		between its output and digest. */
+	virtual bool Verify(const byte *digest)
+		{return TruncatedVerify(digest, DigestSize());}
+
+	//! use this if your input is in one piece and you don't want to call Update() and Verify() separately
+	virtual bool VerifyDigest(const byte *digest, const byte *input, size_t length)
+		{Update(input, length); return Verify(digest);}
+
+	//! truncated version of Final()
+	virtual void TruncatedFinal(byte *digest, size_t digestSize) =0;
+
+	//! truncated version of CalculateDigest()
+	virtual void CalculateTruncatedDigest(byte *digest, size_t digestSize, const byte *input, size_t length)
+		{Update(input, length); TruncatedFinal(digest, digestSize);}
+
+	//! truncated version of Verify()
+	virtual bool TruncatedVerify(const byte *digest, size_t digestLength);
+
+	//! truncated version of VerifyDigest()
+	virtual bool VerifyTruncatedDigest(const byte *digest, size_t digestLength, const byte *input, size_t length)
+		{Update(input, length); return TruncatedVerify(digest, digestLength);}
+
+protected:
+	void ThrowIfInvalidTruncatedSize(size_t size) const;
+};
+
+typedef HashTransformation HashFunction;
+
+//! interface for one direction (encryption or decryption) of a block cipher
+/*! \note These objects usually should not be used directly. See BlockTransformation for more details. */
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE BlockCipher : public SimpleKeyingInterface, public BlockTransformation
+{
+protected:
+	const Algorithm & GetAlgorithm() const {return *this;}
+};
+
+//! interface for one direction (encryption or decryption) of a stream cipher or cipher mode
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE SymmetricCipher : public SimpleKeyingInterface, public StreamTransformation
+{
+protected:
+	const Algorithm & GetAlgorithm() const {return *this;}
+};
+
+//! interface for message authentication codes
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE MessageAuthenticationCode : public SimpleKeyingInterface, public HashTransformation
+{
+protected:
+	const Algorithm & GetAlgorithm() const {return *this;}
+};
+
+//! interface for for one direction (encryption or decryption) of a stream cipher or block cipher mode with authentication
+/*! The StreamTransformation part of this interface is used to encrypt/decrypt the data, and the MessageAuthenticationCode part of this
+	interface is used to input additional authenticated data (AAD, which is MAC'ed but not encrypted), and to generate/verify the MAC. */
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE AuthenticatedSymmetricCipher : public MessageAuthenticationCode, public StreamTransformation
+{
+public:
+	//! this indicates that a member function was called in the wrong state, for example trying to encrypt a message before having set the key or IV
+	class BadState : public Exception
+	{
+	public:
+		explicit BadState(const std::string &name, const char *message) : Exception(OTHER_ERROR, name + ": " + message) {}
+		explicit BadState(const std::string &name, const char *function, const char *state) : Exception(OTHER_ERROR, name + ": " + function + " was called before " + state) {}
+	};
+
+	//! the maximum length of AAD that can be input before the encrypted data
+	virtual lword MaxHeaderLength() const =0;
+	//! the maximum length of encrypted data
+	virtual lword MaxMessageLength() const =0;
+	//! the maximum length of AAD that can be input after the encrypted data
+	virtual lword MaxFooterLength() const {return 0;}
+	//! if this function returns true, SpecifyDataLengths() must be called before attempting to input data
+	/*! This is the case for some schemes, such as CCM. */
+	virtual bool NeedsPrespecifiedDataLengths() const {return false;}
+	//! this function only needs to be called if NeedsPrespecifiedDataLengths() returns true
+	void SpecifyDataLengths(lword headerLength, lword messageLength, lword footerLength=0);
+	//! encrypt and generate MAC in one call. will truncate MAC if macSize < TagSize()
+	virtual void EncryptAndAuthenticate(byte *ciphertext, byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *header, size_t headerLength, const byte *message, size_t messageLength);
+	//! decrypt and verify MAC in one call, returning true iff MAC is valid. will assume MAC is truncated if macLength < TagSize()
+	virtual bool DecryptAndVerify(byte *message, const byte *mac, size_t macLength, const byte *iv, int ivLength, const byte *header, size_t headerLength, const byte *ciphertext, size_t ciphertextLength);
+
+	// redeclare this to avoid compiler ambiguity errors
+	virtual std::string AlgorithmName() const =0;
+
+protected:
+	const Algorithm & GetAlgorithm() const {return *static_cast<const MessageAuthenticationCode *>(this);}
+	virtual void UncheckedSpecifyDataLengths(lword headerLength, lword messageLength, lword footerLength) {}
+};
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+typedef SymmetricCipher StreamCipher;
+#endif
+
+//! interface for random number generators
+/*! All return values are uniformly distributed over the range specified.
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE RandomNumberGenerator : public Algorithm
+{
+public:
+	//! update RNG state with additional unpredictable values
+	virtual void IncorporateEntropy(const byte *input, size_t length) {throw NotImplemented("RandomNumberGenerator: IncorporateEntropy not implemented");}
+
+	//! returns true if IncorporateEntropy is implemented
+	virtual bool CanIncorporateEntropy() const {return false;}
+
+	//! generate new random byte and return it
+	virtual byte GenerateByte();
+
+	//! generate new random bit and return it
+	/*! Default implementation is to call GenerateByte() and return its lowest bit. */
+	virtual unsigned int GenerateBit();
+
+	//! generate a random 32 bit word in the range min to max, inclusive
+	virtual word32 GenerateWord32(word32 a=0, word32 b=0xffffffffL);
+
+	//! generate random array of bytes
+	virtual void GenerateBlock(byte *output, size_t size);
+
+	//! generate and discard n bytes
+	virtual void DiscardBytes(size_t n);
+
+	//! generate random bytes as input to a BufferedTransformation
+	virtual void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword length);
+
+	//! randomly shuffle the specified array, resulting permutation is uniformly distributed
+	template <class IT> void Shuffle(IT begin, IT end)
+	{
+		for (; begin != end; ++begin)
+			std::iter_swap(begin, begin + GenerateWord32(0, end-begin-1));
+	}
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+	byte GetByte() {return GenerateByte();}
+	unsigned int GetBit() {return GenerateBit();}
+	word32 GetLong(word32 a=0, word32 b=0xffffffffL) {return GenerateWord32(a, b);}
+	word16 GetShort(word16 a=0, word16 b=0xffff) {return (word16)GenerateWord32(a, b);}
+	void GetBlock(byte *output, size_t size) {GenerateBlock(output, size);}
+#endif
+};
+
+//! returns a reference that can be passed to functions that ask for a RNG but doesn't actually use it
+CRYPTOPP_DLL RandomNumberGenerator & CRYPTOPP_API NullRNG();
+
+class WaitObjectContainer;
+class CallStack;
+
+//! interface for objects that you can wait for
+
+class CRYPTOPP_NO_VTABLE Waitable
+{
+public:
+	virtual ~Waitable() {}
+
+	//! maximum number of wait objects that this object can return
+	virtual unsigned int GetMaxWaitObjectCount() const =0;
+	//! put wait objects into container
+	/*! \param callStack is used for tracing no wait loops, example:
+	             something.GetWaitObjects(c, CallStack("my func after X", 0));
+			   - or in an outer GetWaitObjects() method that itself takes a callStack parameter:
+			     innerThing.GetWaitObjects(c, CallStack("MyClass::GetWaitObjects at X", &callStack)); */
+	virtual void GetWaitObjects(WaitObjectContainer &container, CallStack const& callStack) =0;
+	//! wait on this object
+	/*! same as creating an empty container, calling GetWaitObjects(), and calling Wait() on the container */
+	bool Wait(unsigned long milliseconds, CallStack const& callStack);
+};
+
+//! the default channel for BufferedTransformation, equal to the empty string
+extern CRYPTOPP_DLL const std::string DEFAULT_CHANNEL;
+
+//! channel for additional authenticated data, equal to "AAD"
+extern CRYPTOPP_DLL const std::string AAD_CHANNEL;
+
+//! interface for buffered transformations
+
+/*! BufferedTransformation is a generalization of BlockTransformation,
+	StreamTransformation, and HashTransformation.
+
+	A buffered transformation is an object that takes a stream of bytes
+	as input (this may be done in stages), does some computation on them, and
+	then places the result into an internal buffer for later retrieval.  Any
+	partial result already in the output buffer is not modified by further
+	input.
+
+	If a method takes a "blocking" parameter, and you
+	pass "false" for it, the method will return before all input has been processed if
+	the input cannot be processed without waiting (for network buffers to become available, for example).
+	In this case the method will return true
+	or a non-zero integer value. When this happens you must continue to call the method with the same
+	parameters until it returns false or zero, before calling any other method on it or
+	attached BufferedTransformation. The integer return value in this case is approximately
+	the number of bytes left to be processed, and can be used to implement a progress bar.
+
+	For functions that take a "propagation" parameter, propagation != 0 means pass on the signal to attached
+	BufferedTransformation objects, with propagation decremented at each step until it reaches 0.
+	-1 means unlimited propagation.
+
+	\nosubgrouping
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE BufferedTransformation : public Algorithm, public Waitable
+{
+public:
+	// placed up here for CW8
+	static const std::string &NULL_CHANNEL;	// same as DEFAULT_CHANNEL, for backwards compatibility
+
+	BufferedTransformation() : Algorithm(false) {}
+
+	//! return a reference to this object
+	/*! This function is useful for passing a temporary BufferedTransformation object to a 
+		function that takes a non-const reference. */
+	BufferedTransformation& Ref() {return *this;}
+
+	//!	\name INPUT
+	//@{
+		//! input a byte for processing
+		size_t Put(byte inByte, bool blocking=true)
+			{return Put(&inByte, 1, blocking);}
+		//! input multiple bytes
+		size_t Put(const byte *inString, size_t length, bool blocking=true)
+			{return Put2(inString, length, 0, blocking);}
+
+		//! input a 16-bit word
+		size_t PutWord16(word16 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true);
+		//! input a 32-bit word
+		size_t PutWord32(word32 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true);
+
+		//! request space which can be written into by the caller, and then used as input to Put()
+		/*! \param size is requested size (as a hint) for input, and size of the returned space for output */
+		/*! \note The purpose of this method is to help avoid doing extra memory allocations. */
+		virtual byte * CreatePutSpace(size_t &size) {size=0; return NULL;}
+
+		virtual bool CanModifyInput() const {return false;}
+
+		//! input multiple bytes that may be modified by callee
+		size_t PutModifiable(byte *inString, size_t length, bool blocking=true)
+			{return PutModifiable2(inString, length, 0, blocking);}
+
+		bool MessageEnd(int propagation=-1, bool blocking=true)
+			{return !!Put2(NULL, 0, propagation < 0 ? -1 : propagation+1, blocking);}
+		size_t PutMessageEnd(const byte *inString, size_t length, int propagation=-1, bool blocking=true)
+			{return Put2(inString, length, propagation < 0 ? -1 : propagation+1, blocking);}
+
+		//! input multiple bytes for blocking or non-blocking processing
+		/*! \param messageEnd means how many filters to signal MessageEnd to, including this one */
+		virtual size_t Put2(const byte *inString, size_t length, int messageEnd, bool blocking) =0;
+		//! input multiple bytes that may be modified by callee for blocking or non-blocking processing
+		/*! \param messageEnd means how many filters to signal MessageEnd to, including this one */
+		virtual size_t PutModifiable2(byte *inString, size_t length, int messageEnd, bool blocking)
+			{return Put2(inString, length, messageEnd, blocking);}
+
+		//! thrown by objects that have not implemented nonblocking input processing
+		struct BlockingInputOnly : public NotImplemented
+			{BlockingInputOnly(const std::string &s) : NotImplemented(s + ": Nonblocking input is not implemented by this object.") {}};
+	//@}
+
+	//!	\name WAITING
+	//@{
+		unsigned int GetMaxWaitObjectCount() const;
+		void GetWaitObjects(WaitObjectContainer &container, CallStack const& callStack);
+	//@}
+
+	//!	\name SIGNALS
+	//@{
+		virtual void IsolatedInitialize(const NameValuePairs &parameters) {throw NotImplemented("BufferedTransformation: this object can't be reinitialized");}
+		virtual bool IsolatedFlush(bool hardFlush, bool blocking) =0;
+		virtual bool IsolatedMessageSeriesEnd(bool blocking) {return false;}
+
+		//! initialize or reinitialize this object
+		virtual void Initialize(const NameValuePairs &parameters=g_nullNameValuePairs, int propagation=-1);
+		//! flush buffered input and/or output
+		/*! \param hardFlush is used to indicate whether all data should be flushed
+			\note Hard flushes must be used with care. It means try to process and output everything, even if
+			there may not be enough data to complete the action. For example, hard flushing a HexDecoder would
+			cause an error if you do it after inputing an odd number of hex encoded characters.
+			For some types of filters, for example ZlibDecompressor, hard flushes can only
+			be done at "synchronization points". These synchronization points are positions in the data
+			stream that are created by hard flushes on the corresponding reverse filters, in this
+			example ZlibCompressor. This is useful when zlib compressed data is moved across a
+			network in packets and compression state is preserved across packets, as in the ssh2 protocol.
+		*/
+		virtual bool Flush(bool hardFlush, int propagation=-1, bool blocking=true);
+		//! mark end of a series of messages
+		/*! There should be a MessageEnd immediately before MessageSeriesEnd. */
+		virtual bool MessageSeriesEnd(int propagation=-1, bool blocking=true);
+
+		//! set propagation of automatically generated and transferred signals
+		/*! propagation == 0 means do not automaticly generate signals */
+		virtual void SetAutoSignalPropagation(int propagation) {}
+
+		//!
+		virtual int GetAutoSignalPropagation() const {return 0;}
+public:
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+		void Close() {MessageEnd();}
+#endif
+	//@}
+
+	//!	\name RETRIEVAL OF ONE MESSAGE
+	//@{
+		//! returns number of bytes that is currently ready for retrieval
+		/*! All retrieval functions return the actual number of bytes
+			retrieved, which is the lesser of the request number and
+			MaxRetrievable(). */
+		virtual lword MaxRetrievable() const;
+
+		//! returns whether any bytes are currently ready for retrieval
+		virtual bool AnyRetrievable() const;
+
+		//! try to retrieve a single byte
+		virtual size_t Get(byte &outByte);
+		//! try to retrieve multiple bytes
+		virtual size_t Get(byte *outString, size_t getMax);
+
+		//! peek at the next byte without removing it from the output buffer
+		virtual size_t Peek(byte &outByte) const;
+		//! peek at multiple bytes without removing them from the output buffer
+		virtual size_t Peek(byte *outString, size_t peekMax) const;
+
+		//! try to retrieve a 16-bit word
+		size_t GetWord16(word16 &value, ByteOrder order=BIG_ENDIAN_ORDER);
+		//! try to retrieve a 32-bit word
+		size_t GetWord32(word32 &value, ByteOrder order=BIG_ENDIAN_ORDER);
+
+		//! try to peek at a 16-bit word
+		size_t PeekWord16(word16 &value, ByteOrder order=BIG_ENDIAN_ORDER) const;
+		//! try to peek at a 32-bit word
+		size_t PeekWord32(word32 &value, ByteOrder order=BIG_ENDIAN_ORDER) const;
+
+		//! move transferMax bytes of the buffered output to target as input
+		lword TransferTo(BufferedTransformation &target, lword transferMax=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL)
+			{TransferTo2(target, transferMax, channel); return transferMax;}
+
+		//! discard skipMax bytes from the output buffer
+		virtual lword Skip(lword skipMax=LWORD_MAX);
+
+		//! copy copyMax bytes of the buffered output to target as input
+		lword CopyTo(BufferedTransformation &target, lword copyMax=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL) const
+			{return CopyRangeTo(target, 0, copyMax, channel);}
+
+		//! copy copyMax bytes of the buffered output, starting at position (relative to current position), to target as input
+		lword CopyRangeTo(BufferedTransformation &target, lword position, lword copyMax=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL) const
+			{lword i = position; CopyRangeTo2(target, i, i+copyMax, channel); return i-position;}
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+		unsigned long MaxRetrieveable() const {return MaxRetrievable();}
+#endif
+	//@}
+
+	//!	\name RETRIEVAL OF MULTIPLE MESSAGES
+	//@{
+		//!
+		virtual lword TotalBytesRetrievable() const;
+		//! number of times MessageEnd() has been received minus messages retrieved or skipped
+		virtual unsigned int NumberOfMessages() const;
+		//! returns true if NumberOfMessages() > 0
+		virtual bool AnyMessages() const;
+		//! start retrieving the next message
+		/*!
+			Returns false if no more messages exist or this message 
+			is not completely retrieved.
+		*/
+		virtual bool GetNextMessage();
+		//! skip count number of messages
+		virtual unsigned int SkipMessages(unsigned int count=UINT_MAX);
+		//!
+		unsigned int TransferMessagesTo(BufferedTransformation &target, unsigned int count=UINT_MAX, const std::string &channel=DEFAULT_CHANNEL)
+			{TransferMessagesTo2(target, count, channel); return count;}
+		//!
+		unsigned int CopyMessagesTo(BufferedTransformation &target, unsigned int count=UINT_MAX, const std::string &channel=DEFAULT_CHANNEL) const;
+
+		//!
+		virtual void SkipAll();
+		//!
+		void TransferAllTo(BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL)
+			{TransferAllTo2(target, channel);}
+		//!
+		void CopyAllTo(BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL) const;
+
+		virtual bool GetNextMessageSeries() {return false;}
+		virtual unsigned int NumberOfMessagesInThisSeries() const {return NumberOfMessages();}
+		virtual unsigned int NumberOfMessageSeries() const {return 0;}
+	//@}
+
+	//!	\name NON-BLOCKING TRANSFER OF OUTPUT
+	//@{
+		//! upon return, byteCount contains number of bytes that have finished being transfered, and returns the number of bytes left in the current transfer block
+		virtual size_t TransferTo2(BufferedTransformation &target, lword &byteCount, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true) =0;
+		//! upon return, begin contains the start position of data yet to be finished copying, and returns the number of bytes left in the current transfer block
+		virtual size_t CopyRangeTo2(BufferedTransformation &target, lword &begin, lword end=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true) const =0;
+		//! upon return, messageCount contains number of messages that have finished being transfered, and returns the number of bytes left in the current transfer block
+		size_t TransferMessagesTo2(BufferedTransformation &target, unsigned int &messageCount, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true);
+		//! returns the number of bytes left in the current transfer block
+		size_t TransferAllTo2(BufferedTransformation &target, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true);
+	//@}
+
+	//!	\name CHANNELS
+	//@{
+		struct NoChannelSupport : public NotImplemented
+			{NoChannelSupport(const std::string &name) : NotImplemented(name + ": this object doesn't support multiple channels") {}};
+		struct InvalidChannelName : public InvalidArgument
+			{InvalidChannelName(const std::string &name, const std::string &channel) : InvalidArgument(name + ": unexpected channel name \"" + channel + "\"") {}};
+
+		size_t ChannelPut(const std::string &channel, byte inByte, bool blocking=true)
+			{return ChannelPut(channel, &inByte, 1, blocking);}
+		size_t ChannelPut(const std::string &channel, const byte *inString, size_t length, bool blocking=true)
+			{return ChannelPut2(channel, inString, length, 0, blocking);}
+
+		size_t ChannelPutModifiable(const std::string &channel, byte *inString, size_t length, bool blocking=true)
+			{return ChannelPutModifiable2(channel, inString, length, 0, blocking);}
+
+		size_t ChannelPutWord16(const std::string &channel, word16 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true);
+		size_t ChannelPutWord32(const std::string &channel, word32 value, ByteOrder order=BIG_ENDIAN_ORDER, bool blocking=true);
+
+		bool ChannelMessageEnd(const std::string &channel, int propagation=-1, bool blocking=true)
+			{return !!ChannelPut2(channel, NULL, 0, propagation < 0 ? -1 : propagation+1, blocking);}
+		size_t ChannelPutMessageEnd(const std::string &channel, const byte *inString, size_t length, int propagation=-1, bool blocking=true)
+			{return ChannelPut2(channel, inString, length, propagation < 0 ? -1 : propagation+1, blocking);}
+
+		virtual byte * ChannelCreatePutSpace(const std::string &channel, size_t &size);
+
+		virtual size_t ChannelPut2(const std::string &channel, const byte *begin, size_t length, int messageEnd, bool blocking);
+		virtual size_t ChannelPutModifiable2(const std::string &channel, byte *begin, size_t length, int messageEnd, bool blocking);
+
+		virtual bool ChannelFlush(const std::string &channel, bool hardFlush, int propagation=-1, bool blocking=true);
+		virtual bool ChannelMessageSeriesEnd(const std::string &channel, int propagation=-1, bool blocking=true);
+
+		virtual void SetRetrievalChannel(const std::string &channel);
+	//@}
+
+	//!	\name ATTACHMENT
+	/*! Some BufferedTransformation objects (e.g. Filter objects)
+		allow other BufferedTransformation objects to be attached. When
+		this is done, the first object instead of buffering its output,
+		sents that output to the attached object as input. The entire
+		attachment chain is deleted when the anchor object is destructed.
+	*/
+	//@{
+		//! returns whether this object allows attachment
+		virtual bool Attachable() {return false;}
+		//! returns the object immediately attached to this object or NULL for no attachment
+		virtual BufferedTransformation *AttachedTransformation() {assert(!Attachable()); return 0;}
+		//!
+		virtual const BufferedTransformation *AttachedTransformation() const
+			{return const_cast<BufferedTransformation *>(this)->AttachedTransformation();}
+		//! delete the current attachment chain and replace it with newAttachment
+		virtual void Detach(BufferedTransformation *newAttachment = 0)
+			{assert(!Attachable()); throw NotImplemented("BufferedTransformation: this object is not attachable");}
+		//! add newAttachment to the end of attachment chain
+		virtual void Attach(BufferedTransformation *newAttachment);
+	//@}
+
+protected:
+	static int DecrementPropagation(int propagation)
+		{return propagation != 0 ? propagation - 1 : 0;}
+
+private:
+	byte m_buf[4];	// for ChannelPutWord16 and ChannelPutWord32, to ensure buffer isn't deallocated before non-blocking operation completes
+};
+
+//! returns a reference to a BufferedTransformation object that discards all input
+BufferedTransformation & TheBitBucket();
+
+//! interface for crypto material, such as public and private keys, and crypto parameters
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE CryptoMaterial : public NameValuePairs
+{
+public:
+	//! exception thrown when invalid crypto material is detected
+	class CRYPTOPP_DLL InvalidMaterial : public InvalidDataFormat
+	{
+	public:
+		explicit InvalidMaterial(const std::string &s) : InvalidDataFormat(s) {}
+	};
+
+	//! assign values from source to this object
+	/*! \note This function can be used to create a public key from a private key. */
+	virtual void AssignFrom(const NameValuePairs &source) =0;
+
+	//! check this object for errors
+	/*! \param level denotes the level of thoroughness:
+		0 - using this object won't cause a crash or exception (rng is ignored)
+		1 - this object will probably function (encrypt, sign, etc.) correctly (but may not check for weak keys and such)
+		2 - make sure this object will function correctly, and do reasonable security checks
+		3 - do checks that may take a long time
+		\return true if the tests pass */
+	virtual bool Validate(RandomNumberGenerator &rng, unsigned int level) const =0;
+
+	//! throws InvalidMaterial if this object fails Validate() test
+	virtual void ThrowIfInvalid(RandomNumberGenerator &rng, unsigned int level) const
+		{if (!Validate(rng, level)) throw InvalidMaterial("CryptoMaterial: this object contains invalid values");}
+
+//	virtual std::vector<std::string> GetSupportedFormats(bool includeSaveOnly=false, bool includeLoadOnly=false);
+
+	//! save key into a BufferedTransformation
+	virtual void Save(BufferedTransformation &bt) const
+		{throw NotImplemented("CryptoMaterial: this object does not support saving");}
+
+	//! load key from a BufferedTransformation
+	/*! \throws KeyingErr if decode fails
+		\note Generally does not check that the key is valid.
+			Call ValidateKey() or ThrowIfInvalidKey() to check that. */
+	virtual void Load(BufferedTransformation &bt)
+		{throw NotImplemented("CryptoMaterial: this object does not support loading");}
+
+	//! \return whether this object supports precomputation
+	virtual bool SupportsPrecomputation() const {return false;}
+	//! do precomputation
+	/*! The exact semantics of Precompute() is varies, but
+		typically it means calculate a table of n objects
+		that can be used later to speed up computation. */
+	virtual void Precompute(unsigned int n)
+		{assert(!SupportsPrecomputation()); throw NotImplemented("CryptoMaterial: this object does not support precomputation");}
+	//! retrieve previously saved precomputation
+	virtual void LoadPrecomputation(BufferedTransformation &storedPrecomputation)
+		{assert(!SupportsPrecomputation()); throw NotImplemented("CryptoMaterial: this object does not support precomputation");}
+	//! save precomputation for later use
+	virtual void SavePrecomputation(BufferedTransformation &storedPrecomputation) const
+		{assert(!SupportsPrecomputation()); throw NotImplemented("CryptoMaterial: this object does not support precomputation");}
+
+	// for internal library use
+	void DoQuickSanityCheck() const	{ThrowIfInvalid(NullRNG(), 0);}
+
+#if (defined(__SUNPRO_CC) && __SUNPRO_CC < 0x590)
+	// Sun Studio 11/CC 5.8 workaround: it generates incorrect code when casting to an empty virtual base class
+	char m_sunCCworkaround;
+#endif
+};
+
+//! interface for generatable crypto material, such as private keys and crypto parameters
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE GeneratableCryptoMaterial : virtual public CryptoMaterial
+{
+public:
+	//! generate a random key or crypto parameters
+	/*! \throws KeyingErr if algorithm parameters are invalid, or if a key can't be generated
+		(e.g., if this is a public key object) */
+	virtual void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &params = g_nullNameValuePairs)
+		{throw NotImplemented("GeneratableCryptoMaterial: this object does not support key/parameter generation");}
+
+	//! calls the above function with a NameValuePairs object that just specifies "KeySize"
+	void GenerateRandomWithKeySize(RandomNumberGenerator &rng, unsigned int keySize);
+};
+
+//! interface for public keys
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PublicKey : virtual public CryptoMaterial
+{
+};
+
+//! interface for private keys
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PrivateKey : public GeneratableCryptoMaterial
+{
+};
+
+//! interface for crypto prameters
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE CryptoParameters : public GeneratableCryptoMaterial
+{
+};
+
+//! interface for asymmetric algorithms
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE AsymmetricAlgorithm : public Algorithm
+{
+public:
+	//! returns a reference to the crypto material used by this object
+	virtual CryptoMaterial & AccessMaterial() =0;
+	//! returns a const reference to the crypto material used by this object
+	virtual const CryptoMaterial & GetMaterial() const =0;
+
+	//! for backwards compatibility, calls AccessMaterial().Load(bt)
+	void BERDecode(BufferedTransformation &bt)
+		{AccessMaterial().Load(bt);}
+	//! for backwards compatibility, calls GetMaterial().Save(bt)
+	void DEREncode(BufferedTransformation &bt) const
+		{GetMaterial().Save(bt);}
+};
+
+//! interface for asymmetric algorithms using public keys
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PublicKeyAlgorithm : public AsymmetricAlgorithm
+{
+public:
+	// VC60 workaround: no co-variant return type
+	CryptoMaterial & AccessMaterial() {return AccessPublicKey();}
+	const CryptoMaterial & GetMaterial() const {return GetPublicKey();}
+
+	virtual PublicKey & AccessPublicKey() =0;
+	virtual const PublicKey & GetPublicKey() const {return const_cast<PublicKeyAlgorithm *>(this)->AccessPublicKey();}
+};
+
+//! interface for asymmetric algorithms using private keys
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PrivateKeyAlgorithm : public AsymmetricAlgorithm
+{
+public:
+	CryptoMaterial & AccessMaterial() {return AccessPrivateKey();}
+	const CryptoMaterial & GetMaterial() const {return GetPrivateKey();}
+
+	virtual PrivateKey & AccessPrivateKey() =0;
+	virtual const PrivateKey & GetPrivateKey() const {return const_cast<PrivateKeyAlgorithm *>(this)->AccessPrivateKey();}
+};
+
+//! interface for key agreement algorithms
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE KeyAgreementAlgorithm : public AsymmetricAlgorithm
+{
+public:
+	CryptoMaterial & AccessMaterial() {return AccessCryptoParameters();}
+	const CryptoMaterial & GetMaterial() const {return GetCryptoParameters();}
+
+	virtual CryptoParameters & AccessCryptoParameters() =0;
+	virtual const CryptoParameters & GetCryptoParameters() const {return const_cast<KeyAgreementAlgorithm *>(this)->AccessCryptoParameters();}
+};
+
+//! interface for public-key encryptors and decryptors
+
+/*! This class provides an interface common to encryptors and decryptors
+	for querying their plaintext and ciphertext lengths.
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_CryptoSystem
+{
+public:
+	virtual ~PK_CryptoSystem() {}
+
+	//! maximum length of plaintext for a given ciphertext length
+	/*! \note This function returns 0 if ciphertextLength is not valid (too long or too short). */
+	virtual size_t MaxPlaintextLength(size_t ciphertextLength) const =0;
+
+	//! calculate length of ciphertext given length of plaintext
+	/*! \note This function returns 0 if plaintextLength is not valid (too long). */
+	virtual size_t CiphertextLength(size_t plaintextLength) const =0;
+
+	//! this object supports the use of the parameter with the given name
+	/*! some possible parameter names: EncodingParameters, KeyDerivationParameters */
+	virtual bool ParameterSupported(const char *name) const =0;
+
+	//! return fixed ciphertext length, if one exists, otherwise return 0
+	/*! \note "Fixed" here means length of ciphertext does not depend on length of plaintext.
+		It usually does depend on the key length. */
+	virtual size_t FixedCiphertextLength() const {return 0;}
+
+	//! return maximum plaintext length given the fixed ciphertext length, if one exists, otherwise return 0
+	virtual size_t FixedMaxPlaintextLength() const {return 0;}
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+	size_t MaxPlainTextLength(size_t cipherTextLength) const {return MaxPlaintextLength(cipherTextLength);}
+	size_t CipherTextLength(size_t plainTextLength) const {return CiphertextLength(plainTextLength);}
+#endif
+};
+
+//! interface for public-key encryptors
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_Encryptor : public PK_CryptoSystem, public PublicKeyAlgorithm
+{
+public:
+	//! exception thrown when trying to encrypt plaintext of invalid length
+	class CRYPTOPP_DLL InvalidPlaintextLength : public Exception
+	{
+	public:
+		InvalidPlaintextLength() : Exception(OTHER_ERROR, "PK_Encryptor: invalid plaintext length") {}
+	};
+
+	//! encrypt a byte string
+	/*! \pre CiphertextLength(plaintextLength) != 0 (i.e., plaintext isn't too long)
+		\pre size of ciphertext == CiphertextLength(plaintextLength)
+	*/
+	virtual void Encrypt(RandomNumberGenerator &rng, 
+		const byte *plaintext, size_t plaintextLength, 
+		byte *ciphertext, const NameValuePairs &parameters = g_nullNameValuePairs) const =0;
+
+	//! create a new encryption filter
+	/*! \note The caller is responsible for deleting the returned pointer.
+		\note Encoding parameters should be passed in the "EP" channel.
+	*/
+	virtual BufferedTransformation * CreateEncryptionFilter(RandomNumberGenerator &rng, 
+		BufferedTransformation *attachment=NULL, const NameValuePairs &parameters = g_nullNameValuePairs) const;
+};
+
+//! interface for public-key decryptors
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_Decryptor : public PK_CryptoSystem, public PrivateKeyAlgorithm
+{
+public:
+	//! decrypt a byte string, and return the length of plaintext
+	/*! \pre size of plaintext == MaxPlaintextLength(ciphertextLength) bytes.
+		\return the actual length of the plaintext, indication that decryption failed.
+	*/
+	virtual DecodingResult Decrypt(RandomNumberGenerator &rng, 
+		const byte *ciphertext, size_t ciphertextLength, 
+		byte *plaintext, const NameValuePairs &parameters = g_nullNameValuePairs) const =0;
+
+	//! create a new decryption filter
+	/*! \note caller is responsible for deleting the returned pointer
+	*/
+	virtual BufferedTransformation * CreateDecryptionFilter(RandomNumberGenerator &rng, 
+		BufferedTransformation *attachment=NULL, const NameValuePairs &parameters = g_nullNameValuePairs) const;
+
+	//! decrypt a fixed size ciphertext
+	DecodingResult FixedLengthDecrypt(RandomNumberGenerator &rng, const byte *ciphertext, byte *plaintext, const NameValuePairs &parameters = g_nullNameValuePairs) const
+		{return Decrypt(rng, ciphertext, FixedCiphertextLength(), plaintext, parameters);}
+};
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+typedef PK_CryptoSystem PK_FixedLengthCryptoSystem;
+typedef PK_Encryptor PK_FixedLengthEncryptor;
+typedef PK_Decryptor PK_FixedLengthDecryptor;
+#endif
+
+//! interface for public-key signers and verifiers
+
+/*! This class provides an interface common to signers and verifiers
+	for querying scheme properties.
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_SignatureScheme
+{
+public:
+	//! invalid key exception, may be thrown by any function in this class if the private or public key has a length that can't be used
+	class CRYPTOPP_DLL InvalidKeyLength : public Exception
+	{
+	public:
+		InvalidKeyLength(const std::string &message) : Exception(OTHER_ERROR, message) {}
+	};
+
+	//! key too short exception, may be thrown by any function in this class if the private or public key is too short to sign or verify anything
+	class CRYPTOPP_DLL KeyTooShort : public InvalidKeyLength
+	{
+	public:
+		KeyTooShort() : InvalidKeyLength("PK_Signer: key too short for this signature scheme") {}
+	};
+
+	virtual ~PK_SignatureScheme() {}
+
+	//! signature length if it only depends on the key, otherwise 0
+	virtual size_t SignatureLength() const =0;
+
+	//! maximum signature length produced for a given length of recoverable message part
+	virtual size_t MaxSignatureLength(size_t recoverablePartLength = 0) const {return SignatureLength();}
+
+	//! length of longest message that can be recovered, or 0 if this signature scheme does not support message recovery
+	virtual size_t MaxRecoverableLength() const =0;
+
+	//! length of longest message that can be recovered from a signature of given length, or 0 if this signature scheme does not support message recovery
+	virtual size_t MaxRecoverableLengthFromSignatureLength(size_t signatureLength) const =0;
+
+	//! requires a random number generator to sign
+	/*! if this returns false, NullRNG() can be passed to functions that take RandomNumberGenerator & */
+	virtual bool IsProbabilistic() const =0;
+
+	//! whether or not a non-recoverable message part can be signed
+	virtual bool AllowNonrecoverablePart() const =0;
+
+	//! if this function returns true, during verification you must input the signature before the message, otherwise you can input it at anytime */
+	virtual bool SignatureUpfront() const {return false;}
+
+	//! whether you must input the recoverable part before the non-recoverable part during signing
+	virtual bool RecoverablePartFirst() const =0;
+};
+
+//! interface for accumulating messages to be signed or verified
+/*! Only Update() should be called
+	on this class. No other functions inherited from HashTransformation should be called.
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_MessageAccumulator : public HashTransformation
+{
+public:
+	//! should not be called on PK_MessageAccumulator
+	unsigned int DigestSize() const
+		{throw NotImplemented("PK_MessageAccumulator: DigestSize() should not be called");}
+	//! should not be called on PK_MessageAccumulator
+	void TruncatedFinal(byte *digest, size_t digestSize) 
+		{throw NotImplemented("PK_MessageAccumulator: TruncatedFinal() should not be called");}
+};
+
+//! interface for public-key signers
+
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_Signer : public PK_SignatureScheme, public PrivateKeyAlgorithm
+{
+public:
+	//! create a new HashTransformation to accumulate the message to be signed
+	virtual PK_MessageAccumulator * NewSignatureAccumulator(RandomNumberGenerator &rng) const =0;
+
+	virtual void InputRecoverableMessage(PK_MessageAccumulator &messageAccumulator, const byte *recoverableMessage, size_t recoverableMessageLength) const =0;
+
+	//! sign and delete messageAccumulator (even in case of exception thrown)
+	/*! \pre size of signature == MaxSignatureLength()
+		\return actual signature length
+	*/
+	virtual size_t Sign(RandomNumberGenerator &rng, PK_MessageAccumulator *messageAccumulator, byte *signature) const;
+
+	//! sign and restart messageAccumulator
+	/*! \pre size of signature == MaxSignatureLength()
+		\return actual signature length
+	*/
+	virtual size_t SignAndRestart(RandomNumberGenerator &rng, PK_MessageAccumulator &messageAccumulator, byte *signature, bool restart=true) const =0;
+
+	//! sign a message
+	/*! \pre size of signature == MaxSignatureLength()
+		\return actual signature length
+	*/
+	virtual size_t SignMessage(RandomNumberGenerator &rng, const byte *message, size_t messageLen, byte *signature) const;
+
+	//! sign a recoverable message
+	/*! \pre size of signature == MaxSignatureLength(recoverableMessageLength)
+		\return actual signature length
+	*/
+	virtual size_t SignMessageWithRecovery(RandomNumberGenerator &rng, const byte *recoverableMessage, size_t recoverableMessageLength, 
+		const byte *nonrecoverableMessage, size_t nonrecoverableMessageLength, byte *signature) const;
+};
+
+//! interface for public-key signature verifiers
+/*! The Recover* functions throw NotImplemented if the signature scheme does not support
+	message recovery.
+	The Verify* functions throw InvalidDataFormat if the scheme does support message
+	recovery and the signature contains a non-empty recoverable message part. The
+	Recovery* functions should be used in that case.
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_Verifier : public PK_SignatureScheme, public PublicKeyAlgorithm
+{
+public:
+	//! create a new HashTransformation to accumulate the message to be verified
+	virtual PK_MessageAccumulator * NewVerificationAccumulator() const =0;
+
+	//! input signature into a message accumulator
+	virtual void InputSignature(PK_MessageAccumulator &messageAccumulator, const byte *signature, size_t signatureLength) const =0;
+
+	//! check whether messageAccumulator contains a valid signature and message, and delete messageAccumulator (even in case of exception thrown)
+	virtual bool Verify(PK_MessageAccumulator *messageAccumulator) const;
+
+	//! check whether messageAccumulator contains a valid signature and message, and restart messageAccumulator
+	virtual bool VerifyAndRestart(PK_MessageAccumulator &messageAccumulator) const =0;
+
+	//! check whether input signature is a valid signature for input message
+	virtual bool VerifyMessage(const byte *message, size_t messageLen, 
+		const byte *signature, size_t signatureLength) const;
+
+	//! recover a message from its signature
+	/*! \pre size of recoveredMessage == MaxRecoverableLengthFromSignatureLength(signatureLength)
+	*/
+	virtual DecodingResult Recover(byte *recoveredMessage, PK_MessageAccumulator *messageAccumulator) const;
+
+	//! recover a message from its signature
+	/*! \pre size of recoveredMessage == MaxRecoverableLengthFromSignatureLength(signatureLength)
+	*/
+	virtual DecodingResult RecoverAndRestart(byte *recoveredMessage, PK_MessageAccumulator &messageAccumulator) const =0;
+
+	//! recover a message from its signature
+	/*! \pre size of recoveredMessage == MaxRecoverableLengthFromSignatureLength(signatureLength)
+	*/
+	virtual DecodingResult RecoverMessage(byte *recoveredMessage, 
+		const byte *nonrecoverableMessage, size_t nonrecoverableMessageLength, 
+		const byte *signature, size_t signatureLength) const;
+};
+
+//! interface for domains of simple key agreement protocols
+
+/*! A key agreement domain is a set of parameters that must be shared
+	by two parties in a key agreement protocol, along with the algorithms
+	for generating key pairs and deriving agreed values.
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE SimpleKeyAgreementDomain : public KeyAgreementAlgorithm
+{
+public:
+	//! return length of agreed value produced
+	virtual unsigned int AgreedValueLength() const =0;
+	//! return length of private keys in this domain
+	virtual unsigned int PrivateKeyLength() const =0;
+	//! return length of public keys in this domain
+	virtual unsigned int PublicKeyLength() const =0;
+	//! generate private key
+	/*! \pre size of privateKey == PrivateKeyLength() */
+	virtual void GeneratePrivateKey(RandomNumberGenerator &rng, byte *privateKey) const =0;
+	//! generate public key
+	/*!	\pre size of publicKey == PublicKeyLength() */
+	virtual void GeneratePublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const =0;
+	//! generate private/public key pair
+	/*! \note equivalent to calling GeneratePrivateKey() and then GeneratePublicKey() */
+	virtual void GenerateKeyPair(RandomNumberGenerator &rng, byte *privateKey, byte *publicKey) const;
+	//! derive agreed value from your private key and couterparty's public key, return false in case of failure
+	/*! \note If you have previously validated the public key, use validateOtherPublicKey=false to save time.
+		\pre size of agreedValue == AgreedValueLength()
+		\pre length of privateKey == PrivateKeyLength()
+		\pre length of otherPublicKey == PublicKeyLength()
+	*/
+	virtual bool Agree(byte *agreedValue, const byte *privateKey, const byte *otherPublicKey, bool validateOtherPublicKey=true) const =0;
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+	bool ValidateDomainParameters(RandomNumberGenerator &rng) const
+		{return GetCryptoParameters().Validate(rng, 2);}
+#endif
+};
+
+//! interface for domains of authenticated key agreement protocols
+
+/*! In an authenticated key agreement protocol, each party has two
+	key pairs. The long-lived key pair is called the static key pair,
+	and the short-lived key pair is called the ephemeral key pair.
+*/
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE AuthenticatedKeyAgreementDomain : public KeyAgreementAlgorithm
+{
+public:
+	//! return length of agreed value produced
+	virtual unsigned int AgreedValueLength() const =0;
+
+	//! return length of static private keys in this domain
+	virtual unsigned int StaticPrivateKeyLength() const =0;
+	//! return length of static public keys in this domain
+	virtual unsigned int StaticPublicKeyLength() const =0;
+	//! generate static private key
+	/*! \pre size of privateKey == PrivateStaticKeyLength() */
+	virtual void GenerateStaticPrivateKey(RandomNumberGenerator &rng, byte *privateKey) const =0;
+	//! generate static public key
+	/*!	\pre size of publicKey == PublicStaticKeyLength() */
+	virtual void GenerateStaticPublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const =0;
+	//! generate private/public key pair
+	/*! \note equivalent to calling GenerateStaticPrivateKey() and then GenerateStaticPublicKey() */
+	virtual void GenerateStaticKeyPair(RandomNumberGenerator &rng, byte *privateKey, byte *publicKey) const;
+
+	//! return length of ephemeral private keys in this domain
+	virtual unsigned int EphemeralPrivateKeyLength() const =0;
+	//! return length of ephemeral public keys in this domain
+	virtual unsigned int EphemeralPublicKeyLength() const =0;
+	//! generate ephemeral private key
+	/*! \pre size of privateKey == PrivateEphemeralKeyLength() */
+	virtual void GenerateEphemeralPrivateKey(RandomNumberGenerator &rng, byte *privateKey) const =0;
+	//! generate ephemeral public key
+	/*!	\pre size of publicKey == PublicEphemeralKeyLength() */
+	virtual void GenerateEphemeralPublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const =0;
+	//! generate private/public key pair
+	/*! \note equivalent to calling GenerateEphemeralPrivateKey() and then GenerateEphemeralPublicKey() */
+	virtual void GenerateEphemeralKeyPair(RandomNumberGenerator &rng, byte *privateKey, byte *publicKey) const;
+
+	//! derive agreed value from your private keys and couterparty's public keys, return false in case of failure
+	/*! \note The ephemeral public key will always be validated.
+		      If you have previously validated the static public key, use validateStaticOtherPublicKey=false to save time.
+		\pre size of agreedValue == AgreedValueLength()
+		\pre length of staticPrivateKey == StaticPrivateKeyLength()
+		\pre length of ephemeralPrivateKey == EphemeralPrivateKeyLength()
+		\pre length of staticOtherPublicKey == StaticPublicKeyLength()
+		\pre length of ephemeralOtherPublicKey == EphemeralPublicKeyLength()
+	*/
+	virtual bool Agree(byte *agreedValue,
+		const byte *staticPrivateKey, const byte *ephemeralPrivateKey,
+		const byte *staticOtherPublicKey, const byte *ephemeralOtherPublicKey,
+		bool validateStaticOtherPublicKey=true) const =0;
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+	bool ValidateDomainParameters(RandomNumberGenerator &rng) const
+		{return GetCryptoParameters().Validate(rng, 2);}
+#endif
+};
+
+// interface for password authenticated key agreement protocols, not implemented yet
+#if 0
+//! interface for protocol sessions
+/*! The methods should be called in the following order:
+
+	InitializeSession(rng, parameters);	// or call initialize method in derived class
+	while (true)
+	{
+		if (OutgoingMessageAvailable())
+		{
+			length = GetOutgoingMessageLength();
+			GetOutgoingMessage(message);
+			; // send outgoing message
+		}
+
+		if (LastMessageProcessed())
+			break;
+
+		; // receive incoming message
+		ProcessIncomingMessage(message);
+	}
+	; // call methods in derived class to obtain result of protocol session
+*/
+class ProtocolSession
+{
+public:
+	//! exception thrown when an invalid protocol message is processed
+	class ProtocolError : public Exception
+	{
+	public:
+		ProtocolError(ErrorType errorType, const std::string &s) : Exception(errorType, s) {}
+	};
+
+	//! exception thrown when a function is called unexpectedly
+	/*! for example calling ProcessIncomingMessage() when ProcessedLastMessage() == true */
+	class UnexpectedMethodCall : public Exception
+	{
+	public:
+		UnexpectedMethodCall(const std::string &s) : Exception(OTHER_ERROR, s) {}
+	};
+
+	ProtocolSession() : m_rng(NULL), m_throwOnProtocolError(true), m_validState(false) {}
+	virtual ~ProtocolSession() {}
+
+	virtual void InitializeSession(RandomNumberGenerator &rng, const NameValuePairs &parameters) =0;
+
+	bool GetThrowOnProtocolError() const {return m_throwOnProtocolError;}
+	void SetThrowOnProtocolError(bool throwOnProtocolError) {m_throwOnProtocolError = throwOnProtocolError;}
+
+	bool HasValidState() const {return m_validState;}
+
+	virtual bool OutgoingMessageAvailable() const =0;
+	virtual unsigned int GetOutgoingMessageLength() const =0;
+	virtual void GetOutgoingMessage(byte *message) =0;
+
+	virtual bool LastMessageProcessed() const =0;
+	virtual void ProcessIncomingMessage(const byte *message, unsigned int messageLength) =0;
+
+protected:
+	void HandleProtocolError(Exception::ErrorType errorType, const std::string &s) const;
+	void CheckAndHandleInvalidState() const;
+	void SetValidState(bool valid) {m_validState = valid;}
+
+	RandomNumberGenerator *m_rng;
+
+private:
+	bool m_throwOnProtocolError, m_validState;
+};
+
+class KeyAgreementSession : public ProtocolSession
+{
+public:
+	virtual unsigned int GetAgreedValueLength() const =0;
+	virtual void GetAgreedValue(byte *agreedValue) const =0;
+};
+
+class PasswordAuthenticatedKeyAgreementSession : public KeyAgreementSession
+{
+public:
+	void InitializePasswordAuthenticatedKeyAgreementSession(RandomNumberGenerator &rng, 
+		const byte *myId, unsigned int myIdLength, 
+		const byte *counterPartyId, unsigned int counterPartyIdLength, 
+		const byte *passwordOrVerifier, unsigned int passwordOrVerifierLength);
+};
+
+class PasswordAuthenticatedKeyAgreementDomain : public KeyAgreementAlgorithm
+{
+public:
+	//! return whether the domain parameters stored in this object are valid
+	virtual bool ValidateDomainParameters(RandomNumberGenerator &rng) const
+		{return GetCryptoParameters().Validate(rng, 2);}
+
+	virtual unsigned int GetPasswordVerifierLength(const byte *password, unsigned int passwordLength) const =0;
+	virtual void GeneratePasswordVerifier(RandomNumberGenerator &rng, const byte *userId, unsigned int userIdLength, const byte *password, unsigned int passwordLength, byte *verifier) const =0;
+
+	enum RoleFlags {CLIENT=1, SERVER=2, INITIATOR=4, RESPONDER=8};
+
+	virtual bool IsValidRole(unsigned int role) =0;
+	virtual PasswordAuthenticatedKeyAgreementSession * CreateProtocolSession(unsigned int role) const =0;
+};
+#endif
+
+//! BER Decode Exception Class, may be thrown during an ASN1 BER decode operation
+class CRYPTOPP_DLL BERDecodeErr : public InvalidArgument
+{
+public: 
+	BERDecodeErr() : InvalidArgument("BER decode error") {}
+	BERDecodeErr(const std::string &s) : InvalidArgument(s) {}
+};
+
+//! interface for encoding and decoding ASN1 objects
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE ASN1Object
+{
+public:
+	virtual ~ASN1Object() {}
+	//! decode this object from a BufferedTransformation, using BER (Basic Encoding Rules)
+	virtual void BERDecode(BufferedTransformation &bt) =0;
+	//! encode this object into a BufferedTransformation, using DER (Distinguished Encoding Rules)
+	virtual void DEREncode(BufferedTransformation &bt) const =0;
+	//! encode this object into a BufferedTransformation, using BER
+	/*! this may be useful if DEREncode() would be too inefficient */
+	virtual void BEREncode(BufferedTransformation &bt) const {DEREncode(bt);}
+};
+
+#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
+typedef PK_SignatureScheme PK_SignatureSystem;
+typedef SimpleKeyAgreementDomain PK_SimpleKeyAgreementDomain;
+typedef AuthenticatedKeyAgreementDomain PK_AuthenticatedKeyAgreementDomain;
+#endif
+
+NAMESPACE_END
+
+#endif