Base class for authenticated encryption modes of operation. More...

#include <authenc.h>

Inheritance diagram for AuthenticatedSymmetricCipherBase:

Public Member Functions
bool	IsRandomAccess () const
	Determines whether the cipher supports random access.

bool	IsSelfInverting () const
	Determines whether the cipher is self-inverting.

void	SetKey (const byte *userKey, size_t keylength, const NameValuePairs &params)
	Sets or reset the key of this object.

void	Restart ()
	Restart the hash.

void	Resynchronize (const byte *iv, int length=-1)
	Resynchronize with an IV.

void	Update (const byte *input, size_t length)
	Updates a hash with additional input.

void	ProcessData (byte outString, const byte inString, size_t length)
	Encrypt or decrypt an array of bytes.

void	TruncatedFinal (byte *mac, size_t macSize)
	Computes the hash of the current message.

Public Member Functions inherited from AuthenticatedSymmetricCipher
virtual lword	MaxHeaderLength () const =0
	Provides the maximum length of AAD that can be input.

virtual lword	MaxMessageLength () const =0
	Provides the maximum length of encrypted data.

virtual lword	MaxFooterLength () const
	Provides the maximum length of AAD.

virtual bool	NeedsPrespecifiedDataLengths () const
	Determines if data lengths must be specified prior to inputting data.

void	SpecifyDataLengths (lword headerLength, lword messageLength, lword footerLength=0)
	Prescribes the data lengths.

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)
	Encrypts and calculates a MAC in one call.

virtual bool	DecryptAndVerify (byte message, const byte mac, size_t macSize, const byte iv, int ivLength, const byte header, size_t headerLength, const byte *ciphertext, size_t ciphertextLength)
	Decrypts and verifies a MAC in one call.

virtual std::string	AlgorithmName () const
	Provides the name of this algorithm.

virtual std::string	AlgorithmProvider () const
	Retrieve the provider of this algorithm.

Public Member Functions inherited from SimpleKeyingInterface
virtual size_t	MinKeyLength () const =0
	Returns smallest valid key length.

virtual size_t	MaxKeyLength () const =0
	Returns largest valid key length.

virtual size_t	DefaultKeyLength () const =0
	Returns default key length.

virtual size_t	GetValidKeyLength (size_t keylength) const =0
	Returns a valid key length for the algorithm.

virtual bool	IsValidKeyLength (size_t keylength) const
	Returns whether keylength is a valid key length.

void	SetKeyWithRounds (const byte *key, size_t length, int rounds)
	Sets or reset the key of this object.

void	SetKeyWithIV (const byte key, size_t length, const byte iv, size_t ivLength)
	Sets or reset the key of this object.

void	SetKeyWithIV (const byte key, size_t length, const byte iv)
	Sets or reset the key of this object.

virtual IV_Requirement	IVRequirement () const =0
	Minimal requirement for secure IVs.

bool	IsResynchronizable () const
	Determines if the object can be resynchronized.

bool	CanUseRandomIVs () const
	Determines if the object can use random IVs.

bool	CanUsePredictableIVs () const
	Determines if the object can use random but possibly predictable IVs.

bool	CanUseStructuredIVs () const
	Determines if the object can use structured IVs.

virtual unsigned int	IVSize () const
	Returns length of the IV accepted by this object.

unsigned int	DefaultIVLength () const
	Provides the default size of an IV.

virtual unsigned int	MinIVLength () const
	Provides the minimum size of an IV.

virtual unsigned int	MaxIVLength () const
	Provides the maximum size of an IV.

virtual void	GetNextIV (RandomNumberGenerator &rng, byte *iv)
	Retrieves a secure IV for the next message.

Public Member Functions inherited from HashTransformation
HashTransformation &	Ref ()
	Provides a reference to this object.

virtual byte *	CreateUpdateSpace (size_t &size)
	Request space which can be written into by the caller.

virtual void	Final (byte *digest)
	Computes the hash of the current message.

virtual unsigned int	DigestSize () const =0
	Provides the digest size of the hash.

unsigned int	TagSize () const
	Provides the tag size of the hash.

virtual unsigned int	BlockSize () const
	Provides the block size of the compression function.

virtual unsigned int	OptimalBlockSize () const
	Provides the input block size most efficient for this hash.

virtual unsigned int	OptimalDataAlignment () const
	Provides input and output data alignment for optimal performance.

virtual void	CalculateDigest (byte digest, const byte input, size_t length)
	Updates the hash with additional input and computes the hash of the current message.

virtual bool	Verify (const byte *digest)
	Verifies the hash of the current message.

virtual bool	VerifyDigest (const byte digest, const byte input, size_t length)
	Updates the hash with additional input and verifies the hash of the current message.

virtual void	CalculateTruncatedDigest (byte digest, size_t digestSize, const byte input, size_t length)
	Updates the hash with additional input and computes the hash of the current message.

virtual bool	TruncatedVerify (const byte *digest, size_t digestLength)
	Verifies the hash of the current message.

virtual bool	VerifyTruncatedDigest (const byte digest, size_t digestLength, const byte input, size_t length)
	Updates the hash with additional input and verifies the hash of the current message.

Public Member Functions inherited from Algorithm
	Algorithm (bool checkSelfTestStatus=true)
	Interface for all crypto algorithms.

Public Member Functions inherited from Clonable
virtual Clonable *	Clone () const
	Copies this object.

Public Member Functions inherited from StreamTransformation
StreamTransformation &	Ref ()
	Provides a reference to this object.

virtual unsigned int	MandatoryBlockSize () const
	Provides the mandatory block size of the cipher.

virtual unsigned int	OptimalBlockSize () const
	Provides the input block size most efficient for this cipher.

virtual unsigned int	GetOptimalBlockSizeUsed () const
	Provides the number of bytes used in the current block when processing at optimal block size.

virtual unsigned int	OptimalDataAlignment () const
	Provides input and output data alignment for optimal performance.

virtual size_t	ProcessLastBlock (byte outString, size_t outLength, const byte inString, size_t inLength)
	Encrypt or decrypt the last block of data.

virtual unsigned int	MinLastBlockSize () const
	Provides the size of the last block.

virtual bool	IsLastBlockSpecial () const
	Determines if the last block receives special processing.

void	ProcessString (byte *inoutString, size_t length)
	Encrypt or decrypt a string of bytes.

void	ProcessString (byte outString, const byte inString, size_t length)
	Encrypt or decrypt a string of bytes.

byte	ProcessByte (byte input)
	Encrypt or decrypt a byte.

virtual void	Seek (lword pos)
	Seek to an absolute position.

virtual bool	IsForwardTransformation () const =0
	Determines if the cipher is being operated in its forward direction.

Additional Inherited Members
Public Types inherited from SimpleKeyingInterface
enum	IV_Requirement { UNIQUE_IV = 0 , RANDOM_IV , UNPREDICTABLE_RANDOM_IV , INTERNALLY_GENERATED_IV , NOT_RESYNCHRONIZABLE }
	Secure IVs requirements as enumerated values. More...

Detailed Description

Base class for authenticated encryption modes of operation.

AuthenticatedSymmetricCipherBase() serves as a base implementation for one direction (encryption or decryption) of a stream cipher or block cipher mode with authentication.

Crypto++ provides four authenticated encryption modes of operation - CCM, EAX, GCM and OCB mode. All modes derive from AuthenticatedSymmetricCipherBase() and the motivation for the API, like calling AAD a "header", can be found in Bellare, Rogaway and Wagner's The EAX Mode of Operation. The EAX paper suggested a basic API to help standardize AEAD schemes in software and promote adoption of the modes.

See also: Authenticated Encryption on the Crypto++ wiki.

Since: Crypto++ 5.6.0

Definition at line 40 of file authenc.h.

Constructor & Destructor Documentation

◆ AuthenticatedSymmetricCipherBase()

AuthenticatedSymmetricCipherBase::AuthenticatedSymmetricCipherBase ( )

inline

Definition at line 43 of file authenc.h.

Member Function Documentation

◆ IsRandomAccess()

bool AuthenticatedSymmetricCipherBase::IsRandomAccess ( ) const

inlinevirtual

Determines whether the cipher supports random access.

Returns: true if the cipher supports random access, false otherwise

Implements StreamTransformation.

Definition at line 47 of file authenc.h.

◆ IsSelfInverting()

bool AuthenticatedSymmetricCipherBase::IsSelfInverting ( ) const

inlinevirtual

Determines whether the cipher is self-inverting.

Returns: true if the cipher is self-inverting, false otherwise

IsSelfInverting determines whether this transformation is self-inverting (e.g. xor with a keystream).

Implements StreamTransformation.

Definition at line 48 of file authenc.h.

◆ SetKey()

void AuthenticatedSymmetricCipherBase::SetKey	(	const byte *	key,
		size_t	length,
		const NameValuePairs &	params
	)

virtual

Sets or reset the key of this object.

Parameters

key	the key to use when keying the object
length	the size of the key, in bytes
params	additional initialization parameters to configure this object

Reimplemented from SimpleKeyingInterface.

◆ Restart()

void AuthenticatedSymmetricCipherBase::Restart ( )

inlinevirtual

Restart the hash.

Discards the current state, and restart for a new message

Reimplemented from HashTransformation.

Definition at line 51 of file authenc.h.

◆ Resynchronize()

void AuthenticatedSymmetricCipherBase::Resynchronize	(	const byte *	iv,
		int	ivLength = `-1`
	)

virtual

Resynchronize with an IV.

Parameters

iv	the initialization vector
ivLength	the size of the initialization vector, in bytes

Resynchronize() resynchronizes with an IV provided by the caller. ivLength=-1 means use IVSize().

Exceptions

NotImplemented() if the object does not support resynchronization

Reimplemented from SimpleKeyingInterface.

◆ Update()

void AuthenticatedSymmetricCipherBase::Update	(	const byte *	input,
		size_t	length
	)

virtual

Updates a hash with additional input.

Parameters

input	the additional input as a buffer
length	the size of the buffer, in bytes

Implements HashTransformation.

◆ ProcessData()

void AuthenticatedSymmetricCipherBase::ProcessData	(	byte *	outString,
		const byte *	inString,
		size_t	length
	)

virtual

Encrypt or decrypt an array of bytes.

Parameters

outString	the output byte buffer
inString	the input byte buffer
length	the size of the input and output byte buffers, in bytes

ProcessData is called with a string of bytes whose size depends on MandatoryBlockSize. Either inString == outString, or they must not overlap.

See also: ProcessData, ProcessLastBlock, MandatoryBlockSize, MinLastBlockSize, BlockPaddingSchemeDef, IsLastBlockSpecial

Implements StreamTransformation.

◆ TruncatedFinal()

void AuthenticatedSymmetricCipherBase::TruncatedFinal	(	byte *	digest,
		size_t	digestSize
	)

virtual

Computes the hash of the current message.

Parameters

digest	a pointer to the buffer to receive the hash
digestSize	the size of the truncated digest, in bytes

TruncatedFinal() calls Final() and then copies digestSize bytes to digest. The hash is restarted the hash for the next message.

Precondition: COUNTOF(digest) <= DigestSize() or COUNTOF(digest) <= HASH::DIGESTSIZE ensures the output byte buffer is a valid size.

Implements HashTransformation.

The documentation for this class was generated from the following file:

authenc.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ AuthenticatedSymmetricCipherBase()

Member Function Documentation

◆ IsRandomAccess()

◆ IsSelfInverting()

◆ SetKey()

◆ Restart()

◆ Resynchronize()

◆ Update()

◆ ProcessData()

◆ TruncatedFinal()