GCM block cipher base implementation. More...

#include <gcm.h>

Inheritance diagram for GCM_Base:

Collaboration diagram for GCM_Base:

Classes
class	GCTR

Public Member Functions
std::string	AlgorithmName () const
	Provides the name of this algorithm. More...

size_t	MinKeyLength () const
	Returns smallest valid key length. More...

size_t	MaxKeyLength () const
	Returns largest valid key length. More...

size_t	DefaultKeyLength () const
	Returns default key length. More...

size_t	GetValidKeyLength (size_t n) const
	Returns a valid key length for the algorithm. More...

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

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

IV_Requirement	IVRequirement () const
	Minimal requirement for secure IVs. More...

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

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

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

unsigned int	DigestSize () const
	Provides the digest size of the hash. More...

lword	MaxHeaderLength () const
	Provides the maximum length of AAD that can be input. More...

lword	MaxMessageLength () const
	Provides the maximum length of encrypted data. More...

Public Member Functions inherited from AuthenticatedSymmetricCipherBase
	AuthenticatedSymmetricCipherBase ()

bool	IsRandomAccess () const
	Determines whether the cipher supports random access. More...

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

void	UncheckedSetKey (const byte *key, unsigned int length, const CryptoPP::NameValuePairs &params)
	Sets the key for this object without performing parameter validation. More...

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

void	Restart ()
	Restart the hash. More...

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

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

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

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

Public Member Functions inherited from AuthenticatedSymmetricCipher
virtual	~AuthenticatedSymmetricCipher ()

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

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

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

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. More...

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)
	Decrypts and verifies a MAC in one call. More...

Public Member Functions inherited from SimpleKeyingInterface
virtual	~SimpleKeyingInterface ()

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

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

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

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

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

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

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

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

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

Public Member Functions inherited from HashTransformation
virtual	~HashTransformation ()

HashTransformation &	Ref ()
	Provides a reference to this object. More...

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

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

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

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

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

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. More...

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

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. More...

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. More...

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

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. More...

Public Member Functions inherited from Algorithm
virtual	~Algorithm ()

	Algorithm (bool checkSelfTestStatus=true)
	Interface for all crypto algorithms. More...

Public Member Functions inherited from Clonable
virtual	~Clonable ()

virtual Clonable *	Clone () const
	Copies this object. More...

Public Member Functions inherited from StreamTransformation
virtual	~StreamTransformation ()

StreamTransformation &	Ref ()
	Provides a reference to this object. More...

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

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

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

virtual void	ProcessLastBlock (byte outString, const byte inString, size_t length)
	Encrypt or decrypt the last block of data. More...

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

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

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

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

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

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

Protected Types
enum	{ REQUIRED_BLOCKSIZE = 16, HASH_BLOCKSIZE = 16 }

Protected Types inherited from AuthenticatedSymmetricCipherBase
enum	State { State_Start, State_KeySet, State_IVSet, State_AuthUntransformed, State_AuthTransformed, State_AuthFooter }

Protected Member Functions
bool	AuthenticationIsOnPlaintext () const

unsigned int	AuthenticationBlockSize () const

void	SetKeyWithoutResync (const byte *userKey, size_t keylength, const NameValuePairs &params)

void	Resync (const byte *iv, size_t len)

size_t	AuthenticateBlocks (const byte *data, size_t len)

void	AuthenticateLastHeaderBlock ()

void	AuthenticateLastConfidentialBlock ()

void	AuthenticateLastFooterBlock (byte *mac, size_t macSize)

SymmetricCipher &	AccessSymmetricCipher ()

virtual BlockCipher &	AccessBlockCipher ()=0

virtual GCM_TablesOption	GetTablesOption () const =0

const BlockCipher &	GetBlockCipher () const

byte *	HashBuffer ()

byte *	HashKey ()

byte *	MulTable ()

void	ReverseHashBufferIfNeeded ()

Protected Member Functions inherited from AuthenticatedSymmetricCipherBase
void	AuthenticateData (const byte *data, size_t len)

const SymmetricCipher &	GetSymmetricCipher () const

Protected Member Functions inherited from AuthenticatedSymmetricCipher
const Algorithm &	GetAlgorithm () const
	Returns the base class Algorithm. More...

virtual void	UncheckedSpecifyDataLengths (lword headerLength, lword messageLength, lword footerLength)

Protected Member Functions inherited from SimpleKeyingInterface
virtual void	UncheckedSetKey (const byte *key, unsigned int length, const NameValuePairs &params)=0
	Sets the key for this object without performing parameter validation. More...

void	ThrowIfInvalidKeyLength (size_t length)
	Validates the key length. More...

void	ThrowIfResynchronizable ()
	Validates the object. More...

void	ThrowIfInvalidIV (const byte *iv)
	Validates the IV. More...

size_t	ThrowIfInvalidIVLength (int length)
	Validates the IV length. More...

const byte *	GetIVAndThrowIfInvalid (const NameValuePairs &params, size_t &size)
	Retrieves and validates the IV. More...

void	AssertValidKeyLength (size_t length) const
	Validates the key length. More...

Protected Member Functions inherited from HashTransformation
void	ThrowIfInvalidTruncatedSize (size_t size) const
	Validates a truncated digest size. More...

Protected Attributes
GCTR	m_ctr

Protected Attributes inherited from AuthenticatedSymmetricCipherBase
State	m_state

unsigned int	m_bufferedDataLength

lword	m_totalHeaderLength

lword	m_totalMessageLength

lword	m_totalFooterLength

AlignedSecByteBlock	m_buffer

Static Protected Attributes
static word16	s_reductionTable [256]

static volatile bool	s_reductionTableInitialized = false

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

GCM block cipher base implementation.

Base implementation of the AuthenticatedSymmetricCipher interface

Since: Crypto++ 5.6.0

Definition at line 27 of file gcm.h.

Member Enumeration Documentation

anonymous enum

protected

Enumerator
REQUIRED_BLOCKSIZE
HASH_BLOCKSIZE

Definition at line 91 of file gcm.h.

Member Function Documentation

virtual BlockCipher& GCM_Base::AccessBlockCipher ( )

protectedpure virtual

Implemented in GCM_Final< T_BlockCipher, T_TablesOption, T_IsEncryption >.

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SymmetricCipher& GCM_Base::AccessSymmetricCipher ( )

inlineprotectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 71 of file gcm.h.

std::string GCM_Base::AlgorithmName ( ) const

inlinevirtual

Provides the name of this algorithm.

Returns: the standard algorithm name

The standard algorithm name can be a name like AES or AES/GCM. Some algorithms do not have standard names yet. For example, there is no standard algorithm name for Shoup's ECIES.

Implements AuthenticatedSymmetricCipher.

Definition at line 31 of file gcm.h.

size_t GCM_Base::AuthenticateBlocks	(	const byte *	data,
		size_t	len
	)

protectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 508 of file gcm.cpp.

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void GCM_Base::AuthenticateLastConfidentialBlock ( )

protectedvirtual

Reimplemented from AuthenticatedSymmetricCipherBase.

Definition at line 1073 of file gcm.cpp.

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void GCM_Base::AuthenticateLastFooterBlock	(	byte *	mac,
		size_t	macSize
	)

protectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 1080 of file gcm.cpp.

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void GCM_Base::AuthenticateLastHeaderBlock ( )

protectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 1063 of file gcm.cpp.

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unsigned int GCM_Base::AuthenticationBlockSize ( ) const

inlineprotectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 63 of file gcm.h.

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bool GCM_Base::AuthenticationIsOnPlaintext ( ) const

inlineprotectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 61 of file gcm.h.

size_t GCM_Base::DefaultKeyLength ( ) const

inlinevirtual

Returns default key length.

Returns: the default (recommended) key length, in bytes

Implements SimpleKeyingInterface.

Definition at line 37 of file gcm.h.

unsigned int GCM_Base::DigestSize ( ) const

inlinevirtual

Provides the digest size of the hash.

Returns: the digest size of the hash.

Implements HashTransformation.

Definition at line 52 of file gcm.h.

const BlockCipher& GCM_Base::GetBlockCipher ( ) const

inlineprotected

Definition at line 76 of file gcm.h.

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virtual GCM_TablesOption GCM_Base::GetTablesOption ( ) const

protectedpure virtual

Implemented in GCM_Final< T_BlockCipher, T_TablesOption, T_IsEncryption >.

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size_t GCM_Base::GetValidKeyLength ( size_t keylength ) const

inlinevirtual

Returns a valid key length for the algorithm.

Parameters

keylength the size of the key, in bytes

Returns: the valid key length, in bytes

keylength is provided in bytes, not bits. If keylength is less than MIN_KEYLENGTH, then the function returns MIN_KEYLENGTH. If keylength is greater than MAX_KEYLENGTH, then the function returns MAX_KEYLENGTH. if If keylength is a multiple of KEYLENGTH_MULTIPLE, then keylength is returned. Otherwise, the function returns a lower multiple of KEYLENGTH_MULTIPLE.

Implements SimpleKeyingInterface.

Definition at line 39 of file gcm.h.

byte* GCM_Base::HashBuffer ( )

inlineprotected

Definition at line 77 of file gcm.h.

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byte* GCM_Base::HashKey ( )

inlineprotected

Definition at line 78 of file gcm.h.

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bool GCM_Base::IsValidKeyLength ( size_t keylength ) const

inlinevirtual

Returns whether keylength is a valid key length.

Parameters

keylength the requested keylength

Returns: true if keylength is valid, false otherwise

Internally the function calls GetValidKeyLength()

Reimplemented from SimpleKeyingInterface.

Definition at line 41 of file gcm.h.

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IV_Requirement GCM_Base::IVRequirement ( ) const

inlinevirtual

Minimal requirement for secure IVs.

Returns: the secure IV requirement of the algorithm

Implements SimpleKeyingInterface.

Definition at line 44 of file gcm.h.

unsigned int GCM_Base::IVSize ( ) const

inlinevirtual

Returns length of the IV accepted by this object.

Returns: the size of an IV, in bytes

Exceptions

NotImplemented() if the object does not support resynchronization

The default implementation throws NotImplemented

Reimplemented from SimpleKeyingInterface.

Definition at line 46 of file gcm.h.

lword GCM_Base::MaxHeaderLength ( ) const

inlinevirtual

Provides the maximum length of AAD that can be input.

Returns: the maximum length of AAD that can be input before the encrypted data

Implements AuthenticatedSymmetricCipher.

Definition at line 54 of file gcm.h.

unsigned int GCM_Base::MaxIVLength ( ) const

inlinevirtual

Provides the maximum size of an IV.

Returns: maximal length of IVs accepted by this object, in bytes

Exceptions

NotImplemented() if the object does not support resynchronization

Reimplemented from SimpleKeyingInterface.

Definition at line 50 of file gcm.h.

size_t GCM_Base::MaxKeyLength ( ) const

inlinevirtual

Returns largest valid key length.

Returns: the maximum key length, in bytes

Implements SimpleKeyingInterface.

Definition at line 35 of file gcm.h.

lword GCM_Base::MaxMessageLength ( ) const

inlinevirtual

Provides the maximum length of encrypted data.

Returns: the maximum length of encrypted data

Implements AuthenticatedSymmetricCipher.

Definition at line 56 of file gcm.h.

unsigned int GCM_Base::MinIVLength ( ) const

inlinevirtual

Provides the minimum size of an IV.

Returns: minimal length of IVs accepted by this object, in bytes

Exceptions

NotImplemented() if the object does not support resynchronization

Reimplemented from SimpleKeyingInterface.

Definition at line 48 of file gcm.h.

size_t GCM_Base::MinKeyLength ( ) const

inlinevirtual

Returns smallest valid key length.

Returns: the minimum key length, in bytes

Implements SimpleKeyingInterface.

Definition at line 33 of file gcm.h.

byte* GCM_Base::MulTable ( )

inlineprotected

Definition at line 79 of file gcm.h.

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unsigned int GCM_Base::OptimalDataAlignment ( ) const

virtual

Provides input and output data alignment for optimal performance.

Returns: the input data alignment that provides optimal performance

Reimplemented from StreamTransformation.

Definition at line 482 of file gcm.cpp.

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void GCM_Base::Resync	(	const byte *	iv,
		size_t	len
	)

protectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 437 of file gcm.cpp.

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void GCM_Base::ReverseHashBufferIfNeeded ( )

inlineprotected

Definition at line 417 of file gcm.cpp.

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void GCM_Base::SetKeyWithoutResync	(	const byte *	userKey,
		size_t	keylength,
		const NameValuePairs &	params
	)

protectedvirtual

Implements AuthenticatedSymmetricCipherBase.

Definition at line 225 of file gcm.cpp.

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Member Data Documentation

GCTR GCM_Base::m_ctr

protected

Definition at line 88 of file gcm.h.

word16 GCM_Base::s_reductionTable

staticprotected

Definition at line 89 of file gcm.h.

volatile bool GCM_Base::s_reductionTableInitialized = false

staticprotected

Definition at line 90 of file gcm.h.

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

src/cryptopp/gcm.h
src/cryptopp/gcm.cpp

Classes

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Static Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Member Function Documentation

Member Data Documentation