Interface for hash functions and data processing part of MACs. More...

#include <cryptlib.h>

Inheritance diagram for HashTransformation:

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

virtual void	Update (const byte *input, size_t length)=0
	Updates a hash with additional input. 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...

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

virtual unsigned int	DigestSize () const =0
	Provides the digest size of the hash. 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 unsigned int	OptimalDataAlignment () const
	Provides input and output data alignment for optimal performance. 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	TruncatedFinal (byte *digest, size_t digestSize)=0
	Computes 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
	Algorithm (bool checkSelfTestStatus=true)
	Interface for all crypto algorithms. More...

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

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

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

Detailed Description

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().

See also: HashFilter(), HashVerificationFilter()

Definition at line 1112 of file cryptlib.h.

Constructor & Destructor Documentation

◆ ~HashTransformation()

virtual HashTransformation::~HashTransformation ( )

inlinevirtual

Definition at line 1115 of file cryptlib.h.

Member Function Documentation

◆ Ref()

HashTransformation & HashTransformation::Ref ( )

inline

Provides a reference to this object.

Returns: A reference to this object

Useful for passing a temporary object to a function that takes a non-const reference

Definition at line 1120 of file cryptlib.h.

◆ Update()

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

pure virtual

Updates a hash with additional input.

Parameters

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

Implemented in Adler32, AuthenticatedSymmetricCipherBase, BLAKE2s, BLAKE2b, CBC_MAC_Base, CMAC_Base, CRC32, CRC32C, DMAC_Base< T >, HMAC_Base, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, MessageAuthenticationCode >, Keccak, Weak::MD2, Poly1305_Base< T >, Poly1305TLS_Base, PK_MessageAccumulatorBase, SHA3, SHAKE, SipHash_Base< C, D, T_128bit >, SipHash_Base< 2, 4, false >, NullHash, TruncatedHashTemplate< T >, LSH256_Base, LSH512_Base, and ed25519_MessageAccumulator.

◆ CreateUpdateSpace()

virtual byte * HashTransformation::CreateUpdateSpace ( size_t & size )

inlinevirtual

Request space which can be written into by the caller.

Parameters

size	the requested size of the buffer

The purpose of this method is to help avoid extra memory allocations.

size is an IN and OUT parameter and used as a hint. When the call is made, size is the requested size of the buffer. When the call returns, size is the size of the array returned to the caller.

The base class implementation sets size to 0 and returns NULL or nullptr.

Note: Some objects, like ArraySink, cannot create a space because its fixed.

Reimplemented in IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, and IteratedHashBase< word64, MessageAuthenticationCode >.

Definition at line 1135 of file cryptlib.h.

◆ Final()

virtual void HashTransformation::Final ( byte * digest )

inlinevirtual

Computes the hash of the current message.

Parameters

digest a pointer to the buffer to receive the hash

Final() restarts the hash for a new message.

Precondition: COUNTOF(digest) <= DigestSize() or COUNTOF(digest) <= HASH::DIGESTSIZE ensures the output byte buffer is large enough for the digest.

Definition at line 1142 of file cryptlib.h.

◆ Restart()

virtual void HashTransformation::Restart ( )

inlinevirtual

Restart the hash.

Discards the current state, and restart for a new message

Reimplemented in AuthenticatedSymmetricCipherBase, BLAKE2s, BLAKE2b, HMAC_Base, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, MessageAuthenticationCode >, Keccak, LSH256_Base, LSH512_Base, Poly1305_Base< T >, Poly1305TLS_Base, SHA3, SHAKE, TruncatedHashTemplate< T >, and ed25519_MessageAccumulator.

Definition at line 1147 of file cryptlib.h.

◆ DigestSize()

virtual unsigned int HashTransformation::DigestSize ( ) const

pure virtual

Provides the digest size of the hash.

Returns: the digest size of the hash.

◆ TagSize()

unsigned int HashTransformation::TagSize ( ) const

inline

Provides the tag size of the hash.

Returns: the tag size of the hash.

Same as DigestSize().

Definition at line 1157 of file cryptlib.h.

◆ BlockSize()

virtual unsigned int HashTransformation::BlockSize ( ) const

inlinevirtual

Provides the block size of the compression function.

Returns: block size of the compression function, in bytes

BlockSize() will return 0 if the hash is not block based or does not have an equivalent block size. For example, Keccak and SHA-3 do not have a block size, but they do have an equivalent block size called rate expressed as r.

Reimplemented in BLAKE2s, BLAKE2b, IteratedHash< T_HashWordType, T_Endianness, T_BlockSize, T_Base >, IteratedHash< word32, LittleEndian, T_BlockSize >, IteratedHash< word32, BigEndian, T_BlockSize >, IteratedHash< word64, BigEndian, T_BlockSize >, IteratedHash< word32, LittleEndian, 64, MessageAuthenticationCode >, IteratedHash< word64, LittleEndian, T_BlockSize >, IteratedHash< word32, NativeByteOrder, 32 >, Keccak_Final< T_DigestSize >, Keccak_Final< 28 >, Keccak_Final< 32 >, Keccak_Final< 48 >, Keccak_Final< 64 >, LSH256_Base, LSH512_Base, Weak::MD2, Poly1305_Base< T >, Poly1305TLS_Base, SHA3_Final< T_DigestSize >, SHA3_Final< 28 >, SHA3_Final< 32 >, SHA3_Final< 48 >, SHA3_Final< 64 >, SHAKE_Final< T_Strength >, SHAKE_Final< 128 >, SHAKE_Final< 256 >, and VMAC_Base.

Definition at line 1165 of file cryptlib.h.

◆ OptimalBlockSize()

virtual unsigned int HashTransformation::OptimalBlockSize ( ) const

inlinevirtual

Provides the input block size most efficient for this hash.

Returns: The input block size that is most efficient for the cipher

The base class implementation returns MandatoryBlockSize().

Optimal input length is n * OptimalBlockSize() - GetOptimalBlockSizeUsed() for any n > 0.

Reimplemented in CMAC_Base, HMAC_Base, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, MessageAuthenticationCode >, SipHash_Base< C, D, T_128bit >, and SipHash_Base< 2, 4, false >.

Definition at line 1172 of file cryptlib.h.

◆ OptimalDataAlignment()

virtual unsigned int HashTransformation::OptimalDataAlignment ( ) const

virtual

Provides input and output data alignment for optimal performance.

Returns: the input data alignment that provides optimal performance

See also: GetAlignment() and OptimalBlockSize()

Reimplemented in BLAKE2s, BLAKE2b, CCM_Base, ChaCha20Poly1305_Base, XChaCha20Poly1305_Base, CMAC_Base, EAX_Base, GCM_Base, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, MessageAuthenticationCode >, Keccak, LSH256_Base, LSH512_Base, SHA3, SHAKE, SipHash_Base< C, D, T_128bit >, SipHash_Base< 2, 4, false >, and VMAC_Base.

◆ CalculateDigest()

virtual void HashTransformation::CalculateDigest	(	byte *	digest,
		const byte *	input,
		size_t	length
	)

inlinevirtual

Updates the hash with additional input and computes the hash of the current message.

Parameters

digest	a pointer to the buffer to receive the hash
input	the additional input as a buffer
length	the size of the buffer, in bytes

Use this if your input is in one piece and you don't want to call Update() and Final() separately

CalculateDigest() restarts the hash for the next message.

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

Definition at line 1188 of file cryptlib.h.

◆ Verify()

virtual bool HashTransformation::Verify ( const byte * digest )

inlinevirtual

Verifies the hash of the current message.

Parameters

digest a pointer to the buffer of an existing hash

Returns: true if the existing hash matches the computed hash, false otherwise

Exceptions

InvalidArgument() if the existing hash's size exceeds DigestSize()

Verify() performs a bitwise compare on the buffers using VerifyBufsEqual(), which is a constant time comparison function. digestLength cannot exceed DigestSize().

Verify() restarts the hash for the next message.

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

Definition at line 1200 of file cryptlib.h.

◆ VerifyDigest()

virtual bool HashTransformation::VerifyDigest	(	const byte *	digest,
		const byte *	input,
		size_t	length
	)

inlinevirtual

Updates the hash with additional input and verifies the hash of the current message.

Parameters

digest	a pointer to the buffer of an existing hash
input	the additional input as a buffer
length	the size of the buffer, in bytes

Returns: true if the existing hash matches the computed hash, false otherwise

Exceptions

InvalidArgument() if the existing hash's size exceeds DigestSize()

Use this if your input is in one piece and you don't want to call Update() and Verify() separately

VerifyDigest() performs a bitwise compare on the buffers using VerifyBufsEqual(), which is a constant time comparison function.

VerifyDigest() restarts the hash for the next message.

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

Definition at line 1216 of file cryptlib.h.

◆ TruncatedFinal()

virtual void HashTransformation::TruncatedFinal	(	byte *	digest,
		size_t	digestSize
	)

pure 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.

Implemented in PK_MessageAccumulator, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, MessageAuthenticationCode >, SipHash_Base< C, D, T_128bit >, SipHash_Base< 2, 4, false >, Tiger, NullHash, TruncatedHashTemplate< T >, Adler32, BLAKE2s, BLAKE2b, CRC32, CRC32C, Keccak, LSH256_Base, LSH512_Base, Weak::MD2, Weak::PanamaHash< B >, Weak::PanamaHash< LittleEndian >, SHA3, SHAKE, Whirlpool, AuthenticatedSymmetricCipherBase, CBC_MAC_Base, CMAC_Base, DMAC_Base< T >, HMAC_Base, Poly1305_Base< T >, Poly1305TLS_Base, TTMAC_Base, and VMAC_Base.

◆ CalculateTruncatedDigest()

virtual void HashTransformation::CalculateTruncatedDigest	(	byte *	digest,
		size_t	digestSize,
		const byte *	input,
		size_t	length
	)

inlinevirtual

Updates the hash with additional input and computes the hash of the current message.

Parameters

digest	a pointer to the buffer to receive the hash
digestSize	the length of the truncated hash, in bytes
input	the additional input as a buffer
length	the size of the buffer, in bytes

Use this if your input is in one piece and you don't want to call Update() and CalculateDigest() separately.

CalculateTruncatedDigest() restarts the hash for the next message.

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

Definition at line 1238 of file cryptlib.h.

◆ TruncatedVerify()

virtual bool HashTransformation::TruncatedVerify	(	const byte *	digest,
		size_t	digestLength
	)

virtual

Verifies the hash of the current message.

Parameters

digest	a pointer to the buffer of an existing hash
digestLength	the size of the truncated hash, in bytes

Returns: true if the existing hash matches the computed hash, false otherwise

Exceptions

InvalidArgument() if digestLength exceeds DigestSize()

TruncatedVerify() is a truncated version of Verify(). It can operate on a buffer smaller than DigestSize(). However, digestLength cannot exceed DigestSize().

Verify() performs a bitwise compare on the buffers using VerifyBufsEqual(), which is a constant time comparison function. digestLength cannot exceed DigestSize().

TruncatedVerify() restarts the hash for the next message.

Precondition: digestLength <= DigestSize() or digestLength <= HASH::DIGESTSIZE ensures the input byte buffer is a valid size.

Reimplemented in NullHash, and TruncatedHashTemplate< T >.

◆ VerifyTruncatedDigest()

virtual bool HashTransformation::VerifyTruncatedDigest	(	const byte *	digest,
		size_t	digestLength,
		const byte *	input,
		size_t	length
	)

inlinevirtual

Updates the hash with additional input and verifies the hash of the current message.

Parameters

digest	a pointer to the buffer of an existing hash
digestLength	the size of the truncated hash, in bytes
input	the additional input as a buffer
length	the size of the buffer, in bytes

Returns: true if the existing hash matches the computed hash, false otherwise

Exceptions

InvalidArgument() if digestLength exceeds DigestSize()

Use this if your input is in one piece and you don't want to call Update() and TruncatedVerify() separately.

VerifyTruncatedDigest() is a truncated version of VerifyDigest(). It can operate on a buffer smaller than DigestSize(). However, digestLength cannot exceed DigestSize().

VerifyTruncatedDigest() restarts the hash for the next message.

Precondition: digestLength <= DigestSize() or digestLength <= HASH::DIGESTSIZE ensures the input byte buffer is a valid size.

Definition at line 1269 of file cryptlib.h.

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

cryptlib.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ~HashTransformation()

Member Function Documentation

◆ Ref()

◆ Update()

◆ CreateUpdateSpace()

◆ Final()

◆ Restart()

◆ DigestSize()

◆ TagSize()

◆ BlockSize()

◆ OptimalBlockSize()

◆ OptimalDataAlignment()

◆ CalculateDigest()

◆ Verify()

◆ VerifyDigest()

◆ TruncatedFinal()

◆ CalculateTruncatedDigest()

◆ TruncatedVerify()

◆ VerifyTruncatedDigest()