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

#include <cryptlib.h>

Inheritance diagram for HashTransformation:

Collaboration diagram for HashTransformation:

Public Member Functions
virtual	~HashTransformation ()

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
virtual	~Algorithm ()

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

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

Public Member Functions inherited from Clonable
virtual	~Clonable ()

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

Protected Member Functions
void	ThrowIfInvalidTruncatedSize (size_t size) const
	Validates a truncated digest size. 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 930 of file cryptlib.h.

Constructor & Destructor Documentation

virtual HashTransformation::~HashTransformation ( )

inlinevirtual

Definition at line 933 of file cryptlib.h.

Member Function Documentation

virtual unsigned int HashTransformation::BlockSize ( ) const

inlinevirtual

Provides the block size of the compression function.

Returns: the block size of the compression function, in bytes

BlockSize() will return 0 if the hash is not block based. For example, SHA3 is a recursive hash (not an iterative hash), and it does not have a block size.

Reimplemented in IteratedHash< word64, LittleEndian, T_BlockSize >, IteratedHash< T_HashWordType, T_Endianness, T_BlockSize >, IteratedHash< word32, LittleEndian, T_BlockSize >, IteratedHash< word32, LittleEndian, 64, MessageAuthenticationCode >, IteratedHash< word32, BigEndian, T_BlockSize >, IteratedHash< word32, NativeByteOrder, 32 >, IteratedHash< word64, BigEndian, T_BlockSize >, HermeticHashFunctionMAC< T_Hash, T_Info >, HermeticHashFunctionMAC< PanamaHash >, Keccak_Final< T_DigestSize >, Poly1305_Base< T >, SHA3_Final< T_DigestSize >, VMAC_Base, and Weak1::MD2.

Definition at line 981 of file cryptlib.h.

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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 large enough for the digest.

Definition at line 1003 of file cryptlib.h.

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

Definition at line 1051 of file cryptlib.h.

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.

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

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

Definition at line 953 of file cryptlib.h.

virtual unsigned int HashTransformation::DigestSize ( ) const

pure virtual

Provides the digest size of the hash.

Returns: the digest size of the hash.

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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 960 of file cryptlib.h.

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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 HermeticHashFunctionMAC< T_Hash, T_Info >, HermeticHashFunctionMAC< PanamaHash >, SipHash_Base< C, D, T_128bit >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word64, MessageAuthenticationCode >, CMAC_Base, and HMAC_Base.

Definition at line 988 of file cryptlib.h.

unsigned int HashTransformation::OptimalDataAlignment ( ) const

virtual

Provides input and output data alignment for optimal performance.

Returns: the input data alignment that provides optimal performance

Reimplemented in BLAKE2_Base< W, T_64bit >, BLAKE2_Base< word32, false >, BLAKE2_Base< word64, true >, HermeticHashFunctionMAC< T_Hash, T_Info >, HermeticHashFunctionMAC< PanamaHash >, SipHash_Base< C, D, T_128bit >, Keccak, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word64, MessageAuthenticationCode >, GCM_Base, SHA3, CCM_Base, VMAC_Base, EAX_Base, and CMAC_Base.

Definition at line 239 of file cryptlib.cpp.

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 938 of file cryptlib.h.

virtual void HashTransformation::Restart ( )

inlinevirtual

Restart the hash.

Discards the current state, and restart for a new message

Reimplemented in BLAKE2_Base< W, T_64bit >, BLAKE2_Base< word32, false >, BLAKE2_Base< word64, true >, SipHash_Base< C, D, T_128bit >, Poly1305_Base< T >, HermeticHashFunctionMAC< T_Hash, T_Info >, HermeticHashFunctionMAC< PanamaHash >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word64, MessageAuthenticationCode >, Keccak, SHA3, AuthenticatedSymmetricCipherBase, TruncatedHashTemplate< T >, and HMAC_Base.

Definition at line 965 of file cryptlib.h.

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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 975 of file cryptlib.h.

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void HashTransformation::ThrowIfInvalidTruncatedSize ( size_t size ) const

protected

Validates a truncated digest size.

Parameters

size	the requested digest size

Exceptions

InvalidArgument if the algorithm's digest size cannot be truncated to the requested size

Throws an exception when the truncated digest size is greater than DigestSize()

Definition at line 416 of file cryptlib.cpp.

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

Implemented in PK_MessageAccumulator, BLAKE2_Base< W, T_64bit >, BLAKE2_Base< word32, false >, BLAKE2_Base< word64, true >, HermeticHashFunctionMAC< T_Hash, T_Info >, HermeticHashFunctionMAC< PanamaHash >, SipHash_Base< C, D, T_128bit >, Poly1305_Base< T >, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word64, MessageAuthenticationCode >, Keccak, CRC32C, Weak::PanamaHash, SHA3, AuthenticatedSymmetricCipherBase, TruncatedHashTemplate< T >, VMAC_Base, CRC32, DMAC_Base< T >, HMAC_Base, CMAC_Base, TTMAC_Base, CBC_MAC_Base, Adler32, Tiger, Weak1::MD2, NullHash, and Whirlpool.

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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

ThrowIfInvalidTruncatedSize() 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.

Reimplemented in TruncatedHashTemplate< T >, and NullHash.

Definition at line 408 of file cryptlib.cpp.

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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 PK_MessageAccumulatorBase, BLAKE2_Base< W, T_64bit >, BLAKE2_Base< word32, false >, BLAKE2_Base< word64, true >, SipHash_Base< C, D, T_128bit >, Poly1305_Base< T >, HermeticHashFunctionMAC< T_Hash, T_Info >, HermeticHashFunctionMAC< PanamaHash >, CRC32C, Keccak, IteratedHashBase< word32, HashTransformation >, IteratedHashBase< T_HashWordType, HashTransformation >, IteratedHashBase< word32, MessageAuthenticationCode >, IteratedHashBase< word64, HashTransformation >, IteratedHashBase< word64, MessageAuthenticationCode >, SHA3, AuthenticatedSymmetricCipherBase, TruncatedHashTemplate< T >, CRC32, DMAC_Base< T >, HMAC_Base, CMAC_Base, CBC_MAC_Base, Adler32, Weak1::MD2, and NullHash.

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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

ThrowIfInvalidTruncatedSize() 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 output byte buffer is large enough for the digest.

Definition at line 1015 of file cryptlib.h.

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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

ThrowIfInvalidTruncatedSize() 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. digestLength cannot exceed DigestSize().

VerifyDigest() restarts the hash for the next message.

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

Definition at line 1031 of file cryptlib.h.

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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

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

Definition at line 1080 of file cryptlib.h.

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

src/cryptopp/cryptlib.h
src/cryptopp/cryptlib.cpp

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation