SHA-256 hash algorithm. More...

#include <SHA256.h>

Inheritance diagram for SHA256:

Public Member Functions
	SHA256 ()
	Constructs a SHA-256 hash object.

virtual	~SHA256 ()
	Destroys this SHA-256 hash object after clearing sensitive information.

size_t	hashSize () const
	Size of the hash result from finalize(). More...

size_t	blockSize () const
	Size of the internal block used by the hash algorithm. More...

void	reset ()
	Resets the hash ready for a new hashing process. More...

void	update (const void *data, size_t len)
	Updates the hash with more data. More...

void	finalize (void *hash, size_t len)
	Finalizes the hashing process and returns the hash. More...

void	clear ()
	Clears the hash state, removing all sensitive data, and then resets the hash ready for a new hashing process. More...

void	resetHMAC (const void *key, size_t keyLen)
	Resets the hash ready for a new HMAC hashing process. More...

void	finalizeHMAC (const void key, size_t keyLen, void hash, size_t hashLen)
	Finalizes the HMAC hashing process and returns the hash. More...

Public Member Functions inherited from Hash
	Hash ()
	Constructs a new hash object.

virtual	~Hash ()
	Destroys this hash object. More...

Static Public Attributes
static const size_t	HASH_SIZE = 32
	Constant for the size of the hash output of SHA256.

static const size_t	BLOCK_SIZE = 64
	Constant for the block size of SHA256.

Protected Member Functions
void	processChunk ()
	Processes a single 512-bit chunk with the core SHA-256 algorithm. More...

Protected Member Functions inherited from Hash
void	formatHMACKey (void block, const void key, size_t len, uint8_t pad)
	Formats a HMAC key into a block. More...

Protected Attributes
struct {
uint32_t h [8]

uint32_t w [16]

uint64_t length

uint8_t chunkSize

}	state

Detailed Description

SHA-256 hash algorithm.

Reference: http://en.wikipedia.org/wiki/SHA-2

See also: SHA224, SHA384, SHA512, SHA3_256, BLAKE2s

Definition at line 28 of file SHA256.h.

Member Function Documentation

◆ blockSize()

size_t SHA256::blockSize ( ) const

virtual

Size of the internal block used by the hash algorithm.

See also: update(), hashSize()

Implements Hash.

Definition at line 71 of file SHA256.cpp.

◆ clear()

void SHA256::clear ( )

virtual

Clears the hash state, removing all sensitive data, and then resets the hash ready for a new hashing process.

See also: reset()

Implements Hash.

Definition at line 144 of file SHA256.cpp.

◆ finalize()

void SHA256::finalize	(	void *	hash,
		size_t	len
	)

virtual

Finalizes the hashing process and returns the hash.

Parameters

hash	The buffer to return the hash value in.
len	The length of the hash buffer, normally hashSize().

If len is less than hashSize(), then the hash value will be truncated to the first len bytes. If len is greater than hashSize(), then the remaining bytes will left unchanged.

If finalize() is called again, then the returned hash value is undefined. Call reset() first to start a new hashing process.

See also: reset(), update(), finalizeHMAC()

Implements Hash.

Definition at line 112 of file SHA256.cpp.

◆ finalizeHMAC()

void SHA256::finalizeHMAC	(	const void *	key,
		size_t	keyLen,
		void *	hash,
		size_t	hashLen
	)

virtual

Finalizes the HMAC hashing process and returns the hash.

Parameters

key	Points to the HMAC key for the hashing process. The contents of this array must be identical to the value passed to resetHMAC().
keyLen	Size of the HMAC key in bytes.
hash	The buffer to return the hash value in.
hashLen	The length of the hash buffer, normally hashSize().

See also: resetHMAC(), finalize()

Implements Hash.

Definition at line 157 of file SHA256.cpp.

◆ hashSize()

size_t SHA256::hashSize ( ) const

virtual

Size of the hash result from finalize().

See also: finalize(), blockSize()

Implements Hash.

Definition at line 66 of file SHA256.cpp.

◆ processChunk()

void SHA256::processChunk ( )

protected

Processes a single 512-bit chunk with the core SHA-256 algorithm.

Reference: http://en.wikipedia.org/wiki/SHA-2

Definition at line 174 of file SHA256.cpp.

◆ reset()

void SHA256::reset ( )

virtual

Resets the hash ready for a new hashing process.

See also: update(), finalize(), resetHMAC()

Implements Hash.

Definition at line 76 of file SHA256.cpp.

◆ resetHMAC()

void SHA256::resetHMAC	(	const void *	key,
		size_t	keyLen
	)

virtual

Resets the hash ready for a new HMAC hashing process.

Parameters

key	Points to the HMAC key for the hashing process.
keyLen	Size of the HMAC key in bytes.

The following example computes a HMAC over a series of data blocks with a specific key:

hash.resetHMAC(key, sizeof(key));
hash.update(data1, sizeof(data1));
hash.update(data2, sizeof(data2));
...
hash.update(dataN, sizeof(dataN));
hash.finalizeHMAC(key, sizeof(key), hmac, sizeof(hmac));

The same key must be passed to both resetHMAC() and finalizeHMAC().

See also: finalizeHMAC(), reset()

Implements Hash.

Definition at line 150 of file SHA256.cpp.

◆ update()

void SHA256::update	(	const void *	data,
		size_t	len
	)

virtual

Updates the hash with more data.

Parameters

data	Data to be hashed.
len	Number of bytes of data to be hashed.

If finalize() has already been called, then the behavior of update() will be undefined. Call reset() first to start a new hashing process.

See also: reset(), finalize()

Implements Hash.

Definition at line 90 of file SHA256.cpp.

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

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ blockSize()

◆ clear()

◆ finalize()

◆ finalizeHMAC()

◆ hashSize()

◆ processChunk()

◆ reset()

◆ resetHMAC()

◆ update()