romulus-hmac.h File Reference

Hashed Message Authentication Code (HMAC) based on Romulus-H. More...

#include "romulus-hash.h"
#include <stddef.h>

Go to the source code of this file.

Macros
#define	ROMULUS_HMAC_SIZE   ROMULUS_HASH_SIZE
	Default size of the output for Romulus-HMAC.

Typedefs
typedef romulus_hash_state_t	romulus_hmac_state_t
	State information for the Romulus-HMAC incremental mode.

Functions
void	romulus_hmac (unsigned char *out, const unsigned char *key, size_t keylen, const unsigned char *in, size_t inlen)
	Computes a HMAC value using Romulus-H. More...
void	romulus_hmac_init (romulus_hmac_state_t *state, const unsigned char *key, size_t keylen)
	Initializes an incremental HMAC state using Romulus-H. More...
void	romulus_hmac_update (romulus_hmac_state_t *state, const unsigned char *in, size_t inlen)
	Updates an incremental Romulus-HMAC state with more input data. More...
void	romulus_hmac_finalize (romulus_hmac_state_t *state, const unsigned char *key, size_t keylen, unsigned char *out)
	Finalizes an incremental Romulus-HMAC state. More...

Detailed Description

Hashed Message Authentication Code (HMAC) based on Romulus-H.

The HMAC mode provides a method to authenticate a sequence of bytes using Romulus-H as the underlying digest algorithm.

HMAC uses an underlying block size to pad the key data. The Romulus-H block absorption rate of 32 bytes is too short so we use the HMAC-SHA-256 block size of 64 instead.

Note

The KMAC construction is preferable for sponge-based hash algorithms as it is simpler and more efficient. HMAC mode is provided for drop-in compatibility with existing designs.

Reference: https://tools.ietf.org/html/rfc2104

Function Documentation

void romulus_hmac	(	unsigned char *	out,
		const unsigned char *	key,
		size_t	keylen,
		const unsigned char *	in,
		size_t	inlen
	)

Computes a HMAC value using Romulus-H.

Parameters

out	Buffer to receive the output HMAC value; must be at least ROMULUS_HMAC_SIZE bytes in length.
key	Points to the key.
keylen	Number of bytes in the key.
in	Points to the data to authenticate.
inlen	Number of bytes of data to authenticate.

void romulus_hmac_finalize	(	romulus_hmac_state_t *	state,
		const unsigned char *	key,
		size_t	keylen,
		unsigned char *	out
	)

Finalizes an incremental Romulus-HMAC state.

Parameters

state	HMAC state to squeeze the output data from.
key	Points to the key.
keylen	Number of bytes in the key.
out	Points to the output buffer to receive the HMAC value; must be at least ROMULUS_HMAC_SIZE bytes in length.

See Also

romulus_hmac_init(), romulus_hmac_update()

void romulus_hmac_init	(	romulus_hmac_state_t *	state,
		const unsigned char *	key,
		size_t	keylen
	)

Initializes an incremental HMAC state using Romulus-H.

Parameters

state	Points to the state to be initialized.
key	Points to the key.
keylen	Number of bytes in the key.

The key needs to be preserved until the romulus_hmac_finalize() call to provide the outer HMAC hashing key.

See Also

romulus_hmac_update(), romulus_hmac_finalize()

void romulus_hmac_update	(	romulus_hmac_state_t *	state,
		const unsigned char *	in,
		size_t	inlen
	)

Updates an incremental Romulus-HMAC state with more input data.

Parameters

state	HMAC state to be updated.
in	Points to the input data to be incorporated into the state.
inlen	Length of the input data to be incorporated into the state.

See Also

romulus_hmac_init(), romulus_hmac_finalize()