romulus-xof.h File Reference

Extensible Output Function (XOF) based on Romulus-H. More...

#include "romulus-hash.h"

Go to the source code of this file.

Data Structures
struct	romulus_xof_state_t
	State information for Romulus-H XOF mode. More...

Functions
int	romulus_xof (unsigned char *out, const unsigned char *in, size_t inlen)
	Hashes a block of input data with Romulus-H in XOF mode. More...
void	romulus_xof_init (romulus_xof_state_t *state)
	Initializes the state for a Romulus-H XOF mode. More...
void	romulus_xof_absorb (romulus_xof_state_t *state, const unsigned char *in, size_t inlen)
	Absorbs more input data into a Romulus-H XOF state. More...
void	romulus_xof_squeeze (romulus_xof_state_t *state, unsigned char *out, size_t outlen)
	Returns the final hash value from a Romulus-H hashing operation. More...

Detailed Description

Extensible Output Function (XOF) based on Romulus-H.

Romulus-H is a hash algorithm based on the block cipher SKINNY-128-384+, using the MDPH construction. We combine it with the mask generation function MGF1 to create an XOF mode.

The XOF output is generated with the sequence Hash(M || [0]), Hash(M || [1]), Hash(M || [2]), etc. "M" is the message input padded to a 32 byte block boundary using the same padding scheme as Romulus-H. [0], [1], [2], etc are 32-bit integers encoded in big-endian.

The application should not generate more than 32 * 2³² bytes (or 128 GiB) of output because after that the MGF1 counter will wrap around and start generating the same output again.

References: https://romulusae.github.io/romulus/, https://www.ietf.org/rfc/rfc2437.html

Function Documentation

int romulus_xof	(	unsigned char *	out,
		const unsigned char *	in,
		size_t	inlen
	)

Hashes a block of input data with Romulus-H in XOF mode.

Parameters

out	Buffer to receive the hash output which must be at least ROMULUS_HASH_SIZE bytes in length.
in	Points to the input data to be hashed.
inlen	Length of the input data in bytes.

Returns

Returns zero on success or -1 if there was an error in the parameters.

See Also

romulus_xof_init(), romulus_xof_absorb(), romulus_xof_squeeze()

void romulus_xof_absorb	(	romulus_xof_state_t *	state,
		const unsigned char *	in,
		size_t	inlen
	)

Absorbs more input data into a Romulus-H XOF state.

Parameters

state	XOF state to be updated.
in	Points to the input data to be absorbed into the state.
inlen	Length of the input data to be absorbed into the state.

See Also

romulus_xof_init(), romulus_xof_squeeze()

void romulus_xof_init

(

romulus_xof_state_t *

state

)

Initializes the state for a Romulus-H XOF mode.

Parameters

state

XOF state to be initialized.

See Also

romulus_xof_update(), romulus_xof_squeeze(), romulus_xof()

void romulus_xof_squeeze	(	romulus_xof_state_t *	state,
		unsigned char *	out,
		size_t	outlen
	)

Returns the final hash value from a Romulus-H hashing operation.

Parameters

state	XOF state to squeeze data from.
out	Buffer to receive the squeezed dara.
outlen	Number of bytes to squeeze from the XOF state.

See Also

romulus_xof_init(), romulus_xof_update()