polyval.h File Reference

Implementation for polyval universal hash function. More...

#include "orconfig.h"
#include "lib/cc/torint.h"

Go to the source code of this file.

Data Structures
struct	polyval_key_t
struct	polyval_t

Macros
#define	POLYVAL_KEY_LEN   16
#define	POLYVAL_BLOCK_LEN   16
#define	POLYVAL_TAG_LEN   16
#define	polyvalx_t   polyval_t
#define	polyvalx_key_init   polyval_key_init
#define	polyvalx_init   polyval_init
#define	polyvalx_init_from_key   polyval_init_from_key
#define	polyvalx_add_block   polyval_add_block
#define	polyvalx_add_zpad   polyval_add_zpad
#define	polyvalx_get_tag   polyval_get_tag
#define	polyvalx_reset   polyval_reset

Functions
void	polyval_key_init (polyval_key_t *, const uint8_t *key)
void	polyval_init (polyval_t *, const uint8_t *key)
void	polyval_init_from_key (polyval_t *, const polyval_key_t *key)
void	polyval_add_block (polyval_t *, const uint8_t *block)
void	polyval_add_zpad (polyval_t *, const uint8_t *data, size_t n)
void	polyval_get_tag (const polyval_t *, uint8_t *tag_out)
void	polyval_reset (polyval_t *)
void	polyval_detect_implementation (void)

Detailed Description

Implementation for polyval universal hash function.

APIs for polyval universal hash function.

Polyval, which was first defined for AES-GCM-SIV, is a universal hash based on multiplication in GF(2^128). Unlike the more familiar GHASH, it is defined to work on little-endian inputs, and so is more straightforward and efficient on little-endian architectures.

In Tor we use it as part of the Counter Galois Onion relay encryption format.

Definition in file polyval.h.

Macro Definition Documentation

POLYVAL_BLOCK_LEN

#define POLYVAL_BLOCK_LEN   16

Length of a polyval block, in bytes.

Definition at line 104 of file polyval.h.

POLYVAL_KEY_LEN

#define POLYVAL_KEY_LEN   16

Length of a polyval key, in bytes.

Definition at line 100 of file polyval.h.

POLYVAL_TAG_LEN

#define POLYVAL_TAG_LEN   16

Length of a polyval tag (output), in bytes.

Definition at line 108 of file polyval.h.

polyvalx_add_block

#define polyvalx_add_block   polyval_add_block

Definition at line 179 of file polyval.h.

polyvalx_add_zpad

#define polyvalx_add_zpad   polyval_add_zpad

Definition at line 180 of file polyval.h.

polyvalx_get_tag

#define polyvalx_get_tag   polyval_get_tag

Definition at line 181 of file polyval.h.

polyvalx_init

#define polyvalx_init   polyval_init

Definition at line 177 of file polyval.h.

polyvalx_init_from_key

#define polyvalx_init_from_key   polyval_init_from_key

Definition at line 178 of file polyval.h.

polyvalx_key_init

#define polyvalx_key_init   polyval_key_init

Definition at line 176 of file polyval.h.

polyvalx_reset

#define polyvalx_reset   polyval_reset

Definition at line 182 of file polyval.h.

polyvalx_t

#define polyvalx_t   polyval_t

Definition at line 175 of file polyval.h.

Function Documentation

polyval_add_block()

void polyval_add_block	(	polyval_t *	,
		const uint8_t *	block
	)

Update a polyval instance with a new 16-byte block.

Referenced by cgo_prf_gen_t1(), and cgo_prf_xor_t0().

polyval_add_zpad()

void polyval_add_zpad	(	polyval_t *	,
		const uint8_t *	data,
		size_t	n
	)

Update a polyval instance with 'n' bytes from 'data'. If 'n' is not evenly divisible by 16, pad it at the end with zeros.

NOTE: This is not a general-purpose padding construction; it can be insecure if your are using it in context where the input length is variable.

polyval_detect_implementation()

void polyval_detect_implementation

(

void

)

If a faster-than-default polyval implementation is available, use it.

Definition at line 444 of file polyval.c.

polyval_get_tag()

void polyval_get_tag	(	const polyval_t *	,
		uint8_t *	tag_out
	)

Copy the 16-byte tag from a polyval instance into 'tag_out'

Referenced by cgo_prf_gen_t1(), and cgo_prf_xor_t0().

polyval_init()

void polyval_init	(	polyval_t *	,
		const uint8_t *	key
	)

Initialize a polyval instance with a given key.

polyval_init_from_key()

void polyval_init_from_key	(	polyval_t *	,
		const polyval_key_t *	key
	)

Initialize a polyval instance with a preconstructed key.

Referenced by cgo_prf_gen_t1(), and cgo_prf_xor_t0().

polyval_key_init()

void polyval_key_init	(	polyval_key_t *	,
		const uint8_t *	key
	)

Do any necessary precomputation from a polyval key, and store it.

Referenced by cgo_prf_set_key().

polyval_reset()

void polyval_reset

(

polyval_t *

)

Reset a polyval instance to its original state, retaining its key.