header for ntru_poly.c More...

#include "ntru_err.h"
#include "ntru_params.h"
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <fmpz_poly.h>

Include dependency graph for ntru_poly.h:

Go to the source code of this file.

Functions
int	fmpz_cmp_si_n (const fmpz_t f, slong g)
void	poly_new (fmpz_poly_t new_poly, int const *const c, const size_t len)
void	poly_delete (fmpz_poly_t poly)
void	poly_delete_array (fmpz_poly_t **poly_array)
void	poly_delete_all (fmpz_poly_t poly,...)
void	fmpz_poly_mod_unsigned (fmpz_poly_t a, const uint32_t mod)
void	fmpz_poly_mod (fmpz_poly_t a, const uint32_t mod)
void	fmpz_poly_set_coeff_fmpz_n (fmpz_poly_t poly, slong n, const fmpz_t x)
int	fmpz_invmod_ui (fmpz_t f, const fmpz_t g, const uint32_t mod)
void	fmpz_add_n (fmpz_t f, const fmpz_t g, const fmpz_t h)
void	poly_starmultiply (const fmpz_poly_t a, const fmpz_poly_t b, fmpz_poly_t c, const ntru_params *params, uint32_t modulus)
bool	poly_inverse_poly_q (const fmpz_poly_t a, fmpz_poly_t Fq, const ntru_params *params)
bool	poly_inverse_poly_p (const fmpz_poly_t a, fmpz_poly_t Fp, const ntru_params *params)
void	poly_draw (const fmpz_poly_t poly)
void	poly_draw_pretty (const fmpz_poly_t poly)

Detailed Description

header for ntru_poly.c

Header for the internal API of ntru_poly.c.

Definition in file ntru_poly.h.

Function Documentation

void fmpz_add_n	(	fmpz_t	f,
		const fmpz_t	g,
		const fmpz_t	h
	)

The same as fmpz_add() except that it handles NULL pointer for g and h.

Definition at line 222 of file ntru_poly.c.

int fmpz_cmp_si_n	(	const fmpz_t	f,
		slong	g
	)

The same as fmpz_cmp_si except that it will interpret f as a 0-coefficient if it is a NULL pointer.

Parameters:

f	the fmpz value to use for comparison
g	the signed long integer to use for comparison

Returns:: negative value if f < g, positiv evalue if g < f, otherwise 0

Definition at line 93 of file ntru_poly.c.

int fmpz_invmod_ui	(	fmpz_t	f,
		const fmpz_t	g,
		const uint32_t	mod
	)

Wrapper around fmpz_invmod() where we convert mod to an fmpz_t implicitly.

Parameters:

f	result [out]
g	the inverse
mod	the modulo

Definition at line 210 of file ntru_poly.c.

void fmpz_poly_mod	(	fmpz_poly_t	a,
		const uint32_t	mod
	)

Calls fmpz_poly_get_nmod_poly() and fmpz_poly_set_nmod_poly() in a row, so we don't have to deal with the intermediate nmod_poly_t type if we don't need it.

This also normalises the coefficients to the interval -m/2 <= r < m/2.

Parameters:

a	the polynom to apply the modulus to
mod	the modulus

Definition at line 182 of file ntru_poly.c.

void fmpz_poly_mod_unsigned	(	fmpz_poly_t	a,
		const uint32_t	mod
	)

Calls fmpz_poly_get_nmod_poly() and fmpz_poly_set_nmod_poly_unsigned() in a row, so we don't have to deal with the intermediate nmod_poly_t type if we don't need it.

This also normalises the coefficients to the interval 0 <= r < m.

Parameters:

a	the polynom to apply the modulus to
mod	the modulus

Definition at line 166 of file ntru_poly.c.

void fmpz_poly_set_coeff_fmpz_n	(	fmpz_poly_t	poly,
		slong	n,
		const fmpz_t	x
	)

The same as fmpz_poly_set_coeff_fmpz() except that it will take care of null-pointer coefficients and use fmpz_poly_set_coeff_si() in that case.

Parameters:

poly	the polynom we want to change a coefficient of
n	the coefficient we want to set
x	the value to assign to the coefficient

Definition at line 198 of file ntru_poly.c.

void poly_delete ( fmpz_poly_t poly )

This deletes the internal structure of a polynomial, and frees the pointer.

Parameters:

poly	the polynomial to delete

Definition at line 123 of file ntru_poly.c.

void poly_delete_all	(	fmpz_poly_t	poly,
			...
	)

This deletes the internal structure of all polynomials, and frees the pointers. You must call this with NULL as last argument!

Parameters:

poly	the polynomial to delete
...	follow up polynomials

Definition at line 149 of file ntru_poly.c.

void poly_delete_array ( fmpz_poly_t ** poly_array )

Delete the internal structure of a polynomial array which must be NULL terminated. It is expected that poly_array is not on the stack and was obtained by a function like ascii_to_poly().

Parameters:

poly_array the polynomial array

Definition at line 131 of file ntru_poly.c.

void poly_draw ( const fmpz_poly_t poly )

Draws a polynomial to stdout.

Parameters:

poly draw this

Definition at line 574 of file ntru_poly.c.

void poly_draw_pretty ( const fmpz_poly_t poly )

Draws a polynomial to stdout, in pretty format.

Parameters:

poly draw this

Definition at line 583 of file ntru_poly.c.

bool poly_inverse_poly_p	(	const fmpz_poly_t	a,
		fmpz_poly_t	Fp,
		const ntru_params *	params
	)

Compute the inverse of a polynomial in (Z/pZ)[X]/(X^N - 1). See NTRU Cryptosystems Tech Report #014 "Almost Inverses and Fast NTRU Key Creation."

Parameters:

a	polynomial to invert
Fp	polynomial [out]
params	NTRU parameters

Returns:: true if invertible, false if not

Definition at line 409 of file ntru_poly.c.

bool poly_inverse_poly_q	(	const fmpz_poly_t	a,
		fmpz_poly_t	Fq,
		const ntru_params *	params
	)

Compute the inverse of a polynomial in modulo a power of 2, which is q. This is based off the pseudo-code for "Inversion in (Z/2Z)[X](X^N - 1)" and "Inversion in (Z/p^r Z)[X](X^N - 1)". See NTRU Cryptosystems Tech Report #014 "Almost Inverses and Fast NTRU Key Creation."

Parameters:

a	polynomial to invert (is allowed to be the same as param Fq)
Fq	polynomial [out]
params	NTRU parameters

Returns:: true if invertible, false if not

Definition at line 297 of file ntru_poly.c.

void poly_new	(	fmpz_poly_t	new_poly,
		int const *const	c,
		const size_t	len
	)

Initializes and builds a polynomial with the coefficient values of c[] of size len within NTRU parameters and returns a newly allocated polynomial. For an empty polynom, both c and len can be NULL/0.

Parameters:

new_poly	the polynomial to initialize and fill with coefficients [out]
c	array of polynomial coefficients, can be NULL
len	size of the coefficient array, can be 0

Returns:: newly allocated polynomial pointer, must be freed with fmpz_poly_clear()

Definition at line 110 of file ntru_poly.c.

void poly_starmultiply	(	const fmpz_poly_t	a,
		const fmpz_poly_t	b,
		fmpz_poly_t	c,
		const ntru_params *	params,
		uint32_t	modulus
	)

Starmultiplication, as follows: c = a * b mod (x^N − 1)

Parameters:

a	polynom to multiply (can be the same as c)
b	polynom to multiply
c	polynom [out]
params	NTRU parameters
modulus	whether we use p or q

Definition at line 239 of file ntru_poly.c.

Functions

Detailed Description

Function Documentation