pqc/crypto_kem/ledakemlt12/clean/gf2x_arith_mod_xPplusOne.h

301 lines
12 KiB
C

/**
*
* <gf2x_arith_mod_xPplusOne.h>
*
* @version 2.0 (March 2019)
*
* Reference ISO-C11 Implementation of the LEDAcrypt KEM-LT cipher using GCC built-ins.
*
* In alphabetical order:
*
* @author Marco Baldi <m.baldi@univpm.it>
* @author Alessandro Barenghi <alessandro.barenghi@polimi.it>
* @author Franco Chiaraluce <f.chiaraluce@univpm.it>
* @author Gerardo Pelosi <gerardo.pelosi@polimi.it>
* @author Paolo Santini <p.santini@pm.univpm.it>
*
* This code is hereby placed in the public domain.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ''AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
**/
#pragma once
#include "gf2x_limbs.h"
#include "qc_ldpc_parameters.h"
#include "gf2x_arith.h"
#include "rng.h"
/*----------------------------------------------------------------------------*/
#define NUM_BITS_GF2X_ELEMENT (P)
#define NUM_DIGITS_GF2X_ELEMENT ((P+DIGIT_SIZE_b-1)/DIGIT_SIZE_b)
#define MSb_POSITION_IN_MSB_DIGIT_OF_ELEMENT ( (P % DIGIT_SIZE_b) ? (P % DIGIT_SIZE_b)-1 : DIGIT_SIZE_b-1 )
#define NUM_BITS_GF2X_MODULUS (P+1)
#define NUM_DIGITS_GF2X_MODULUS ((P+1+DIGIT_SIZE_b-1)/DIGIT_SIZE_b)
#define MSb_POSITION_IN_MSB_DIGIT_OF_MODULUS (P-DIGIT_SIZE_b*(NUM_DIGITS_GF2X_MODULUS-1))
#define INVALID_POS_VALUE (P)
#define IS_REPRESENTABLE_IN_D_BITS(D, N) \
(((unsigned long) N >= (1UL << (D - 1)) && (unsigned long) N < (1UL << D)) ? D : -1)
#define BITS_TO_REPRESENT(N) \
(N == 0 ? 1 : (31 \
+ IS_REPRESENTABLE_IN_D_BITS( 1, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 2, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 3, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 4, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 5, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 6, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 7, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 8, N) \
+ IS_REPRESENTABLE_IN_D_BITS( 9, N) \
+ IS_REPRESENTABLE_IN_D_BITS(10, N) \
+ IS_REPRESENTABLE_IN_D_BITS(11, N) \
+ IS_REPRESENTABLE_IN_D_BITS(12, N) \
+ IS_REPRESENTABLE_IN_D_BITS(13, N) \
+ IS_REPRESENTABLE_IN_D_BITS(14, N) \
+ IS_REPRESENTABLE_IN_D_BITS(15, N) \
+ IS_REPRESENTABLE_IN_D_BITS(16, N) \
+ IS_REPRESENTABLE_IN_D_BITS(17, N) \
+ IS_REPRESENTABLE_IN_D_BITS(18, N) \
+ IS_REPRESENTABLE_IN_D_BITS(19, N) \
+ IS_REPRESENTABLE_IN_D_BITS(20, N) \
+ IS_REPRESENTABLE_IN_D_BITS(21, N) \
+ IS_REPRESENTABLE_IN_D_BITS(22, N) \
+ IS_REPRESENTABLE_IN_D_BITS(23, N) \
+ IS_REPRESENTABLE_IN_D_BITS(24, N) \
+ IS_REPRESENTABLE_IN_D_BITS(25, N) \
+ IS_REPRESENTABLE_IN_D_BITS(26, N) \
+ IS_REPRESENTABLE_IN_D_BITS(27, N) \
+ IS_REPRESENTABLE_IN_D_BITS(28, N) \
+ IS_REPRESENTABLE_IN_D_BITS(29, N) \
+ IS_REPRESENTABLE_IN_D_BITS(30, N) \
+ IS_REPRESENTABLE_IN_D_BITS(31, N) \
+ IS_REPRESENTABLE_IN_D_BITS(32, N) \
) \
)
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
static inline void gf2x_copy(DIGIT dest[], const DIGIT in[]) {
for (int i = NUM_DIGITS_GF2X_ELEMENT - 1; i >= 0; i--) {
dest[i] = in[i];
}
} // end gf2x_copy
/*---------------------------------------------------------------------------*/
void gf2x_mod(DIGIT out[],
const int nin, const DIGIT in[]); /* out(x) = in(x) mod x^P+1 */
/*---------------------------------------------------------------------------*/
void gf2x_mod_mul(DIGIT Res[], const DIGIT A[], const DIGIT B[]);
/*---------------------------------------------------------------------------*/
static inline void gf2x_mod_add(DIGIT Res[], const DIGIT A[], const DIGIT B[]) {
gf2x_add(NUM_DIGITS_GF2X_ELEMENT, Res,
NUM_DIGITS_GF2X_ELEMENT, A,
NUM_DIGITS_GF2X_ELEMENT, B);
} // end gf2x_mod_add
/*----------------------------------------------------------------------------*/
/*
* Optimized extended GCD algorithm to compute the multiplicative inverse of
* a non-zero element in GF(2)[x] mod x^P+1, in polyn. representation.
*
* H. Brunner, A. Curiger, and M. Hofstetter. 1993.
* On Computing Multiplicative Inverses in GF(2^m).
* IEEE Trans. Comput. 42, 8 (August 1993), 1010-1015.
* DOI=http://dx.doi.org/10.1109/12.238496
*
*
* Henri Cohen, Gerhard Frey, Roberto Avanzi, Christophe Doche, Tanja Lange,
* Kim Nguyen, and Frederik Vercauteren. 2012.
* Handbook of Elliptic and Hyperelliptic Curve Cryptography,
* Second Edition (2nd ed.). Chapman & Hall/CRC.
* (Chapter 11 -- Algorithm 11.44 -- pag 223)
*
*/
int gf2x_mod_inverse(DIGIT out[], const DIGIT in[]);/* ret. 1 if inv. exists */
/*---------------------------------------------------------------------------*/
void gf2x_transpose_in_place(DIGIT
A[]); /* in place bit-transp. of a(x) % x^P+1 *
* e.g.: a3 a2 a1 a0 --> a1 a2 a3 a0 */
/*---------------------------------------------------------------------------*/
/* population count for a single polynomial */
static inline int population_count(DIGIT upc[]) {
int ret = 0;
for (int i = NUM_DIGITS_GF2X_ELEMENT - 1; i >= 0; i--) {
#if defined(DIGIT_IS_ULLONG)
ret += __builtin_popcountll((unsigned long long int) (upc[i]));
#elif defined(DIGIT_IS_ULONG)
ret += __builtin_popcountl((unsigned long int) (upc[i]));
#elif defined(DIGIT_IS_UINT)
ret += __builtin_popcount((unsigned int) (upc[i]));
#elif defined(DIGIT_IS_UCHAR)
const unsigned char split_lookup[] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4
};
ret += split_lookup[upc[i] & 0xF] + split_lookup[upc[i] >> 4];
#else
#error "Missing implementation for population_count(...) \
with this CPU word bitsize !!! "
#endif
}
return ret;
} // end population_count
/*--------------------------------------------------------------------------*/
/* returns the coefficient of the x^exponent term as the LSB of a digit */
static inline
DIGIT gf2x_get_coeff(const DIGIT poly[], const unsigned int exponent) {
unsigned int straightIdx = (NUM_DIGITS_GF2X_ELEMENT * DIGIT_SIZE_b - 1) - exponent;
unsigned int digitIdx = straightIdx / DIGIT_SIZE_b;
unsigned int inDigitIdx = straightIdx % DIGIT_SIZE_b;
return (poly[digitIdx] >> (DIGIT_SIZE_b - 1 - inDigitIdx)) & ((DIGIT) 1) ;
}
/*--------------------------------------------------------------------------*/
/* sets the coefficient of the x^exponent term as the LSB of a digit */
static inline
void gf2x_set_coeff(DIGIT poly[], const unsigned int exponent, DIGIT value) {
int straightIdx = (NUM_DIGITS_GF2X_ELEMENT * DIGIT_SIZE_b - 1) - exponent;
int digitIdx = straightIdx / DIGIT_SIZE_b;
unsigned int inDigitIdx = straightIdx % DIGIT_SIZE_b;
/* clear given coefficient */
DIGIT mask = ~( ((DIGIT) 1) << (DIGIT_SIZE_b - 1 - inDigitIdx));
poly[digitIdx] = poly[digitIdx] & mask;
poly[digitIdx] = poly[digitIdx] | (( value & ((DIGIT) 1)) <<
(DIGIT_SIZE_b - 1 - inDigitIdx));
}
/*--------------------------------------------------------------------------*/
/* toggles (flips) the coefficient of the x^exponent term as the LSB of a digit */
static inline
void gf2x_toggle_coeff(DIGIT poly[], const unsigned int exponent) {
int straightIdx = (NUM_DIGITS_GF2X_ELEMENT * DIGIT_SIZE_b - 1) - exponent;
int digitIdx = straightIdx / DIGIT_SIZE_b;
unsigned int inDigitIdx = straightIdx % DIGIT_SIZE_b;
/* clear given coefficient */
DIGIT mask = ( ((DIGIT) 1) << (DIGIT_SIZE_b - 1 - inDigitIdx));
poly[digitIdx] = poly[digitIdx] ^ mask;
}
/*--------------------------------------------------------------------------*/
void rand_circulant_sparse_block(POSITION_T *pos_ones,
const int countOnes,
AES_XOF_struct *seed_expander_ctx);
/*--------------------------------------------------------------------------*/
void rand_circulant_blocks_sequence(DIGIT sequence[N0 * NUM_DIGITS_GF2X_ELEMENT],
const int countOnes,
AES_XOF_struct *seed_expander_ctx
);
/*---------------------------------------------------------------------------*/
void gf2x_mod_add_sparse(int sizeR,
POSITION_T Res[],
int sizeA,
POSITION_T A[],
int sizeB,
POSITION_T B[]);
/*----------------------------------------------------------------------------*/
void gf2x_transpose_in_place_sparse(int sizeA, POSITION_T A[]);
/*----------------------------------------------------------------------------*/
void gf2x_mod_mul_sparse(int
sizeR, /*number of ones in the result, max sizeA*sizeB */
POSITION_T Res[],
int sizeA, /*number of ones in A*/
const POSITION_T A[],
int sizeB, /*number of ones in B*/
const POSITION_T B[]);
/*----------------------------------------------------------------------------*/
void gf2x_mod_mul_dense_to_sparse(DIGIT Res[],
const DIGIT dense[],
POSITION_T sparse[],
unsigned int nPos);
/*----------------------------------------------------------------------------*/
static inline
int partition (POSITION_T arr[], int lo, int hi) {
POSITION_T x = arr[hi];
POSITION_T tmp;
int i = (lo - 1);
for (int j = lo; j <= hi - 1; j++) {
if (arr[j] <= x) {
i++;
tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
}
}
tmp = arr[i + 1];
arr[i + 1] = arr[hi];
arr[hi] = tmp;
return i + 1;
} // end partition
/*----------------------------------------------------------------------------*/
static inline
void quicksort(POSITION_T Res[], unsigned int sizeR) {
/* sort the result */
int stack[sizeR];
int hi, lo, pivot, tos = -1;
stack[++tos] = 0;
stack[++tos] = sizeR - 1;
while (tos >= 0 ) {
hi = stack[tos--];
lo = stack[tos--];
pivot = partition(Res, lo, hi);
if ( (pivot - 1) > lo) {
stack[++tos] = lo;
stack[++tos] = pivot - 1;
}
if ( (pivot + 1) < hi) {
stack[++tos] = pivot + 1;
stack[++tos] = hi;
}
}
}
/*---------------------------------------------------------------------------*/