pqc/crypto_kem/kyber768/clean/poly.c
cryptojedi 56a3715ddc Kyberv2 (#150)
* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Making MS compiler happy

* More fixes for MS compiler

* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Making MS compiler happy

* More fixes for MS compiler

* Started more cleanup work on Kyber768

* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Replaced round-1 Kyber code with round-2 Kyber code (not yet cleaned/namespaced)

* Namespacing for Kyber

* Some more work on round-2 Kyber (more namespacing)

* Added missing files

* Round-2 Kyber768 now passing all tests under Linux

* Various small tweaks to make MS compiler happy

* Two more tweaks for MS compiler

* Added Kyber512 and Kyber1024 (round-2 versions)

* Making MS compiler happy

* Making MS compiler happy

* More fixes for MS compiler

* More fixes for MS compiler

* Started more cleanup work on Kyber768

* Kyber768 passing all tests locally

* Kyber512 passes all tests locally

* Kyber1024 now also passing all tests locally

* Now passing all tests with -Wmissing-prototypes

* Local tests (on Linux) passing again
2019-05-06 14:50:27 +02:00

289 lines
10 KiB
C

#include "poly.h"
#include "cbd.h"
#include "ntt.h"
#include "params.h"
#include "reduce.h"
#include "symmetric.h"
#include <stdint.h>
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_compress
*
* Description: Compression and subsequent serialization of a polynomial
*
* Arguments: - unsigned char *r: pointer to output byte array (needs space for KYBER_POLYCOMPRESSEDBYTES bytes)
* - const poly *a: pointer to input polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_compress(unsigned char *r, poly *a) {
uint8_t t[8];
int i, j, k = 0;
PQCLEAN_KYBER768_CLEAN_poly_csubq(a);
for (i = 0; i < KYBER_N; i += 8) {
for (j = 0; j < 8; j++) {
t[j] = ((((uint32_t)a->coeffs[i + j] << 4) + KYBER_Q / 2) / KYBER_Q) & 15;
}
r[k] = t[0] | (t[1] << 4);
r[k + 1] = t[2] | (t[3] << 4);
r[k + 2] = t[4] | (t[5] << 4);
r[k + 3] = t[6] | (t[7] << 4);
k += 4;
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_decompress
*
* Description: De-serialization and subsequent decompression of a polynomial;
* approximate inverse of PQCLEAN_KYBER768_CLEAN_poly_compress
*
* Arguments: - poly *r: pointer to output polynomial
* - const unsigned char *a: pointer to input byte array (of length KYBER_POLYCOMPRESSEDBYTES bytes)
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_decompress(poly *r, const unsigned char *a) {
int i;
for (i = 0; i < KYBER_N; i += 8) {
r->coeffs[i + 0] = (((a[0] & 15) * KYBER_Q) + 8) >> 4;
r->coeffs[i + 1] = (((a[0] >> 4) * KYBER_Q) + 8) >> 4;
r->coeffs[i + 2] = (((a[1] & 15) * KYBER_Q) + 8) >> 4;
r->coeffs[i + 3] = (((a[1] >> 4) * KYBER_Q) + 8) >> 4;
r->coeffs[i + 4] = (((a[2] & 15) * KYBER_Q) + 8) >> 4;
r->coeffs[i + 5] = (((a[2] >> 4) * KYBER_Q) + 8) >> 4;
r->coeffs[i + 6] = (((a[3] & 15) * KYBER_Q) + 8) >> 4;
r->coeffs[i + 7] = (((a[3] >> 4) * KYBER_Q) + 8) >> 4;
a += 4;
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_tobytes
*
* Description: Serialization of a polynomial
*
* Arguments: - unsigned char *r: pointer to output byte array (needs space for KYBER_POLYBYTES bytes)
* - const poly *a: pointer to input polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_tobytes(unsigned char *r, poly *a) {
int i;
uint16_t t0, t1;
PQCLEAN_KYBER768_CLEAN_poly_csubq(a);
for (i = 0; i < KYBER_N / 2; i++) {
t0 = a->coeffs[2 * i];
t1 = a->coeffs[2 * i + 1];
r[3 * i] = t0 & 0xff;
r[3 * i + 1] = (t0 >> 8) | ((t1 & 0xf) << 4);
r[3 * i + 2] = (t1 >> 4) & 0xff;
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_frombytes
*
* Description: De-serialization of a polynomial;
* inverse of PQCLEAN_KYBER768_CLEAN_poly_tobytes
*
* Arguments: - poly *r: pointer to output polynomial
* - const unsigned char *a: pointer to input byte array (of KYBER_POLYBYTES bytes)
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_frombytes(poly *r, const unsigned char *a) {
int i;
for (i = 0; i < KYBER_N / 2; i++) {
r->coeffs[2 * i] = a[3 * i] | ((uint16_t)a[3 * i + 1] & 0x0f) << 8;
r->coeffs[2 * i + 1] = a[3 * i + 1] >> 4 | ((uint16_t)a[3 * i + 2] & 0xff) << 4;
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_getnoise
*
* Description: Sample a polynomial deterministically from a seed and a nonce,
* with output polynomial close to centered binomial distribution
* with parameter KYBER_ETA
*
* Arguments: - poly *r: pointer to output polynomial
* - const unsigned char *seed: pointer to input seed (pointing to array of length KYBER_SYMBYTES bytes)
* - unsigned char nonce: one-byte input nonce
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_getnoise(poly *r, const unsigned char *seed, unsigned char nonce) {
unsigned char buf[KYBER_ETA * KYBER_N / 4];
prf(buf, KYBER_ETA * KYBER_N / 4, seed, nonce);
PQCLEAN_KYBER768_CLEAN_cbd(r, buf);
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_ntt
*
* Description: Computes negacyclic number-theoretic transform (NTT) of
* a polynomial in place;
* inputs assumed to be in normal order, output in bitreversed order
*
* Arguments: - uint16_t *r: pointer to in/output polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_ntt(poly *r) {
PQCLEAN_KYBER768_CLEAN_ntt(r->coeffs);
PQCLEAN_KYBER768_CLEAN_poly_reduce(r);
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_invntt
*
* Description: Computes inverse of negacyclic number-theoretic transform (NTT) of
* a polynomial in place;
* inputs assumed to be in bitreversed order, output in normal order
*
* Arguments: - uint16_t *a: pointer to in/output polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_invntt(poly *r) {
PQCLEAN_KYBER768_CLEAN_invntt(r->coeffs);
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_basemul
*
* Description: Multiplication of two polynomials in NTT domain
*
* Arguments: - poly *r: pointer to output polynomial
* - const poly *a: pointer to first input polynomial
* - const poly *b: pointer to second input polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_basemul(poly *r, const poly *a, const poly *b) {
unsigned int i;
for (i = 0; i < KYBER_N / 4; ++i) {
PQCLEAN_KYBER768_CLEAN_basemul(r->coeffs + 4 * i, a->coeffs + 4 * i, b->coeffs + 4 * i, PQCLEAN_KYBER768_CLEAN_zetas[64 + i]);
PQCLEAN_KYBER768_CLEAN_basemul(r->coeffs + 4 * i + 2, a->coeffs + 4 * i + 2, b->coeffs + 4 * i + 2, - PQCLEAN_KYBER768_CLEAN_zetas[64 + i]);
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_frommont
*
* Description: Inplace conversion of all coefficients of a polynomial
* from Montgomery domain to normal domain
*
* Arguments: - poly *r: pointer to input/output polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_frommont(poly *r) {
int i;
const int16_t f = (1ULL << 32) % KYBER_Q;
for (i = 0; i < KYBER_N; i++) {
r->coeffs[i] = PQCLEAN_KYBER768_CLEAN_montgomery_reduce((int32_t)r->coeffs[i] * f);
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_reduce
*
* Description: Applies Barrett reduction to all coefficients of a polynomial
* for details of the Barrett reduction see comments in reduce.c
*
* Arguments: - poly *r: pointer to input/output polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_reduce(poly *r) {
int i;
for (i = 0; i < KYBER_N; i++) {
r->coeffs[i] = PQCLEAN_KYBER768_CLEAN_barrett_reduce(r->coeffs[i]);
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_csubq
*
* Description: Applies conditional subtraction of q to each coefficient of a polynomial
* for details of conditional subtraction of q see comments in reduce.c
*
* Arguments: - poly *r: pointer to input/output polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_csubq(poly *r) {
int i;
for (i = 0; i < KYBER_N; i++) {
r->coeffs[i] = PQCLEAN_KYBER768_CLEAN_csubq(r->coeffs[i]);
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_add
*
* Description: Add two polynomials
*
* Arguments: - poly *r: pointer to output polynomial
* - const poly *a: pointer to first input polynomial
* - const poly *b: pointer to second input polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_add(poly *r, const poly *a, const poly *b) {
int i;
for (i = 0; i < KYBER_N; i++) {
r->coeffs[i] = a->coeffs[i] + b->coeffs[i];
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_sub
*
* Description: Subtract two polynomials
*
* Arguments: - poly *r: pointer to output polynomial
* - const poly *a: pointer to first input polynomial
* - const poly *b: pointer to second input polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_sub(poly *r, const poly *a, const poly *b) {
int i;
for (i = 0; i < KYBER_N; i++) {
r->coeffs[i] = a->coeffs[i] - b->coeffs[i];
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_frommsg
*
* Description: Convert 32-byte message to polynomial
*
* Arguments: - poly *r: pointer to output polynomial
* - const unsigned char *msg: pointer to input message
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_frommsg(poly *r, const unsigned char msg[KYBER_SYMBYTES]) {
int i, j;
uint16_t mask;
for (i = 0; i < KYBER_SYMBYTES; i++) {
for (j = 0; j < 8; j++) {
mask = -((msg[i] >> j) & 1);
r->coeffs[8 * i + j] = mask & ((KYBER_Q + 1) / 2);
}
}
}
/*************************************************
* Name: PQCLEAN_KYBER768_CLEAN_poly_tomsg
*
* Description: Convert polynomial to 32-byte message
*
* Arguments: - unsigned char *msg: pointer to output message
* - const poly *a: pointer to input polynomial
**************************************************/
void PQCLEAN_KYBER768_CLEAN_poly_tomsg(unsigned char msg[KYBER_SYMBYTES], poly *a) {
uint16_t t;
int i, j;
PQCLEAN_KYBER768_CLEAN_poly_csubq(a);
for (i = 0; i < KYBER_SYMBYTES; i++) {
msg[i] = 0;
for (j = 0; j < 8; j++) {
t = (((a->coeffs[8 * i + j] << 1) + KYBER_Q / 2) / KYBER_Q) & 1;
msg[i] |= t << j;
}
}
}