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#include <stdint.h>
#include "kyber512r3_params.h"
#include "kyber512r3_poly.h"
#include "kyber512r3_polyvec.h"
S2N_ENSURE_PORTABLE_OPTIMIZATIONS
/*************************************************
* Name: polyvec_compress
*
* Description: Compress and serialize vector of polynomials
*
* Arguments: - uint8_t *r: pointer to output byte array
* (needs space for S2N_KYBER_512_R3_POLYVECCOMPRESSEDBYTES)
* - polyvec *a: pointer to input vector of polynomials
**************************************************/
void polyvec_compress(uint8_t r[S2N_KYBER_512_R3_POLYVECCOMPRESSEDBYTES], polyvec *a) {
polyvec_csubq(a);
uint16_t t[4];
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
for (unsigned int j = 0; j < S2N_KYBER_512_R3_N / 4; j++) {
for (unsigned int k = 0; k < 4; k++)
t[k] = ((((uint32_t)a->vec[i].coeffs[4 * j + k] << 10) + S2N_KYBER_512_R3_Q / 2)
/ S2N_KYBER_512_R3_Q) & 0x3ff;
r[0] = (t[0] >> 0);
r[1] = (t[0] >> 8) | (t[1] << 2);
r[2] = (t[1] >> 6) | (t[2] << 4);
r[3] = (t[2] >> 4) | (t[3] << 6);
r[4] = (t[3] >> 2);
r += 5;
}
}
}
/*************************************************
* Name: polyvec_decompress
*
* Description: De-serialize and decompress vector of polynomials;
* approximate inverse of polyvec_compress
*
* Arguments: - polyvec *r: pointer to output vector of polynomials
* - const uint8_t *a: pointer to input byte array
* (of length S2N_KYBER_512_R3_POLYVECCOMPRESSEDBYTES)
**************************************************/
void polyvec_decompress(polyvec *r, const uint8_t a[S2N_KYBER_512_R3_POLYVECCOMPRESSEDBYTES]) {
uint16_t t[4];
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
for (unsigned int j = 0; j < S2N_KYBER_512_R3_N / 4; j++) {
t[0] = (a[0] >> 0) | ((uint16_t)a[1] << 8);
t[1] = (a[1] >> 2) | ((uint16_t)a[2] << 6);
t[2] = (a[2] >> 4) | ((uint16_t)a[3] << 4);
t[3] = (a[3] >> 6) | ((uint16_t)a[4] << 2);
a += 5;
for (unsigned int k = 0; k < 4; k++) {
r->vec[i].coeffs[4 * j + k] = ((uint32_t)(t[k] & 0x3FF) * S2N_KYBER_512_R3_Q + 512) >> 10;
}
}
}
}
/*************************************************
* Name: polyvec_tobytes
*
* Description: Serialize vector of polynomials
*
* Arguments: - uint8_t *r: pointer to output byte array
* (needs space for S2N_KYBER_512_R3_POLYVECBYTES)
* - polyvec *a: pointer to input vector of polynomials
**************************************************/
void polyvec_tobytes(uint8_t r[S2N_KYBER_512_R3_POLYVECBYTES], polyvec *a) {
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
poly_tobytes(r + i * S2N_KYBER_512_R3_POLYBYTES, &a->vec[i]);
}
}
/*************************************************
* Name: polyvec_frombytes
*
* Description: De-serialize vector of polynomials;
* inverse of polyvec_tobytes
*
* Arguments: - uint8_t *r: pointer to output byte array
* - const polyvec *a: pointer to input vector of polynomials
* (of length S2N_KYBER_512_R3_POLYVECBYTES)
**************************************************/
void polyvec_frombytes(polyvec *r, const uint8_t a[S2N_KYBER_512_R3_POLYVECBYTES]) {
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
poly_frombytes(&r->vec[i], a + i * S2N_KYBER_512_R3_POLYBYTES);
}
}
/*************************************************
* Name: polyvec_ntt
*
* Description: Apply forward NTT to all elements of a vector of polynomials
*
* Arguments: - polyvec *r: pointer to in/output vector of polynomials
**************************************************/
void polyvec_ntt(polyvec *r) {
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
poly_ntt(&r->vec[i]);
}
}
/*************************************************
* Name: polyvec_invntt_tomont
*
* Description: Apply inverse NTT to all elements of a vector of polynomials
* and multiply by Montgomery factor 2^16
*
* Arguments: - polyvec *r: pointer to in/output vector of polynomials
**************************************************/
void polyvec_invntt_tomont(polyvec *r) {
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
poly_invntt_tomont(&r->vec[i]);
}
}
/*************************************************
* Name: polyvec_pointwise_acc_montgomery
*
* Description: Pointwise multiply elements of a and b, accumulate into r,
* and multiply by 2^-16.
*
* Arguments: - poly *r: pointer to output polynomial
* - const polyvec *a: pointer to first input vector of polynomials
* - const polyvec *b: pointer to second input vector of polynomials
**************************************************/
void polyvec_pointwise_acc_montgomery(poly *r, const polyvec *a, const polyvec *b) {
poly t;
poly_basemul_montgomery(r, &a->vec[0], &b->vec[0]);
for (unsigned int i = 1; i < S2N_KYBER_512_R3_K; i++) {
poly_basemul_montgomery(&t, &a->vec[i], &b->vec[i]);
poly_add(r, r, &t);
}
poly_reduce(r);
}
/*************************************************
* Name: polyvec_reduce
*
* Description: Applies Barrett reduction to each coefficient
* of each element of a vector of polynomials
* for details of the Barrett reduction see comments in reduce.c
*
* Arguments: - poly *r: pointer to input/output polynomial
**************************************************/
void polyvec_reduce(polyvec *r) {
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
poly_reduce(&r->vec[i]);
}
}
/*************************************************
* Name: polyvec_csubq
*
* Description: Applies conditional subtraction of q to each coefficient
* of each element of a vector of polynomials
* for details of conditional subtraction of q see comments in
* reduce.c
*
* Arguments: - poly *r: pointer to input/output polynomial
**************************************************/
void polyvec_csubq(polyvec *r) {
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
poly_csubq(&r->vec[i]);
}
}
/*************************************************
* Name: polyvec_add
*
* Description: Add vectors of polynomials
*
* Arguments: - polyvec *r: pointer to output vector of polynomials
* - const polyvec *a: pointer to first input vector of polynomials
* - const polyvec *b: pointer to second input vector of polynomials
**************************************************/
void polyvec_add(polyvec *r, const polyvec *a, const polyvec *b) {
for (unsigned int i = 0; i < S2N_KYBER_512_R3_K; i++) {
poly_add(&r->vec[i], &a->vec[i], &b->vec[i]);
}
}
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