109 lines
4.9 KiB
C
109 lines
4.9 KiB
C
/********************************************************************************************
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* FrodoKEM: Learning with Errors Key Encapsulation
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*
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* Abstract: matrix arithmetic functions used by the KEM
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*********************************************************************************************/
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#include <stdint.h>
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#include <string.h>
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#include "fips202.h"
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#include "api.h"
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#include "common.h"
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#include "params.h"
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int PQCLEAN_FRODOKEM1344SHAKE_OPT_mul_add_as_plus_e(uint16_t *out, const uint16_t *s, const uint16_t *e, const uint8_t *seed_A) {
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// Generate-and-multiply: generate matrix A (N x N) row-wise, multiply by s on the right.
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// Inputs: s, e (N x N_BAR)
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// Output: out = A*s + e (N x N_BAR)
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int j, k;
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uint16_t i;
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int16_t a_row[4 * PARAMS_N];
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for (i = 0; i < (PARAMS_N * PARAMS_NBAR); i += 2) {
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*((uint32_t *)&out[i]) = *((uint32_t *)&e[i]);
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}
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uint8_t seed_A_separated[2 + BYTES_SEED_A];
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uint16_t *seed_A_origin = (uint16_t *)&seed_A_separated;
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memcpy(&seed_A_separated[2], seed_A, BYTES_SEED_A);
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for (i = 0; i < PARAMS_N; i += 4) {
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(i + 0);
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shake128((unsigned char *)(a_row + 0 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(i + 1);
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shake128((unsigned char *)(a_row + 1 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(i + 2);
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shake128((unsigned char *)(a_row + 2 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(i + 3);
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shake128((unsigned char *)(a_row + 3 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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for (k = 0; k < 4 * PARAMS_N; k++) {
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a_row[k] = PQCLEAN_FRODOKEM1344SHAKE_OPT_LE_TO_UINT16(a_row[k]);
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}
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for (k = 0; k < PARAMS_NBAR; k++) {
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uint16_t sum[4] = {0};
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for (j = 0; j < PARAMS_N; j++) { // Matrix-vector multiplication
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uint16_t sp = s[k * PARAMS_N + j];
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sum[0] += a_row[0 * PARAMS_N + j] * sp; // Go through four lines with same s
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sum[1] += a_row[1 * PARAMS_N + j] * sp;
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sum[2] += a_row[2 * PARAMS_N + j] * sp;
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sum[3] += a_row[3 * PARAMS_N + j] * sp;
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}
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out[(i + 0)*PARAMS_NBAR + k] += sum[0];
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out[(i + 2)*PARAMS_NBAR + k] += sum[2];
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out[(i + 1)*PARAMS_NBAR + k] += sum[1];
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out[(i + 3)*PARAMS_NBAR + k] += sum[3];
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}
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}
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return 1;
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}
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int PQCLEAN_FRODOKEM1344SHAKE_OPT_mul_add_sa_plus_e(uint16_t *out, const uint16_t *s, const uint16_t *e, const uint8_t *seed_A) {
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// Generate-and-multiply: generate matrix A (N x N) column-wise, multiply by s' on the left.
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// Inputs: s', e' (N_BAR x N)
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// Output: out = s'*A + e' (N_BAR x N)
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int i, j;
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uint16_t kk;
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for (i = 0; i < (PARAMS_N * PARAMS_NBAR); i += 2) {
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*((uint32_t *)&out[i]) = *((uint32_t *)&e[i]);
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}
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int t = 0;
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uint16_t a_cols[4 * PARAMS_N];
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int k;
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uint8_t seed_A_separated[2 + BYTES_SEED_A];
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uint16_t *seed_A_origin = (uint16_t *)&seed_A_separated;
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memcpy(&seed_A_separated[2], seed_A, BYTES_SEED_A);
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for (kk = 0; kk < PARAMS_N; kk += 4) {
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(kk + 0);
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shake128((unsigned char *)(a_cols + 0 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(kk + 1);
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shake128((unsigned char *)(a_cols + 1 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(kk + 2);
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shake128((unsigned char *)(a_cols + 2 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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seed_A_origin[0] = PQCLEAN_FRODOKEM1344SHAKE_OPT_UINT16_TO_LE(kk + 3);
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shake128((unsigned char *)(a_cols + 3 * PARAMS_N), (unsigned long long)(2 * PARAMS_N), seed_A_separated, 2 + BYTES_SEED_A);
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for (i = 0; i < 4 * PARAMS_N; i++) {
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a_cols[i] = PQCLEAN_FRODOKEM1344SHAKE_OPT_LE_TO_UINT16(a_cols[i]);
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}
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for (i = 0; i < PARAMS_NBAR; i++) {
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uint16_t sum[PARAMS_N] = {0};
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for (j = 0; j < 4; j++) {
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uint16_t sp = s[i * PARAMS_N + kk + j];
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for (k = 0; k < PARAMS_N; k++) { // Matrix-vector multiplication
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sum[k] += sp * a_cols[(t + j) * PARAMS_N + k];
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}
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}
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for (k = 0; k < PARAMS_N; k++) {
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out[i * PARAMS_N + k] += sum[k];
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}
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}
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}
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return 1;
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}
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