mirror of
https://github.com/henrydcase/pqc.git
synced 2024-11-24 00:11:27 +00:00
228 lines
7.2 KiB
C
228 lines
7.2 KiB
C
#include "nistseedexpander.h"
|
|
#include "parameters.h"
|
|
#include "parsing.h"
|
|
#include "randombytes.h"
|
|
#include "vector.h"
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
/**
|
|
* @file vector.c
|
|
* @brief Implementation of vectors sampling and some utilities for the HQC scheme
|
|
*/
|
|
|
|
|
|
/**
|
|
* @brief Generates a vector of a given Hamming weight
|
|
*
|
|
* This function generates uniformly at random a binary vector of a Hamming weight equal to the parameter <b>weight</b>. The vector
|
|
* is stored by position.
|
|
* To generate the vector we have to sample uniformly at random values in the interval [0, PARAM_N -1]. Suppose the PARAM_N is equal to \f$ 70853 \f$, to select a position \f$ r\f$ the function works as follow:
|
|
* 1. It makes a call to the seedexpander function to obtain a random number \f$ x\f$ in \f$ [0, 2^{24}[ \f$.
|
|
* 2. Let \f$ t = \lfloor {2^{24} \over 70853} \rfloor \times 70853\f$
|
|
* 3. If \f$ x \geq t\f$, go to 1
|
|
* 4. It return \f$ r = x \mod 70853\f$
|
|
*
|
|
* The parameter \f$ t \f$ is precomputed and it's denoted by UTILS_REJECTION_THRESHOLD (see the file parameters.h).
|
|
*
|
|
* @param[in] v Pointer to an array
|
|
* @param[in] weight Integer that is the Hamming weight
|
|
* @param[in] ctx Pointer to the context of the seed expander
|
|
*/
|
|
void PQCLEAN_HQC256_CLEAN_vect_set_random_fixed_weight_by_coordinates(AES_XOF_struct *ctx, uint32_t *v, uint16_t weight) {
|
|
size_t random_bytes_size = 3 * weight;
|
|
uint8_t rand_bytes[3 * PARAM_OMEGA_R] = {0}; // weight is expected to be <= PARAM_OMEGA_R
|
|
uint32_t random_data = 0;
|
|
uint8_t exist = 0;
|
|
size_t j = 0;
|
|
|
|
seedexpander(ctx, rand_bytes, random_bytes_size);
|
|
|
|
for (uint32_t i = 0; i < weight; ++i) {
|
|
exist = 0;
|
|
do {
|
|
if (j == random_bytes_size) {
|
|
seedexpander(ctx, rand_bytes, random_bytes_size);
|
|
j = 0;
|
|
}
|
|
|
|
random_data = ((uint32_t) rand_bytes[j++]) << 16;
|
|
random_data |= ((uint32_t) rand_bytes[j++]) << 8;
|
|
random_data |= rand_bytes[j++];
|
|
|
|
} while (random_data >= UTILS_REJECTION_THRESHOLD);
|
|
|
|
random_data = random_data % PARAM_N;
|
|
|
|
for (uint32_t k = 0; k < i; k++) {
|
|
if (v[k] == random_data) {
|
|
exist = 1;
|
|
}
|
|
}
|
|
|
|
if (exist == 1) {
|
|
i--;
|
|
} else {
|
|
v[i] = random_data;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* @brief Generates a vector of a given Hamming weight
|
|
*
|
|
* This function generates uniformly at random a binary vector of a Hamming weight equal to the parameter <b>weight</b>.
|
|
* To generate the vector we have to sample uniformly at random values in the interval [0, PARAM_N -1]. Suppose the PARAM_N is equal to \f$ 70853 \f$, to select a position \f$ r\f$ the function works as follow:
|
|
* 1. It makes a call to the seedexpander function to obtain a random number \f$ x\f$ in \f$ [0, 2^{24}[ \f$.
|
|
* 2. Let \f$ t = \lfloor {2^{24} \over 70853} \rfloor \times 70853\f$
|
|
* 3. If \f$ x \geq t\f$, go to 1
|
|
* 4. It return \f$ r = x \mod 70853\f$
|
|
*
|
|
* The parameter \f$ t \f$ is precomputed and it's denoted by UTILS_REJECTION_THRESHOLD (see the file parameters.h).
|
|
*
|
|
* @param[in] v Pointer to an array
|
|
* @param[in] weight Integer that is the Hamming weight
|
|
* @param[in] ctx Pointer to the context of the seed expander
|
|
*/
|
|
void PQCLEAN_HQC256_CLEAN_vect_set_random_fixed_weight(AES_XOF_struct *ctx, uint64_t *v, uint16_t weight) {
|
|
|
|
size_t random_bytes_size = 3 * weight;
|
|
uint8_t rand_bytes[3 * PARAM_OMEGA_R] = {0}; // weight is expected to be <= PARAM_OMEGA_R
|
|
uint32_t random_data = 0;
|
|
uint32_t tmp[PARAM_OMEGA_R] = {0};
|
|
uint8_t exist = 0;
|
|
size_t j = 0;
|
|
|
|
seedexpander(ctx, rand_bytes, random_bytes_size);
|
|
|
|
for (uint32_t i = 0; i < weight; ++i) {
|
|
exist = 0;
|
|
do {
|
|
if (j == random_bytes_size) {
|
|
seedexpander(ctx, rand_bytes, random_bytes_size);
|
|
j = 0;
|
|
}
|
|
|
|
random_data = ((uint32_t) rand_bytes[j++]) << 16;
|
|
random_data |= ((uint32_t) rand_bytes[j++]) << 8;
|
|
random_data |= rand_bytes[j++];
|
|
|
|
} while (random_data >= UTILS_REJECTION_THRESHOLD);
|
|
|
|
random_data = random_data % PARAM_N;
|
|
|
|
for (uint32_t k = 0; k < i; k++) {
|
|
if (tmp[k] == random_data) {
|
|
exist = 1;
|
|
}
|
|
}
|
|
|
|
if (exist == 1) {
|
|
i--;
|
|
} else {
|
|
tmp[i] = random_data;
|
|
}
|
|
}
|
|
|
|
for (uint16_t i = 0; i < weight; ++i) {
|
|
int32_t index = tmp[i] / 64;
|
|
int32_t pos = tmp[i] % 64;
|
|
v[index] |= ((uint64_t) 1) << pos;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* @brief Generates a random vector of dimension <b>PARAM_N</b>
|
|
*
|
|
* This function generates a random binary vector of dimension <b>PARAM_N</b>. It generates a random
|
|
* array of bytes using the seedexpander function, and drop the extra bits using a mask.
|
|
*
|
|
* @param[in] v Pointer to an array
|
|
* @param[in] ctx Pointer to the context of the seed expander
|
|
*/
|
|
void PQCLEAN_HQC256_CLEAN_vect_set_random(AES_XOF_struct *ctx, uint64_t *v) {
|
|
uint8_t rand_bytes[VEC_N_SIZE_BYTES] = {0};
|
|
|
|
seedexpander(ctx, rand_bytes, VEC_N_SIZE_BYTES);
|
|
|
|
PQCLEAN_HQC256_CLEAN_load8_arr(v, VEC_N_SIZE_64, rand_bytes, VEC_N_SIZE_BYTES);
|
|
v[VEC_N_SIZE_64 - 1] &= RED_MASK;
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* @brief Generates a random vector
|
|
*
|
|
* This function generates a random binary vector. It uses the the randombytes function.
|
|
*
|
|
* @param[in] v Pointer to an array
|
|
*/
|
|
void PQCLEAN_HQC256_CLEAN_vect_set_random_from_randombytes(uint64_t *v) {
|
|
uint8_t rand_bytes [VEC_K_SIZE_BYTES] = {0};
|
|
|
|
randombytes(rand_bytes, VEC_K_SIZE_BYTES);
|
|
memcpy(v, rand_bytes, VEC_K_SIZE_BYTES);
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* @brief Adds two vectors
|
|
*
|
|
* @param[out] o Pointer to an array that is the result
|
|
* @param[in] v1 Pointer to an array that is the first vector
|
|
* @param[in] v2 Pointer to an array that is the second vector
|
|
* @param[in] size Integer that is the size of the vectors
|
|
*/
|
|
void PQCLEAN_HQC256_CLEAN_vect_add(uint64_t *o, const uint64_t *v1, const uint64_t *v2, uint32_t size) {
|
|
for (uint32_t i = 0; i < size; ++i) {
|
|
o[i] = v1[i] ^ v2[i];
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* @brief Compares two vectors
|
|
*
|
|
* @param[in] v1 Pointer to an array that is first vector
|
|
* @param[in] v2 Pointer to an array that is second vector
|
|
* @param[in] size Integer that is the size of the vectors
|
|
* @returns 0 if the vectors are equals and a negative/psotive value otherwise
|
|
*/
|
|
int PQCLEAN_HQC256_CLEAN_vect_compare(const uint64_t *v1, const uint64_t *v2, uint32_t size) {
|
|
return memcmp(v1, v2, size);
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* @brief Resize a vector so that it contains <b>size_o</b> bits
|
|
*
|
|
* @param[out] o Pointer to the output vector
|
|
* @param[in] size_o Integer that is the size of the output vector in bits
|
|
* @param[in] v Pointer to the input vector
|
|
* @param[in] size_v Integer that is the size of the input vector in bits
|
|
*/
|
|
void PQCLEAN_HQC256_CLEAN_vect_resize(uint64_t *o, uint32_t size_o, const uint64_t *v, uint32_t size_v) {
|
|
if (size_o < size_v) {
|
|
uint64_t mask = 0x7FFFFFFFFFFFFFFF;
|
|
int8_t val = 0;
|
|
|
|
if (size_o % 64) {
|
|
val = 64 - (size_o % 64);
|
|
}
|
|
|
|
memcpy(o, v, VEC_N1N2_SIZE_BYTES);
|
|
|
|
for (int8_t i = 0; i < val; ++i) {
|
|
o[VEC_N1N2_SIZE_64 - 1] &= (mask >> i);
|
|
}
|
|
} else {
|
|
memcpy(o, v, CEIL_DIVIDE(size_v, 8));
|
|
}
|
|
}
|