pqc/crypto_kem/hqc-rmrs-192/avx2/parsing.c
2020-09-13 12:23:25 -04:00

187 lines
6.2 KiB
C

#include "nistseedexpander.h"
#include "parameters.h"
#include "parsing.h"
#include "randombytes.h"
#include "vector.h"
#include <stdint.h>
#include <string.h>
/**
* @file parsing.c
* @brief Functions to parse secret key, public key and ciphertext of the HQC scheme
*/
void PQCLEAN_HQCRMRS192_AVX2_store8(unsigned char *out, uint64_t in) {
out[0] = (in >> 0x00) & 0xFF;
out[1] = (in >> 0x08) & 0xFF;
out[2] = (in >> 0x10) & 0xFF;
out[3] = (in >> 0x18) & 0xFF;
out[4] = (in >> 0x20) & 0xFF;
out[5] = (in >> 0x28) & 0xFF;
out[6] = (in >> 0x30) & 0xFF;
out[7] = (in >> 0x38) & 0xFF;
}
uint64_t PQCLEAN_HQCRMRS192_AVX2_load8(const unsigned char *in) {
uint64_t ret = in[7];
for (int8_t i = 6; i >= 0; i--) {
ret <<= 8;
ret |= in[i];
}
return ret;
}
void PQCLEAN_HQCRMRS192_AVX2_load8_arr(uint64_t *out64, size_t outlen, const uint8_t *in8, size_t inlen) {
size_t index_in = 0;
size_t index_out = 0;
// first copy by 8 bytes
if (inlen >= 8 && outlen >= 1) {
while (index_out < outlen && index_in + 8 <= inlen) {
out64[index_out] = PQCLEAN_HQCRMRS192_AVX2_load8(in8 + index_in);
index_in += 8;
index_out += 1;
}
}
// we now need to do the last 7 bytes if necessary
if (index_in >= inlen || index_out >= outlen) {
return;
}
out64[index_out] = in8[inlen - 1];
for (int8_t i = (int8_t)(inlen - index_in) - 2; i >= 0; i--) {
out64[index_out] <<= 8;
out64[index_out] |= in8[index_in + i];
}
}
void PQCLEAN_HQCRMRS192_AVX2_store8_arr(uint8_t *out8, size_t outlen, const uint64_t *in64, size_t inlen) {
for (size_t index_out = 0, index_in = 0; index_out < outlen && index_in < inlen;) {
out8[index_out] = (in64[index_in] >> ((index_out % 8) * 8)) & 0xFF;
index_out++;
if (index_out % 8 == 0) {
index_in++;
}
}
}
/**
* @brief Parse a secret key into a string
*
* The secret key is composed of the seed used to generate vectors <b>x</b> and <b>y</b>.
* As technicality, the public key is appended to the secret key in order to respect NIST API.
*
* @param[out] sk String containing the secret key
* @param[in] sk_seed Seed used to generate the secret key
* @param[in] pk String containing the public key
*/
void PQCLEAN_HQCRMRS192_AVX2_hqc_secret_key_to_string(uint8_t *sk, const uint8_t *sk_seed, const uint8_t *pk) {
memcpy(sk, sk_seed, SEED_BYTES);
sk += SEED_BYTES;
memcpy(sk, pk, PUBLIC_KEY_BYTES);
}
/**
* @brief Parse a secret key from a string
*
* The secret key is composed of the seed used to generate vectors <b>x</b> and <b>y</b>.
* As technicality, the public key is appended to the secret key in order to respect NIST API.
*
* @param[out] x uint64_t representation of vector x
* @param[out] y uint64_t representation of vector y
* @param[out] pk String containing the public key
* @param[in] sk String containing the secret key
*/
void PQCLEAN_HQCRMRS192_AVX2_hqc_secret_key_from_string(uint64_t *x, uint64_t *y, uint8_t *pk, const uint8_t *sk) {
AES_XOF_struct sk_seedexpander;
uint8_t sk_seed[SEED_BYTES] = {0};
memcpy(sk_seed, sk, SEED_BYTES);
sk += SEED_BYTES;
memcpy(pk, sk, PUBLIC_KEY_BYTES);
seedexpander_init(&sk_seedexpander, sk_seed, sk_seed + 32, SEEDEXPANDER_MAX_LENGTH);
PQCLEAN_HQCRMRS192_AVX2_vect_set_random_fixed_weight(&sk_seedexpander, x, PARAM_OMEGA);
PQCLEAN_HQCRMRS192_AVX2_vect_set_random_fixed_weight(&sk_seedexpander, y, PARAM_OMEGA);
}
/**
* @brief Parse a public key into a string
*
* The public key is composed of the syndrome <b>s</b> as well as the seed used to generate the vector <b>h</b>
*
* @param[out] pk String containing the public key
* @param[in] pk_seed Seed used to generate the public key
* @param[in] s uint8_t representation of vector s
*/
void PQCLEAN_HQCRMRS192_AVX2_hqc_public_key_to_string(uint8_t *pk, const uint8_t *pk_seed, const uint64_t *s) {
memcpy(pk, pk_seed, SEED_BYTES);
PQCLEAN_HQCRMRS192_AVX2_store8_arr(pk + SEED_BYTES, VEC_N_SIZE_BYTES, s, VEC_N_SIZE_64);
}
/**
* @brief Parse a public key from a string
*
* The public key is composed of the syndrome <b>s</b> as well as the seed used to generate the vector <b>h</b>
*
* @param[out] h uint8_t representation of vector h
* @param[out] s uint8_t representation of vector s
* @param[in] pk String containing the public key
*/
void PQCLEAN_HQCRMRS192_AVX2_hqc_public_key_from_string(uint64_t *h, uint64_t *s, const uint8_t *pk) {
AES_XOF_struct pk_seedexpander;
uint8_t pk_seed[SEED_BYTES] = {0};
memcpy(pk_seed, pk, SEED_BYTES);
pk += SEED_BYTES;
PQCLEAN_HQCRMRS192_AVX2_load8_arr(s, VEC_N_SIZE_64, pk, VEC_N_SIZE_BYTES);
seedexpander_init(&pk_seedexpander, pk_seed, pk_seed + 32, SEEDEXPANDER_MAX_LENGTH);
PQCLEAN_HQCRMRS192_AVX2_vect_set_random(&pk_seedexpander, h);
}
/**
* @brief Parse a ciphertext into a string
*
* The ciphertext is composed of vectors <b>u</b>, <b>v</b> and hash <b>d</b>.
*
* @param[out] ct String containing the ciphertext
* @param[in] u uint8_t representation of vector u
* @param[in] v uint8_t representation of vector v
* @param[in] d String containing the hash d
*/
void PQCLEAN_HQCRMRS192_AVX2_hqc_ciphertext_to_string(uint8_t *ct, const uint64_t *u, const uint64_t *v, const uint8_t *d) {
PQCLEAN_HQCRMRS192_AVX2_store8_arr(ct, VEC_N_SIZE_BYTES, u, VEC_N_SIZE_64);
ct += VEC_N_SIZE_BYTES;
PQCLEAN_HQCRMRS192_AVX2_store8_arr(ct, VEC_N1N2_SIZE_BYTES, v, VEC_N1N2_SIZE_64);
ct += VEC_N1N2_SIZE_BYTES;
memcpy(ct, d, SHA512_BYTES);
}
/**
* @brief Parse a ciphertext from a string
*
* The ciphertext is composed of vectors <b>u</b>, <b>v</b> and hash <b>d</b>.
*
* @param[out] u uint8_t representation of vector u
* @param[out] v uint8_t representation of vector v
* @param[out] d String containing the hash d
* @param[in] ct String containing the ciphertext
*/
void PQCLEAN_HQCRMRS192_AVX2_hqc_ciphertext_from_string(uint64_t *u, uint64_t *v, uint8_t *d, const uint8_t *ct) {
PQCLEAN_HQCRMRS192_AVX2_load8_arr(u, VEC_N_SIZE_64, ct, VEC_N_SIZE_BYTES);
ct += VEC_N_SIZE_BYTES;
PQCLEAN_HQCRMRS192_AVX2_load8_arr(v, VEC_N1N2_SIZE_64, ct, VEC_N1N2_SIZE_BYTES);
ct += VEC_N1N2_SIZE_BYTES;
memcpy(d, ct, SHA512_BYTES);
}