mirror of
https://github.com/henrydcase/pqc.git
synced 2024-11-27 01:41:40 +00:00
79 lines
2.7 KiB
C
79 lines
2.7 KiB
C
#include "SABER_indcpa.h"
|
|
#include "SABER_params.h"
|
|
#include "api.h"
|
|
#include "fips202.h"
|
|
#include "randombytes.h"
|
|
#include "verify.h"
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
|
|
int PQCLEAN_SABER_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk) {
|
|
int i;
|
|
|
|
PQCLEAN_SABER_CLEAN_indcpa_kem_keypair(pk, sk); // sk[0:SABER_INDCPA_SECRETKEYBYTES-1] <-- sk
|
|
for (i = 0; i < SABER_INDCPA_PUBLICKEYBYTES; i++) {
|
|
sk[i + SABER_INDCPA_SECRETKEYBYTES] = pk[i]; // sk[SABER_INDCPA_SECRETKEYBYTES:SABER_INDCPA_SECRETKEYBYTES+SABER_INDCPA_SECRETKEYBYTES-1] <-- pk
|
|
}
|
|
|
|
sha3_256(sk + SABER_SECRETKEYBYTES - 64, pk, SABER_INDCPA_PUBLICKEYBYTES); // Then hash(pk) is appended.
|
|
|
|
randombytes(sk + SABER_SECRETKEYBYTES - SABER_KEYBYTES, SABER_KEYBYTES); // Remaining part of sk contains a pseudo-random number.
|
|
// This is output when check in PQCLEAN_SABER_CLEAN_crypto_kem_dec() fails.
|
|
return (0);
|
|
}
|
|
|
|
int PQCLEAN_SABER_CLEAN_crypto_kem_enc(uint8_t *c, uint8_t *k, const uint8_t *pk) {
|
|
|
|
uint8_t kr[64]; // Will contain key, coins
|
|
uint8_t buf[64];
|
|
|
|
randombytes(buf, 32);
|
|
|
|
sha3_256(buf, buf, 32); // BUF[0:31] <-- random message (will be used as the key for client) Note: hash doesnot release system RNG output
|
|
|
|
sha3_256(buf + 32, pk, SABER_INDCPA_PUBLICKEYBYTES); // BUF[32:63] <-- Hash(public key); Multitarget countermeasure for coins + contributory KEM
|
|
|
|
sha3_512(kr, buf, 64); // kr[0:63] <-- Hash(buf[0:63]);
|
|
// K^ <-- kr[0:31]
|
|
// noiseseed (r) <-- kr[32:63];
|
|
PQCLEAN_SABER_CLEAN_indcpa_kem_enc(c, buf, kr + 32, pk); // buf[0:31] contains message; kr[32:63] contains randomness r;
|
|
|
|
sha3_256(kr + 32, c, SABER_BYTES_CCA_DEC);
|
|
|
|
sha3_256(k, kr, 64); // hash concatenation of pre-k and h(c) to k
|
|
|
|
return (0);
|
|
}
|
|
|
|
int PQCLEAN_SABER_CLEAN_crypto_kem_dec(uint8_t *k, const uint8_t *c, const uint8_t *sk) {
|
|
int i;
|
|
uint8_t fail;
|
|
uint8_t cmp[SABER_BYTES_CCA_DEC];
|
|
uint8_t buf[64];
|
|
uint8_t kr[64]; // Will contain key, coins
|
|
const uint8_t *pk = sk + SABER_INDCPA_SECRETKEYBYTES;
|
|
|
|
PQCLEAN_SABER_CLEAN_indcpa_kem_dec(buf, sk, c); // buf[0:31] <-- message
|
|
|
|
// Multitarget countermeasure for coins + contributory KEM
|
|
for (i = 0; i < 32; i++) { // Save hash by storing h(pk) in sk
|
|
buf[32 + i] = sk[SABER_SECRETKEYBYTES - 64 + i];
|
|
}
|
|
|
|
sha3_512(kr, buf, 64);
|
|
|
|
PQCLEAN_SABER_CLEAN_indcpa_kem_enc(cmp, buf, kr + 32, pk);
|
|
|
|
fail = PQCLEAN_SABER_CLEAN_verify(c, cmp, SABER_BYTES_CCA_DEC);
|
|
|
|
sha3_256(kr + 32, c, SABER_BYTES_CCA_DEC); // overwrite coins in kr with h(c)
|
|
|
|
PQCLEAN_SABER_CLEAN_cmov(kr, sk + SABER_SECRETKEYBYTES - SABER_KEYBYTES, SABER_KEYBYTES, fail);
|
|
|
|
sha3_256(k, kr, 64); // hash concatenation of pre-k and h(c) to k
|
|
|
|
return (0);
|
|
}
|