61 lines
1.8 KiB
C
61 lines
1.8 KiB
C
#include <stdint.h>
|
|
|
|
#include "api.h"
|
|
#include "fips202.h"
|
|
#include "owcpa.h"
|
|
#include "params.h"
|
|
#include "randombytes.h"
|
|
#include "verify.h"
|
|
|
|
// API FUNCTIONS
|
|
int PQCLEAN_NTRUHPS4096821_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk) {
|
|
uint8_t seed[NTRU_SAMPLE_FG_BYTES];
|
|
|
|
randombytes(seed, NTRU_SAMPLE_FG_BYTES);
|
|
PQCLEAN_NTRUHPS4096821_CLEAN_owcpa_keypair(pk, sk, seed);
|
|
|
|
randombytes(sk + NTRU_OWCPA_SECRETKEYBYTES, NTRU_PRFKEYBYTES);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int PQCLEAN_NTRUHPS4096821_CLEAN_crypto_kem_enc(uint8_t *c, uint8_t *k, const uint8_t *pk) {
|
|
uint8_t rm[NTRU_OWCPA_MSGBYTES];
|
|
uint8_t rm_seed[NTRU_SAMPLE_RM_BYTES];
|
|
|
|
randombytes(rm_seed, NTRU_SAMPLE_RM_BYTES);
|
|
PQCLEAN_NTRUHPS4096821_CLEAN_owcpa_samplemsg(rm, rm_seed);
|
|
|
|
sha3_256(k, rm, NTRU_OWCPA_MSGBYTES);
|
|
|
|
PQCLEAN_NTRUHPS4096821_CLEAN_owcpa_enc(c, rm, pk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int PQCLEAN_NTRUHPS4096821_CLEAN_crypto_kem_dec(uint8_t *k, const uint8_t *c, const uint8_t *sk) {
|
|
int i, fail;
|
|
uint8_t rm[NTRU_OWCPA_MSGBYTES];
|
|
uint8_t buf[NTRU_PRFKEYBYTES + NTRU_CIPHERTEXTBYTES];
|
|
uint8_t *cmp = buf + NTRU_PRFKEYBYTES;
|
|
|
|
fail = PQCLEAN_NTRUHPS4096821_CLEAN_owcpa_dec(rm, c, sk);
|
|
/* If fail = 0 then c = Enc(h, rm), there is no need to re-encapsulate. */
|
|
/* See comment in PQCLEAN_NTRUHPS4096821_CLEAN_owcpa_dec for details. */
|
|
|
|
sha3_256(k, rm, NTRU_OWCPA_MSGBYTES);
|
|
|
|
/* shake(secret PRF key || input ciphertext) */
|
|
for (i = 0; i < NTRU_PRFKEYBYTES; i++) {
|
|
buf[i] = sk[i + NTRU_OWCPA_SECRETKEYBYTES];
|
|
}
|
|
for (i = 0; i < NTRU_CIPHERTEXTBYTES; i++) {
|
|
cmp[i] = c[i];
|
|
}
|
|
sha3_256(rm, cmp, NTRU_PRFKEYBYTES + NTRU_CIPHERTEXTBYTES);
|
|
|
|
PQCLEAN_NTRUHPS4096821_CLEAN_cmov(k, rm, NTRU_SHAREDKEYBYTES, (unsigned char) fail);
|
|
|
|
return 0;
|
|
}
|