mirror of
https://github.com/henrydcase/pqc.git
synced 2024-11-26 09:21:28 +00:00
97 lines
2.9 KiB
C
97 lines
2.9 KiB
C
#include "SABER_indcpa.h"
|
|
#include "SABER_params.h"
|
|
#include "fips202.h"
|
|
#include "randombytes.h"
|
|
#include "verify.h"
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
int PQCLEAN_LIGHTSABER_CLEAN_crypto_kem_keypair(unsigned char *pk, unsigned char *sk) {
|
|
int i;
|
|
|
|
// sk[0:SABER_INDCPA_SECRETKEYBYTES-1] <-- sk
|
|
PQCLEAN_LIGHTSABER_CLEAN_indcpa_kem_keypair(pk, sk);
|
|
|
|
// sk[SABER_INDCPA_SECRETKEYBYTES:SABER_INDCPA_SECRETKEYBYTES+SABER_INDCPA_SECRETKEYBYTES-1] <-- pk
|
|
for (i = 0; i < SABER_INDCPA_PUBLICKEYBYTES; i++) {
|
|
sk[i + SABER_INDCPA_SECRETKEYBYTES] = pk[i];
|
|
}
|
|
|
|
// Then hash(pk) is appended.
|
|
sha3_256(sk + SABER_SECRETKEYBYTES - 64, pk, SABER_INDCPA_PUBLICKEYBYTES);
|
|
|
|
// Remaining part of sk contains a pseudo-random number.
|
|
// This is output when check in crypto_kem_dec() fails.
|
|
randombytes(sk + SABER_SECRETKEYBYTES - SABER_KEYBYTES, SABER_KEYBYTES );
|
|
return (0);
|
|
}
|
|
|
|
int PQCLEAN_LIGHTSABER_CLEAN_crypto_kem_enc(unsigned char *ct, unsigned char *ss, const unsigned char *pk) {
|
|
// Will contain key, coins
|
|
unsigned char kr[64];
|
|
unsigned char buf[64];
|
|
|
|
randombytes(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, buf, 32);
|
|
|
|
// BUF[32:63] <-- Hash(public key); Multitarget countermeasure for coins + contributory KEM
|
|
sha3_256(buf + 32, pk, SABER_INDCPA_PUBLICKEYBYTES);
|
|
|
|
// kr[0:63] <-- Hash(buf[0:63]);
|
|
sha3_512(kr, buf, 64);
|
|
|
|
// K^ <-- kr[0:31]
|
|
// noiseseed (r) <-- kr[32:63];
|
|
// buf[0:31] contains message; kr[32:63] contains randomness r;
|
|
PQCLEAN_LIGHTSABER_CLEAN_indcpa_kem_enc(buf, kr + 32, pk, ct);
|
|
|
|
sha3_256(kr + 32, ct, SABER_BYTES_CCA_DEC);
|
|
|
|
// hash concatenation of pre-k and h(c) to k
|
|
sha3_256(ss, kr, 64);
|
|
|
|
return (0);
|
|
}
|
|
|
|
|
|
int PQCLEAN_LIGHTSABER_CLEAN_crypto_kem_dec(unsigned char *ss, const unsigned char *ct, const unsigned char *sk) {
|
|
int i;
|
|
unsigned char fail;
|
|
unsigned char cmp[SABER_BYTES_CCA_DEC];
|
|
unsigned char buf[64];
|
|
|
|
// Will contain key, coins
|
|
unsigned char kr[64];
|
|
const unsigned char *pk = sk + SABER_INDCPA_SECRETKEYBYTES;
|
|
|
|
// buf[0:31] <-- message
|
|
PQCLEAN_LIGHTSABER_CLEAN_indcpa_kem_dec(sk, ct, buf);
|
|
|
|
|
|
// Multitarget countermeasure for coins + contributory KEM
|
|
// Save hash by storing h(pk) in sk
|
|
for (i = 0; i < 32; i++) {
|
|
buf[32 + i] = sk[SABER_SECRETKEYBYTES - 64 + i];
|
|
}
|
|
|
|
sha3_512(kr, buf, 64);
|
|
|
|
PQCLEAN_LIGHTSABER_CLEAN_indcpa_kem_enc(buf, kr + 32, pk, cmp);
|
|
|
|
|
|
fail = PQCLEAN_LIGHTSABER_CLEAN_verify(ct, cmp, SABER_BYTES_CCA_DEC);
|
|
|
|
// overwrite coins in kr with h(c)
|
|
sha3_256(kr + 32, ct, SABER_BYTES_CCA_DEC);
|
|
|
|
PQCLEAN_LIGHTSABER_CLEAN_cmov(kr, sk + SABER_SECRETKEYBYTES - SABER_KEYBYTES, SABER_KEYBYTES, fail);
|
|
|
|
// hash concatenation of pre-k and h(c) to k
|
|
sha3_256(ss, kr, 64);
|
|
|
|
return (0);
|
|
}
|