mirror of
https://github.com/henrydcase/pqc.git
synced 2024-11-30 03:11:43 +00:00
311 lines
11 KiB
C
311 lines
11 KiB
C
#include "indcpa.h"
|
|
#include "fips202.h"
|
|
#include "ntt.h"
|
|
#include "poly.h"
|
|
#include "polyvec.h"
|
|
#include "randombytes.h"
|
|
#include <string.h>
|
|
|
|
/*************************************************
|
|
* Name: pack_pk
|
|
*
|
|
* Description: Serialize the public key as concatenation of the
|
|
* compressed and serialized vector of polynomials pk
|
|
* and the public seed used to generate the matrix A.
|
|
*
|
|
* Arguments: unsigned char *r: pointer to the output serialized
|
|
*public key const poly *pk: pointer to the input public-key
|
|
*polynomial const unsigned char *seed: pointer to the input public seed
|
|
**************************************************/
|
|
static void pack_pk(unsigned char *r, const polyvec *pk, const unsigned char *seed) {
|
|
int i;
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_compress(r, pk);
|
|
for (i = 0; i < KYBER_SYMBYTES; i++) {
|
|
r[i + KYBER_POLYVECCOMPRESSEDBYTES] = seed[i];
|
|
}
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: unpack_pk
|
|
*
|
|
* Description: De-serialize and decompress public key from a byte array;
|
|
* approximate inverse of pack_pk
|
|
*
|
|
* Arguments: - polyvec *pk: pointer to output public-key
|
|
*vector of polynomials
|
|
* - unsigned char *seed: pointer to output seed to
|
|
*generate matrix A
|
|
* - const unsigned char *packedpk: pointer to input serialized
|
|
*public key
|
|
**************************************************/
|
|
static void unpack_pk(polyvec *pk, unsigned char *seed, const unsigned char *packedpk) {
|
|
int i;
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_decompress(pk, packedpk);
|
|
|
|
for (i = 0; i < KYBER_SYMBYTES; i++) {
|
|
seed[i] = packedpk[i + KYBER_POLYVECCOMPRESSEDBYTES];
|
|
}
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: pack_ciphertext
|
|
*
|
|
* Description: Serialize the ciphertext as concatenation of the
|
|
* compressed and serialized vector of polynomials b
|
|
* and the compressed and serialized polynomial v
|
|
*
|
|
* Arguments: unsigned char *r: pointer to the output serialized
|
|
*ciphertext const poly *pk: pointer to the input vector of
|
|
*polynomials b const unsigned char *seed: pointer to the input polynomial v
|
|
**************************************************/
|
|
static void pack_ciphertext(unsigned char *r, const polyvec *b, const poly *v) {
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_compress(r, b);
|
|
PQCLEAN_KYBER768_CLEAN_poly_compress(r + KYBER_POLYVECCOMPRESSEDBYTES, v);
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: unpack_ciphertext
|
|
*
|
|
* Description: De-serialize and decompress ciphertext from a byte array;
|
|
* approximate inverse of pack_ciphertext
|
|
*
|
|
* Arguments: - polyvec *b: pointer to the output vector of
|
|
*polynomials b
|
|
* - poly *v: pointer to the output polynomial v
|
|
* - const unsigned char *c: pointer to the input serialized
|
|
*ciphertext
|
|
**************************************************/
|
|
static void unpack_ciphertext(polyvec *b, poly *v, const unsigned char *c) {
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_decompress(b, c);
|
|
PQCLEAN_KYBER768_CLEAN_poly_decompress(v, c + KYBER_POLYVECCOMPRESSEDBYTES);
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: pack_sk
|
|
*
|
|
* Description: Serialize the secret key
|
|
*
|
|
* Arguments: - unsigned char *r: pointer to output serialized secret key
|
|
* - const polyvec *sk: pointer to input vector of polynomials
|
|
*(secret key)
|
|
**************************************************/
|
|
static void pack_sk(unsigned char *r, const polyvec *sk) {
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_tobytes(r, sk);
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: unpack_sk
|
|
*
|
|
* Description: De-serialize the secret key;
|
|
* inverse of pack_sk
|
|
*
|
|
* Arguments: - polyvec *sk: pointer to output vector of
|
|
*polynomials (secret key)
|
|
* - const unsigned char *packedsk: pointer to input serialized
|
|
*secret key
|
|
**************************************************/
|
|
static void unpack_sk(polyvec *sk, const unsigned char *packedsk) {
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_frombytes(sk, packedsk);
|
|
}
|
|
|
|
#define gen_a(A, B) gen_matrix(A, B, 0)
|
|
#define gen_at(A, B) gen_matrix(A, B, 1)
|
|
|
|
/*************************************************
|
|
* Name: gen_matrix
|
|
*
|
|
* Description: Deterministically generate matrix A (or the transpose of A)
|
|
* from a seed. Entries of the matrix are polynomials that look
|
|
* uniformly random. Performs rejection sampling on output of
|
|
* SHAKE-128
|
|
*
|
|
* Arguments: - polyvec *a: pointer to ouptput matrix A
|
|
* - const unsigned char *seed: pointer to input seed
|
|
* - int transposed: boolean deciding whether A or A^T
|
|
*is generated
|
|
**************************************************/
|
|
static void gen_matrix(polyvec *a, const unsigned char *seed, int transposed) {
|
|
unsigned int pos = 0, ctr;
|
|
uint16_t val;
|
|
unsigned int nblocks;
|
|
const unsigned int maxnblocks = 4;
|
|
uint8_t buf[SHAKE128_RATE * /* maxnblocks = */ 4];
|
|
int i, j;
|
|
uint64_t state[25]; // SHAKE state
|
|
unsigned char extseed[KYBER_SYMBYTES + 2];
|
|
|
|
for (i = 0; i < KYBER_SYMBYTES; i++) {
|
|
extseed[i] = seed[i];
|
|
}
|
|
|
|
for (i = 0; i < KYBER_K; i++) {
|
|
for (j = 0; j < KYBER_K; j++) {
|
|
ctr = pos = 0;
|
|
nblocks = maxnblocks;
|
|
if (transposed) {
|
|
extseed[KYBER_SYMBYTES] = (unsigned char)i;
|
|
extseed[KYBER_SYMBYTES + 1] = (unsigned char)j;
|
|
} else {
|
|
extseed[KYBER_SYMBYTES] = (unsigned char)j;
|
|
extseed[KYBER_SYMBYTES + 1] = (unsigned char)i;
|
|
}
|
|
|
|
shake128_absorb(state, extseed, KYBER_SYMBYTES + 2);
|
|
shake128_squeezeblocks(buf, nblocks, state);
|
|
|
|
while (ctr < KYBER_N) {
|
|
val = (buf[pos] | ((uint16_t)buf[pos + 1] << 8)) & 0x1fff;
|
|
if (val < KYBER_Q) {
|
|
a[i].vec[j].coeffs[ctr++] = val;
|
|
}
|
|
pos += 2;
|
|
|
|
if (pos > SHAKE128_RATE * nblocks - 2) {
|
|
nblocks = 1;
|
|
shake128_squeezeblocks(buf, nblocks, state);
|
|
pos = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: indcpa_keypair
|
|
*
|
|
* Description: Generates public and private key for the CPA-secure
|
|
* public-key encryption scheme underlying Kyber
|
|
*
|
|
* Arguments: - unsigned char *pk: pointer to output public key (of length
|
|
*KYBER_INDCPA_PUBLICKEYBYTES bytes)
|
|
* - unsigned char *sk: pointer to output private key (of length
|
|
*KYBER_INDCPA_SECRETKEYBYTES bytes)
|
|
**************************************************/
|
|
void PQCLEAN_KYBER768_CLEAN_indcpa_keypair(unsigned char *pk, unsigned char *sk) {
|
|
polyvec a[KYBER_K], e, pkpv, skpv;
|
|
unsigned char buf[KYBER_SYMBYTES + KYBER_SYMBYTES];
|
|
unsigned char *publicseed = buf;
|
|
unsigned char *noiseseed = buf + KYBER_SYMBYTES;
|
|
int i;
|
|
unsigned char nonce = 0;
|
|
|
|
randombytes(buf, KYBER_SYMBYTES);
|
|
sha3_512(buf, buf, KYBER_SYMBYTES);
|
|
|
|
gen_a(a, publicseed);
|
|
|
|
for (i = 0; i < KYBER_K; i++) {
|
|
PQCLEAN_KYBER768_CLEAN_poly_getnoise(skpv.vec + i, noiseseed, nonce++);
|
|
}
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_ntt(&skpv);
|
|
|
|
for (i = 0; i < KYBER_K; i++) {
|
|
PQCLEAN_KYBER768_CLEAN_poly_getnoise(e.vec + i, noiseseed, nonce++);
|
|
}
|
|
|
|
// matrix-vector multiplication
|
|
for (i = 0; i < KYBER_K; i++) {
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_pointwise_acc(&pkpv.vec[i], &skpv, a + i);
|
|
}
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_invntt(&pkpv);
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_add(&pkpv, &pkpv, &e);
|
|
|
|
pack_sk(sk, &skpv);
|
|
pack_pk(pk, &pkpv, publicseed);
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: indcpa_enc
|
|
*
|
|
* Description: Encryption function of the CPA-secure
|
|
* public-key encryption scheme underlying Kyber.
|
|
*
|
|
* Arguments: - unsigned char *c: pointer to output ciphertext (of
|
|
*length KYBER_INDCPA_BYTES bytes)
|
|
* - const unsigned char *m: pointer to input message (of length
|
|
*KYBER_INDCPA_MSGBYTES bytes)
|
|
* - const unsigned char *pk: pointer to input public key (of
|
|
*length KYBER_INDCPA_PUBLICKEYBYTES bytes)
|
|
* - const unsigned char *coin: pointer to input random coins used
|
|
*as seed (of length KYBER_SYMBYTES bytes) to deterministically generate all
|
|
*randomness
|
|
**************************************************/
|
|
void PQCLEAN_KYBER768_CLEAN_indcpa_enc(unsigned char *c, const unsigned char *m,
|
|
const unsigned char *pk,
|
|
const unsigned char *coins) {
|
|
polyvec sp, pkpv, ep, at[KYBER_K], bp;
|
|
poly v, k, epp;
|
|
unsigned char seed[KYBER_SYMBYTES];
|
|
int i;
|
|
unsigned char nonce = 0;
|
|
|
|
unpack_pk(&pkpv, seed, pk);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_poly_frommsg(&k, m);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_ntt(&pkpv);
|
|
|
|
gen_at(at, seed);
|
|
|
|
for (i = 0; i < KYBER_K; i++) {
|
|
PQCLEAN_KYBER768_CLEAN_poly_getnoise(sp.vec + i, coins, nonce++);
|
|
}
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_ntt(&sp);
|
|
|
|
for (i = 0; i < KYBER_K; i++) {
|
|
PQCLEAN_KYBER768_CLEAN_poly_getnoise(ep.vec + i, coins, nonce++);
|
|
}
|
|
|
|
// matrix-vector multiplication
|
|
for (i = 0; i < KYBER_K; i++) {
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_pointwise_acc(&bp.vec[i], &sp, at + i);
|
|
}
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_invntt(&bp);
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_add(&bp, &bp, &ep);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_pointwise_acc(&v, &pkpv, &sp);
|
|
PQCLEAN_KYBER768_CLEAN_poly_invntt(&v);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_poly_getnoise(&epp, coins, nonce++);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_poly_add(&v, &v, &epp);
|
|
PQCLEAN_KYBER768_CLEAN_poly_add(&v, &v, &k);
|
|
|
|
pack_ciphertext(c, &bp, &v);
|
|
}
|
|
|
|
/*************************************************
|
|
* Name: indcpa_dec
|
|
*
|
|
* Description: Decryption function of the CPA-secure
|
|
* public-key encryption scheme underlying Kyber.
|
|
*
|
|
* Arguments: - unsigned char *m: pointer to output decrypted message
|
|
*(of length KYBER_INDCPA_MSGBYTES)
|
|
* - const unsigned char *c: pointer to input ciphertext (of
|
|
*length KYBER_INDCPA_BYTES)
|
|
* - const unsigned char *sk: pointer to input secret key (of
|
|
*length KYBER_INDCPA_SECRETKEYBYTES)
|
|
**************************************************/
|
|
void PQCLEAN_KYBER768_CLEAN_indcpa_dec(unsigned char *m, const unsigned char *c,
|
|
const unsigned char *sk) {
|
|
polyvec bp, skpv;
|
|
poly v, mp;
|
|
|
|
unpack_ciphertext(&bp, &v, c);
|
|
unpack_sk(&skpv, sk);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_ntt(&bp);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_polyvec_pointwise_acc(&mp, &skpv, &bp);
|
|
PQCLEAN_KYBER768_CLEAN_poly_invntt(&mp);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_poly_sub(&mp, &mp, &v);
|
|
|
|
PQCLEAN_KYBER768_CLEAN_poly_tomsg(m, &mp);
|
|
}
|