pqc/crypto_sign/dilithium2aes/avx2/sign.c
2021-02-09 10:43:16 -05:00

426 lines
15 KiB
C

#include "aes256ctr.h"
#include "align.h"
#include "fips202.h"
#include "packing.h"
#include "params.h"
#include "poly.h"
#include "polyvec.h"
#include "randombytes.h"
#include "sign.h"
#include "symmetric.h"
#include <stdint.h>
#include <string.h>
/*************************************************
* Name: PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_keypair
*
* Description: Generates public and private key.
*
* Arguments: - uint8_t *pk: pointer to output public key (allocated
* array of PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_PUBLICKEYBYTES bytes)
* - uint8_t *sk: pointer to output private key (allocated
* array of PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_SECRETKEYBYTES bytes)
*
* Returns 0 (success)
**************************************************/
int PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_keypair(uint8_t *pk, uint8_t *sk) {
unsigned int i;
uint8_t seedbuf[2 * SEEDBYTES + CRHBYTES];
const uint8_t *rho, *rhoprime, *key;
uint64_t nonce;
aes256ctr_ctx aesctx;
polyvecl rowbuf[1];
polyvecl s1, *row = rowbuf;
polyveck s2;
poly t1, t0;
/* Get randomness for rho, rhoprime and key */
randombytes(seedbuf, SEEDBYTES);
shake256(seedbuf, 2 * SEEDBYTES + CRHBYTES, seedbuf, SEEDBYTES);
rho = seedbuf;
rhoprime = rho + SEEDBYTES;
key = rhoprime + CRHBYTES;
/* Store rho, key */
memcpy(pk, rho, SEEDBYTES);
memcpy(sk, rho, SEEDBYTES);
memcpy(sk + SEEDBYTES, key, SEEDBYTES);
/* Sample short vectors s1 and s2 */
PQCLEAN_DILITHIUM2AES_AVX2_aes256ctr_init(&aesctx, rhoprime, 0);
for (i = 0; i < L; ++i) {
nonce = i;
aesctx.n = _mm_loadl_epi64((__m128i *)&nonce);
PQCLEAN_DILITHIUM2AES_AVX2_poly_uniform_eta_preinit(&s1.vec[i], &aesctx);
}
for (i = 0; i < K; ++i) {
nonce = L + i;
aesctx.n = _mm_loadl_epi64((__m128i *)&nonce);
PQCLEAN_DILITHIUM2AES_AVX2_poly_uniform_eta_preinit(&s2.vec[i], &aesctx);
}
/* Pack secret vectors */
for (i = 0; i < L; i++) {
PQCLEAN_DILITHIUM2AES_AVX2_polyeta_pack(sk + 3 * SEEDBYTES + i * POLYETA_PACKEDBYTES, &s1.vec[i]);
}
for (i = 0; i < K; i++) {
PQCLEAN_DILITHIUM2AES_AVX2_polyeta_pack(sk + 3 * SEEDBYTES + (L + i)*POLYETA_PACKEDBYTES, &s2.vec[i]);
}
/* Transform s1 */
PQCLEAN_DILITHIUM2AES_AVX2_polyvecl_ntt(&s1);
PQCLEAN_DILITHIUM2AES_AVX2_aes256ctr_init(&aesctx, rho, 0);
for (i = 0; i < K; i++) {
/* Expand matrix row */
for (unsigned int j = 0; j < L; j++) {
nonce = (i << 8) + j;
aesctx.n = _mm_loadl_epi64((__m128i *)&nonce);
PQCLEAN_DILITHIUM2AES_AVX2_poly_uniform_preinit(&row->vec[j], &aesctx);
PQCLEAN_DILITHIUM2AES_AVX2_poly_nttunpack(&row->vec[j]);
}
/* Compute inner-product */
PQCLEAN_DILITHIUM2AES_AVX2_polyvecl_pointwise_acc_montgomery(&t1, row, &s1);
PQCLEAN_DILITHIUM2AES_AVX2_poly_invntt_tomont(&t1);
/* Add error polynomial */
PQCLEAN_DILITHIUM2AES_AVX2_poly_add(&t1, &t1, &s2.vec[i]);
/* Round t and pack t1, t0 */
PQCLEAN_DILITHIUM2AES_AVX2_poly_caddq(&t1);
PQCLEAN_DILITHIUM2AES_AVX2_poly_power2round(&t1, &t0, &t1);
PQCLEAN_DILITHIUM2AES_AVX2_polyt1_pack(pk + SEEDBYTES + i * POLYT1_PACKEDBYTES, &t1);
PQCLEAN_DILITHIUM2AES_AVX2_polyt0_pack(sk + 3 * SEEDBYTES + (L + K)*POLYETA_PACKEDBYTES + i * POLYT0_PACKEDBYTES, &t0);
}
/* Compute H(rho, t1) and store in secret key */
shake256(sk + 2 * SEEDBYTES, SEEDBYTES, pk, PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_PUBLICKEYBYTES);
return 0;
}
/*************************************************
* Name: PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_signature
*
* Description: Computes signature.
*
* Arguments: - uint8_t *sig: pointer to output signature (of length PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES)
* - size_t *siglen: pointer to output length of signature
* - uint8_t *m: pointer to message to be signed
* - size_t mlen: length of message
* - uint8_t *sk: pointer to bit-packed secret key
*
* Returns 0 (success)
**************************************************/
int PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_signature(uint8_t *sig, size_t *siglen, const uint8_t *m, size_t mlen, const uint8_t *sk) {
unsigned int i, n, pos;
uint8_t seedbuf[3 * SEEDBYTES + 2 * CRHBYTES];
uint8_t *rho, *tr, *key, *mu, *rhoprime;
uint8_t hintbuf[N];
uint8_t *hint = sig + SEEDBYTES + L * POLYZ_PACKEDBYTES;
uint64_t nonce = 0;
polyvecl mat[K], s1, z;
polyveck t0, s2, w1;
poly c, tmp;
union {
polyvecl y;
polyveck w0;
} tmpv;
shake256incctx state;
rho = seedbuf;
tr = rho + SEEDBYTES;
key = tr + SEEDBYTES;
mu = key + SEEDBYTES;
rhoprime = mu + CRHBYTES;
PQCLEAN_DILITHIUM2AES_AVX2_unpack_sk(rho, tr, key, &t0, &s1, &s2, sk);
/* Compute CRH(tr, msg) */
shake256_inc_init(&state);
shake256_inc_absorb(&state, tr, SEEDBYTES);
shake256_inc_absorb(&state, m, mlen);
shake256_inc_finalize(&state);
shake256_inc_squeeze(mu, CRHBYTES, &state);
shake256_inc_ctx_release(&state);
shake256(rhoprime, CRHBYTES, key, SEEDBYTES + CRHBYTES);
/* Expand matrix and transform vectors */
PQCLEAN_DILITHIUM2AES_AVX2_polyvec_matrix_expand(mat, rho);
PQCLEAN_DILITHIUM2AES_AVX2_polyvecl_ntt(&s1);
PQCLEAN_DILITHIUM2AES_AVX2_polyveck_ntt(&s2);
PQCLEAN_DILITHIUM2AES_AVX2_polyveck_ntt(&t0);
aes256ctr_ctx aesctx;
PQCLEAN_DILITHIUM2AES_AVX2_aes256ctr_init(&aesctx, rhoprime, 0);
rej:
/* Sample intermediate vector y */
for (i = 0; i < L; ++i) {
aesctx.n = _mm_loadl_epi64((__m128i *)&nonce);
nonce++;
PQCLEAN_DILITHIUM2AES_AVX2_poly_uniform_gamma1_preinit(&z.vec[i], &aesctx);
}
/* Matrix-vector product */
tmpv.y = z;
PQCLEAN_DILITHIUM2AES_AVX2_polyvecl_ntt(&tmpv.y);
PQCLEAN_DILITHIUM2AES_AVX2_polyvec_matrix_pointwise_montgomery(&w1, mat, &tmpv.y);
PQCLEAN_DILITHIUM2AES_AVX2_polyveck_invntt_tomont(&w1);
/* Decompose w and call the random oracle */
PQCLEAN_DILITHIUM2AES_AVX2_polyveck_caddq(&w1);
PQCLEAN_DILITHIUM2AES_AVX2_polyveck_decompose(&w1, &tmpv.w0, &w1);
PQCLEAN_DILITHIUM2AES_AVX2_polyveck_pack_w1(sig, &w1);
shake256_inc_init(&state);
shake256_inc_absorb(&state, mu, CRHBYTES);
shake256_inc_absorb(&state, sig, K * POLYW1_PACKEDBYTES);
shake256_inc_finalize(&state);
shake256_inc_squeeze(sig, SEEDBYTES, &state);
shake256_inc_ctx_release(&state);
PQCLEAN_DILITHIUM2AES_AVX2_poly_challenge(&c, sig);
PQCLEAN_DILITHIUM2AES_AVX2_poly_ntt(&c);
/* Compute z, reject if it reveals secret */
for (i = 0; i < L; i++) {
PQCLEAN_DILITHIUM2AES_AVX2_poly_pointwise_montgomery(&tmp, &c, &s1.vec[i]);
PQCLEAN_DILITHIUM2AES_AVX2_poly_invntt_tomont(&tmp);
PQCLEAN_DILITHIUM2AES_AVX2_poly_add(&z.vec[i], &z.vec[i], &tmp);
PQCLEAN_DILITHIUM2AES_AVX2_poly_reduce(&z.vec[i]);
if (PQCLEAN_DILITHIUM2AES_AVX2_poly_chknorm(&z.vec[i], GAMMA1 - BETA)) {
goto rej;
}
}
/* Zero hint vector in signature */
pos = 0;
memset(hint, 0, OMEGA);
for (i = 0; i < K; i++) {
/* Check that subtracting cs2 does not change high bits of w and low bits
* do not reveal secret information */
PQCLEAN_DILITHIUM2AES_AVX2_poly_pointwise_montgomery(&tmp, &c, &s2.vec[i]);
PQCLEAN_DILITHIUM2AES_AVX2_poly_invntt_tomont(&tmp);
PQCLEAN_DILITHIUM2AES_AVX2_poly_sub(&tmpv.w0.vec[i], &tmpv.w0.vec[i], &tmp);
PQCLEAN_DILITHIUM2AES_AVX2_poly_reduce(&tmpv.w0.vec[i]);
if (PQCLEAN_DILITHIUM2AES_AVX2_poly_chknorm(&tmpv.w0.vec[i], GAMMA2 - BETA)) {
goto rej;
}
/* Compute hints */
PQCLEAN_DILITHIUM2AES_AVX2_poly_pointwise_montgomery(&tmp, &c, &t0.vec[i]);
PQCLEAN_DILITHIUM2AES_AVX2_poly_invntt_tomont(&tmp);
PQCLEAN_DILITHIUM2AES_AVX2_poly_reduce(&tmp);
if (PQCLEAN_DILITHIUM2AES_AVX2_poly_chknorm(&tmp, GAMMA2)) {
goto rej;
}
PQCLEAN_DILITHIUM2AES_AVX2_poly_add(&tmpv.w0.vec[i], &tmpv.w0.vec[i], &tmp);
n = PQCLEAN_DILITHIUM2AES_AVX2_poly_make_hint(hintbuf, &tmpv.w0.vec[i], &w1.vec[i]);
if (pos + n > OMEGA) {
goto rej;
}
/* Store hints in signature */
memcpy(&hint[pos], hintbuf, n);
hint[OMEGA + i] = pos = pos + n;
}
/* Pack z into signature */
for (i = 0; i < L; i++) {
PQCLEAN_DILITHIUM2AES_AVX2_polyz_pack(sig + SEEDBYTES + i * POLYZ_PACKEDBYTES, &z.vec[i]);
}
*siglen = PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES;
return 0;
}
/*************************************************
* Name: PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign
*
* Description: Compute signed message.
*
* Arguments: - uint8_t *sm: pointer to output signed message (allocated
* array with PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES + mlen bytes),
* can be equal to m
* - size_t *smlen: pointer to output length of signed
* message
* - const uint8_t *m: pointer to message to be signed
* - size_t mlen: length of message
* - const uint8_t *sk: pointer to bit-packed secret key
*
* Returns 0 (success)
**************************************************/
int PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign(uint8_t *sm, size_t *smlen, const uint8_t *m, size_t mlen, const uint8_t *sk) {
size_t i;
for (i = 0; i < mlen; ++i) {
sm[PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES + mlen - 1 - i] = m[mlen - 1 - i];
}
PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_signature(sm, smlen, sm + PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES, mlen, sk);
*smlen += mlen;
return 0;
}
/*************************************************
* Name: PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_verify
*
* Description: Verifies signature.
*
* Arguments: - uint8_t *m: pointer to input signature
* - size_t siglen: length of signature
* - const uint8_t *m: pointer to message
* - size_t mlen: length of message
* - const uint8_t *pk: pointer to bit-packed public key
*
* Returns 0 if signature could be verified correctly and -1 otherwise
**************************************************/
int PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_verify(const uint8_t *sig, size_t siglen, const uint8_t *m, size_t mlen, const uint8_t *pk) {
unsigned int i, j, pos = 0;
/* PQCLEAN_DILITHIUM2AES_AVX2_polyw1_pack writes additional 14 bytes */
ALIGNED_UINT8(K * POLYW1_PACKEDBYTES + 14) buf;
uint8_t mu[CRHBYTES];
const uint8_t *hint = sig + SEEDBYTES + L * POLYZ_PACKEDBYTES;
uint64_t nonce;
aes256ctr_ctx aesctx;
polyvecl rowbuf[1];
polyvecl *row = rowbuf;
polyvecl z;
poly c, w1, h;
shake256incctx state;
if (siglen != PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES) {
return -1;
}
/* Compute CRH(H(rho, t1), msg) */
shake256(mu, SEEDBYTES, pk, PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_PUBLICKEYBYTES);
shake256_inc_init(&state);
shake256_inc_absorb(&state, mu, SEEDBYTES);
shake256_inc_absorb(&state, m, mlen);
shake256_inc_finalize(&state);
shake256_inc_squeeze(mu, CRHBYTES, &state);
shake256_inc_ctx_release(&state);
/* Expand PQCLEAN_DILITHIUM2AES_AVX2_challenge */
PQCLEAN_DILITHIUM2AES_AVX2_poly_challenge(&c, sig);
PQCLEAN_DILITHIUM2AES_AVX2_poly_ntt(&c);
/* Unpack z; shortness follows from unpacking */
for (i = 0; i < L; i++) {
PQCLEAN_DILITHIUM2AES_AVX2_polyz_unpack(&z.vec[i], sig + SEEDBYTES + i * POLYZ_PACKEDBYTES);
PQCLEAN_DILITHIUM2AES_AVX2_poly_ntt(&z.vec[i]);
}
PQCLEAN_DILITHIUM2AES_AVX2_aes256ctr_init(&aesctx, pk, 0);
for (i = 0; i < K; i++) {
/* Expand matrix row */
for (j = 0; j < L; j++) {
nonce = (i << 8) + j;
aesctx.n = _mm_loadl_epi64((__m128i *)&nonce);
PQCLEAN_DILITHIUM2AES_AVX2_poly_uniform_preinit(&row->vec[j], &aesctx);
PQCLEAN_DILITHIUM2AES_AVX2_poly_nttunpack(&row->vec[j]);
}
/* Compute i-th row of Az - c2^Dt1 */
PQCLEAN_DILITHIUM2AES_AVX2_polyvecl_pointwise_acc_montgomery(&w1, row, &z);
PQCLEAN_DILITHIUM2AES_AVX2_polyt1_unpack(&h, pk + SEEDBYTES + i * POLYT1_PACKEDBYTES);
PQCLEAN_DILITHIUM2AES_AVX2_poly_shiftl(&h);
PQCLEAN_DILITHIUM2AES_AVX2_poly_ntt(&h);
PQCLEAN_DILITHIUM2AES_AVX2_poly_pointwise_montgomery(&h, &c, &h);
PQCLEAN_DILITHIUM2AES_AVX2_poly_sub(&w1, &w1, &h);
PQCLEAN_DILITHIUM2AES_AVX2_poly_reduce(&w1);
PQCLEAN_DILITHIUM2AES_AVX2_poly_invntt_tomont(&w1);
/* Get hint polynomial and reconstruct w1 */
memset(h.vec, 0, sizeof(poly));
if (hint[OMEGA + i] < pos || hint[OMEGA + i] > OMEGA) {
return -1;
}
for (j = pos; j < hint[OMEGA + i]; ++j) {
/* Coefficients are ordered for strong unforgeability */
if (j > pos && hint[j] <= hint[j - 1]) {
return -1;
}
h.coeffs[hint[j]] = 1;
}
pos = hint[OMEGA + i];
PQCLEAN_DILITHIUM2AES_AVX2_poly_caddq(&w1);
PQCLEAN_DILITHIUM2AES_AVX2_poly_use_hint(&w1, &w1, &h);
PQCLEAN_DILITHIUM2AES_AVX2_polyw1_pack(buf.coeffs + i * POLYW1_PACKEDBYTES, &w1);
}
/* Extra indices are zero for strong unforgeability */
for (j = pos; j < OMEGA; ++j) {
if (hint[j]) {
return -1;
}
}
/* Call random oracle and verify PQCLEAN_DILITHIUM2AES_AVX2_challenge */
shake256_inc_init(&state);
shake256_inc_absorb(&state, mu, CRHBYTES);
shake256_inc_absorb(&state, buf.coeffs, K * POLYW1_PACKEDBYTES);
shake256_inc_finalize(&state);
shake256_inc_squeeze(buf.coeffs, SEEDBYTES, &state);
shake256_inc_ctx_release(&state);
for (i = 0; i < SEEDBYTES; ++i) {
if (buf.coeffs[i] != sig[i]) {
return -1;
}
}
return 0;
}
/*************************************************
* Name: PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_open
*
* Description: Verify signed message.
*
* Arguments: - uint8_t *m: pointer to output message (allocated
* array with smlen bytes), can be equal to sm
* - size_t *mlen: pointer to output length of message
* - const uint8_t *sm: pointer to signed message
* - size_t smlen: length of signed message
* - const uint8_t *pk: pointer to bit-packed public key
*
* Returns 0 if signed message could be verified correctly and -1 otherwise
**************************************************/
int PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_open(uint8_t *m, size_t *mlen, const uint8_t *sm, size_t smlen, const uint8_t *pk) {
size_t i;
if (smlen < PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES) {
goto badsig;
}
*mlen = smlen - PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES;
if (PQCLEAN_DILITHIUM2AES_AVX2_crypto_sign_verify(sm, PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES, sm + PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES, *mlen, pk)) {
goto badsig;
} else {
/* All good, copy msg, return 0 */
for (i = 0; i < *mlen; ++i) {
m[i] = sm[PQCLEAN_DILITHIUM2AES_AVX2_CRYPTO_BYTES + i];
}
return 0;
}
badsig:
/* Signature verification failed */
*mlen = -1;
for (i = 0; i < smlen; ++i) {
m[i] = 0;
}
return -1;
}