385 lines
14 KiB
C
385 lines
14 KiB
C
#include <assert.h>
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include "api.h"
|
|
#include "fips202.h"
|
|
#include "gf31.h"
|
|
#include "mq.h"
|
|
#include "params.h"
|
|
#include "randombytes.h"
|
|
|
|
/* Takes an array of len bytes and computes a hash digest.
|
|
This is used as a hash function in the Fiat-Shamir transform. */
|
|
static void H(unsigned char *out, const unsigned char *in, const size_t len) {
|
|
shake256(out, HASH_BYTES, in, len);
|
|
}
|
|
|
|
/* Takes two arrays of N packed elements and an array of M packed elements,
|
|
and computes a HASH_BYTES commitment. */
|
|
static void com_0(unsigned char *c,
|
|
const unsigned char *rho,
|
|
const unsigned char *inn, const unsigned char *inn2,
|
|
const unsigned char *inm) {
|
|
unsigned char buffer[HASH_BYTES + 2 * NPACKED_BYTES + MPACKED_BYTES];
|
|
memcpy(buffer, rho, HASH_BYTES);
|
|
memcpy(buffer + HASH_BYTES, inn, NPACKED_BYTES);
|
|
memcpy(buffer + HASH_BYTES + NPACKED_BYTES, inn2, NPACKED_BYTES);
|
|
memcpy(buffer + HASH_BYTES + 2 * NPACKED_BYTES, inm, MPACKED_BYTES);
|
|
shake256(c, HASH_BYTES, buffer, HASH_BYTES + 2 * NPACKED_BYTES + MPACKED_BYTES);
|
|
}
|
|
|
|
/* Takes an array of N packed elements and an array of M packed elements,
|
|
and computes a HASH_BYTES commitment. */
|
|
static void com_1(unsigned char *c,
|
|
const unsigned char *rho,
|
|
const unsigned char *inn, const unsigned char *inm) {
|
|
unsigned char buffer[HASH_BYTES + NPACKED_BYTES + MPACKED_BYTES];
|
|
memcpy(buffer, rho, HASH_BYTES);
|
|
memcpy(buffer + HASH_BYTES, inn, NPACKED_BYTES);
|
|
memcpy(buffer + HASH_BYTES + NPACKED_BYTES, inm, MPACKED_BYTES);
|
|
shake256(c, HASH_BYTES, buffer, HASH_BYTES + NPACKED_BYTES + MPACKED_BYTES);
|
|
}
|
|
|
|
/*
|
|
* Generates an MQDSS key pair.
|
|
*/
|
|
int PQCLEAN_MQDSS64_CLEAN_crypto_sign_keypair(uint8_t *pk, uint8_t *sk) {
|
|
signed char F[F_LEN];
|
|
unsigned char skbuf[SEED_BYTES * 2];
|
|
gf31 sk_gf31[N];
|
|
gf31 pk_gf31[M];
|
|
|
|
// Expand sk to obtain a seed for F and the secret input s.
|
|
// We also expand to obtain a value for sampling r0, t0 and e0 during
|
|
// signature generation, but that is not relevant here.
|
|
randombytes(sk, SEED_BYTES);
|
|
shake256(skbuf, SEED_BYTES * 2, sk, SEED_BYTES);
|
|
|
|
memcpy(pk, skbuf, SEED_BYTES);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nrand_schar(F, F_LEN, pk, SEED_BYTES);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nrand(sk_gf31, N, skbuf + SEED_BYTES, SEED_BYTES);
|
|
PQCLEAN_MQDSS64_CLEAN_MQ(pk_gf31, sk_gf31, F);
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_unique(pk_gf31, pk_gf31);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(pk + SEED_BYTES, pk_gf31, M);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Returns an array containing a detached signature.
|
|
*/
|
|
int PQCLEAN_MQDSS64_CLEAN_crypto_sign_signature(
|
|
uint8_t *sig, size_t *siglen,
|
|
const uint8_t *m, size_t mlen, const uint8_t *sk) {
|
|
|
|
signed char F[F_LEN];
|
|
unsigned char skbuf[SEED_BYTES * 4];
|
|
gf31 pk_gf31[M];
|
|
unsigned char pk[SEED_BYTES + MPACKED_BYTES];
|
|
// Concatenated for convenient hashing.
|
|
unsigned char D_sigma0_h0_sigma1[HASH_BYTES * 3 + ROUNDS * (NPACKED_BYTES + MPACKED_BYTES)];
|
|
unsigned char *D = D_sigma0_h0_sigma1;
|
|
unsigned char *sigma0 = D_sigma0_h0_sigma1 + HASH_BYTES;
|
|
unsigned char *h0 = D_sigma0_h0_sigma1 + 2 * HASH_BYTES;
|
|
unsigned char *t1packed = D_sigma0_h0_sigma1 + 3 * HASH_BYTES;
|
|
unsigned char *e1packed = D_sigma0_h0_sigma1 + 3 * HASH_BYTES + ROUNDS * NPACKED_BYTES;
|
|
uint64_t shakestate[25] = {0};
|
|
unsigned char shakeblock[SHAKE256_RATE];
|
|
unsigned char h1[((ROUNDS + 7) & ~7) >> 3];
|
|
unsigned char rnd_seed[HASH_BYTES + SEED_BYTES];
|
|
unsigned char rho[2 * ROUNDS * HASH_BYTES];
|
|
unsigned char *rho0 = rho;
|
|
unsigned char *rho1 = rho + ROUNDS * HASH_BYTES;
|
|
gf31 sk_gf31[N];
|
|
gf31 rnd[(2 * N + M) * ROUNDS]; // Concatenated for easy RNG.
|
|
gf31 *r0 = rnd;
|
|
gf31 *t0 = rnd + N * ROUNDS;
|
|
gf31 *e0 = rnd + 2 * N * ROUNDS;
|
|
gf31 r1[N * ROUNDS];
|
|
gf31 t1[N * ROUNDS];
|
|
gf31 e1[M * ROUNDS];
|
|
gf31 gx[M * ROUNDS];
|
|
unsigned char packbuf0[NPACKED_BYTES];
|
|
unsigned char packbuf1[NPACKED_BYTES];
|
|
unsigned char packbuf2[MPACKED_BYTES];
|
|
unsigned char c[HASH_BYTES * ROUNDS * 2];
|
|
gf31 alpha;
|
|
int alpha_count = 0;
|
|
int b;
|
|
int i, j;
|
|
uint64_t s_inc[26];
|
|
|
|
shake256(skbuf, SEED_BYTES * 4, sk, SEED_BYTES);
|
|
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nrand_schar(F, F_LEN, skbuf, SEED_BYTES);
|
|
|
|
shake256_inc_init(s_inc);
|
|
shake256_inc_absorb(s_inc, sk, SEED_BYTES);
|
|
shake256_inc_absorb(s_inc, m, mlen);
|
|
shake256_inc_finalize(s_inc);
|
|
shake256_inc_squeeze(sig, HASH_BYTES, s_inc); // Compute R.
|
|
|
|
memcpy(pk, skbuf, SEED_BYTES);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nrand(sk_gf31, N, skbuf + SEED_BYTES, SEED_BYTES);
|
|
PQCLEAN_MQDSS64_CLEAN_MQ(pk_gf31, sk_gf31, F);
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_unique(pk_gf31, pk_gf31);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(pk + SEED_BYTES, pk_gf31, M);
|
|
|
|
shake256_inc_init(s_inc);
|
|
shake256_inc_absorb(s_inc, pk, PK_BYTES);
|
|
shake256_inc_absorb(s_inc, sig, HASH_BYTES);
|
|
shake256_inc_absorb(s_inc, m, mlen);
|
|
shake256_inc_finalize(s_inc);
|
|
shake256_inc_squeeze(D, HASH_BYTES, s_inc);
|
|
|
|
sig += HASH_BYTES; // Compensate for prefixed R.
|
|
|
|
memcpy(rnd_seed, skbuf + 2 * SEED_BYTES, SEED_BYTES);
|
|
memcpy(rnd_seed + SEED_BYTES, D, HASH_BYTES);
|
|
shake256(rho, 2 * ROUNDS * HASH_BYTES, rnd_seed, SEED_BYTES + HASH_BYTES);
|
|
|
|
memcpy(rnd_seed, skbuf + 3 * SEED_BYTES, SEED_BYTES);
|
|
memcpy(rnd_seed + SEED_BYTES, D, HASH_BYTES);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nrand(rnd, (2 * N + M) * ROUNDS, rnd_seed, SEED_BYTES + HASH_BYTES);
|
|
|
|
for (i = 0; i < ROUNDS; i++) {
|
|
for (j = 0; j < N; j++) {
|
|
r1[j + i * N] = (gf31)(31 + sk_gf31[j] - r0[j + i * N]);
|
|
}
|
|
PQCLEAN_MQDSS64_CLEAN_G(gx + i * M, t0 + i * N, r1 + i * N, F);
|
|
}
|
|
for (i = 0; i < ROUNDS * M; i++) {
|
|
gx[i] = (gf31)(gx[i] + e0[i]);
|
|
}
|
|
for (i = 0; i < ROUNDS; i++) {
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf0, r0 + i * N, N);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf1, t0 + i * N, N);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf2, e0 + i * M, M);
|
|
com_0(c + HASH_BYTES * (2 * i + 0), rho0 + i * HASH_BYTES, packbuf0, packbuf1, packbuf2);
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_shorten_unique(r1 + i * N, r1 + i * N);
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_shorten_unique(gx + i * M, gx + i * M);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf0, r1 + i * N, N);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf1, gx + i * M, M);
|
|
com_1(c + HASH_BYTES * (2 * i + 1), rho1 + i * HASH_BYTES, packbuf0, packbuf1);
|
|
}
|
|
|
|
H(sigma0, c, HASH_BYTES * ROUNDS * 2); // Compute sigma_0.
|
|
shake256_absorb(shakestate, D_sigma0_h0_sigma1, 2 * HASH_BYTES);
|
|
shake256_squeezeblocks(shakeblock, 1, shakestate);
|
|
|
|
memcpy(h0, shakeblock, HASH_BYTES);
|
|
|
|
memcpy(sig, sigma0, HASH_BYTES);
|
|
sig += HASH_BYTES; // Compensate for sigma_0.
|
|
|
|
for (i = 0; i < ROUNDS; i++) {
|
|
do {
|
|
alpha = shakeblock[alpha_count] & 31;
|
|
alpha_count++;
|
|
if (alpha_count == SHAKE256_RATE) {
|
|
alpha_count = 0;
|
|
shake256_squeezeblocks(shakeblock, 1, shakestate);
|
|
}
|
|
} while (alpha == 31);
|
|
for (j = 0; j < N; j++) {
|
|
t1[i * N + j] = (gf31)(alpha * r0[j + i * N] - t0[j + i * N] + 31);
|
|
}
|
|
PQCLEAN_MQDSS64_CLEAN_MQ(e1 + i * M, r0 + i * N, F);
|
|
for (j = 0; j < N; j++) {
|
|
e1[i * N + j] = (gf31)(alpha * e1[j + i * M] - e0[j + i * M] + 31);
|
|
}
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_shorten_unique(t1 + i * N, t1 + i * N);
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_shorten_unique(e1 + i * N, e1 + i * N);
|
|
}
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(t1packed, t1, N * ROUNDS);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(e1packed, e1, M * ROUNDS);
|
|
|
|
memcpy(sig, t1packed, NPACKED_BYTES * ROUNDS);
|
|
sig += NPACKED_BYTES * ROUNDS;
|
|
memcpy(sig, e1packed, MPACKED_BYTES * ROUNDS);
|
|
sig += MPACKED_BYTES * ROUNDS;
|
|
|
|
shake256(h1, ((ROUNDS + 7) & ~7) >> 3, D_sigma0_h0_sigma1, 3 * HASH_BYTES + ROUNDS * (NPACKED_BYTES + MPACKED_BYTES));
|
|
|
|
for (i = 0; i < ROUNDS; i++) {
|
|
b = (h1[(i >> 3)] >> (i & 7)) & 1;
|
|
if (b == 0) {
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(sig, r0 + i * N, N);
|
|
} else if (b == 1) {
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(sig, r1 + i * N, N);
|
|
}
|
|
memcpy(sig + NPACKED_BYTES, c + HASH_BYTES * (2 * i + (1 - b)), HASH_BYTES);
|
|
memcpy(sig + NPACKED_BYTES + HASH_BYTES, rho + (i + b * ROUNDS) * HASH_BYTES, HASH_BYTES);
|
|
sig += NPACKED_BYTES + 2 * HASH_BYTES;
|
|
}
|
|
|
|
*siglen = SIG_LEN;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Verifies a detached signature and message under a given public key.
|
|
*/
|
|
int PQCLEAN_MQDSS64_CLEAN_crypto_sign_verify(
|
|
const uint8_t *sig, size_t siglen,
|
|
const uint8_t *m, size_t mlen, const uint8_t *pk) {
|
|
|
|
gf31 r[N];
|
|
gf31 t[N];
|
|
gf31 e[M];
|
|
signed char F[F_LEN];
|
|
gf31 pk_gf31[M];
|
|
// Concatenated for convenient hashing.
|
|
unsigned char D_sigma0_h0_sigma1[HASH_BYTES * 3 + ROUNDS * (NPACKED_BYTES + MPACKED_BYTES)];
|
|
unsigned char *D = D_sigma0_h0_sigma1;
|
|
unsigned char *sigma0 = D_sigma0_h0_sigma1 + HASH_BYTES;
|
|
unsigned char *h0 = D_sigma0_h0_sigma1 + 2 * HASH_BYTES;
|
|
unsigned char *t1packed = D_sigma0_h0_sigma1 + 3 * HASH_BYTES;
|
|
unsigned char *e1packed = D_sigma0_h0_sigma1 + 3 * HASH_BYTES + ROUNDS * NPACKED_BYTES;
|
|
unsigned char h1[((ROUNDS + 7) & ~7) >> 3];
|
|
unsigned char c[HASH_BYTES * ROUNDS * 2];
|
|
memset(c, 0, HASH_BYTES * 2);
|
|
gf31 x[N];
|
|
gf31 y[M];
|
|
gf31 z[M];
|
|
unsigned char packbuf0[NPACKED_BYTES];
|
|
unsigned char packbuf1[MPACKED_BYTES];
|
|
uint64_t shakestate[25] = {0};
|
|
unsigned char shakeblock[SHAKE256_RATE];
|
|
int i, j;
|
|
gf31 alpha;
|
|
int alpha_count = 0;
|
|
int b;
|
|
uint64_t s_inc[26];
|
|
|
|
if (siglen != SIG_LEN) {
|
|
return -1;
|
|
}
|
|
|
|
shake256_inc_init(s_inc);
|
|
shake256_inc_absorb(s_inc, pk, PK_BYTES);
|
|
shake256_inc_absorb(s_inc, sig, HASH_BYTES);
|
|
shake256_inc_absorb(s_inc, m, mlen);
|
|
shake256_inc_finalize(s_inc);
|
|
shake256_inc_squeeze(D, HASH_BYTES, s_inc);
|
|
|
|
sig += HASH_BYTES;
|
|
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nrand_schar(F, F_LEN, pk, SEED_BYTES);
|
|
pk += SEED_BYTES;
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nunpack(pk_gf31, pk, M);
|
|
|
|
memcpy(sigma0, sig, HASH_BYTES);
|
|
|
|
shake256_absorb(shakestate, D_sigma0_h0_sigma1, 2 * HASH_BYTES);
|
|
shake256_squeezeblocks(shakeblock, 1, shakestate);
|
|
|
|
memcpy(h0, shakeblock, HASH_BYTES);
|
|
|
|
sig += HASH_BYTES;
|
|
|
|
memcpy(t1packed, sig, ROUNDS * NPACKED_BYTES);
|
|
sig += ROUNDS * NPACKED_BYTES;
|
|
memcpy(e1packed, sig, ROUNDS * MPACKED_BYTES);
|
|
sig += ROUNDS * MPACKED_BYTES;
|
|
|
|
shake256(h1, ((ROUNDS + 7) & ~7) >> 3, D_sigma0_h0_sigma1, 3 * HASH_BYTES + ROUNDS * (NPACKED_BYTES + MPACKED_BYTES));
|
|
|
|
for (i = 0; i < ROUNDS; i++) {
|
|
do {
|
|
alpha = shakeblock[alpha_count] & 31;
|
|
alpha_count++;
|
|
if (alpha_count == SHAKE256_RATE) {
|
|
alpha_count = 0;
|
|
shake256_squeezeblocks(shakeblock, 1, shakestate);
|
|
}
|
|
} while (alpha == 31);
|
|
b = (h1[(i >> 3)] >> (i & 7)) & 1;
|
|
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nunpack(r, sig, N);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nunpack(t, t1packed + NPACKED_BYTES * i, N);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_nunpack(e, e1packed + MPACKED_BYTES * i, M);
|
|
|
|
if (b == 0) {
|
|
PQCLEAN_MQDSS64_CLEAN_MQ(y, r, F);
|
|
for (j = 0; j < N; j++) {
|
|
x[j] = (gf31)(alpha * r[j] - t[j] + 31);
|
|
}
|
|
for (j = 0; j < N; j++) {
|
|
y[j] = (gf31)(alpha * y[j] - e[j] + 31);
|
|
}
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_shorten_unique(x, x);
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_shorten_unique(y, y);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf0, x, N);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf1, y, M);
|
|
com_0(c + HASH_BYTES * (2 * i + 0), sig + HASH_BYTES + NPACKED_BYTES, sig, packbuf0, packbuf1);
|
|
} else {
|
|
PQCLEAN_MQDSS64_CLEAN_MQ(y, r, F);
|
|
PQCLEAN_MQDSS64_CLEAN_G(z, t, r, F);
|
|
for (j = 0; j < N; j++) {
|
|
y[j] = (gf31)(alpha * (31 + pk_gf31[j] - y[j]) - z[j] - e[j] + 62);
|
|
}
|
|
PQCLEAN_MQDSS64_CLEAN_vgf31_shorten_unique(y, y);
|
|
PQCLEAN_MQDSS64_CLEAN_gf31_npack(packbuf0, y, M);
|
|
com_1(c + HASH_BYTES * (2 * i + 1), sig + HASH_BYTES + NPACKED_BYTES, sig, packbuf0);
|
|
}
|
|
memcpy(c + HASH_BYTES * (2 * i + (1 - b)), sig + NPACKED_BYTES, HASH_BYTES);
|
|
sig += NPACKED_BYTES + 2 * HASH_BYTES;
|
|
}
|
|
|
|
H(c, c, HASH_BYTES * ROUNDS * 2);
|
|
if (memcmp(c, sigma0, HASH_BYTES) != 0) {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Returns an array containing the signature followed by the message.
|
|
*/
|
|
int PQCLEAN_MQDSS64_CLEAN_crypto_sign(
|
|
uint8_t *sm, size_t *smlen,
|
|
const uint8_t *m, size_t mlen, const uint8_t *sk) {
|
|
size_t siglen;
|
|
|
|
PQCLEAN_MQDSS64_CLEAN_crypto_sign_signature(
|
|
sm, &siglen, m, mlen, sk);
|
|
|
|
memmove(sm + SIG_LEN, m, mlen);
|
|
*smlen = siglen + mlen;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Verifies a given signature-message pair under a given public key.
|
|
*/
|
|
int PQCLEAN_MQDSS64_CLEAN_crypto_sign_open(
|
|
uint8_t *m, size_t *mlen,
|
|
const uint8_t *sm, size_t smlen, const uint8_t *pk) {
|
|
/* The API caller does not necessarily know what size a signature should be
|
|
but MQDSS signatures are always exactly SIG_LEN. */
|
|
if (smlen < SIG_LEN) {
|
|
memset(m, 0, smlen);
|
|
*mlen = 0;
|
|
return -1;
|
|
}
|
|
|
|
*mlen = smlen - SIG_LEN;
|
|
|
|
if (PQCLEAN_MQDSS64_CLEAN_crypto_sign_verify(
|
|
sm, SIG_LEN, sm + SIG_LEN, *mlen, pk)) {
|
|
memset(m, 0, smlen);
|
|
*mlen = 0;
|
|
return -1;
|
|
}
|
|
|
|
/* If verification was successful, move the message to the right place. */
|
|
memmove(m, sm + SIG_LEN, *mlen);
|
|
|
|
return 0;
|
|
}
|