int secp256k1_ecdsa_sign_compact(const unsigned char *message, int messagelen, unsigned char *sig64, const unsigned char *seckey, const unsigned char *nonce, int *recid) {
secp256k1_num_t sec, non, msg;
secp256k1_num_init(&sec);
secp256k1_num_init(&non);
secp256k1_num_init(&msg);
secp256k1_num_set_bin(&sec, seckey, 32);
secp256k1_num_set_bin(&non, nonce, 32);
secp256k1_num_set_bin(&msg, message, messagelen);
int ret = !secp256k1_num_is_zero(&non) &&
(secp256k1_num_cmp(&non, &secp256k1_ge_consts->order) < 0);
secp256k1_ecdsa_sig_t sig;
secp256k1_ecdsa_sig_init(&sig);
if (ret) {
ret = secp256k1_ecdsa_sig_sign(&sig, &sec, &msg, &non, recid);
}
if (ret) {
secp256k1_num_get_bin(sig64, 32, &sig.r);
secp256k1_num_get_bin(sig64 + 32, 32, &sig.s);
}
secp256k1_ecdsa_sig_free(&sig);
secp256k1_num_clear(&msg);
secp256k1_num_clear(&non);
secp256k1_num_clear(&sec);
secp256k1_num_free(&msg);
secp256k1_num_free(&non);
secp256k1_num_free(&sec);
return ret;
}
int secp256k1_ecdsa_privkey_tweak_add(unsigned char *seckey, const unsigned char *tweak) {
DEBUG_CHECK(seckey != NULL);
DEBUG_CHECK(tweak != NULL);
int ret = 1;
secp256k1_num_t term;
secp256k1_num_init(&term);
secp256k1_num_set_bin(&term, tweak, 32);
if (secp256k1_num_cmp(&term, &secp256k1_ge_consts->order) >= 0)
ret = 0;
secp256k1_num_t sec;
secp256k1_num_init(&sec);
if (ret) {
secp256k1_num_set_bin(&sec, seckey, 32);
secp256k1_num_add(&sec, &sec, &term);
secp256k1_num_mod(&sec, &secp256k1_ge_consts->order);
if (secp256k1_num_is_zero(&sec))
ret = 0;
}
if (ret)
secp256k1_num_get_bin(seckey, 32, &sec);
secp256k1_num_clear(&sec);
secp256k1_num_clear(&term);
secp256k1_num_free(&sec);
secp256k1_num_free(&term);
return ret;
}
void run_scalar_tests(void) {
for (int i = 0; i < 128 * count; i++) {
scalar_test();
}
{
/* (-1)+1 should be zero. */
secp256k1_scalar_t s, o;
secp256k1_scalar_set_int(&s, 1);
secp256k1_scalar_negate(&o, &s);
secp256k1_scalar_add(&o, &o, &s);
CHECK(secp256k1_scalar_is_zero(&o));
}
#ifndef USE_NUM_NONE
{
/* A scalar with value of the curve order should be 0. */
secp256k1_num_t order;
secp256k1_scalar_order_get_num(&order);
unsigned char bin[32];
secp256k1_num_get_bin(bin, 32, &order);
secp256k1_scalar_t zero;
int overflow = 0;
secp256k1_scalar_set_b32(&zero, bin, &overflow);
CHECK(overflow == 1);
CHECK(secp256k1_scalar_is_zero(&zero));
}
#endif
}
int secp256k1_ecdsa_privkey_import(unsigned char *seckey, const unsigned char *privkey, int privkeylen) {
secp256k1_num_t key;
secp256k1_num_init(&key);
int ret = secp256k1_ecdsa_privkey_parse(&key, privkey, privkeylen);
if (ret)
secp256k1_num_get_bin(seckey, 32, &key);
secp256k1_num_free(&key);
return ret;
}
void run_num_int(void) {
secp256k1_num_t n1;
for (int i=-255; i<256; i++) {
unsigned char c1[3] = {};
c1[2] = abs(i);
unsigned char c2[3] = {0x11,0x22,0x33};
secp256k1_num_set_int(&n1, i);
secp256k1_num_get_bin(c2, 3, &n1);
CHECK(memcmp(c1, c2, 3) == 0);
}
}
void test_num_get_set_bin(void) {
secp256k1_num_t n1,n2;
random_num_order_test(&n1);
unsigned char c[32];
secp256k1_num_get_bin(c, 32, &n1);
secp256k1_num_set_bin(&n2, c, 32);
CHECK(secp256k1_num_eq(&n1, &n2));
for (int i=0; i<32; i++) {
/* check whether the lower 8 bits correspond to the last byte */
int low1 = secp256k1_num_shift(&n1, 8);
int low2 = c[31];
CHECK(low1 == low2);
/* shift bits off the byte representation, and compare */
memmove(c+1, c, 31);
c[0] = 0;
secp256k1_num_set_bin(&n2, c, 32);
CHECK(secp256k1_num_eq(&n1, &n2));
}
}
int secp256k1_ecdsa_privkey_tweak_mul(unsigned char *seckey, const unsigned char *tweak) {
int ret = 1;
secp256k1_num_t factor;
secp256k1_num_init(&factor);
secp256k1_num_set_bin(&factor, tweak, 32);
if (secp256k1_num_is_zero(&factor))
ret = 0;
if (secp256k1_num_cmp(&factor, &secp256k1_ge_consts->order) >= 0)
ret = 0;
secp256k1_num_t sec;
secp256k1_num_init(&sec);
if (ret) {
secp256k1_num_set_bin(&sec, seckey, 32);
secp256k1_num_mod_mul(&sec, &sec, &factor, &secp256k1_ge_consts->order);
}
if (ret)
secp256k1_num_get_bin(seckey, 32, &sec);
secp256k1_num_free(&sec);
secp256k1_num_free(&factor);
return ret;
}
void test_num_get_set_bin() {
secp256k1_num_t n1,n2;
secp256k1_num_init(&n1);
secp256k1_num_init(&n2);
random_num_order_test(&n1);
unsigned char c[32];
secp256k1_num_get_bin(c, 32, &n1);
secp256k1_num_set_bin(&n2, c, 32);
assert(secp256k1_num_cmp(&n1, &n2) == 0);
for (int i=0; i<32; i++) {
// check whether the lower 8 bits correspond to the last byte
int low1 = secp256k1_num_shift(&n1, 8);
int low2 = c[31];
assert(low1 == low2);
// shift bits off the byte representation, and compare
memmove(c+1, c, 31);
c[0] = 0;
secp256k1_num_set_bin(&n2, c, 32);
assert(secp256k1_num_cmp(&n1, &n2) == 0);
}
secp256k1_num_free(&n2);
secp256k1_num_free(&n1);
}
void test_ecdsa_end_to_end(void) {
unsigned char privkey[32];
unsigned char message[32];
/* Generate a random key and message. */
{
secp256k1_num_t msg, key;
random_num_order_test(&msg);
random_num_order_test(&key);
secp256k1_num_get_bin(privkey, 32, &key);
secp256k1_num_get_bin(message, 32, &msg);
}
/* Construct and verify corresponding public key. */
CHECK(secp256k1_ec_seckey_verify(privkey) == 1);
unsigned char pubkey[65]; int pubkeylen = 65;
CHECK(secp256k1_ec_pubkey_create(pubkey, &pubkeylen, privkey, secp256k1_rand32() % 2) == 1);
CHECK(secp256k1_ec_pubkey_verify(pubkey, pubkeylen));
/* Verify private key import and export. */
unsigned char seckey[300]; int seckeylen = 300;
CHECK(secp256k1_ec_privkey_export(privkey, seckey, &seckeylen, secp256k1_rand32() % 2) == 1);
unsigned char privkey2[32];
CHECK(secp256k1_ec_privkey_import(privkey2, seckey, seckeylen) == 1);
CHECK(memcmp(privkey, privkey2, 32) == 0);
/* Optionally tweak the keys using addition. */
if (secp256k1_rand32() % 3 == 0) {
unsigned char rnd[32];
secp256k1_rand256_test(rnd);
int ret1 = secp256k1_ec_privkey_tweak_add(privkey, rnd);
int ret2 = secp256k1_ec_pubkey_tweak_add(pubkey, pubkeylen, rnd);
CHECK(ret1 == ret2);
if (ret1 == 0) return;
unsigned char pubkey2[65]; int pubkeylen2 = 65;
CHECK(secp256k1_ec_pubkey_create(pubkey2, &pubkeylen2, privkey, pubkeylen == 33) == 1);
CHECK(memcmp(pubkey, pubkey2, pubkeylen) == 0);
}
/* Optionally tweak the keys using multiplication. */
if (secp256k1_rand32() % 3 == 0) {
unsigned char rnd[32];
secp256k1_rand256_test(rnd);
int ret1 = secp256k1_ec_privkey_tweak_mul(privkey, rnd);
int ret2 = secp256k1_ec_pubkey_tweak_mul(pubkey, pubkeylen, rnd);
CHECK(ret1 == ret2);
if (ret1 == 0) return;
unsigned char pubkey2[65]; int pubkeylen2 = 65;
CHECK(secp256k1_ec_pubkey_create(pubkey2, &pubkeylen2, privkey, pubkeylen == 33) == 1);
CHECK(memcmp(pubkey, pubkey2, pubkeylen) == 0);
}
/* Sign. */
unsigned char signature[72]; int signaturelen = 72;
while(1) {
unsigned char rnd[32];
secp256k1_rand256_test(rnd);
if (secp256k1_ecdsa_sign(message, 32, signature, &signaturelen, privkey, rnd) == 1) {
break;
}
}
/* Verify. */
CHECK(secp256k1_ecdsa_verify(message, 32, signature, signaturelen, pubkey, pubkeylen) == 1);
/* Destroy signature and verify again. */
signature[signaturelen - 1 - secp256k1_rand32() % 20] += 1 + (secp256k1_rand32() % 255);
CHECK(secp256k1_ecdsa_verify(message, 32, signature, signaturelen, pubkey, pubkeylen) != 1);
/* Compact sign. */
unsigned char csignature[64]; int recid = 0;
while(1) {
unsigned char rnd[32];
secp256k1_rand256_test(rnd);
if (secp256k1_ecdsa_sign_compact(message, 32, csignature, privkey, rnd, &recid) == 1) {
break;
}
}
/* Recover. */
unsigned char recpubkey[65]; int recpubkeylen = 0;
CHECK(secp256k1_ecdsa_recover_compact(message, 32, csignature, recpubkey, &recpubkeylen, pubkeylen == 33, recid) == 1);
CHECK(recpubkeylen == pubkeylen);
CHECK(memcmp(pubkey, recpubkey, pubkeylen) == 0);
/* Destroy signature and verify again. */
csignature[secp256k1_rand32() % 64] += 1 + (secp256k1_rand32() % 255);
CHECK(secp256k1_ecdsa_recover_compact(message, 32, csignature, recpubkey, &recpubkeylen, pubkeylen == 33, recid) != 1 ||
memcmp(pubkey, recpubkey, pubkeylen) != 0);
CHECK(recpubkeylen == pubkeylen);
}
void scalar_test(void) {
unsigned char c[32];
/* Set 's' to a random scalar, with value 'snum'. */
secp256k1_rand256_test(c);
secp256k1_scalar_t s;
secp256k1_scalar_set_b32(&s, c, NULL);
secp256k1_num_t snum;
secp256k1_num_set_bin(&snum, c, 32);
secp256k1_num_mod(&snum, &secp256k1_ge_consts->order);
/* Set 's1' to a random scalar, with value 's1num'. */
secp256k1_rand256_test(c);
secp256k1_scalar_t s1;
secp256k1_scalar_set_b32(&s1, c, NULL);
secp256k1_num_t s1num;
secp256k1_num_set_bin(&s1num, c, 32);
secp256k1_num_mod(&s1num, &secp256k1_ge_consts->order);
/* Set 's2' to a random scalar, with value 'snum2', and byte array representation 'c'. */
secp256k1_rand256_test(c);
secp256k1_scalar_t s2;
int overflow = 0;
secp256k1_scalar_set_b32(&s2, c, &overflow);
secp256k1_num_t s2num;
secp256k1_num_set_bin(&s2num, c, 32);
secp256k1_num_mod(&s2num, &secp256k1_ge_consts->order);
{
/* Test that fetching groups of 4 bits from a scalar and recursing n(i)=16*n(i-1)+p(i) reconstructs it. */
secp256k1_num_t n, t, m;
secp256k1_num_set_int(&n, 0);
secp256k1_num_set_int(&m, 16);
for (int i = 0; i < 256; i += 4) {
secp256k1_num_set_int(&t, secp256k1_scalar_get_bits(&s, 256 - 4 - i, 4));
secp256k1_num_mul(&n, &n, &m);
secp256k1_num_add(&n, &n, &t);
}
CHECK(secp256k1_num_eq(&n, &snum));
}
{
/* Test that get_b32 returns the same as get_bin on the number. */
unsigned char r1[32];
secp256k1_scalar_get_b32(r1, &s2);
unsigned char r2[32];
secp256k1_num_get_bin(r2, 32, &s2num);
CHECK(memcmp(r1, r2, 32) == 0);
/* If no overflow occurred when assigning, it should also be equal to the original byte array. */
CHECK((memcmp(r1, c, 32) == 0) == (overflow == 0));
}
{
/* Test that adding the scalars together is equal to adding their numbers together modulo the order. */
secp256k1_num_t rnum;
secp256k1_num_add(&rnum, &snum, &s2num);
secp256k1_num_mod(&rnum, &secp256k1_ge_consts->order);
secp256k1_scalar_t r;
secp256k1_scalar_add(&r, &s, &s2);
secp256k1_num_t r2num;
secp256k1_scalar_get_num(&r2num, &r);
CHECK(secp256k1_num_eq(&rnum, &r2num));
}
{
/* Test that multipying the scalars is equal to multiplying their numbers modulo the order. */
secp256k1_num_t rnum;
secp256k1_num_mul(&rnum, &snum, &s2num);
secp256k1_num_mod(&rnum, &secp256k1_ge_consts->order);
secp256k1_scalar_t r;
secp256k1_scalar_mul(&r, &s, &s2);
secp256k1_num_t r2num;
secp256k1_scalar_get_num(&r2num, &r);
CHECK(secp256k1_num_eq(&rnum, &r2num));
/* The result can only be zero if at least one of the factors was zero. */
CHECK(secp256k1_scalar_is_zero(&r) == (secp256k1_scalar_is_zero(&s) || secp256k1_scalar_is_zero(&s2)));
/* The results can only be equal to one of the factors if that factor was zero, or the other factor was one. */
CHECK(secp256k1_num_eq(&rnum, &snum) == (secp256k1_scalar_is_zero(&s) || secp256k1_scalar_is_one(&s2)));
CHECK(secp256k1_num_eq(&rnum, &s2num) == (secp256k1_scalar_is_zero(&s2) || secp256k1_scalar_is_one(&s)));
}
{
/* Check that comparison with zero matches comparison with zero on the number. */
CHECK(secp256k1_num_is_zero(&snum) == secp256k1_scalar_is_zero(&s));
/* Check that comparison with the half order is equal to testing for high scalar. */
CHECK(secp256k1_scalar_is_high(&s) == (secp256k1_num_cmp(&snum, &secp256k1_ge_consts->half_order) > 0));
secp256k1_scalar_t neg;
secp256k1_scalar_negate(&neg, &s);
secp256k1_num_t negnum;
secp256k1_num_sub(&negnum, &secp256k1_ge_consts->order, &snum);
secp256k1_num_mod(&negnum, &secp256k1_ge_consts->order);
/* Check that comparison with the half order is equal to testing for high scalar after negation. */
CHECK(secp256k1_scalar_is_high(&neg) == (secp256k1_num_cmp(&negnum, &secp256k1_ge_consts->half_order) > 0));
/* Negating should change the high property, unless the value was already zero. */
CHECK((secp256k1_scalar_is_high(&s) == secp256k1_scalar_is_high(&neg)) == secp256k1_scalar_is_zero(&s));
secp256k1_num_t negnum2;
secp256k1_scalar_get_num(&negnum2, &neg);
/* Negating a scalar should be equal to (order - n) mod order on the number. */
CHECK(secp256k1_num_eq(&negnum, &negnum2));
secp256k1_scalar_add(&neg, &neg, &s);
/* Adding a number to its negation should result in zero. */
CHECK(secp256k1_scalar_is_zero(&neg));
secp256k1_scalar_negate(&neg, &neg);
/* Negating zero should still result in zero. */
CHECK(secp256k1_scalar_is_zero(&neg));
}
{
/* Test that scalar inverses are equal to the inverse of their number modulo the order. */
if (!secp256k1_scalar_is_zero(&s)) {
secp256k1_scalar_t inv;
secp256k1_scalar_inverse(&inv, &s);
secp256k1_num_t invnum;
secp256k1_num_mod_inverse(&invnum, &snum, &secp256k1_ge_consts->order);
secp256k1_num_t invnum2;
secp256k1_scalar_get_num(&invnum2, &inv);
CHECK(secp256k1_num_eq(&invnum, &invnum2));
secp256k1_scalar_mul(&inv, &inv, &s);
/* Multiplying a scalar with its inverse must result in one. */
CHECK(secp256k1_scalar_is_one(&inv));
secp256k1_scalar_inverse(&inv, &inv);
/* Inverting one must result in one. */
CHECK(secp256k1_scalar_is_one(&inv));
}
}
{
/* Test commutativity of add. */
secp256k1_scalar_t r1, r2;
secp256k1_scalar_add(&r1, &s1, &s2);
secp256k1_scalar_add(&r2, &s2, &s1);
CHECK(secp256k1_scalar_eq(&r1, &r2));
}
{
/* Test commutativity of mul. */
secp256k1_scalar_t r1, r2;
secp256k1_scalar_mul(&r1, &s1, &s2);
secp256k1_scalar_mul(&r2, &s2, &s1);
CHECK(secp256k1_scalar_eq(&r1, &r2));
}
{
/* Test associativity of add. */
secp256k1_scalar_t r1, r2;
secp256k1_scalar_add(&r1, &s1, &s2);
secp256k1_scalar_add(&r1, &r1, &s);
secp256k1_scalar_add(&r2, &s2, &s);
secp256k1_scalar_add(&r2, &s1, &r2);
CHECK(secp256k1_scalar_eq(&r1, &r2));
}
{
/* Test associativity of mul. */
secp256k1_scalar_t r1, r2;
secp256k1_scalar_mul(&r1, &s1, &s2);
secp256k1_scalar_mul(&r1, &r1, &s);
secp256k1_scalar_mul(&r2, &s2, &s);
secp256k1_scalar_mul(&r2, &s1, &r2);
CHECK(secp256k1_scalar_eq(&r1, &r2));
}
{
/* Test distributitivity of mul over add. */
secp256k1_scalar_t r1, r2, t;
secp256k1_scalar_add(&r1, &s1, &s2);
secp256k1_scalar_mul(&r1, &r1, &s);
secp256k1_scalar_mul(&r2, &s1, &s);
secp256k1_scalar_mul(&t, &s2, &s);
secp256k1_scalar_add(&r2, &r2, &t);
CHECK(secp256k1_scalar_eq(&r1, &r2));
}
{
/* Test square. */
secp256k1_scalar_t r1, r2;
secp256k1_scalar_sqr(&r1, &s1);
secp256k1_scalar_mul(&r2, &s1, &s1);
CHECK(secp256k1_scalar_eq(&r1, &r2));
}
}