void crypto_ops::generate_keys(public_key &pub, secret_key &sec) {
lock_guard<mutex> lock(random_lock);
ge_p3 point;
random_scalar(sec);
ge_scalarmult_base(&point, &sec);
ge_p3_tobytes(&pub, &point);
}
Matrix *random_matrix(int N) {
Matrix *buff = new Matrix(Halide::type_of<T>(), N, N);
Scalar *A = (Scalar*)buff->host_ptr();
for (int i=0; i<N*N; ++i) {
A[i] = random_scalar();
}
return buff;
}
Vector *random_vector(int N) {
Vector *buff = new Vector(Halide::type_of<T>(), N);
Scalar *x = (Scalar*)buff->host_ptr();
for (int i=0; i<N; ++i) {
x[i] = random_scalar();
}
return buff;
}
Matrix *random_matrix(int N) {
Matrix *buff = new Matrix(N * N);
Matrix &A = *buff;
for (int i=0; i<N*N; ++i) {
A[i] = random_scalar();
}
return buff;
}
Vector *random_vector(int N) {
Vector *buff = new Vector(N);
Vector &x = *buff;
for (int i=0; i<N; ++i) {
x[i] = random_scalar();
}
return buff;
}
/*
* generate public and secret keys from a random 256-bit integer
* TODO: allow specifiying random value (for wallet recovery)
*
*/
secret_key crypto_ops::generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key, bool recover) {
boost::lock_guard<boost::mutex> lock(random_lock);
ge_p3 point;
secret_key rng;
if (recover)
{
rng = recovery_key;
}
else
{
random_scalar(rng);
}
sec = rng;
sc_reduce32(&sec); // reduce in case second round of keys (sendkeys)
ge_scalarmult_base(&point, &sec);
ge_p3_tobytes(&pub, &point);
return rng;
}
void crypto_ops::generate_signature(const hash &prefix_hash, const public_key &pub, const secret_key &sec, signature &sig) {
lock_guard<mutex> lock(random_lock);
ge_p3 tmp3;
ec_scalar k;
s_comm buf;
#if !defined(NDEBUG)
{
ge_p3 t;
public_key t2;
assert(sc_check(&sec) == 0);
ge_scalarmult_base(&t, &sec);
ge_p3_tobytes(&t2, &t);
assert(pub == t2);
}
#endif
buf.h = prefix_hash;
buf.key = pub;
random_scalar(k);
ge_scalarmult_base(&tmp3, &k);
ge_p3_tobytes(&buf.comm, &tmp3);
hash_to_scalar(&buf, sizeof(s_comm), sig.c);
sc_mulsub(&sig.r, &sig.c, &sec, &k);
}
void crypto_ops::generate_ring_signature(const hash &prefix_hash, const key_image &image,
const public_key *const *pubs, size_t pubs_count,
const secret_key &sec, size_t sec_index,
signature *sig) {
lock_guard<mutex> lock(random_lock);
size_t i;
ge_p3 image_unp;
ge_dsmp image_pre;
ec_scalar sum, k, h;
rs_comm *const buf = reinterpret_cast<rs_comm *>(alloca(rs_comm_size(pubs_count)));
assert(sec_index < pubs_count);
#if !defined(NDEBUG)
{
ge_p3 t;
public_key t2;
key_image t3;
assert(sc_check(&sec) == 0);
ge_scalarmult_base(&t, &sec);
ge_p3_tobytes(&t2, &t);
assert(*pubs[sec_index] == t2);
generate_key_image(*pubs[sec_index], sec, t3);
assert(image == t3);
for (i = 0; i < pubs_count; i++) {
assert(check_key(*pubs[i]));
}
}
#endif
if (ge_frombytes_vartime(&image_unp, &image) != 0) {
abort();
}
ge_dsm_precomp(image_pre, &image_unp);
sc_0(&sum);
buf->h = prefix_hash;
for (i = 0; i < pubs_count; i++) {
ge_p2 tmp2;
ge_p3 tmp3;
if (i == sec_index) {
random_scalar(k);
ge_scalarmult_base(&tmp3, &k);
ge_p3_tobytes(&buf->ab[i].a, &tmp3);
hash_to_ec(*pubs[i], tmp3);
ge_scalarmult(&tmp2, &k, &tmp3);
ge_tobytes(&buf->ab[i].b, &tmp2);
} else {
random_scalar(sig[i].c);
random_scalar(sig[i].r);
if (ge_frombytes_vartime(&tmp3, &*pubs[i]) != 0) {
abort();
}
ge_double_scalarmult_base_vartime(&tmp2, &sig[i].c, &tmp3, &sig[i].r);
ge_tobytes(&buf->ab[i].a, &tmp2);
hash_to_ec(*pubs[i], tmp3);
ge_double_scalarmult_precomp_vartime(&tmp2, &sig[i].r, &tmp3, &sig[i].c, image_pre);
ge_tobytes(&buf->ab[i].b, &tmp2);
sc_add(&sum, &sum, &sig[i].c);
}
}
hash_to_scalar(buf, rs_comm_size(pubs_count), h);
sc_sub(&sig[sec_index].c, &h, &sum);
sc_mulsub(&sig[sec_index].r, &sig[sec_index].c, &sec, &k);
}
