int cp_pss_ver(g1_t a, g1_t b, uint8_t *msg, int len, g2_t g, g2_t x, g2_t y) {
g1_t p[2];
g2_t r[2];
gt_t e;
bn_t m, n;
int result = 1;
g1_null(p[0]);
g1_null(p[1]);
g2_null(r[0]);
g2_null(r[1]);
gt_null(e);
bn_null(m);
bn_null(n);
TRY {
g1_new(p[0]);
g1_new(p[1]);
g2_new(r[0]);
g2_new(r[1]);
gt_new(e);
bn_new(m);
bn_new(n);
if (g1_is_infty(a)) {
result = 0;
}
g1_copy(p[0], a);
g1_copy(p[1], b);
g2_copy(r[1], g);
g2_neg(r[1], r[1]);
g1_get_ord(n);
bn_read_bin(m, msg, len);
bn_mod(m, m, n);
g2_mul(r[0], y, m);
g2_add(r[0], r[0], x);
g2_norm(r[0], r[0]);
pc_map_sim(e, p, r, 2);
if (!gt_is_unity(e)) {
result = 0;
}
}
CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
g1_free(p[0]);
g1_free(p[1]);
g2_free(r[0]);
g2_free(r[1]);
gt_free(e);
bn_free(m);
bn_free(n);
}
return result;
}
int cp_bgn_dec1(dig_t *out, g1_t in[2], bgn_t prv) {
bn_t r, n;
g1_t s, t, u;
int i, result = STS_ERR;
bn_null(n);
bn_null(r);
g1_null(s);
g1_null(t);
g1_null(u);
TRY {
bn_new(n);
bn_new(r);
g1_new(s);
g1_new(t);
g1_new(u);
g1_get_ord(n);
/* Compute T = x(ym + r)G - (zm + xr)G = m(xy - z)G. */
g1_mul(t, in[0], prv->x);
g1_sub(t, t, in[1]);
g1_norm(t, t);
/* Compute U = (xy - z)G and find m. */
bn_mul(r, prv->x, prv->y);
bn_sub(r, r, prv->z);
bn_mod(r, r, n);
g1_mul_gen(s, r);
g1_copy(u, s);
if (g1_is_infty(t) == 1){
*out = 0;
result = STS_OK;
} else {
for (i = 0; i < INT_MAX; i++) {
if (g1_cmp(t, u) == CMP_EQ) {
*out = i + 1;
result = STS_OK;
break;
}
g1_add(u, u, s);
g1_norm(u, u);
}
}
} CATCH_ANY {
result = STS_ERR;
}
FINALLY {
bn_free(n);
bn_free(r);
g1_free(s);
g1_free(t);
g1_free(u);
}
return result;
}
int element_is_member(element_t e)
{
LEAVE_IF(e->isInitialized != TRUE, "uninitialized argument.");
int result;
if(e->type == ZR) {
if(bn_cmp(e->bn, e->order) <= CMP_EQ)
result = TRUE;
else
result = FALSE;
}
else if(e->type == G1) {
g1_t r;
g1_inits(r);
g1_mul(r, e->g1, e->order);
if(g1_is_infty(r) == 1)
result = TRUE;
else
result = FALSE;
g1_free(r);
}
else if(e->type == G2) {
g2_t r;
g2_inits(r);
g2_mul(r, e->g2, e->order);
if(g2_is_infty(r) == 1)
result = TRUE;
else
result = FALSE;
g2_free(r);
}
else if(e->type == GT) {
gt_t r;
gt_inits(r);
gt_exp(r, e->gt, e->order);
if(gt_is_unity(r) == 1)
result = TRUE;
else
result = FALSE;
gt_free(r);
}
else {
result = ELEMENT_INVALID_ARG;
}
return result;
}
int cp_psb_ver(g1_t a, g1_t b, uint8_t *msgs[], int lens[], g2_t g, g2_t x,
g2_t y[], int l) {
g1_t p[2];
g2_t q[2];
gt_t e;
bn_t m, n;
int i, result = 1;
g1_null(p[0]);
g1_null(p[1]);
g2_null(q[0]);
g2_null(q[1]);
gt_null(e);
bn_null(m);
bn_null(n);
TRY {
g1_new(p[0]);
g1_new(p[1]);
g2_new(q[0]);
g2_new(q[1]);
gt_new(e);
bn_new(m);
bn_new(n);
if (g1_is_infty(a)) {
result = 0;
}
/* Check that e(a, x \prod y_i^m_i) = e(b, g). */
g1_copy(p[0], a);
g1_copy(p[1], b);
g2_copy(q[0], x);
g1_get_ord(n);
for (i = 0; i < l; i++) {
bn_read_bin(m, msgs[i], lens[i]);
bn_mod(m, m, n);
g2_mul(q[1], y[i], m);
g2_add(q[0], q[0], q[1]);
}
g2_norm(q[0], q[0]);
g2_copy(q[1], g);
g2_neg(q[1], q[1]);
pc_map_sim(e, p, q, 2);
if (!gt_is_unity(e)) {
result = 0;
}
}
CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
g1_free(p[0]);
g1_free(p[1]);
g2_free(q[0]);
g2_free(q[1]);
gt_free(e);
bn_free(m);
bn_free(n);
}
return result;
}
