status_t element_mul_int(element_t c, element_t a, integer_t b)
{
GroupType type = a->type;
// TODO: c (type) = a (type) * b (ZR)
LEAVE_IF(a->isInitialized != TRUE, "invalid argument.");
LEAVE_IF(c->isInitialized != TRUE || c->type != type, "result not initialized or invalid type.");
if(type == ZR) {
bn_mul(c->bn, a->bn, b);
bn_mod(c->bn, c->bn, c->order);
}
else if(type == G1) {
g1_mul(c->g1, a->g1, b);
}
else if(type == G2) {
g2_mul(c->g2, a->g2, b);
}
else if(type == GT) {
gt_exp(c->gt, a->gt, b);
}
else {
return ELEMENT_INVALID_TYPES;
}
return ELEMENT_OK;
}
status_t element_pow_zr(element_t c, element_t a, element_t b)
{
GroupType type = a->type;
// c (type) = a (type) ^ b (ZR)
LEAVE_IF( c->isInitialized != TRUE || a->isInitialized != TRUE, "uninitialized argument.");
EXIT_IF_NOT_SAME(c, a);
LEAVE_IF(a->isInitialized != TRUE, "invalid argument.");
LEAVE_IF(b->isInitialized != TRUE || b->type != ZR, "invalid type.");
if(type == ZR) {
bn_mxp(c->bn, a->bn, b->bn, a->order);
}
else if(type == G1) {
g1_mul(c->g1, a->g1, b->bn);
}
else if(type == G2) {
g2_mul(c->g2, a->g2, b->bn);
}
else if(type == GT) {
gt_exp(c->gt, a->gt, b->bn);
}
else {
return ELEMENT_INVALID_TYPES;
}
return ELEMENT_OK;
}
status_t element_pow_int(element_t c, element_t a, integer_t b)
{
GroupType type = a->type;
// TODO: c (type) = a (type) ^ b (ZR)
LEAVE_IF( c->isInitialized != TRUE || a->isInitialized != TRUE, "uninitialized argument.");
EXIT_IF_NOT_SAME(c, a);
LEAVE_IF(b == NULL, "uninitialized integer.");
status_t result = ELEMENT_OK;
LEAVE_IF( c->type != type, "result initialized but invalid type.");
switch(type) {
case ZR: bn_mxp(c->bn, a->bn, b, a->order);
break;
case G1: g1_mul(c->g1, a->g1, b);
break;
case G2: g2_mul(c->g2, a->g2, b);
break;
case GT: if(bn_is_zero(b)) gt_set_unity(c->gt);
else gt_exp(c->gt, a->gt, b);
break;
default:
result = ELEMENT_INVALID_TYPES;
break;
}
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_bls_sig(g1_t s, uint8_t *msg, int len, bn_t d) {
g1_t p;
int result = STS_OK;
g1_null(p);
TRY {
g1_new(p);
g1_map(p, msg, len);
g1_mul(s, p, d);
}
CATCH_ANY {
result = STS_ERR;
}
FINALLY {
g1_free(p);
}
return result;
}
int cp_bgn_enc1(g1_t out[2], dig_t in, bgn_t pub) {
bn_t r, n;
g1_t t;
int result = STS_OK;
bn_null(n);
bn_null(r);
g1_null(t);
TRY {
bn_new(n);
bn_new(r);
g1_new(t);
g1_get_ord(n);
bn_rand_mod(r, n);
/* Compute c0 = (ym + r)G. */
g1_mul_dig(out[0], pub->gy, in);
g1_mul_gen(t, r);
g1_add(out[0], out[0], t);
g1_norm(out[0], out[0]);
/* Compute c1 = (zm + xr)G. */
g1_mul_dig(out[1], pub->gz, in);
g1_mul(t, pub->gx, r);
g1_add(out[1], out[1], t);
g1_norm(out[1], out[1]);
}
CATCH_ANY {
result = STS_ERR;
}
FINALLY {
bn_free(n);
bn_free(r);
g1_free(t);
}
return result;
}
int cp_psb_sig(g1_t a, g1_t b, uint8_t *msgs[], int lens[], bn_t r, bn_t s[],
int l) {
bn_t m, n, t;
int i, result = RLC_OK;
bn_null(m);
bn_null(n);
bn_null(t);
TRY {
bn_new(m);
bn_new(n);
bn_new(t);
/* Choose random a in G1. */
g1_rand(a);
/* Compute b = a^x+\sum y_im_i. */
g1_get_ord(n);
bn_copy(t, r);
for (i = 0; i < l; i++) {
bn_read_bin(m, msgs[i], lens[i]);
bn_mod(m, m, n);
bn_mul(m, m, s[i]);
bn_mod(m, m, n);
bn_add(t, t, m);
bn_mod(t, t, n);
}
g1_mul(b, a, t);
}
CATCH_ANY {
result = RLC_ERR;
}
FINALLY {
bn_free(m);
bn_free(n);
bn_free(t);
}
return result;
}