static void do_vert(element_ptr z, element_ptr V, element_ptr Q)
{
element_ptr Vx = curve_x_coord(V);
element_ptr Qx = curve_x_coord(Q);
element_ptr Qy = curve_y_coord(Q);
element_t a, b, c;
element_init_same_as(a, Vx);
element_init_same_as(b, Vx);
element_init_same_as(c, Vx);
//a = 1
//b = 0;
//c = -Vx
element_set1(a);
element_set0(b);
element_neg(c, Vx);
element_printf("vert at %B: %B %B %B\n", Vx, a, b, c);
element_mul(a, a, Qx);
element_mul(b, b, Qy);
element_add(c, c, a);
element_add(z, c, b);
element_printf("vert eval = %B\n", z);
element_clear(a);
element_clear(b);
element_clear(c);
}
void miller(element_t res, mpz_t q, element_t P, element_ptr Qx, element_ptr Qy) {
int m;
element_t v;
element_t Z;
element_t a, b, c;
element_t t0;
element_t e0;
const element_ptr cca = curve_a_coeff(P);
const element_ptr Px = curve_x_coord(P);
const element_ptr Py = curve_y_coord(P);
element_ptr Zx, Zy;
void do_tangent(void) {
// a = -(3 Zx^2 + cc->a)
// b = 2 * Zy
// c = -(2 Zy^2 + a Zx);
element_square(a, Zx); mult1++;
element_mul_si(a, a, 3); add1++; add1++; add1++;
element_add(a, a, cca); add1++;
element_neg(a, a);
element_add(b, Zy, Zy); add1++;
element_mul(t0, b, Zy); mult1++;
element_mul(c, a, Zx); mult1++;
element_add(c, c, t0); add1++;
element_neg(c, c);
d_miller_evalfn(e0, a, b, c, Qx, Qy);
element_mul(v, v, e0); multk++;
}
void bb_sign(unsigned char *sig, unsigned int hashlen, unsigned char *hash, bb_public_key_t pk, bb_private_key_t sk)
{
int len;
element_t sigma;
element_t r, z, m;
bb_sys_param_ptr param = pk->param;
pairing_ptr pairing = param->pairing;
element_init(r, pairing->Zr);
element_init(z, pairing->Zr);
element_init(m, pairing->Zr);
element_random(r);
element_from_hash(m, hash, hashlen);
element_mul(z, sk->y, r);
element_add(z, z, sk->x);
element_add(z, z, m);
element_invert(z, z);
element_init(sigma, pairing->G1);
element_pow_zn(sigma, pk->g1, z);
len = element_to_bytes_x_only(sig, sigma);
element_to_bytes(&sig[len], r);
element_clear(sigma);
element_clear(r);
element_clear(z);
element_clear(m);
}
static void curve_from_hash(element_t a, void *data, int len) {
element_t t, t1;
point_ptr p = (point_ptr)a->data;
curve_data_ptr cdp = (curve_data_ptr)a->field->data;
element_init(t, cdp->field);
element_init(t1, cdp->field);
p->inf_flag = 0;
element_from_hash(p->x, data, len);
for(;;) {
element_square(t, p->x);
element_add(t, t, cdp->a);
element_mul(t, t, p->x);
element_add(t, t, cdp->b);
if (element_is_sqr(t)) break;
// Compute x <- x^2 + 1 and try again.
element_square(p->x, p->x);
element_set1(t);
element_add(p->x, p->x, t);
}
element_sqrt(p->y, t);
if (element_sgn(p->y) < 0) element_neg(p->y, p->y);
if (cdp->cofac) element_mul_mpz(a, a, cdp->cofac);
element_clear(t);
element_clear(t1);
}
/* $e<- a*b$ */
static void gf32m_mult(element_t e, element_t a, element_t b) {
element_ptr a0 = GF32M(a)->_0, a1 = GF32M(a)->_1, b0 = GF32M(b)->_0, b1 =
GF32M(b)->_1, e0 = GF32M(e)->_0, e1 = GF32M(e)->_1;
field_ptr base = BASE(a);
element_t a0b0, a1b1, t0, t1, c1;
element_init(a0b0, base);
element_init(a1b1, base);
element_init(t0, base);
element_init(t1, base);
element_init(c1, base);
element_mul(a0b0, a0, b0);
element_mul(a1b1, a1, b1);
element_add(t0, a1, a0);
element_add(t1, b1, b0);
element_mul(c1, t0, t1); // c1 == (a1+a0)*(b1+b0)
element_sub(c1, c1, a1b1);
element_sub(c1, c1, a0b0);
element_ptr c0 = a0b0;
element_sub(c0, c0, a1b1); // c0 == a0*b0 - a1*b1
element_set(e0, c0);
element_set(e1, c1);
element_clear(a0b0);
element_clear(a1b1);
element_clear(t0);
element_clear(t1);
element_clear(c1);
}
void do_line(element_ptr e, element_ptr edenom, element_ptr A, element_ptr B)
{
element_ptr Ax = curve_x_coord(A);
element_ptr Ay = curve_y_coord(A);
element_ptr Bx = curve_x_coord(B);
element_ptr By = curve_y_coord(B);
element_sub(b, Bx, Ax);
element_sub(a, Ay, By);
element_mul(c, Ax, By);
element_mul(e0, Ay, Bx);
element_sub(c, c, e0);
element_mul(e0, a, numx);
element_mul(e1, b, numy);
element_add(e0, e0, e1);
element_add(e0, e0, c);
element_mul(e, e, e0);
element_mul(e0, a, denomx);
element_mul(e1, b, denomy);
element_add(e0, e0, e1);
element_add(e0, e0, c);
element_mul(edenom, edenom, e0);
}
static void fq_add(element_ptr n, element_ptr a, element_ptr b) {
eptr p = a->data;
eptr q = b->data;
eptr r = n->data;
element_add(r->x, p->x, q->x);
element_add(r->y, p->y, q->y);
}
static void fi_mul(element_ptr n, element_ptr a, element_ptr b) {
eptr p = a->data;
eptr q = b->data;
eptr r = n->data;
element_t e0, e1, e2;
element_init(e0, p->x->field);
element_init(e1, e0->field);
element_init(e2, e0->field);
/* Naive method:
element_mul(e0, p->x, q->x);
element_mul(e1, p->y, q->y);
element_sub(e0, e0, e1);
element_mul(e1, p->x, q->y);
element_mul(e2, p->y, q->x);
element_add(e1, e1, e2);
element_set(r->x, e0);
element_set(r->y, e1);
*/
// Karatsuba multiplicaiton:
element_add(e0, p->x, p->y);
element_add(e1, q->x, q->y);
element_mul(e2, e0, e1);
element_mul(e0, p->x, q->x);
element_sub(e2, e2, e0);
element_mul(e1, p->y, q->y);
element_sub(r->x, e0, e1);
element_sub(r->y, e2, e1);
element_clear(e0);
element_clear(e1);
element_clear(e2);
}
static void fi_sqrt(element_ptr n, element_ptr e) {
eptr p = e->data;
eptr r = n->data;
element_t e0, e1, e2;
// If (a+bi)^2 = x+yi then 2a^2 = x +- sqrt(x^2 + y^2)
// where we choose the sign so that a exists, and 2ab = y.
// Thus 2b^2 = - (x -+ sqrt(x^2 + y^2)).
element_init(e0, p->x->field);
element_init(e1, e0->field);
element_init(e2, e0->field);
element_square(e0, p->x);
element_square(e1, p->y);
element_add(e0, e0, e1);
element_sqrt(e0, e0);
// e0 = sqrt(x^2 + y^2)
element_add(e1, p->x, e0);
element_set_si(e2, 2);
element_invert(e2, e2);
element_mul(e1, e1, e2);
// e1 = (x + sqrt(x^2 + y^2))/2
if (!element_is_sqr(e1)) {
element_sub(e1, e1, e0);
// e1 should be a square.
}
element_sqrt(e0, e1);
element_add(e1, e0, e0);
element_invert(e1, e1);
element_mul(r->y, p->y, e1);
element_set(r->x, e0);
element_clear(e0);
element_clear(e1);
element_clear(e2);
}
static void point_add(element_t c, element_t a, element_t b) {
point_ptr p1 = DATA(a), p2 = DATA(b), p3 = DATA(c);
int inf1 = p1->isinf, inf2 = p2->isinf;
element_ptr x1 = p1->x, y1 = p1->y, x2 = p2->x, y2 = p2->y;
field_ptr f = FIELD(x1);
if (inf1) {
point_set(c, b);
return;
}
if (inf2) {
point_set(c, a);
return;
}
element_t v0, v1, v2, v3, v4, ny2;
element_init(v0, f);
element_init(v1, f);
element_init(v2, f);
element_init(v3, f);
element_init(v4, f);
element_init(ny2, f);
if (!element_cmp(x1, x2)) { // x1 == x2
element_neg(ny2, y2); // ny2 == -y2
if (!element_cmp(y1, ny2)) {
p3->isinf = 1;
goto end;
}
if (!element_cmp(y1, y2)) { // y1 == y2
element_invert(v0, y1); // v0 == y1^{-1}
element_mul(v1, v0, v0); // v1 == [y1^{-1}]^2
element_add(p3->x, v1, x1); // v1 == [y1^{-1}]^2 + x1
element_cubic(v2, v0); // v2 == [y1^{-1}]^3
element_add(v2, v2, y1); // v2 == [y1^{-1}]^3 + y1
element_neg(p3->y, v2); // p3 == -([y1^{-1}]^3 + y1)
p3->isinf = 0;
goto end;
}
}
// $P1 \ne \pm P2$
element_sub(v0, x2, x1); // v0 == x2-x1
element_invert(v1, v0); // v1 == (x2-x1)^{-1}
element_sub(v0, y2, y1); // v0 == y2-y1
element_mul(v2, v0, v1); // v2 == (y2-y1)/(x2-x1)
element_mul(v3, v2, v2); // v3 == [(y2-y1)/(x2-x1)]^2
element_cubic(v4, v2); // v4 == [(y2-y1)/(x2-x1)]^3
element_add(v0, x1, x2); // v0 == x1+x2
element_sub(v3, v3, v0); // v3 == [(y2-y1)/(x2-x1)]^2 - (x1+x2)
element_add(v0, y1, y2); // v0 == y1+y2
element_sub(v4, v0, v4); // v4 == (y1+y2) - [(y2-y1)/(x2-x1)]^3
p3->isinf = 0;
element_set(p3->x, v3);
element_set(p3->y, v4);
end:
element_clear(v0);
element_clear(v1);
element_clear(v2);
element_clear(v3);
element_clear(v4);
element_clear(ny2);
}
/* $c <- a+b$ */
static void gf33m_add(element_t c, element_t a, element_t b) {
element_ptr a0 = GF33M(a)->_0, a1 = GF33M(a)->_1, a2 = GF33M(a)->_2, b0 =
GF33M(b)->_0, b1 = GF33M(b)->_1, b2 = GF33M(b)->_2, c0 =
GF33M(c)->_0, c1 = GF33M(c)->_1, c2 = GF33M(c)->_2;
element_add(c0, a0, b0);
element_add(c1, a1, b1);
element_add(c2, a2, b2);
}
/* $e <- a^{-1}$ */
static void gf33m_invert(element_t e, element_t a) {
element_ptr a0 = GF33M(a)->_0, a1 = GF33M(a)->_1, a2 = GF33M(a)->_2, e0 =
GF33M(e)->_0, e1 = GF33M(e)->_1, e2 = GF33M(e)->_2;
field_ptr base = BASE(e);
element_t a02, a12, a22;
element_init(a02, base);
element_init(a12, base);
element_init(a22, base);
element_mul(a02, a0, a0);
element_mul(a12, a1, a1);
element_mul(a22, a2, a2);
element_t v0;
element_init(v0, base);
element_sub(v0, a0, a2); // v0 == a0-a2
element_t delta;
element_init(delta, base);
element_mul(delta, v0, a02); // delta = (a0-a2)*(a0^2), free
element_sub(v0, a1, a0); // v0 == a1-a0
element_t c0;
element_init(c0, base);
element_mul(c0, v0, a12); // c0 == (a1-a0)*(a1^2)
element_add(delta, delta, c0); // delta = (a0-a2)*(a0^2) + (a1-a0)*(a1^2)
element_sub(v0, a2, v0); // v0 == a2-(a1-a0) = a0-a1+a2
element_t c1;
element_init(c1, base);
element_mul(c1, v0, a22); // c1 == (a0-a1+a2)*(a2^2)
element_add(delta, delta, c1); // delta = (a0-a2)*(a0^2) + (a1-a0)*(a1^2) + (a0-a1+a2)*(a2^2)
element_invert(delta, delta); // delta = [(a0-a2)*(a0^2) + (a1-a0)*(a1^2) + (a0-a1+a2)*(a2^2)] ^ {-1}
element_add(v0, a02, a22); // v0 == a0^2+a2^2
element_t c2;
element_init(c2, base);
element_mul(c2, a0, a2); // c2 == a0*a2
element_sub(c0, v0, c2); // c0 == a0^2+a2^2-a0*a2
element_add(v0, a1, a2); // v0 == a1+a2
element_t c3;
element_init(c3, base);
element_mul(c3, a1, v0); // c3 == a1*(a1+a2)
element_sub(c0, c0, c3); // c0 == a0^2+a2^2-a0*a2-a1*(a1+a2)
element_mul(c0, c0, delta); // c0 *= delta
element_mul(c1, a0, a1); // c1 == a0*a1
element_sub(c1, a22, c1); // c1 == a2^2-a0*a1
element_mul(c1, c1, delta); // c1 *= delta
element_sub(c2, a12, c2); // c2 == a1^2-a0*a2
element_sub(c2, c2, a22); // c2 == a1^2-a0*a2-a2^2
element_mul(c2, c2, delta); // c2 *= delta
element_set(e0, c0);
element_set(e1, c1);
element_set(e2, c2);
element_clear(a02);
element_clear(a12);
element_clear(a22);
element_clear(v0);
element_clear(delta);
element_clear(c0);
element_clear(c1);
element_clear(c2);
element_clear(c3);
}
static void do_line(element_ptr z, element_ptr V, element_ptr P, element_ptr Q)
{
element_ptr Vx = curve_x_coord(V);
element_ptr Vy = curve_y_coord(V);
element_ptr Px = curve_x_coord(P);
element_ptr Py = curve_y_coord(P);
element_ptr Qx = curve_x_coord(Q);
element_ptr Qy = curve_y_coord(Q);
element_t a, b, c, e0;
element_init_same_as(a, Vx);
element_init_same_as(b, Vx);
element_init_same_as(c, Vx);
element_init_same_as(e0, Vx);
//a = -(B.y - A.y) / (B.x - A.x);
//b = 1;
//c = -(A.y + a * A.x);
element_sub(a, Py, Vy);
element_sub(b, Vx, Px);
element_div(a, a, b);
element_set1(b);
element_mul(c, a, Vx);
element_add(c, c, Vy);
element_neg(c, c);
/*
//but we could multiply by B.x - A.x to avoid division, so
//a = -(By - Ay)
//b = Bx - Ax
//c = -(Ay b + a Ax);
element_sub(a, Vy, Py);
element_sub(b, Px, Vx);
element_mul(c, Vx, Py);
element_mul(e0, Vy, Px);
element_sub(c, c, e0);
//
//actually no, since fasterweil won't work if we do this
*/
element_printf("line at %B: %B %B %B\n", V, a, b, c);
element_mul(a, a, Qx);
element_mul(b, b, Qy);
element_add(c, c, a);
element_add(z, c, b);
element_printf(" = %B\n", z);
element_clear(a);
element_clear(b);
element_clear(c);
element_clear(e0);
}
void weil(element_t w, element_t g, element_t h)
{
element_t gr;
element_t hs;
element_t r;
element_t s;
element_t z, z0, z1;
element_init(z, Fq2);
element_init(z0, Fq2);
element_init(z1, Fq2);
element_init_same_as(gr, g);
element_init_same_as(hs, h);
element_init_same_as(r, g);
element_init_same_as(s, h);
element_random(r);
element_random(s);
//point_random always takes the same square root
//why not take the other one for once?
element_neg(r, r);
element_set_str(r, "[[40,0],[54,0]]", 0);
element_set_str(s, "[[48,55],[28,51]]", 0);
element_printf("chose R = %B\n", r);
element_printf("chose S = %B\n", s);
element_add(gr, g, r);
element_add(hs, h, s);
element_printf("P+R = %B\n", gr);
element_printf("Q+S = %B\n", hs);
miller(z, gr, r, g, hs);
miller(z0, gr, r, g, s);
element_div(z1, z, z0);
element_printf("num: %B\n", z1);
miller(z, hs, s, h, gr);
miller(z0, hs, s, h, r);
element_div(w, z, z0);
element_printf("denom: %B\n", w);
element_div(w, z1, w);
element_clear(gr);
element_clear(r);
element_clear(hs);
element_clear(s);
element_clear(z);
element_clear(z0);
element_clear(z1);
}
static void test_gf3m_add(void) {
element_random(a);
element_add(b, a, a);
element_add(b, b, b);
element_sub(b, b, a);
element_sub(b, b, a);
element_sub(b, b, a);
EXPECT(!element_cmp(a, b));
element_add(b, params(a)->p, a);
element_sub(b, b, params(a)->p);
EXPECT(!element_cmp(a, b));
}
// Computes a point on the elliptic curve Y^2 = X^3 + a X + b given its
// x-coordinate.
// Requires a solution to exist.
static void point_from_x(point_ptr p, element_t x, element_t a, element_t b) {
element_t t;
element_init(t, x->field);
p->inf_flag = 0;
element_square(t, x);
element_add(t, t, a);
element_mul(t, t, x);
element_add(t, t, b);
element_sqrt(p->y, t);
element_set(p->x, x);
element_clear(t);
}
static void point_random(element_t a) {
point_ptr p = DATA(a);
element_ptr x = p->x, y = p->y;
field_ptr f = x->field;
p->isinf = 0;
element_t t, t2, e1;
element_init(t, f);
element_init(e1, f);
element_set1(e1);
element_init(t2, f);
do {
element_random(x);
if (element_is0(x))
continue;
element_cubic(t, x); // t == x^3
element_sub(t, t, x); // t == x^3 - x
element_add(t, t, e1); // t == x^3 - x + 1
element_sqrt(y, t); // y == sqrt(x^3 - x + 1)
element_mul(t2, y, y); // t2 == x^3 - x + 1
} while (element_cmp(t2, t)); // t2 != t
// make sure order of $a$ is order of $G_1$
pairing_ptr pairing = FIELD(a)->pairing;
pairing_data_ptr dp = pairing->data;
element_pow_mpz(a, a, dp->n2);
element_clear(t);
element_clear(t2);
element_clear(e1);
}
void tate(element_t z, element_t P, element_t Q)
{
mpz_t q1r;
mpz_init(q1r);
mpz_set_ui(q1r, 696);
/*
millertate(z, P, Q);
element_printf("prepow: z = %B\n", z);
element_pow_mpz(z, z, q1r);
*/
{
element_t R, QR;
element_t z0;
element_init_same_as(R, P);
element_init_same_as(QR, P);
element_init_same_as(z0, z);
element_random(R);
element_add(QR, Q, R);
millertate(z, P, QR);
millertate(z0, P, R);
element_div(z, z, z0);
element_pow_mpz(z, z, q1r);
element_clear(R);
element_clear(QR);
}
mpz_clear(q1r);
}
void CipherText::langrange(element_t* ys, int index, int k, int num){
element_t delta;
element_t numerator;
element_t denominator;
element_t temp;
element_init_Zr(delta, *(this->p));
element_init_Zr(numerator, *(this->p));
element_init_Zr(denominator, *(this->p));
element_init_Zr(temp, *(this->p));
element_init_Zr(ys[index], *(this->p));
element_set0(ys[index]);
int i, j;
for(i = 0; i < k; i++){
//compute the langrange coefficent l
element_set1(delta);
for(j = 0; j < k; j++){
if( j != i){
element_set_si(numerator, index - j);
element_set_si(denominator, i - j);
element_div(numerator, numerator, denominator);
element_mul(delta, delta, numerator);
}
}
element_mul(temp, ys[i], delta);
element_add(ys[index], ys[index], temp);
}
}
static int fi_is_sqr(element_ptr e) {
// x + yi is a square <=> x^2 + y^2 is (in the base field).
// Proof: (=>) if x+yi = (a+bi)^2, then a^2 - b^2 = x, 2ab = y,
// thus (a^2 + b^2)^2 = (a^2 - b^2)^2 + (2ab)^2 = x^2 + y^2
// (<=) Suppose A^2 = x^2 + y^2. If there exist a, b satisfying:
// a^2 = (+-A + x)/2, b^2 = (+-A - x)/2
// then (a + bi)^2 = x + yi.
//
// We show that exactly one of (A + x)/2, (-A + x)/2 is a quadratic residue
// (thus a, b do exist). Suppose not. Then the product (x^2 - A^2) / 4 is
// some quadratic residue, a contradiction since this would imply x^2 - A^2 =
// -y^2 is also a quadratic residue, but we know -1 is not a quadratic
// residue. QED.
eptr p = e->data;
element_t e0, e1;
int result;
element_init(e0, p->x->field);
element_init(e1, e0->field);
element_square(e0, p->x);
element_square(e1, p->y);
element_add(e0, e0, e1);
result = element_is_sqr(e0);
element_clear(e0);
element_clear(e1);
return result;
}
static void curve_random_no_cofac_solvefory(element_ptr a) {
//TODO: with 0.5 probability negate y-coord
curve_data_ptr cdp = (curve_data_ptr)a->field->data;
point_ptr p = (point_ptr)a->data;
element_t t;
element_init(t, cdp->field);
p->inf_flag = 0;
do {
element_random(p->x);
element_square(t, p->x);
element_add(t, t, cdp->a);
element_mul(t, t, p->x);
element_add(t, t, cdp->b);
} while (!element_is_sqr(t));
element_sqrt(p->y, t);
element_clear(t);
}
void proj_double(void)
{
const element_ptr x = Zx;
const element_ptr y = Zy;
//e0 = 3x^2 + (cc->a) z^4
element_square(e0, x);
//element_mul_si(e0, e0, 3);
element_double(e1, e0);
element_add(e0, e0, e1);
element_square(e1, z2);
element_mul(e1, e1, cca);
element_add(e0, e0, e1);
//z_out = 2 y z
element_mul(z, y, z);
//element_mul_si(z, z, 2);
element_double(z, z);
element_square(z2, z);
//e1 = 4 x y^2
element_square(e2, y);
element_mul(e1, x, e2);
//element_mul_si(e1, e1, 4);
element_double(e1, e1);
element_double(e1, e1);
//x_out = e0^2 - 2 e1
//element_mul_si(e3, e1, 2);
element_double(e3, e1);
element_square(x, e0);
element_sub(x, x, e3);
//e2 = 8y^4
element_square(e2, e2);
//element_mul_si(e2, e2, 8);
element_double(e2, e2);
element_double(e2, e2);
element_double(e2, e2);
//y_out = e0(e1 - x_out) - e2
element_sub(e1, e1, x);
element_mul(e0, e0, e1);
element_sub(y, e0, e2);
}
static void fi_square(element_ptr n, element_ptr a) {
eptr p = a->data;
eptr r = n->data;
element_t e0, e1;
element_init(e0, p->x->field);
element_init(e1, e0->field);
// Re(n) = x^2 - y^2 = (x+y)(x-y)
element_add(e0, p->x, p->y);
element_sub(e1, p->x, p->y);
element_mul(e0, e0, e1);
// Im(n) = 2xy
element_mul(e1, p->x, p->y);
element_add(e1, e1, e1);
element_set(r->x, e0);
element_set(r->y, e1);
element_clear(e0);
element_clear(e1);
}
// Requires j != 0, 1728.
void field_init_curve_j(field_ptr f, element_ptr j, mpz_t order, mpz_t cofac) {
element_t a, b;
element_init(a, j->field);
element_init(b, j->field);
element_set_si(a, 1728);
element_sub(a, a, j);
element_invert(a, a);
element_mul(a, a, j);
//b = 2 j / (1728 - j)
element_add(b, a, a);
//a = 3 j / (1728 - j)
element_add(a, a, b);
field_init_curve_ab(f, a, b, order, cofac);
element_clear(a);
element_clear(b);
}
static void e_pairing(element_ptr out, element_ptr in1, element_ptr in2,
pairing_t pairing) {
e_pairing_data_ptr p = pairing->data;
element_ptr Q = in2;
element_t QR;
element_init(QR, p->Eq);
element_add(QR, Q, p->R);
e_miller_fn(out, in1, QR, p->R, p);
element_pow_mpz(out, out, pairing->phikonr);
element_clear(QR);
}
static void tate_9(element_ptr out, element_ptr P, element_ptr Q, element_ptr R) {
element_t QR;
element_init(QR, P->field);
element_add(QR, Q, R);
miller(out, P, QR, R, 9);
element_square(out, out);
element_clear(QR);
}
static int curve_is_valid_point(element_ptr e) {
element_t t0, t1;
int result;
curve_data_ptr cdp = (curve_data_ptr)e->field->data;
point_ptr p = (point_ptr)e->data;
if (p->inf_flag) return 1;
element_init(t0, cdp->field);
element_init(t1, cdp->field);
element_square(t0, p->x);
element_add(t0, t0, cdp->a);
element_mul(t0, t0, p->x);
element_add(t0, t0, cdp->b);
element_square(t1, p->y);
result = !element_cmp(t0, t1);
element_clear(t0);
element_clear(t1);
return result;
}
// Define l = aX + bY + c where a, b, c are in Fq.
// Compute e0 = l(Q) specialized for the case when Q has the form
// (Qx, Qy * sqrt(v)) where Qx, Qy are in Fqd and v is the quadratic nonresidue
// used to construct the quadratic field extension Fqk of Fqd.
static inline void d_miller_evalfn(element_t e0,
element_t a, element_t b, element_t c, element_t Qx, element_t Qy) {
element_ptr re_out = element_x(e0);
element_ptr im_out = element_y(e0);
int i;
int d = polymod_field_degree(re_out->field);
for (i = 0; i < d; i++) {
element_mul(element_item(re_out, i), element_item(Qx, i), a);
element_mul(element_item(im_out, i), element_item(Qy, i), b);
}
element_add(element_item(re_out, 0), element_item(re_out, 0), c);
}
static void tate_18(element_ptr out, element_ptr P, element_ptr Q, element_ptr R, element_ptr S) {
mpz_t pow;
element_t PR;
element_t QS;
element_init(PR, P->field);
element_init(QS, P->field);
element_t outd;
element_init(outd, out->field);
mpz_init(pow);
mpz_set_ui(pow, (19*19-1)/18);
element_add(PR, P, R);
element_add(QS, Q, S);
if (element_is0(QS)) {
element_t S2;
element_init(S2, P->field);
element_double(S2, S);
miller(out, PR, S, S2, 18);
miller(outd, R, S, S2, 18);
element_clear(S2);
} else {
miller(out, PR, QS, S, 18);
miller(outd, R, QS, S, 18);
}
element_clear(PR);
element_clear(QS);
element_invert(outd, outd);
element_mul(out, out, outd);
element_pow_mpz(out, out, pow);
element_clear(outd);
mpz_clear(pow);
}
static void test_gf3m_mult(void) {
element_random(a);
element_mul(a, a, e0);
EXPECT(!element_cmp(a, e0));
element_random(a);
element_mul(b, a, e1);
EXPECT(!element_cmp(a, b));
element_random(a);
element_mul(b, a, e2);
element_add(a, a, b);
EXPECT(!element_cmp(a, e0));
}
