crypto/ec/ec2_mult.c

84 static int gf2m_Mdouble(const EC_GROUP *group, BIGNUM *x, BIGNUM *z, BN_CTX *ctx)
94 	if (!group->meth->field_sqr(group, x, x, ctx)) goto err;
95 	if (!group->meth->field_sqr(group, t1, z, ctx)) goto err;
96 	if (!group->meth->field_mul(group, z, x, t1, ctx)) goto err;
97 	if (!group->meth->field_sqr(group, x, x, ctx)) goto err;
98 	if (!group->meth->field_sqr(group, t1, t1, ctx)) goto err;
99 	if (!group->meth->field_mul(group, t1, &group->b, t1, ctx)) goto err;
115 static int gf2m_Madd(const EC_GROUP *group, const BIGNUM *x, BIGNUM *x1, BIGNUM *z1,
128 	if (!group->meth->field_mul(group, x1, x1, z2, ctx)) goto err;
129 	if (!group->meth->field_mul(group, z1, z1, x2, ctx)) goto err;
130 	if (!group->meth->field_mul(group, t2, x1, z1, ctx)) goto err;
132 	if (!group->meth->field_sqr(group, z1, z1, ctx)) goto err;
133 	if (!group->meth->field_mul(group, x1, z1, t1, ctx)) goto err;
152 static int gf2m_Mxy(const EC_GROUP *group, const BIGNUM *x, const BIGNUM *y, BIGNUM *x1,
181 	if (!group->meth->field_mul(group, t3, z1, z2, ctx)) goto err;
183 	if (!group->meth->field_mul(group, z1, z1, x, ctx)) goto err;
185 	if (!group->meth->field_mul(group, z2, z2, x, ctx)) goto err;
186 	if (!group->meth->field_mul(group, x1, z2, x1, ctx)) goto err;
189 	if (!group->meth->field_mul(group, z2, z2, z1, ctx)) goto err;
190 	if (!group->meth->field_sqr(group, t4, x, ctx)) goto err;
192 	if (!group->meth->field_mul(group, t4, t4, t3, ctx)) goto err;
195 	if (!group->meth->field_mul(group, t3, t3, x, ctx)) goto err;
196 	if (!group->meth->field_div(group, t3, t5, t3, ctx)) goto err;
197 	if (!group->meth->field_mul(group, t4, t3, t4, ctx)) goto err;
198 	if (!group->meth->field_mul(group, x2, x1, t3, ctx)) goto err;
201 	if (!group->meth->field_mul(group, z2, z2, t4, ctx)) goto err;
221 static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
236 		EC_POINT_is_at_infinity(group, point))
238 		return EC_POINT_set_to_infinity(group, r);
253 	bn_wexpand(x1, group->field.top);
254 	bn_wexpand(z1, group->field.top);
255 	bn_wexpand(x2, group->field.top);
256 	bn_wexpand(z2, group->field.top);
258 	if (!BN_GF2m_mod_arr(x1, &point->X, group->poly)) goto err; /* x1 = x */
260 	if (!group->meth->field_sqr(group, z2, x1, ctx)) goto err; /* z2 = x1^2 = x^2 */
261 	if (!group->meth->field_sqr(group, x2, z2, ctx)) goto err;
262 	if (!BN_GF2m_add(x2, x2, &group->b)) goto err; /* x2 = x^4 + b */
282 			BN_consttime_swap(word & mask, x1, x2, group->field.top);
283 			BN_consttime_swap(word & mask, z1, z2, group->field.top);
284 			if (!gf2m_Madd(group, &point->X, x2, z2, x1, z1, ctx)) goto err;
285 			if (!gf2m_Mdouble(group, x1, z1, ctx)) goto err;
286 			BN_consttime_swap(word & mask, x1, x2, group->field.top);
287 			BN_consttime_swap(word & mask, z1, z2, group->field.top);
294 	i = gf2m_Mxy(group, &point->X, &point->Y, x1, z1, x2, z2, ctx);
298 		if (!EC_POINT_set_to_infinity(group, r)) goto err;
319  *     scalar*group->generator + scalars[0]*points[0] + ... + scalars[num-1]*points[num-1]
322 int ec_GF2m_simple_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
342 	if ((scalar && (num > 1)) || (num > 2) || (num == 0 && EC_GROUP_have_precompute_mult(group)))
344 		ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
348 	if ((p = EC_POINT_new(group)) == NULL) goto err;
349 	if ((acc = EC_POINT_new(group)) == NULL) goto err;
351 	if (!EC_POINT_set_to_infinity(group, acc)) goto err;
355 		if (!ec_GF2m_montgomery_point_multiply(group, p, scalar, group->generator, ctx)) goto err;
357 			if (!group->meth->invert(group, p, ctx)) goto err;
358 		if (!group->meth->add(group, acc, acc, p, ctx)) goto err;
363 		if (!ec_GF2m_montgomery_point_multiply(group, p, scalars[i], points[i], ctx)) goto err;
365 			if (!group->meth->invert(group, p, ctx)) goto err;
366 		if (!group->meth->add(group, acc, acc, p, ctx)) goto err;
385 int ec_GF2m_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
387 	return ec_wNAF_precompute_mult(group, ctx);
390 int ec_GF2m_have_precompute_mult(const EC_GROUP *group)
392 	return ec_wNAF_have_precompute_mult(group);