aboutsummaryrefslogtreecommitdiff
path: root/openssl-1.1.0h/crypto/ec/ec2_mult.c
diff options
context:
space:
mode:
authorWojtek Kosior <wk@koszkonutek-tmp.pl.eu.org>2021-04-30 00:33:56 +0200
committerWojtek Kosior <wk@koszkonutek-tmp.pl.eu.org>2021-04-30 00:33:56 +0200
commitaa4d426b4d3527d7e166df1a05058c9a4a0f6683 (patch)
tree4ff17ce8b89a2321b9d0ed4bcfc37c447bcb6820 /openssl-1.1.0h/crypto/ec/ec2_mult.c
downloadsmtps-and-pop3s-console-program-master.tar.gz
smtps-and-pop3s-console-program-master.zip
initial/final commitHEADmaster
Diffstat (limited to 'openssl-1.1.0h/crypto/ec/ec2_mult.c')
-rw-r--r--openssl-1.1.0h/crypto/ec/ec2_mult.c418
1 files changed, 418 insertions, 0 deletions
diff --git a/openssl-1.1.0h/crypto/ec/ec2_mult.c b/openssl-1.1.0h/crypto/ec/ec2_mult.c
new file mode 100644
index 0000000..e4a1ec5
--- /dev/null
+++ b/openssl-1.1.0h/crypto/ec/ec2_mult.c
@@ -0,0 +1,418 @@
+/*
+ * Copyright 2002-2016 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/* ====================================================================
+ * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
+ *
+ * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
+ * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
+ * to the OpenSSL project.
+ *
+ * The ECC Code is licensed pursuant to the OpenSSL open source
+ * license provided below.
+ *
+ * The software is originally written by Sheueling Chang Shantz and
+ * Douglas Stebila of Sun Microsystems Laboratories.
+ *
+ */
+
+#include <openssl/err.h>
+
+#include "internal/bn_int.h"
+#include "ec_lcl.h"
+
+#ifndef OPENSSL_NO_EC2M
+
+/*-
+ * Compute the x-coordinate x/z for the point 2*(x/z) in Montgomery projective
+ * coordinates.
+ * Uses algorithm Mdouble in appendix of
+ * Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ * modified to not require precomputation of c=b^{2^{m-1}}.
+ */
+static int gf2m_Mdouble(const EC_GROUP *group, BIGNUM *x, BIGNUM *z,
+ BN_CTX *ctx)
+{
+ BIGNUM *t1;
+ int ret = 0;
+
+ /* Since Mdouble is static we can guarantee that ctx != NULL. */
+ BN_CTX_start(ctx);
+ t1 = BN_CTX_get(ctx);
+ if (t1 == NULL)
+ goto err;
+
+ if (!group->meth->field_sqr(group, x, x, ctx))
+ goto err;
+ if (!group->meth->field_sqr(group, t1, z, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, z, x, t1, ctx))
+ goto err;
+ if (!group->meth->field_sqr(group, x, x, ctx))
+ goto err;
+ if (!group->meth->field_sqr(group, t1, t1, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, t1, group->b, t1, ctx))
+ goto err;
+ if (!BN_GF2m_add(x, x, t1))
+ goto err;
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+/*-
+ * Compute the x-coordinate x1/z1 for the point (x1/z1)+(x2/x2) in Montgomery
+ * projective coordinates.
+ * Uses algorithm Madd in appendix of
+ * Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ */
+static int gf2m_Madd(const EC_GROUP *group, const BIGNUM *x, BIGNUM *x1,
+ BIGNUM *z1, const BIGNUM *x2, const BIGNUM *z2,
+ BN_CTX *ctx)
+{
+ BIGNUM *t1, *t2;
+ int ret = 0;
+
+ /* Since Madd is static we can guarantee that ctx != NULL. */
+ BN_CTX_start(ctx);
+ t1 = BN_CTX_get(ctx);
+ t2 = BN_CTX_get(ctx);
+ if (t2 == NULL)
+ goto err;
+
+ if (!BN_copy(t1, x))
+ goto err;
+ if (!group->meth->field_mul(group, x1, x1, z2, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, z1, z1, x2, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, t2, x1, z1, ctx))
+ goto err;
+ if (!BN_GF2m_add(z1, z1, x1))
+ goto err;
+ if (!group->meth->field_sqr(group, z1, z1, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, x1, z1, t1, ctx))
+ goto err;
+ if (!BN_GF2m_add(x1, x1, t2))
+ goto err;
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+/*-
+ * Compute the x, y affine coordinates from the point (x1, z1) (x2, z2)
+ * using Montgomery point multiplication algorithm Mxy() in appendix of
+ * Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ * Returns:
+ * 0 on error
+ * 1 if return value should be the point at infinity
+ * 2 otherwise
+ */
+static int gf2m_Mxy(const EC_GROUP *group, const BIGNUM *x, const BIGNUM *y,
+ BIGNUM *x1, BIGNUM *z1, BIGNUM *x2, BIGNUM *z2,
+ BN_CTX *ctx)
+{
+ BIGNUM *t3, *t4, *t5;
+ int ret = 0;
+
+ if (BN_is_zero(z1)) {
+ BN_zero(x2);
+ BN_zero(z2);
+ return 1;
+ }
+
+ if (BN_is_zero(z2)) {
+ if (!BN_copy(x2, x))
+ return 0;
+ if (!BN_GF2m_add(z2, x, y))
+ return 0;
+ return 2;
+ }
+
+ /* Since Mxy is static we can guarantee that ctx != NULL. */
+ BN_CTX_start(ctx);
+ t3 = BN_CTX_get(ctx);
+ t4 = BN_CTX_get(ctx);
+ t5 = BN_CTX_get(ctx);
+ if (t5 == NULL)
+ goto err;
+
+ if (!BN_one(t5))
+ goto err;
+
+ if (!group->meth->field_mul(group, t3, z1, z2, ctx))
+ goto err;
+
+ if (!group->meth->field_mul(group, z1, z1, x, ctx))
+ goto err;
+ if (!BN_GF2m_add(z1, z1, x1))
+ goto err;
+ if (!group->meth->field_mul(group, z2, z2, x, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, x1, z2, x1, ctx))
+ goto err;
+ if (!BN_GF2m_add(z2, z2, x2))
+ goto err;
+
+ if (!group->meth->field_mul(group, z2, z2, z1, ctx))
+ goto err;
+ if (!group->meth->field_sqr(group, t4, x, ctx))
+ goto err;
+ if (!BN_GF2m_add(t4, t4, y))
+ goto err;
+ if (!group->meth->field_mul(group, t4, t4, t3, ctx))
+ goto err;
+ if (!BN_GF2m_add(t4, t4, z2))
+ goto err;
+
+ if (!group->meth->field_mul(group, t3, t3, x, ctx))
+ goto err;
+ if (!group->meth->field_div(group, t3, t5, t3, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, t4, t3, t4, ctx))
+ goto err;
+ if (!group->meth->field_mul(group, x2, x1, t3, ctx))
+ goto err;
+ if (!BN_GF2m_add(z2, x2, x))
+ goto err;
+
+ if (!group->meth->field_mul(group, z2, z2, t4, ctx))
+ goto err;
+ if (!BN_GF2m_add(z2, z2, y))
+ goto err;
+
+ ret = 2;
+
+ err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+/*-
+ * Computes scalar*point and stores the result in r.
+ * point can not equal r.
+ * Uses a modified algorithm 2P of
+ * Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
+ *
+ * To protect against side-channel attack the function uses constant time swap,
+ * avoiding conditional branches.
+ */
+static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group,
+ EC_POINT *r,
+ const BIGNUM *scalar,
+ const EC_POINT *point,
+ BN_CTX *ctx)
+{
+ BIGNUM *x1, *x2, *z1, *z2;
+ int ret = 0, i, group_top;
+ BN_ULONG mask, word;
+
+ if (r == point) {
+ ECerr(EC_F_EC_GF2M_MONTGOMERY_POINT_MULTIPLY, EC_R_INVALID_ARGUMENT);
+ return 0;
+ }
+
+ /* if result should be point at infinity */
+ if ((scalar == NULL) || BN_is_zero(scalar) || (point == NULL) ||
+ EC_POINT_is_at_infinity(group, point)) {
+ return EC_POINT_set_to_infinity(group, r);
+ }
+
+ /* only support affine coordinates */
+ if (!point->Z_is_one)
+ return 0;
+
+ /*
+ * Since point_multiply is static we can guarantee that ctx != NULL.
+ */
+ BN_CTX_start(ctx);
+ x1 = BN_CTX_get(ctx);
+ z1 = BN_CTX_get(ctx);
+ if (z1 == NULL)
+ goto err;
+
+ x2 = r->X;
+ z2 = r->Y;
+
+ group_top = bn_get_top(group->field);
+ if (bn_wexpand(x1, group_top) == NULL
+ || bn_wexpand(z1, group_top) == NULL
+ || bn_wexpand(x2, group_top) == NULL
+ || bn_wexpand(z2, group_top) == NULL)
+ goto err;
+
+ if (!BN_GF2m_mod_arr(x1, point->X, group->poly))
+ goto err; /* x1 = x */
+ if (!BN_one(z1))
+ goto err; /* z1 = 1 */
+ if (!group->meth->field_sqr(group, z2, x1, ctx))
+ goto err; /* z2 = x1^2 = x^2 */
+ if (!group->meth->field_sqr(group, x2, z2, ctx))
+ goto err;
+ if (!BN_GF2m_add(x2, x2, group->b))
+ goto err; /* x2 = x^4 + b */
+
+ /* find top most bit and go one past it */
+ i = bn_get_top(scalar) - 1;
+ mask = BN_TBIT;
+ word = bn_get_words(scalar)[i];
+ while (!(word & mask))
+ mask >>= 1;
+ mask >>= 1;
+ /* if top most bit was at word break, go to next word */
+ if (!mask) {
+ i--;
+ mask = BN_TBIT;
+ }
+
+ for (; i >= 0; i--) {
+ word = bn_get_words(scalar)[i];
+ while (mask) {
+ BN_consttime_swap(word & mask, x1, x2, group_top);
+ BN_consttime_swap(word & mask, z1, z2, group_top);
+ if (!gf2m_Madd(group, point->X, x2, z2, x1, z1, ctx))
+ goto err;
+ if (!gf2m_Mdouble(group, x1, z1, ctx))
+ goto err;
+ BN_consttime_swap(word & mask, x1, x2, group_top);
+ BN_consttime_swap(word & mask, z1, z2, group_top);
+ mask >>= 1;
+ }
+ mask = BN_TBIT;
+ }
+
+ /* convert out of "projective" coordinates */
+ i = gf2m_Mxy(group, point->X, point->Y, x1, z1, x2, z2, ctx);
+ if (i == 0)
+ goto err;
+ else if (i == 1) {
+ if (!EC_POINT_set_to_infinity(group, r))
+ goto err;
+ } else {
+ if (!BN_one(r->Z))
+ goto err;
+ r->Z_is_one = 1;
+ }
+
+ /* GF(2^m) field elements should always have BIGNUM::neg = 0 */
+ BN_set_negative(r->X, 0);
+ BN_set_negative(r->Y, 0);
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+/*-
+ * Computes the sum
+ * scalar*group->generator + scalars[0]*points[0] + ... + scalars[num-1]*points[num-1]
+ * gracefully ignoring NULL scalar values.
+ */
+int ec_GF2m_simple_mul(const EC_GROUP *group, EC_POINT *r,
+ const BIGNUM *scalar, size_t num,
+ const EC_POINT *points[], const BIGNUM *scalars[],
+ BN_CTX *ctx)
+{
+ BN_CTX *new_ctx = NULL;
+ int ret = 0;
+ size_t i;
+ EC_POINT *p = NULL;
+ EC_POINT *acc = NULL;
+
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ /*
+ * This implementation is more efficient than the wNAF implementation for
+ * 2 or fewer points. Use the ec_wNAF_mul implementation for 3 or more
+ * points, or if we can perform a fast multiplication based on
+ * precomputation.
+ */
+ if ((scalar && (num > 1)) || (num > 2)
+ || (num == 0 && EC_GROUP_have_precompute_mult(group))) {
+ ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
+ goto err;
+ }
+
+ if ((p = EC_POINT_new(group)) == NULL)
+ goto err;
+ if ((acc = EC_POINT_new(group)) == NULL)
+ goto err;
+
+ if (!EC_POINT_set_to_infinity(group, acc))
+ goto err;
+
+ if (scalar) {
+ if (!ec_GF2m_montgomery_point_multiply
+ (group, p, scalar, group->generator, ctx))
+ goto err;
+ if (BN_is_negative(scalar))
+ if (!group->meth->invert(group, p, ctx))
+ goto err;
+ if (!group->meth->add(group, acc, acc, p, ctx))
+ goto err;
+ }
+
+ for (i = 0; i < num; i++) {
+ if (!ec_GF2m_montgomery_point_multiply
+ (group, p, scalars[i], points[i], ctx))
+ goto err;
+ if (BN_is_negative(scalars[i]))
+ if (!group->meth->invert(group, p, ctx))
+ goto err;
+ if (!group->meth->add(group, acc, acc, p, ctx))
+ goto err;
+ }
+
+ if (!EC_POINT_copy(r, acc))
+ goto err;
+
+ ret = 1;
+
+ err:
+ EC_POINT_free(p);
+ EC_POINT_free(acc);
+ BN_CTX_free(new_ctx);
+ return ret;
+}
+
+/*
+ * Precomputation for point multiplication: fall back to wNAF methods because
+ * ec_GF2m_simple_mul() uses ec_wNAF_mul() if appropriate
+ */
+
+int ec_GF2m_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
+{
+ return ec_wNAF_precompute_mult(group, ctx);
+}
+
+int ec_GF2m_have_precompute_mult(const EC_GROUP *group)
+{
+ return ec_wNAF_have_precompute_mult(group);
+}
+
+#endif