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Diffstat (limited to 'thirdparty/openssl/crypto/ec/ecp_nistputil.c')
| -rw-r--r-- | thirdparty/openssl/crypto/ec/ecp_nistputil.c | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/thirdparty/openssl/crypto/ec/ecp_nistputil.c b/thirdparty/openssl/crypto/ec/ecp_nistputil.c deleted file mode 100644 index 8ba2a25e93..0000000000 --- a/thirdparty/openssl/crypto/ec/ecp_nistputil.c +++ /dev/null @@ -1,218 +0,0 @@ -/* crypto/ec/ecp_nistputil.c */ -/* - * Written by Bodo Moeller for the OpenSSL project. - */ -/* Copyright 2011 Google Inc. - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -#include <openssl/opensslconf.h> -#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128 - -/* - * Common utility functions for ecp_nistp224.c, ecp_nistp256.c, ecp_nistp521.c. - */ - -# include <stddef.h> -# include "ec_lcl.h" - -/* - * Convert an array of points into affine coordinates. (If the point at - * infinity is found (Z = 0), it remains unchanged.) This function is - * essentially an equivalent to EC_POINTs_make_affine(), but works with the - * internal representation of points as used by ecp_nistp###.c rather than - * with (BIGNUM-based) EC_POINT data structures. point_array is the - * input/output buffer ('num' points in projective form, i.e. three - * coordinates each), based on an internal representation of field elements - * of size 'felem_size'. tmp_felems needs to point to a temporary array of - * 'num'+1 field elements for storage of intermediate values. - */ -void ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array, - size_t felem_size, - void *tmp_felems, - void (*felem_one) (void *out), - int (*felem_is_zero) (const void - *in), - void (*felem_assign) (void *out, - const void - *in), - void (*felem_square) (void *out, - const void - *in), - void (*felem_mul) (void *out, - const void - *in1, - const void - *in2), - void (*felem_inv) (void *out, - const void - *in), - void (*felem_contract) (void - *out, - const - void - *in)) -{ - int i = 0; - -# define tmp_felem(I) (&((char *)tmp_felems)[(I) * felem_size]) -# define X(I) (&((char *)point_array)[3*(I) * felem_size]) -# define Y(I) (&((char *)point_array)[(3*(I) + 1) * felem_size]) -# define Z(I) (&((char *)point_array)[(3*(I) + 2) * felem_size]) - - if (!felem_is_zero(Z(0))) - felem_assign(tmp_felem(0), Z(0)); - else - felem_one(tmp_felem(0)); - for (i = 1; i < (int)num; i++) { - if (!felem_is_zero(Z(i))) - felem_mul(tmp_felem(i), tmp_felem(i - 1), Z(i)); - else - felem_assign(tmp_felem(i), tmp_felem(i - 1)); - } - /* - * Now each tmp_felem(i) is the product of Z(0) .. Z(i), skipping any - * zero-valued factors: if Z(i) = 0, we essentially pretend that Z(i) = 1 - */ - - felem_inv(tmp_felem(num - 1), tmp_felem(num - 1)); - for (i = num - 1; i >= 0; i--) { - if (i > 0) - /* - * tmp_felem(i-1) is the product of Z(0) .. Z(i-1), tmp_felem(i) - * is the inverse of the product of Z(0) .. Z(i) - */ - /* 1/Z(i) */ - felem_mul(tmp_felem(num), tmp_felem(i - 1), tmp_felem(i)); - else - felem_assign(tmp_felem(num), tmp_felem(0)); /* 1/Z(0) */ - - if (!felem_is_zero(Z(i))) { - if (i > 0) - /* - * For next iteration, replace tmp_felem(i-1) by its inverse - */ - felem_mul(tmp_felem(i - 1), tmp_felem(i), Z(i)); - - /* - * Convert point (X, Y, Z) into affine form (X/(Z^2), Y/(Z^3), 1) - */ - felem_square(Z(i), tmp_felem(num)); /* 1/(Z^2) */ - felem_mul(X(i), X(i), Z(i)); /* X/(Z^2) */ - felem_mul(Z(i), Z(i), tmp_felem(num)); /* 1/(Z^3) */ - felem_mul(Y(i), Y(i), Z(i)); /* Y/(Z^3) */ - felem_contract(X(i), X(i)); - felem_contract(Y(i), Y(i)); - felem_one(Z(i)); - } else { - if (i > 0) - /* - * For next iteration, replace tmp_felem(i-1) by its inverse - */ - felem_assign(tmp_felem(i - 1), tmp_felem(i)); - } - } -} - -/*- - * This function looks at 5+1 scalar bits (5 current, 1 adjacent less - * significant bit), and recodes them into a signed digit for use in fast point - * multiplication: the use of signed rather than unsigned digits means that - * fewer points need to be precomputed, given that point inversion is easy - * (a precomputed point dP makes -dP available as well). - * - * BACKGROUND: - * - * Signed digits for multiplication were introduced by Booth ("A signed binary - * multiplication technique", Quart. Journ. Mech. and Applied Math., vol. IV, - * pt. 2 (1951), pp. 236-240), in that case for multiplication of integers. - * Booth's original encoding did not generally improve the density of nonzero - * digits over the binary representation, and was merely meant to simplify the - * handling of signed factors given in two's complement; but it has since been - * shown to be the basis of various signed-digit representations that do have - * further advantages, including the wNAF, using the following general approach: - * - * (1) Given a binary representation - * - * b_k ... b_2 b_1 b_0, - * - * of a nonnegative integer (b_k in {0, 1}), rewrite it in digits 0, 1, -1 - * by using bit-wise subtraction as follows: - * - * b_k b_(k-1) ... b_2 b_1 b_0 - * - b_k ... b_3 b_2 b_1 b_0 - * ------------------------------------- - * s_k b_(k-1) ... s_3 s_2 s_1 s_0 - * - * A left-shift followed by subtraction of the original value yields a new - * representation of the same value, using signed bits s_i = b_(i+1) - b_i. - * This representation from Booth's paper has since appeared in the - * literature under a variety of different names including "reversed binary - * form", "alternating greedy expansion", "mutual opposite form", and - * "sign-alternating {+-1}-representation". - * - * An interesting property is that among the nonzero bits, values 1 and -1 - * strictly alternate. - * - * (2) Various window schemes can be applied to the Booth representation of - * integers: for example, right-to-left sliding windows yield the wNAF - * (a signed-digit encoding independently discovered by various researchers - * in the 1990s), and left-to-right sliding windows yield a left-to-right - * equivalent of the wNAF (independently discovered by various researchers - * around 2004). - * - * To prevent leaking information through side channels in point multiplication, - * we need to recode the given integer into a regular pattern: sliding windows - * as in wNAFs won't do, we need their fixed-window equivalent -- which is a few - * decades older: we'll be using the so-called "modified Booth encoding" due to - * MacSorley ("High-speed arithmetic in binary computers", Proc. IRE, vol. 49 - * (1961), pp. 67-91), in a radix-2^5 setting. That is, we always combine five - * signed bits into a signed digit: - * - * s_(4j + 4) s_(4j + 3) s_(4j + 2) s_(4j + 1) s_(4j) - * - * The sign-alternating property implies that the resulting digit values are - * integers from -16 to 16. - * - * Of course, we don't actually need to compute the signed digits s_i as an - * intermediate step (that's just a nice way to see how this scheme relates - * to the wNAF): a direct computation obtains the recoded digit from the - * six bits b_(4j + 4) ... b_(4j - 1). - * - * This function takes those five bits as an integer (0 .. 63), writing the - * recoded digit to *sign (0 for positive, 1 for negative) and *digit (absolute - * value, in the range 0 .. 8). Note that this integer essentially provides the - * input bits "shifted to the left" by one position: for example, the input to - * compute the least significant recoded digit, given that there's no bit b_-1, - * has to be b_4 b_3 b_2 b_1 b_0 0. - * - */ -void ec_GFp_nistp_recode_scalar_bits(unsigned char *sign, - unsigned char *digit, unsigned char in) -{ - unsigned char s, d; - - s = ~((in >> 5) - 1); /* sets all bits to MSB(in), 'in' seen as - * 6-bit value */ - d = (1 << 6) - in - 1; - d = (d & s) | (in & ~s); - d = (d >> 1) + (d & 1); - - *sign = s & 1; - *digit = d; -} -#else -static void *dummy = &dummy; -#endif |