diff options
Diffstat (limited to 'thirdparty/openssl/crypto/ec/ec_mult.c')
| -rw-r--r-- | thirdparty/openssl/crypto/ec/ec_mult.c | 917 |
1 files changed, 0 insertions, 917 deletions
diff --git a/thirdparty/openssl/crypto/ec/ec_mult.c b/thirdparty/openssl/crypto/ec/ec_mult.c deleted file mode 100644 index 24ca67a6ef..0000000000 --- a/thirdparty/openssl/crypto/ec/ec_mult.c +++ /dev/null @@ -1,917 +0,0 @@ -/* crypto/ec/ec_mult.c */ -/* - * Originally written by Bodo Moeller and Nils Larsch for the OpenSSL project. - */ -/* ==================================================================== - * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * 3. All advertising materials mentioning features or use of this - * software must display the following acknowledgment: - * "This product includes software developed by the OpenSSL Project - * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" - * - * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to - * endorse or promote products derived from this software without - * prior written permission. For written permission, please contact - * openssl-core@openssl.org. - * - * 5. Products derived from this software may not be called "OpenSSL" - * nor may "OpenSSL" appear in their names without prior written - * permission of the OpenSSL Project. - * - * 6. Redistributions of any form whatsoever must retain the following - * acknowledgment: - * "This product includes software developed by the OpenSSL Project - * for use in the OpenSSL Toolkit (http://www.openssl.org/)" - * - * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY - * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR - * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR - * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; - * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, - * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED - * OF THE POSSIBILITY OF SUCH DAMAGE. - * ==================================================================== - * - * This product includes cryptographic software written by Eric Young - * (eay@cryptsoft.com). This product includes software written by Tim - * Hudson (tjh@cryptsoft.com). - * - */ -/* ==================================================================== - * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. - * Portions of this software developed by SUN MICROSYSTEMS, INC., - * and contributed to the OpenSSL project. - */ - -#include <string.h> - -#include <openssl/err.h> - -#include "ec_lcl.h" - -/* - * This file implements the wNAF-based interleaving multi-exponentiation method - * Formerly at: - * http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/moeller.html#multiexp - * You might now find it here: - * http://link.springer.com/chapter/10.1007%2F3-540-45537-X_13 - * http://www.bmoeller.de/pdf/TI-01-08.multiexp.pdf - * For multiplication with precomputation, we use wNAF splitting, formerly at: - * http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/moeller.html#fastexp - */ - -/* structure for precomputed multiples of the generator */ -typedef struct ec_pre_comp_st { - const EC_GROUP *group; /* parent EC_GROUP object */ - size_t blocksize; /* block size for wNAF splitting */ - size_t numblocks; /* max. number of blocks for which we have - * precomputation */ - size_t w; /* window size */ - EC_POINT **points; /* array with pre-calculated multiples of - * generator: 'num' pointers to EC_POINT - * objects followed by a NULL */ - size_t num; /* numblocks * 2^(w-1) */ - int references; -} EC_PRE_COMP; - -/* functions to manage EC_PRE_COMP within the EC_GROUP extra_data framework */ -static void *ec_pre_comp_dup(void *); -static void ec_pre_comp_free(void *); -static void ec_pre_comp_clear_free(void *); - -static EC_PRE_COMP *ec_pre_comp_new(const EC_GROUP *group) -{ - EC_PRE_COMP *ret = NULL; - - if (!group) - return NULL; - - ret = (EC_PRE_COMP *)OPENSSL_malloc(sizeof(EC_PRE_COMP)); - if (!ret) { - ECerr(EC_F_EC_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE); - return ret; - } - ret->group = group; - ret->blocksize = 8; /* default */ - ret->numblocks = 0; - ret->w = 4; /* default */ - ret->points = NULL; - ret->num = 0; - ret->references = 1; - return ret; -} - -static void *ec_pre_comp_dup(void *src_) -{ - EC_PRE_COMP *src = src_; - - /* no need to actually copy, these objects never change! */ - - CRYPTO_add(&src->references, 1, CRYPTO_LOCK_EC_PRE_COMP); - - return src_; -} - -static void ec_pre_comp_free(void *pre_) -{ - int i; - EC_PRE_COMP *pre = pre_; - - if (!pre) - return; - - i = CRYPTO_add(&pre->references, -1, CRYPTO_LOCK_EC_PRE_COMP); - if (i > 0) - return; - - if (pre->points) { - EC_POINT **p; - - for (p = pre->points; *p != NULL; p++) - EC_POINT_free(*p); - OPENSSL_free(pre->points); - } - OPENSSL_free(pre); -} - -static void ec_pre_comp_clear_free(void *pre_) -{ - int i; - EC_PRE_COMP *pre = pre_; - - if (!pre) - return; - - i = CRYPTO_add(&pre->references, -1, CRYPTO_LOCK_EC_PRE_COMP); - if (i > 0) - return; - - if (pre->points) { - EC_POINT **p; - - for (p = pre->points; *p != NULL; p++) { - EC_POINT_clear_free(*p); - OPENSSL_cleanse(p, sizeof *p); - } - OPENSSL_free(pre->points); - } - OPENSSL_cleanse(pre, sizeof *pre); - OPENSSL_free(pre); -} - -/*- - * Determine the modified width-(w+1) Non-Adjacent Form (wNAF) of 'scalar'. - * This is an array r[] of values that are either zero or odd with an - * absolute value less than 2^w satisfying - * scalar = \sum_j r[j]*2^j - * where at most one of any w+1 consecutive digits is non-zero - * with the exception that the most significant digit may be only - * w-1 zeros away from that next non-zero digit. - */ -static signed char *compute_wNAF(const BIGNUM *scalar, int w, size_t *ret_len) -{ - int window_val; - int ok = 0; - signed char *r = NULL; - int sign = 1; - int bit, next_bit, mask; - size_t len = 0, j; - - if (BN_is_zero(scalar)) { - r = OPENSSL_malloc(1); - if (!r) { - ECerr(EC_F_COMPUTE_WNAF, ERR_R_MALLOC_FAILURE); - goto err; - } - r[0] = 0; - *ret_len = 1; - return r; - } - - if (w <= 0 || w > 7) { /* 'signed char' can represent integers with - * absolute values less than 2^7 */ - ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); - goto err; - } - bit = 1 << w; /* at most 128 */ - next_bit = bit << 1; /* at most 256 */ - mask = next_bit - 1; /* at most 255 */ - - if (BN_is_negative(scalar)) { - sign = -1; - } - - if (scalar->d == NULL || scalar->top == 0) { - ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); - goto err; - } - - len = BN_num_bits(scalar); - r = OPENSSL_malloc(len + 1); /* modified wNAF may be one digit longer - * than binary representation (*ret_len will - * be set to the actual length, i.e. at most - * BN_num_bits(scalar) + 1) */ - if (r == NULL) { - ECerr(EC_F_COMPUTE_WNAF, ERR_R_MALLOC_FAILURE); - goto err; - } - window_val = scalar->d[0] & mask; - j = 0; - while ((window_val != 0) || (j + w + 1 < len)) { /* if j+w+1 >= len, - * window_val will not - * increase */ - int digit = 0; - - /* 0 <= window_val <= 2^(w+1) */ - - if (window_val & 1) { - /* 0 < window_val < 2^(w+1) */ - - if (window_val & bit) { - digit = window_val - next_bit; /* -2^w < digit < 0 */ - -#if 1 /* modified wNAF */ - if (j + w + 1 >= len) { - /* - * special case for generating modified wNAFs: no new - * bits will be added into window_val, so using a - * positive digit here will decrease the total length of - * the representation - */ - - digit = window_val & (mask >> 1); /* 0 < digit < 2^w */ - } -#endif - } else { - digit = window_val; /* 0 < digit < 2^w */ - } - - if (digit <= -bit || digit >= bit || !(digit & 1)) { - ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); - goto err; - } - - window_val -= digit; - - /* - * now window_val is 0 or 2^(w+1) in standard wNAF generation; - * for modified window NAFs, it may also be 2^w - */ - if (window_val != 0 && window_val != next_bit - && window_val != bit) { - ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); - goto err; - } - } - - r[j++] = sign * digit; - - window_val >>= 1; - window_val += bit * BN_is_bit_set(scalar, j + w); - - if (window_val > next_bit) { - ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); - goto err; - } - } - - if (j > len + 1) { - ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); - goto err; - } - len = j; - ok = 1; - - err: - if (!ok) { - OPENSSL_free(r); - r = NULL; - } - if (ok) - *ret_len = len; - return r; -} - -/* - * TODO: table should be optimised for the wNAF-based implementation, - * sometimes smaller windows will give better performance (thus the - * boundaries should be increased) - */ -#define EC_window_bits_for_scalar_size(b) \ - ((size_t) \ - ((b) >= 2000 ? 6 : \ - (b) >= 800 ? 5 : \ - (b) >= 300 ? 4 : \ - (b) >= 70 ? 3 : \ - (b) >= 20 ? 2 : \ - 1)) - -/*- - * Compute - * \sum scalars[i]*points[i], - * also including - * scalar*generator - * in the addition if scalar != NULL - */ -int ec_wNAF_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; - const EC_POINT *generator = NULL; - EC_POINT *tmp = NULL; - size_t totalnum; - size_t blocksize = 0, numblocks = 0; /* for wNAF splitting */ - size_t pre_points_per_block = 0; - size_t i, j; - int k; - int r_is_inverted = 0; - int r_is_at_infinity = 1; - size_t *wsize = NULL; /* individual window sizes */ - signed char **wNAF = NULL; /* individual wNAFs */ - size_t *wNAF_len = NULL; - size_t max_len = 0; - size_t num_val; - EC_POINT **val = NULL; /* precomputation */ - EC_POINT **v; - EC_POINT ***val_sub = NULL; /* pointers to sub-arrays of 'val' or - * 'pre_comp->points' */ - const EC_PRE_COMP *pre_comp = NULL; - int num_scalar = 0; /* flag: will be set to 1 if 'scalar' must be - * treated like other scalars, i.e. - * precomputation is not available */ - int ret = 0; - - if (group->meth != r->meth) { - ECerr(EC_F_EC_WNAF_MUL, EC_R_INCOMPATIBLE_OBJECTS); - return 0; - } - - if ((scalar == NULL) && (num == 0)) { - return EC_POINT_set_to_infinity(group, r); - } - - for (i = 0; i < num; i++) { - if (group->meth != points[i]->meth) { - ECerr(EC_F_EC_WNAF_MUL, EC_R_INCOMPATIBLE_OBJECTS); - return 0; - } - } - - if (ctx == NULL) { - ctx = new_ctx = BN_CTX_new(); - if (ctx == NULL) - goto err; - } - - if (scalar != NULL) { - generator = EC_GROUP_get0_generator(group); - if (generator == NULL) { - ECerr(EC_F_EC_WNAF_MUL, EC_R_UNDEFINED_GENERATOR); - goto err; - } - - /* look if we can use precomputed multiples of generator */ - - pre_comp = - EC_EX_DATA_get_data(group->extra_data, ec_pre_comp_dup, - ec_pre_comp_free, ec_pre_comp_clear_free); - - if (pre_comp && pre_comp->numblocks - && (EC_POINT_cmp(group, generator, pre_comp->points[0], ctx) == - 0)) { - blocksize = pre_comp->blocksize; - - /* - * determine maximum number of blocks that wNAF splitting may - * yield (NB: maximum wNAF length is bit length plus one) - */ - numblocks = (BN_num_bits(scalar) / blocksize) + 1; - - /* - * we cannot use more blocks than we have precomputation for - */ - if (numblocks > pre_comp->numblocks) - numblocks = pre_comp->numblocks; - - pre_points_per_block = (size_t)1 << (pre_comp->w - 1); - - /* check that pre_comp looks sane */ - if (pre_comp->num != (pre_comp->numblocks * pre_points_per_block)) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); - goto err; - } - } else { - /* can't use precomputation */ - pre_comp = NULL; - numblocks = 1; - num_scalar = 1; /* treat 'scalar' like 'num'-th element of - * 'scalars' */ - } - } - - totalnum = num + numblocks; - - wsize = OPENSSL_malloc(totalnum * sizeof wsize[0]); - wNAF_len = OPENSSL_malloc(totalnum * sizeof wNAF_len[0]); - wNAF = OPENSSL_malloc((totalnum + 1) * sizeof wNAF[0]); /* includes space - * for pivot */ - val_sub = OPENSSL_malloc(totalnum * sizeof val_sub[0]); - - /* Ensure wNAF is initialised in case we end up going to err */ - if (wNAF) - wNAF[0] = NULL; /* preliminary pivot */ - - if (!wsize || !wNAF_len || !wNAF || !val_sub) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); - goto err; - } - - /* - * num_val will be the total number of temporarily precomputed points - */ - num_val = 0; - - for (i = 0; i < num + num_scalar; i++) { - size_t bits; - - bits = i < num ? BN_num_bits(scalars[i]) : BN_num_bits(scalar); - wsize[i] = EC_window_bits_for_scalar_size(bits); - num_val += (size_t)1 << (wsize[i] - 1); - wNAF[i + 1] = NULL; /* make sure we always have a pivot */ - wNAF[i] = - compute_wNAF((i < num ? scalars[i] : scalar), wsize[i], - &wNAF_len[i]); - if (wNAF[i] == NULL) - goto err; - if (wNAF_len[i] > max_len) - max_len = wNAF_len[i]; - } - - if (numblocks) { - /* we go here iff scalar != NULL */ - - if (pre_comp == NULL) { - if (num_scalar != 1) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); - goto err; - } - /* we have already generated a wNAF for 'scalar' */ - } else { - signed char *tmp_wNAF = NULL; - size_t tmp_len = 0; - - if (num_scalar != 0) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); - goto err; - } - - /* - * use the window size for which we have precomputation - */ - wsize[num] = pre_comp->w; - tmp_wNAF = compute_wNAF(scalar, wsize[num], &tmp_len); - if (!tmp_wNAF) - goto err; - - if (tmp_len <= max_len) { - /* - * One of the other wNAFs is at least as long as the wNAF - * belonging to the generator, so wNAF splitting will not buy - * us anything. - */ - - numblocks = 1; - totalnum = num + 1; /* don't use wNAF splitting */ - wNAF[num] = tmp_wNAF; - wNAF[num + 1] = NULL; - wNAF_len[num] = tmp_len; - if (tmp_len > max_len) - max_len = tmp_len; - /* - * pre_comp->points starts with the points that we need here: - */ - val_sub[num] = pre_comp->points; - } else { - /* - * don't include tmp_wNAF directly into wNAF array - use wNAF - * splitting and include the blocks - */ - - signed char *pp; - EC_POINT **tmp_points; - - if (tmp_len < numblocks * blocksize) { - /* - * possibly we can do with fewer blocks than estimated - */ - numblocks = (tmp_len + blocksize - 1) / blocksize; - if (numblocks > pre_comp->numblocks) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); - goto err; - } - totalnum = num + numblocks; - } - - /* split wNAF in 'numblocks' parts */ - pp = tmp_wNAF; - tmp_points = pre_comp->points; - - for (i = num; i < totalnum; i++) { - if (i < totalnum - 1) { - wNAF_len[i] = blocksize; - if (tmp_len < blocksize) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); - goto err; - } - tmp_len -= blocksize; - } else - /* - * last block gets whatever is left (this could be - * more or less than 'blocksize'!) - */ - wNAF_len[i] = tmp_len; - - wNAF[i + 1] = NULL; - wNAF[i] = OPENSSL_malloc(wNAF_len[i]); - if (wNAF[i] == NULL) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); - OPENSSL_free(tmp_wNAF); - goto err; - } - memcpy(wNAF[i], pp, wNAF_len[i]); - if (wNAF_len[i] > max_len) - max_len = wNAF_len[i]; - - if (*tmp_points == NULL) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); - OPENSSL_free(tmp_wNAF); - goto err; - } - val_sub[i] = tmp_points; - tmp_points += pre_points_per_block; - pp += blocksize; - } - OPENSSL_free(tmp_wNAF); - } - } - } - - /* - * All points we precompute now go into a single array 'val'. - * 'val_sub[i]' is a pointer to the subarray for the i-th point, or to a - * subarray of 'pre_comp->points' if we already have precomputation. - */ - val = OPENSSL_malloc((num_val + 1) * sizeof val[0]); - if (val == NULL) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); - goto err; - } - val[num_val] = NULL; /* pivot element */ - - /* allocate points for precomputation */ - v = val; - for (i = 0; i < num + num_scalar; i++) { - val_sub[i] = v; - for (j = 0; j < ((size_t)1 << (wsize[i] - 1)); j++) { - *v = EC_POINT_new(group); - if (*v == NULL) - goto err; - v++; - } - } - if (!(v == val + num_val)) { - ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); - goto err; - } - - if (!(tmp = EC_POINT_new(group))) - goto err; - - /*- - * prepare precomputed values: - * val_sub[i][0] := points[i] - * val_sub[i][1] := 3 * points[i] - * val_sub[i][2] := 5 * points[i] - * ... - */ - for (i = 0; i < num + num_scalar; i++) { - if (i < num) { - if (!EC_POINT_copy(val_sub[i][0], points[i])) - goto err; - } else { - if (!EC_POINT_copy(val_sub[i][0], generator)) - goto err; - } - - if (wsize[i] > 1) { - if (!EC_POINT_dbl(group, tmp, val_sub[i][0], ctx)) - goto err; - for (j = 1; j < ((size_t)1 << (wsize[i] - 1)); j++) { - if (!EC_POINT_add - (group, val_sub[i][j], val_sub[i][j - 1], tmp, ctx)) - goto err; - } - } - } - -#if 1 /* optional; EC_window_bits_for_scalar_size - * assumes we do this step */ - if (!EC_POINTs_make_affine(group, num_val, val, ctx)) - goto err; -#endif - - r_is_at_infinity = 1; - - for (k = max_len - 1; k >= 0; k--) { - if (!r_is_at_infinity) { - if (!EC_POINT_dbl(group, r, r, ctx)) - goto err; - } - - for (i = 0; i < totalnum; i++) { - if (wNAF_len[i] > (size_t)k) { - int digit = wNAF[i][k]; - int is_neg; - - if (digit) { - is_neg = digit < 0; - - if (is_neg) - digit = -digit; - - if (is_neg != r_is_inverted) { - if (!r_is_at_infinity) { - if (!EC_POINT_invert(group, r, ctx)) - goto err; - } - r_is_inverted = !r_is_inverted; - } - - /* digit > 0 */ - - if (r_is_at_infinity) { - if (!EC_POINT_copy(r, val_sub[i][digit >> 1])) - goto err; - r_is_at_infinity = 0; - } else { - if (!EC_POINT_add - (group, r, r, val_sub[i][digit >> 1], ctx)) - goto err; - } - } - } - } - } - - if (r_is_at_infinity) { - if (!EC_POINT_set_to_infinity(group, r)) - goto err; - } else { - if (r_is_inverted) - if (!EC_POINT_invert(group, r, ctx)) - goto err; - } - - ret = 1; - - err: - if (new_ctx != NULL) - BN_CTX_free(new_ctx); - if (tmp != NULL) - EC_POINT_free(tmp); - if (wsize != NULL) - OPENSSL_free(wsize); - if (wNAF_len != NULL) - OPENSSL_free(wNAF_len); - if (wNAF != NULL) { - signed char **w; - - for (w = wNAF; *w != NULL; w++) - OPENSSL_free(*w); - - OPENSSL_free(wNAF); - } - if (val != NULL) { - for (v = val; *v != NULL; v++) - EC_POINT_clear_free(*v); - - OPENSSL_free(val); - } - if (val_sub != NULL) { - OPENSSL_free(val_sub); - } - return ret; -} - -/*- - * ec_wNAF_precompute_mult() - * creates an EC_PRE_COMP object with preprecomputed multiples of the generator - * for use with wNAF splitting as implemented in ec_wNAF_mul(). - * - * 'pre_comp->points' is an array of multiples of the generator - * of the following form: - * points[0] = generator; - * points[1] = 3 * generator; - * ... - * points[2^(w-1)-1] = (2^(w-1)-1) * generator; - * points[2^(w-1)] = 2^blocksize * generator; - * points[2^(w-1)+1] = 3 * 2^blocksize * generator; - * ... - * points[2^(w-1)*(numblocks-1)-1] = (2^(w-1)) * 2^(blocksize*(numblocks-2)) * generator - * points[2^(w-1)*(numblocks-1)] = 2^(blocksize*(numblocks-1)) * generator - * ... - * points[2^(w-1)*numblocks-1] = (2^(w-1)) * 2^(blocksize*(numblocks-1)) * generator - * points[2^(w-1)*numblocks] = NULL - */ -int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *ctx) -{ - const EC_POINT *generator; - EC_POINT *tmp_point = NULL, *base = NULL, **var; - BN_CTX *new_ctx = NULL; - BIGNUM *order; - size_t i, bits, w, pre_points_per_block, blocksize, numblocks, num; - EC_POINT **points = NULL; - EC_PRE_COMP *pre_comp; - int ret = 0; - - /* if there is an old EC_PRE_COMP object, throw it away */ - EC_EX_DATA_free_data(&group->extra_data, ec_pre_comp_dup, - ec_pre_comp_free, ec_pre_comp_clear_free); - - if ((pre_comp = ec_pre_comp_new(group)) == NULL) - return 0; - - generator = EC_GROUP_get0_generator(group); - if (generator == NULL) { - ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, EC_R_UNDEFINED_GENERATOR); - goto err; - } - - if (ctx == NULL) { - ctx = new_ctx = BN_CTX_new(); - if (ctx == NULL) - goto err; - } - - BN_CTX_start(ctx); - order = BN_CTX_get(ctx); - if (order == NULL) - goto err; - - if (!EC_GROUP_get_order(group, order, ctx)) - goto err; - if (BN_is_zero(order)) { - ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, EC_R_UNKNOWN_ORDER); - goto err; - } - - bits = BN_num_bits(order); - /* - * The following parameters mean we precompute (approximately) one point - * per bit. TBD: The combination 8, 4 is perfect for 160 bits; for other - * bit lengths, other parameter combinations might provide better - * efficiency. - */ - blocksize = 8; - w = 4; - if (EC_window_bits_for_scalar_size(bits) > w) { - /* let's not make the window too small ... */ - w = EC_window_bits_for_scalar_size(bits); - } - - numblocks = (bits + blocksize - 1) / blocksize; /* max. number of blocks - * to use for wNAF - * splitting */ - - pre_points_per_block = (size_t)1 << (w - 1); - num = pre_points_per_block * numblocks; /* number of points to compute - * and store */ - - points = OPENSSL_malloc(sizeof(EC_POINT *) * (num + 1)); - if (!points) { - ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); - goto err; - } - - var = points; - var[num] = NULL; /* pivot */ - for (i = 0; i < num; i++) { - if ((var[i] = EC_POINT_new(group)) == NULL) { - ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); - goto err; - } - } - - if (!(tmp_point = EC_POINT_new(group)) || !(base = EC_POINT_new(group))) { - ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); - goto err; - } - - if (!EC_POINT_copy(base, generator)) - goto err; - - /* do the precomputation */ - for (i = 0; i < numblocks; i++) { - size_t j; - - if (!EC_POINT_dbl(group, tmp_point, base, ctx)) - goto err; - - if (!EC_POINT_copy(*var++, base)) - goto err; - - for (j = 1; j < pre_points_per_block; j++, var++) { - /* - * calculate odd multiples of the current base point - */ - if (!EC_POINT_add(group, *var, tmp_point, *(var - 1), ctx)) - goto err; - } - - if (i < numblocks - 1) { - /* - * get the next base (multiply current one by 2^blocksize) - */ - size_t k; - - if (blocksize <= 2) { - ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_INTERNAL_ERROR); - goto err; - } - - if (!EC_POINT_dbl(group, base, tmp_point, ctx)) - goto err; - for (k = 2; k < blocksize; k++) { - if (!EC_POINT_dbl(group, base, base, ctx)) - goto err; - } - } - } - - if (!EC_POINTs_make_affine(group, num, points, ctx)) - goto err; - - pre_comp->group = group; - pre_comp->blocksize = blocksize; - pre_comp->numblocks = numblocks; - pre_comp->w = w; - pre_comp->points = points; - points = NULL; - pre_comp->num = num; - - if (!EC_EX_DATA_set_data(&group->extra_data, pre_comp, - ec_pre_comp_dup, ec_pre_comp_free, - ec_pre_comp_clear_free)) - goto err; - pre_comp = NULL; - - ret = 1; - err: - if (ctx != NULL) - BN_CTX_end(ctx); - if (new_ctx != NULL) - BN_CTX_free(new_ctx); - if (pre_comp) - ec_pre_comp_free(pre_comp); - if (points) { - EC_POINT **p; - - for (p = points; *p != NULL; p++) - EC_POINT_free(*p); - OPENSSL_free(points); - } - if (tmp_point) - EC_POINT_free(tmp_point); - if (base) - EC_POINT_free(base); - return ret; -} - -int ec_wNAF_have_precompute_mult(const EC_GROUP *group) -{ - if (EC_EX_DATA_get_data - (group->extra_data, ec_pre_comp_dup, ec_pre_comp_free, - ec_pre_comp_clear_free) != NULL) - return 1; - else - return 0; -} |