Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(163)

Issues Search
    My Issues | Starred     Open | Closed | All

Unified Diff: openssl/crypto/ec/ec_mult.c

Issue 2072073002: Delete bundled copy of OpenSSL and replace with README. (Closed) Base URL: https://chromium.googlesource.com/chromium/deps/openssl@master
Patch Set: Delete bundled copy of OpenSSL and replace with README. Created 4 years, 6 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « openssl/crypto/ec/ec_lib.c ('k') | openssl/crypto/ec/ec_oct.c » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: openssl/crypto/ec/ec_mult.c
diff --git a/openssl/crypto/ec/ec_mult.c b/openssl/crypto/ec/ec_mult.c
deleted file mode 100644
index 19f21675fbd804e139334f8f736b86b89f23388a..0000000000000000000000000000000000000000
--- a/openssl/crypto/ec/ec_mult.c
+++ /dev/null
@@ -1,940 +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-exponentation method
- * (<URL:http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/moeller.html#multiexp>);
- * for multiplication with precomputation, we use wNAF splitting
- * (<URL: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]);
-
- if (!wsize || !wNAF_len || !wNAF || !val_sub)
- {
- ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- wNAF[0] = NULL; /* preliminary pivot */
-
- /* 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;
- }
« no previous file with comments | « openssl/crypto/ec/ec_lib.c ('k') | openssl/crypto/ec/ec_oct.c » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698