1 /* $OpenBSD: ec_mult.c,v 1.18 2015/02/15 08:44:35 miod Exp $ */
3 * Originally written by Bodo Moeller and Nils Larsch for the OpenSSL project.
5 /* ====================================================================
6 * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * openssl-core@openssl.org.
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
34 * 6. Redistributions of any form whatsoever must retain the following
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
58 /* ====================================================================
59 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
60 * Portions of this software developed by SUN MICROSYSTEMS, INC.,
61 * and contributed to the OpenSSL project.
66 #include <openssl/err.h>
72 * This file implements the wNAF-based interleaving multi-exponentation method
73 * (<URL:http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/moeller.html#multiexp>);
74 * for multiplication with precomputation, we use wNAF splitting
75 * (<URL:http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/moeller.html#fastexp>).
81 /* structure for precomputed multiples of the generator */
82 typedef struct ec_pre_comp_st
{
83 const EC_GROUP
*group
; /* parent EC_GROUP object */
84 size_t blocksize
; /* block size for wNAF splitting */
85 size_t numblocks
; /* max. number of blocks for which we have
87 size_t w
; /* window size */
88 EC_POINT
**points
; /* array with pre-calculated multiples of
89 * generator: 'num' pointers to EC_POINT
90 * objects followed by a NULL */
91 size_t num
; /* numblocks * 2^(w-1) */
95 /* functions to manage EC_PRE_COMP within the EC_GROUP extra_data framework */
96 static void *ec_pre_comp_dup(void *);
97 static void ec_pre_comp_free(void *);
98 static void ec_pre_comp_clear_free(void *);
101 ec_pre_comp_new(const EC_GROUP
* group
)
103 EC_PRE_COMP
*ret
= NULL
;
108 ret
= malloc(sizeof(EC_PRE_COMP
));
110 ECerr(EC_F_EC_PRE_COMP_NEW
, ERR_R_MALLOC_FAILURE
);
114 ret
->blocksize
= 8; /* default */
116 ret
->w
= 4; /* default */
124 ec_pre_comp_dup(void *src_
)
126 EC_PRE_COMP
*src
= src_
;
128 /* no need to actually copy, these objects never change! */
130 CRYPTO_add(&src
->references
, 1, CRYPTO_LOCK_EC_PRE_COMP
);
136 ec_pre_comp_free(void *pre_
)
139 EC_PRE_COMP
*pre
= pre_
;
144 i
= CRYPTO_add(&pre
->references
, -1, CRYPTO_LOCK_EC_PRE_COMP
);
151 for (p
= pre
->points
; *p
!= NULL
; p
++)
159 ec_pre_comp_clear_free(void *pre_
)
162 EC_PRE_COMP
*pre
= pre_
;
167 i
= CRYPTO_add(&pre
->references
, -1, CRYPTO_LOCK_EC_PRE_COMP
);
174 for (p
= pre
->points
; *p
!= NULL
; p
++) {
175 EC_POINT_clear_free(*p
);
176 explicit_bzero(p
, sizeof *p
);
180 explicit_bzero(pre
, sizeof *pre
);
187 /* Determine the modified width-(w+1) Non-Adjacent Form (wNAF) of 'scalar'.
188 * This is an array r[] of values that are either zero or odd with an
189 * absolute value less than 2^w satisfying
190 * scalar = \sum_j r[j]*2^j
191 * where at most one of any w+1 consecutive digits is non-zero
192 * with the exception that the most significant digit may be only
193 * w-1 zeros away from that next non-zero digit.
196 compute_wNAF(const BIGNUM
* scalar
, int w
, size_t * ret_len
)
200 signed char *r
= NULL
;
202 int bit
, next_bit
, mask
;
205 if (BN_is_zero(scalar
)) {
208 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_MALLOC_FAILURE
);
215 if (w
<= 0 || w
> 7) {
216 /* 'signed char' can represent integers with
217 * absolute values less than 2^7 */
218 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_INTERNAL_ERROR
);
221 bit
= 1 << w
; /* at most 128 */
222 next_bit
= bit
<< 1; /* at most 256 */
223 mask
= next_bit
- 1; /* at most 255 */
225 if (BN_is_negative(scalar
)) {
228 if (scalar
->d
== NULL
|| scalar
->top
== 0) {
229 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_INTERNAL_ERROR
);
232 len
= BN_num_bits(scalar
);
233 r
= malloc(len
+ 1); /* modified wNAF may be one digit longer than
234 * binary representation (*ret_len will be
235 * set to the actual length, i.e. at most
236 * BN_num_bits(scalar) + 1) */
238 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_MALLOC_FAILURE
);
241 window_val
= scalar
->d
[0] & mask
;
243 while ((window_val
!= 0) || (j
+ w
+ 1 < len
)) {
244 /* if j+w+1 >= len, window_val will not increase */
247 /* 0 <= window_val <= 2^(w+1) */
248 if (window_val
& 1) {
249 /* 0 < window_val < 2^(w+1) */
250 if (window_val
& bit
) {
251 digit
= window_val
- next_bit
; /* -2^w < digit < 0 */
253 #if 1 /* modified wNAF */
254 if (j
+ w
+ 1 >= len
) {
256 * special case for generating
257 * modified wNAFs: no new bits will
258 * be added into window_val, so using
259 * a positive digit here will
260 * decrease the total length of the
264 digit
= window_val
& (mask
>> 1); /* 0 < digit < 2^w */
268 digit
= window_val
; /* 0 < digit < 2^w */
271 if (digit
<= -bit
|| digit
>= bit
|| !(digit
& 1)) {
272 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_INTERNAL_ERROR
);
278 * now window_val is 0 or 2^(w+1) in standard wNAF
279 * generation; for modified window NAFs, it may also
282 if (window_val
!= 0 && window_val
!= next_bit
&& window_val
!= bit
) {
283 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_INTERNAL_ERROR
);
287 r
[j
++] = sign
* digit
;
290 window_val
+= bit
* BN_is_bit_set(scalar
, j
+ w
);
292 if (window_val
> next_bit
) {
293 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_INTERNAL_ERROR
);
299 ECerr(EC_F_COMPUTE_WNAF
, ERR_R_INTERNAL_ERROR
);
316 /* TODO: table should be optimised for the wNAF-based implementation,
317 * sometimes smaller windows will give better performance
318 * (thus the boundaries should be increased)
320 #define EC_window_bits_for_scalar_size(b) \
330 * \sum scalars[i]*points[i],
333 * in the addition if scalar != NULL
336 ec_wNAF_mul(const EC_GROUP
* group
, EC_POINT
* r
, const BIGNUM
* scalar
,
337 size_t num
, const EC_POINT
* points
[], const BIGNUM
* scalars
[], BN_CTX
* ctx
)
339 BN_CTX
*new_ctx
= NULL
;
340 const EC_POINT
*generator
= NULL
;
341 EC_POINT
*tmp
= NULL
;
343 size_t blocksize
= 0, numblocks
= 0; /* for wNAF splitting */
344 size_t pre_points_per_block
= 0;
347 int r_is_inverted
= 0;
348 int r_is_at_infinity
= 1;
349 size_t *wsize
= NULL
; /* individual window sizes */
350 signed char **wNAF
= NULL
; /* individual wNAFs */
351 signed char *tmp_wNAF
= NULL
;
352 size_t *wNAF_len
= NULL
;
355 EC_POINT
**val
= NULL
; /* precomputation */
357 EC_POINT
***val_sub
= NULL
; /* pointers to sub-arrays of 'val' or
358 * 'pre_comp->points' */
359 const EC_PRE_COMP
*pre_comp
= NULL
;
360 int num_scalar
= 0; /* flag: will be set to 1 if 'scalar' must be
361 * treated like other scalars, i.e.
362 * precomputation is not available */
365 if (group
->meth
!= r
->meth
) {
366 ECerr(EC_F_EC_WNAF_MUL
, EC_R_INCOMPATIBLE_OBJECTS
);
369 if ((scalar
== NULL
) && (num
== 0)) {
370 return EC_POINT_set_to_infinity(group
, r
);
372 for (i
= 0; i
< num
; i
++) {
373 if (group
->meth
!= points
[i
]->meth
) {
374 ECerr(EC_F_EC_WNAF_MUL
, EC_R_INCOMPATIBLE_OBJECTS
);
380 ctx
= new_ctx
= BN_CTX_new();
384 if (scalar
!= NULL
) {
385 generator
= EC_GROUP_get0_generator(group
);
386 if (generator
== NULL
) {
387 ECerr(EC_F_EC_WNAF_MUL
, EC_R_UNDEFINED_GENERATOR
);
390 /* look if we can use precomputed multiples of generator */
392 pre_comp
= EC_EX_DATA_get_data(group
->extra_data
, ec_pre_comp_dup
, ec_pre_comp_free
, ec_pre_comp_clear_free
);
394 if (pre_comp
&& pre_comp
->numblocks
&&
395 (EC_POINT_cmp(group
, generator
, pre_comp
->points
[0], ctx
) == 0)) {
396 blocksize
= pre_comp
->blocksize
;
399 * determine maximum number of blocks that wNAF
400 * splitting may yield (NB: maximum wNAF length is
401 * bit length plus one)
403 numblocks
= (BN_num_bits(scalar
) / blocksize
) + 1;
406 * we cannot use more blocks than we have
409 if (numblocks
> pre_comp
->numblocks
)
410 numblocks
= pre_comp
->numblocks
;
412 pre_points_per_block
= (size_t) 1 << (pre_comp
->w
- 1);
414 /* check that pre_comp looks sane */
415 if (pre_comp
->num
!= (pre_comp
->numblocks
* pre_points_per_block
)) {
416 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_INTERNAL_ERROR
);
420 /* can't use precomputation */
423 num_scalar
= 1; /* treat 'scalar' like 'num'-th
424 * element of 'scalars' */
427 totalnum
= num
+ numblocks
;
429 /* includes space for pivot */
430 wNAF
= reallocarray(NULL
, (totalnum
+ 1), sizeof wNAF
[0]);
432 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_MALLOC_FAILURE
);
436 wNAF
[0] = NULL
; /* preliminary pivot */
438 wsize
= reallocarray(NULL
, totalnum
, sizeof wsize
[0]);
439 wNAF_len
= reallocarray(NULL
, totalnum
, sizeof wNAF_len
[0]);
440 val_sub
= reallocarray(NULL
, totalnum
, sizeof val_sub
[0]);
442 if (wsize
== NULL
|| wNAF_len
== NULL
|| val_sub
== NULL
) {
443 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_MALLOC_FAILURE
);
447 /* num_val will be the total number of temporarily precomputed points */
450 for (i
= 0; i
< num
+ num_scalar
; i
++) {
453 bits
= i
< num
? BN_num_bits(scalars
[i
]) : BN_num_bits(scalar
);
454 wsize
[i
] = EC_window_bits_for_scalar_size(bits
);
455 num_val
+= (size_t) 1 << (wsize
[i
] - 1);
456 wNAF
[i
+ 1] = NULL
; /* make sure we always have a pivot */
457 wNAF
[i
] = compute_wNAF((i
< num
? scalars
[i
] : scalar
), wsize
[i
], &wNAF_len
[i
]);
460 if (wNAF_len
[i
] > max_len
)
461 max_len
= wNAF_len
[i
];
465 /* we go here iff scalar != NULL */
467 if (pre_comp
== NULL
) {
468 if (num_scalar
!= 1) {
469 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_INTERNAL_ERROR
);
472 /* we have already generated a wNAF for 'scalar' */
476 if (num_scalar
!= 0) {
477 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_INTERNAL_ERROR
);
481 * use the window size for which we have
484 wsize
[num
] = pre_comp
->w
;
485 tmp_wNAF
= compute_wNAF(scalar
, wsize
[num
], &tmp_len
);
486 if (tmp_wNAF
== NULL
)
489 if (tmp_len
<= max_len
) {
491 * One of the other wNAFs is at least as long
492 * as the wNAF belonging to the generator, so
493 * wNAF splitting will not buy us anything.
497 totalnum
= num
+ 1; /* don't use wNAF
499 wNAF
[num
] = tmp_wNAF
;
501 wNAF
[num
+ 1] = NULL
;
502 wNAF_len
[num
] = tmp_len
;
503 if (tmp_len
> max_len
)
506 * pre_comp->points starts with the points
509 val_sub
[num
] = pre_comp
->points
;
512 * don't include tmp_wNAF directly into wNAF
513 * array - use wNAF splitting and include the
518 EC_POINT
**tmp_points
;
520 if (tmp_len
< numblocks
* blocksize
) {
522 * possibly we can do with fewer
523 * blocks than estimated
525 numblocks
= (tmp_len
+ blocksize
- 1) / blocksize
;
526 if (numblocks
> pre_comp
->numblocks
) {
527 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_INTERNAL_ERROR
);
530 totalnum
= num
+ numblocks
;
532 /* split wNAF in 'numblocks' parts */
534 tmp_points
= pre_comp
->points
;
536 for (i
= num
; i
< totalnum
; i
++) {
537 if (i
< totalnum
- 1) {
538 wNAF_len
[i
] = blocksize
;
539 if (tmp_len
< blocksize
) {
540 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_INTERNAL_ERROR
);
543 tmp_len
-= blocksize
;
546 * last block gets whatever
547 * is left (this could be
551 wNAF_len
[i
] = tmp_len
;
554 wNAF
[i
] = malloc(wNAF_len
[i
]);
555 if (wNAF
[i
] == NULL
) {
556 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_MALLOC_FAILURE
);
559 memcpy(wNAF
[i
], pp
, wNAF_len
[i
]);
560 if (wNAF_len
[i
] > max_len
)
561 max_len
= wNAF_len
[i
];
563 if (*tmp_points
== NULL
) {
564 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_INTERNAL_ERROR
);
567 val_sub
[i
] = tmp_points
;
568 tmp_points
+= pre_points_per_block
;
575 * All points we precompute now go into a single array 'val'.
576 * 'val_sub[i]' is a pointer to the subarray for the i-th point, or
577 * to a subarray of 'pre_comp->points' if we already have
580 val
= reallocarray(NULL
, (num_val
+ 1), sizeof val
[0]);
582 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_MALLOC_FAILURE
);
585 val
[num_val
] = NULL
; /* pivot element */
587 /* allocate points for precomputation */
589 for (i
= 0; i
< num
+ num_scalar
; i
++) {
591 for (j
= 0; j
< ((size_t) 1 << (wsize
[i
] - 1)); j
++) {
592 *v
= EC_POINT_new(group
);
598 if (!(v
== val
+ num_val
)) {
599 ECerr(EC_F_EC_WNAF_MUL
, ERR_R_INTERNAL_ERROR
);
602 if (!(tmp
= EC_POINT_new(group
)))
606 * prepare precomputed values: val_sub[i][0] := points[i]
607 * val_sub[i][1] := 3 * points[i] val_sub[i][2] := 5 * points[i] ...
609 for (i
= 0; i
< num
+ num_scalar
; i
++) {
611 if (!EC_POINT_copy(val_sub
[i
][0], points
[i
]))
614 if (!EC_POINT_copy(val_sub
[i
][0], generator
))
619 if (!EC_POINT_dbl(group
, tmp
, val_sub
[i
][0], ctx
))
621 for (j
= 1; j
< ((size_t) 1 << (wsize
[i
] - 1)); j
++) {
622 if (!EC_POINT_add(group
, val_sub
[i
][j
], val_sub
[i
][j
- 1], tmp
, ctx
))
628 if (!EC_POINTs_make_affine(group
, num_val
, val
, ctx
))
631 r_is_at_infinity
= 1;
633 for (k
= max_len
- 1; k
>= 0; k
--) {
634 if (!r_is_at_infinity
) {
635 if (!EC_POINT_dbl(group
, r
, r
, ctx
))
638 for (i
= 0; i
< totalnum
; i
++) {
639 if (wNAF_len
[i
] > (size_t) k
) {
640 int digit
= wNAF
[i
][k
];
649 if (is_neg
!= r_is_inverted
) {
650 if (!r_is_at_infinity
) {
651 if (!EC_POINT_invert(group
, r
, ctx
))
654 r_is_inverted
= !r_is_inverted
;
658 if (r_is_at_infinity
) {
659 if (!EC_POINT_copy(r
, val_sub
[i
][digit
>> 1]))
661 r_is_at_infinity
= 0;
663 if (!EC_POINT_add(group
, r
, r
, val_sub
[i
][digit
>> 1], ctx
))
671 if (r_is_at_infinity
) {
672 if (!EC_POINT_set_to_infinity(group
, r
))
676 if (!EC_POINT_invert(group
, r
, ctx
))
683 BN_CTX_free(new_ctx
);
691 for (w
= wNAF
; *w
!= NULL
; w
++)
697 for (v
= val
; *v
!= NULL
; v
++)
698 EC_POINT_clear_free(*v
);
706 /* ec_wNAF_precompute_mult()
707 * creates an EC_PRE_COMP object with preprecomputed multiples of the generator
708 * for use with wNAF splitting as implemented in ec_wNAF_mul().
710 * 'pre_comp->points' is an array of multiples of the generator
711 * of the following form:
712 * points[0] = generator;
713 * points[1] = 3 * generator;
715 * points[2^(w-1)-1] = (2^(w-1)-1) * generator;
716 * points[2^(w-1)] = 2^blocksize * generator;
717 * points[2^(w-1)+1] = 3 * 2^blocksize * generator;
719 * points[2^(w-1)*(numblocks-1)-1] = (2^(w-1)) * 2^(blocksize*(numblocks-2)) * generator
720 * points[2^(w-1)*(numblocks-1)] = 2^(blocksize*(numblocks-1)) * generator
722 * points[2^(w-1)*numblocks-1] = (2^(w-1)) * 2^(blocksize*(numblocks-1)) * generator
723 * points[2^(w-1)*numblocks] = NULL
726 ec_wNAF_precompute_mult(EC_GROUP
* group
, BN_CTX
* ctx
)
728 const EC_POINT
*generator
;
729 EC_POINT
*tmp_point
= NULL
, *base
= NULL
, **var
;
730 BN_CTX
*new_ctx
= NULL
;
732 size_t i
, bits
, w
, pre_points_per_block
, blocksize
, numblocks
,
734 EC_POINT
**points
= NULL
;
735 EC_PRE_COMP
*pre_comp
;
738 /* if there is an old EC_PRE_COMP object, throw it away */
739 EC_EX_DATA_free_data(&group
->extra_data
, ec_pre_comp_dup
, ec_pre_comp_free
, ec_pre_comp_clear_free
);
741 if ((pre_comp
= ec_pre_comp_new(group
)) == NULL
)
744 generator
= EC_GROUP_get0_generator(group
);
745 if (generator
== NULL
) {
746 ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT
, EC_R_UNDEFINED_GENERATOR
);
750 ctx
= new_ctx
= BN_CTX_new();
755 if ((order
= BN_CTX_get(ctx
)) == NULL
)
758 if (!EC_GROUP_get_order(group
, order
, ctx
))
760 if (BN_is_zero(order
)) {
761 ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT
, EC_R_UNKNOWN_ORDER
);
764 bits
= BN_num_bits(order
);
766 * The following parameters mean we precompute (approximately) one
769 * TBD: The combination 8, 4 is perfect for 160 bits; for other bit
770 * lengths, other parameter combinations might provide better
775 if (EC_window_bits_for_scalar_size(bits
) > w
) {
776 /* let's not make the window too small ... */
777 w
= EC_window_bits_for_scalar_size(bits
);
779 numblocks
= (bits
+ blocksize
- 1) / blocksize
; /* max. number of blocks
783 pre_points_per_block
= (size_t) 1 << (w
- 1);
784 num
= pre_points_per_block
* numblocks
; /* number of points to
785 * compute and store */
787 points
= reallocarray(NULL
, (num
+ 1), sizeof(EC_POINT
*));
789 ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT
, ERR_R_MALLOC_FAILURE
);
793 var
[num
] = NULL
; /* pivot */
794 for (i
= 0; i
< num
; i
++) {
795 if ((var
[i
] = EC_POINT_new(group
)) == NULL
) {
796 ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT
, ERR_R_MALLOC_FAILURE
);
801 if (!(tmp_point
= EC_POINT_new(group
)) || !(base
= EC_POINT_new(group
))) {
802 ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT
, ERR_R_MALLOC_FAILURE
);
805 if (!EC_POINT_copy(base
, generator
))
808 /* do the precomputation */
809 for (i
= 0; i
< numblocks
; i
++) {
812 if (!EC_POINT_dbl(group
, tmp_point
, base
, ctx
))
815 if (!EC_POINT_copy(*var
++, base
))
818 for (j
= 1; j
< pre_points_per_block
; j
++, var
++) {
819 /* calculate odd multiples of the current base point */
820 if (!EC_POINT_add(group
, *var
, tmp_point
, *(var
- 1), ctx
))
824 if (i
< numblocks
- 1) {
826 * get the next base (multiply current one by
831 if (blocksize
<= 2) {
832 ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT
, ERR_R_INTERNAL_ERROR
);
835 if (!EC_POINT_dbl(group
, base
, tmp_point
, ctx
))
837 for (k
= 2; k
< blocksize
; k
++) {
838 if (!EC_POINT_dbl(group
, base
, base
, ctx
))
844 if (!EC_POINTs_make_affine(group
, num
, points
, ctx
))
847 pre_comp
->group
= group
;
848 pre_comp
->blocksize
= blocksize
;
849 pre_comp
->numblocks
= numblocks
;
851 pre_comp
->points
= points
;
855 if (!EC_EX_DATA_set_data(&group
->extra_data
, pre_comp
,
856 ec_pre_comp_dup
, ec_pre_comp_free
, ec_pre_comp_clear_free
))
864 BN_CTX_free(new_ctx
);
865 ec_pre_comp_free(pre_comp
);
869 for (p
= points
; *p
!= NULL
; p
++)
873 EC_POINT_free(tmp_point
);
880 ec_wNAF_have_precompute_mult(const EC_GROUP
* group
)
882 if (EC_EX_DATA_get_data(group
->extra_data
, ec_pre_comp_dup
, ec_pre_comp_free
, ec_pre_comp_clear_free
) != NULL
)