40 lines
1.2 KiB
C
40 lines
1.2 KiB
C
#include "amplify_tommath_private.h"
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#ifdef AMPLIFY_BN_MP_GROW_C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis */
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/* SPDX-License-Identifier: Unlicense */
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/* Modifications Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. */
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/* grow as required */
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amplify_mp_err amplify_mp_grow(amplify_mp_int *a, int size)
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{
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int i;
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amplify_mp_digit *tmp;
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/* if the alloc size is smaller alloc more ram */
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if (a->alloc < size) {
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/* reallocate the array a->dp
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*
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* We store the return in a temporary variable
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* in case the operation failed we don't want
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* to overwrite the dp member of a.
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*/
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tmp = (amplify_mp_digit *) AMPLIFY_MP_REALLOC(a->dp,
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(size_t)a->alloc * sizeof(amplify_mp_digit),
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(size_t)size * sizeof(amplify_mp_digit));
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if (tmp == NULL) {
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/* reallocation failed but "a" is still valid [can be freed] */
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return AMPLIFY_MP_MEM;
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}
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/* reallocation succeeded so set a->dp */
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a->dp = tmp;
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/* zero excess digits */
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i = a->alloc;
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a->alloc = size;
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AMPLIFY_MP_ZERO_DIGITS(a->dp + i, a->alloc - i);
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}
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return AMPLIFY_MP_OKAY;
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}
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#endif
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