45 lines
1.1 KiB
C
45 lines
1.1 KiB
C
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#include "tommath_private.h"
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#ifdef 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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/* grow as required */
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mp_err mp_grow(mp_int *a, int size)
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{
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if (size < 0) {
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return MP_VAL;
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}
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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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mp_digit *dp;
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if (size > MP_MAX_DIGIT_COUNT) {
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return MP_OVF;
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}
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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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dp = (mp_digit *) MP_REALLOC(a->dp,
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(size_t)a->alloc * sizeof(mp_digit),
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(size_t)size * sizeof(mp_digit));
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if (dp == NULL) {
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/* reallocation failed but "a" is still valid [can be freed] */
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return MP_MEM;
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}
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/* reallocation succeeded so set a->dp */
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a->dp = dp;
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/* zero excess digits */
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s_mp_zero_digs(a->dp + a->alloc, size - a->alloc);
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a->alloc = size;
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}
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return MP_OKAY;
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}
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#endif
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