48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
#include "amplify_tommath_private.h"
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#ifdef AMPLIFY_BN_MP_RAND_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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amplify_mp_err(*amplify_s_mp_rand_source)(void *out, size_t size) = amplify_s_mp_rand_platform;
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void amplify_mp_rand_source(amplify_mp_err(*source)(void *out, size_t size))
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{
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amplify_s_mp_rand_source = (source == NULL) ? amplify_s_mp_rand_platform : source;
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}
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amplify_mp_err amplify_mp_rand(amplify_mp_int *a, int digits)
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{
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int i;
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amplify_mp_err err;
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amplify_mp_zero(a);
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if (digits <= 0) {
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return AMPLIFY_MP_OKAY;
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}
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if ((err = amplify_mp_grow(a, digits)) != AMPLIFY_MP_OKAY) {
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return err;
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}
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if ((err = amplify_s_mp_rand_source(a->dp, (size_t)digits * sizeof(amplify_mp_digit))) != AMPLIFY_MP_OKAY) {
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return err;
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}
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/* TODO: We ensure that the highest digit is nonzero. Should this be removed? */
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while ((a->dp[digits - 1] & AMPLIFY_MP_MASK) == 0u) {
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if ((err = amplify_s_mp_rand_source(a->dp + digits - 1, sizeof(amplify_mp_digit))) != AMPLIFY_MP_OKAY) {
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return err;
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}
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}
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a->used = digits;
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for (i = 0; i < digits; ++i) {
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a->dp[i] &= AMPLIFY_MP_MASK;
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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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