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				// Copyright (c) 2019 The Bitcoin developers
				// Distributed under the MIT software license, see the accompanying
				// file COPYING or http://www.opensource.org/licenses/mit-license.php.

				#include <script/bitfield.h>

				#include <script/script_error.h>

				#include <cstddef>
				#include <limits>

				bool DecodeBitfield(const std::vector<uint8_t> &vch, unsigned size,
				uint32_t &bitfield, ScriptError *serror) {
				if (size > 32) {
				return set_error(serror, ScriptError::INVALID_BITFIELD_SIZE);
				}

				const size_t bitfield_size = (size + 7) / 8;
				if (vch.size() != bitfield_size) {
				return set_error(serror, ScriptError::INVALID_BITFIELD_SIZE);
				}

				bitfield = 0;
				for (size_t i = 0; i < bitfield_size; i++) {
				// Decode the bitfield as little endian.
				bitfield \|= uint32_t(vch[i]) << (8 * i);
				}

				const uint32_t mask = (uint64_t(1) << size) - 1;
				if ((bitfield & mask) != bitfield) {
				return set_error(serror, ScriptError::INVALID_BIT_RANGE);
				}

				return true;
				}