Contract Source Code:

/*
 * Copyright 2024 Circle Internet Group, Inc. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
pragma solidity 0.7.6;

/**
 * @title AddressUtilsExternal Library
 * @notice Helper functions for converting addresses to and from bytes
 **/
library AddressUtilsExternal {
    /**
     * @notice converts address to bytes32 (alignment preserving cast.)
     * @param addr the address to convert to bytes32
     */
    function addressToBytes32(address addr) external pure returns (bytes32) {
        return bytes32(uint256(uint160(addr)));
    }

    /**
     * @notice converts bytes32 to address (alignment preserving cast.)
     * @dev Warning: it is possible to have different input values _buf map to the same address.
     * For use cases where this is not acceptable, validate that the first 12 bytes of _buf are zero-padding.
     * @param _buf the bytes32 to convert to address
     */
    function bytes32ToAddress(bytes32 _buf) external pure returns (address) {
        return address(uint160(uint256(_buf)));
    }
}