Grab the last 32 bytes of 64-bytes input

Question

In assembly, how do I grab the last 32 bytes in a 64-bytes input?

I know that this code is for grabbing the first 32:

bytes32 half;

assembly {
   half := mload(add(accData2, 32))
}

Answer 1

Consider this example:

// input 64 bytes 0x11112233445566778899aabbccddeeff00112233445566778899aabbccddeeff22112233445566778899aabbccddeeff00112233445566778899aabbccddeeff
// input 64 bytes 0x11111111111111111111111111111111111111111111111111111111111111112222222222222222222222222222222222222222222222222222222222222222
contract Bytes {
    function getLast32Bytes(bytes memory input) public returns (bytes32 half) {
        require(input.length == 64, "input must be exactly 64 bytes");

        assembly {
            half := mload(add(input, 64))
        }
    }

    function getFirst32Bytes(bytes memory input) public returns (bytes32 half) {
        require(input.length == 64, "input must be exactly 64 bytes");

        assembly {
            half := mload(add(input, 32))
        }
    }
}