[Protocol Upgrade] Hash hashes as binary instead of hex representation

Currently the hasher is using strings which are concatenated and then hashed again. We would like to change this behavior to use the binary representation of the hashes instead.

If a hash is not present (like signature or witness as optional input hashes) they are not added to the hasher-digest (input hashes for the verifiction_hash).

Example: using binary-representation of hashes and using a SHA3 hasher like this one to hash it.

In PHP this is done via:

<!DOCTYPE html>
<html>
<body>

<?php
$hash = "a69f73cca23a9ac5c8b567dc185a756e97c982164fe25859e0d1dcc1475c80a615b2123af1f5f94c11e3e9402c3ac558f500199d95b6d3e301758586281dcd26";
$binhash = hex2bin($hash);
$hashed = hash('sha3-512', $binhash);
echo "$hashed";
?>

</body>
</html>

When calculating the different hashes we choose binary input or string input as follows.

binary

verification { content_hash (sha3 / 64 bytes) metadata_hash (sha3 / 64 bytes) prev_ref_hash? (sha3 / 64 bytes) merge_ref_hash? (sha3 / 64 bytes) }
signature { eth signature (libsecp256k1 signature + recoveryid / 65 bytes) eth pubkey (libsecp256k1 public_key / 65 bytes) }
merkle-tree/merkle-node { left_hash (sha3 / 64 bytes) right_hash (sha3 / 64 bytes) }
witness_hash { domain_snapshot_genesis_hash (sha3 / 64 bytes) merkle_root (sha3 / 64 bytes) witness_network (uint64 / little-endian / 8 bytes) witness_event_transaction_hash (eth tx hash / 32 bytes) }

text

metadata { "AQUA" (exactly this), version (exactly 4 characters / version number / string), time ("YYYYMMDDhhmmss" / numbers only / string), domain (variable length, maximum of 64 bytes / hex encoded / string), }
content { like currently }

inblockio / Aqua-Improvement-Process

[Protocol Upgrade] Hash hashes as binary instead of hex representation #1