What is the signature generation process for a ViewState?

The signature is generated by first converting the validationKey from hex to bytes. The generator (a hex string) is converted to a 4-byte little-endian integer. The serialized data is concatenated with these 4 bytes, then passed to HMACSHA1 with the validationKey to compute a hash. This hash is appended to the original serialized data before Base64 encoding, a process derived from code in the CVE-2020-0688 exploit and critical for server acceptance.