Correction for hash_hmac and hash_hmac_file.
From PHP's documentation:
hash_hmac:

Returns FALSE when algo is unknown or is a non-cryptographic hash function.

hash_hmac_file:

Returns a string containing the calculated message digest as lowercase hexits unless raw_output is set to true in which case the raw binary representation of the message digest is returned. Returns FALSE when algo is unknown or is a non-cryptographic hash function, or if the file filename cannot be read.