Safe cookie authentication failure replies do not end with a CRLF
On the control socket, AUTHCHALLENGE's failure replies do not end with a CRLF.
+12:29% nc localhost 9100
AUTHCHALLENGE SAFEOHJOIE
513 AUTHCHALLENGE only supports SAFECOOKIE authentication%
+1:43% nc localhost 9100
AUTHCHALLENGE SAFECOOKIE FOOFA
513 Invalid base16 client nonce%
That is all.