Server will reject connection with
if it discovers that client capabilities are not sufficient to
complete authenticaiton. This can happen in the following
A client which does not support pluggable authentication (
CLIENT_PLUGIN_AUTHflag not set) connects to an account which uses authentication method different from
Secure Password Authenticationor
Old Password Authentication.
Server's default authentication method used to generate authentication data in the
Initial Handshake Packetis different from
Secure Password Authenticationand client does not support pluggable authentication (
CLIENT_PLUGIN_AUTHflag not set).
In either of these cases authentication phase will look as follows: