Question- Does ArubaOS support special characters?
Environment- Any controller running any ArubaOS version
Answer- ArubaOS CLI doesn't support special characters (i.e. non-ascII). Hence, it wouldn't be possible to use such values in names, database entry (internal-db).
As CLI doesn't support these characters, RADIUS debug command "aaa test-server" would fail for passwords which contain special character.
In case of 802.1x client authentication against server with username / password having special character; the communication is between client and server and controller would pass over credentials from client to the server (both termination enabled & disabled scenarios). In these scenarioes, it's dependent on the client and server.