If you refer to the ssh ciphers supported by the controller for SSH console connections, check out this Airheads post first.
The command that was referenced is available in recent versions, I checked the CLI guide for ArubaOS 6.5.4 and 8.3.0 which both show the following configuration commands:
ssh disable-ciphers {aes-cbc | aes-ctr}
ssh disable-mac hmac-sha1-96
ssh disable_dsa
Full details are in the CLI Reference Guide under the ssh command.