'Specify MAC algorithms'

def opt_macs(self, macs):

    if isinstance(macs, unicode):
        macs = macs.encode('utf-8')
    macs = macs.split(',')
    for mac in macs:
        if (mac not in SSHCiphers.macMap):
            sys.exit(("Unknown    mac    type    '%r'" % mac))
    self['macs'] = macs
