capistrano_extension.rb

module Capistrano
  class SSH
    class << self
      alias :original_connect :connect
      def connect(server, options={}, &block)
       additional_server_settings = options[:server_authentication] ? options[:server_authentication] =~ /#{server.to_s}/ : nil
        if additional_server_settings.nil?
         return original_connect(server, options, &block)
        else
          methods = [ %w(publickey hostbased), %w(password keyboard-interactive) ]
          password_value = nil
          ssh_options = (options[:ssh_options] || {}).dup
          port = server.port || options[:port] || ssh_options[:port]
          ssh_options[:port] = port if(port)
          begin
            connection_options = ssh_options.merge(
              :password => password_value,
              :auth_methods => ssh_options[:auth_methods] || methods.shift
            )
            connection = Net::SSH.start(server.host, server.user, connection_options, &block)
            Server.apply_to(connection, server)
          rescue Net::SSH::AuthenticationFailed
            raise if methods.empty? || ssh_options[:auth_methods]
            password_value = Capistrano::CLI.password_prompt
            retry
          end
        end
      end
    end
  end
end