Class: Net::SSH::Authentication::Methods::KeyboardInteractive

Inherits:
Abstract
  • Object
show all
Defined in:
lib/net/ssh/authentication/methods/keyboard_interactive.rb

Overview

Implements the “keyboard-interactive” SSH authentication method.

Constant Summary collapse

USERAUTH_INFO_REQUEST =
60
USERAUTH_INFO_RESPONSE =
61

Constants included from Constants

Constants::USERAUTH_BANNER, Constants::USERAUTH_FAILURE, Constants::USERAUTH_METHOD_RANGE, Constants::USERAUTH_PASSWD_CHANGEREQ, Constants::USERAUTH_PK_OK, Constants::USERAUTH_REQUEST, Constants::USERAUTH_SUCCESS

Instance Attribute Summary

Attributes inherited from Abstract

#key_manager, #session

Attributes included from Loggable

#logger

Instance Method Summary collapse

Methods inherited from Abstract

#initialize, #send_message, #session_id, #userauth_request

Methods included from Loggable

#debug, #error, #fatal, #info, #lwarn

Constructor Details

This class inherits a constructor from Net::SSH::Authentication::Methods::Abstract

Instance Method Details

#authenticate(next_service, username, password = nil) ⇒ Object

Attempt to authenticate the given user for the given service.


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# File 'lib/net/ssh/authentication/methods/keyboard_interactive.rb', line 15

def authenticate(next_service, username, password=nil)
  debug { "trying keyboard-interactive" }
  send_message(userauth_request(username, next_service, "keyboard-interactive", "", ""))

  prompter = nil
  loop do
    message = session.next_message

    case message.type
    when USERAUTH_SUCCESS
      debug { "keyboard-interactive succeeded" }
      prompter.success if prompter
      return true
    when USERAUTH_FAILURE
      debug { "keyboard-interactive failed" }

      raise Net::SSH::Authentication::DisallowedMethod unless
        message[:authentications].split(/,/).include? 'keyboard-interactive'

      return false unless interactive?
      password = nil
      debug { "retrying keyboard-interactive" }
      send_message(userauth_request(username, next_service, "keyboard-interactive", "", ""))
    when USERAUTH_INFO_REQUEST
      name = message.read_string
      instruction = message.read_string
      debug { "keyboard-interactive info request" }

      if password.nil? && interactive? && prompter.nil?
        prompter = prompt.start(type: 'keyboard-interactive', name: name, instruction: instruction)
      end

      _ = message.read_string # lang_tag
      responses = []

      message.read_long.times do
        text = message.read_string
        echo = message.read_bool
        password_to_send = password || (prompter && prompter.ask(text, echo))
        responses << password_to_send
      end

      # if the password failed the first time around, don't try
      # and use it on subsequent requests.
      password = nil

      msg = Buffer.from(:byte, USERAUTH_INFO_RESPONSE, :long, responses.length, :string, responses)
      send_message(msg)
    else
      raise Net::SSH::Exception, "unexpected reply in keyboard interactive: #{message.type} (#{message.inspect})"
    end
  end
end

#interactive?Boolean

Returns:

  • (Boolean)

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# File 'lib/net/ssh/authentication/methods/keyboard_interactive.rb', line 69

def interactive?
  options = session.transport.options || {}
  !options[:non_interactive]
end