# File lib/net/ssh/authentication/session.rb, line 49
49:     def authenticate(next_service, username, password=nil)
50:       debug { "beginning authentication of `#{username}'" }
51: 
52:       transport.send_message(transport.service_request("ssh-userauth"))
53:       message = expect_message(SERVICE_ACCEPT)
54: 
55:       key_manager = KeyManager.new(logger, options)
56:       keys.each { |key| key_manager.add(key) } unless keys.empty?
57:       key_data.each { |key2| key_manager.add_key_data(key2) } unless key_data.empty?
58: 
59:       attempted = []
60: 
61:       @auth_methods.each do |name|
62:         next unless @allowed_auth_methods.include?(name)
63:         attempted << name
64: 
65:         debug { "trying #{name}" }
66:         method = Methods.const_get(name.split(/\W+/).map { |p| p.capitalize }.join).new(self, :key_manager => key_manager)
67: 
68:         return true if method.authenticate(next_service, username, password)
69:       end
70: 
71:       error { "all authorization methods failed (tried #{attempted.join(', ')})" }
72:       return false
73:     ensure
74:       key_manager.finish if key_manager
75:     end