🌻 📖 AnyEvent::Ident

NAME

AnyEvent::Ident - Simple asynchronous ident client and server

VERSION

version 0.08

SYNOPSIS

client:

 use AnyEvent::Ident qw( ident_client );
 
 ident_client '127.0.0.1', 113, $server_port, $client_port, sub {
   my($res) = @_; # isa AnyEvent::Client::Response 
   if($res->is_success)
   {
     print "user: ", $res->username, "\n"
     print "os:   ", $res->os, "\n"
   }
   else
   {
     warn "Ident error: " $res->error_type;
   }
 };

server:

 use AnyEvent::Ident qw( ident_server );
 
 ident_server '127.0.0.1', 113, sub {
   my $tx = shift;
   if($tx->req->server_port == 400
   && $tx->req->client_port == 500)
   {
     $tx->reply_with_user('UNIX', 'grimlock');
   }
   else
   {
     $tx->reply_with_error('NO-USER');
   }
 };

DESCRIPTION

This module provides a simple procedural interface to AnyEvent::Ident::Client and AnyEvent::Ident::Server.

FUNCTIONS

ident_server

 my $server = ident_server $hostname, $port, $callback;
 my $server = ident_server $hostname, $port, $callback, \%opt;

Start an ident server listening to the address given by $hostname on port $port. For each request $callback will be called and passed in an instance of AnyEvent::Ident::Transaction.

%opt is optional hash of arguments. See AnyEvent::Ident::Server#CONSTRUCTOR for legal key/value pairs and defaults.

ident_client

 my $client = ident_client $hostname, $port, $server_port, $client_port, $callback;

Make an ident request with the ident server at $hostname on port $port with the given port pair $server_port,$client_port. When the response comes back call $callback, with an instance of AnyEvent::Ident::Response.

CAVEATS

ident is an oldish protocol and almost nobody uses it anymore. The RFC for the protocol clearly states that ident should not be used for authentication, at most it should be used only for audit (for example annotation of log files). In Windows and possibly other operating systems, an unprivileged user can listen to port 113 and on any untrusted network, a remote ident server is not a secure authentication mechanism.

No modern operating systems enable the ident service by default, so you can't expect it to be there unless you have control of the server and have specifically enabled it.

Most of the time a client wanting to use the ident protocol expects to find ident listening to port 113, which on many platforms (such as UNIX) requires special privileges (such as root).

Under Linux you can use iptables to forward requests from port 113 to an unprivileged port. I was able to use this incantation to forward port 113 to port 8113:

 # iptables -t nat -A PREROUTING -p tcp --dport 113 -j REDIRECT --to-port 8113
 # iptables -t nat -I OUTPUT -p tcp -d 127.0.0.1 --dport 113 -j REDIRECT --to-port 8113

The first rule is sufficient for external clients, the second rule was required for clients connecting via the loopback interface (localhost).

SEE ALSO

AnyEvent::Ident::Client

Client OO Interface

AnyEvent::Ident::Server

Server OO Interface

Net::Ident

Blocking implementation of client only.

RFC1413

AUTHOR

Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2013 by Graham Ollis.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.