Created
July 21, 2013 09:34
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Freenode's cap_sasl.pl updated to use Crypt::DH::GMP, and fallback to Crypt:DH, when using encrypted sasl passwords.
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use strict; | |
use Irssi; | |
use vars qw($VERSION %IRSSI); | |
# $Id$ | |
use MIME::Base64; | |
$VERSION = "1.5"; | |
%IRSSI = ( | |
authors => 'Michael Tharp and Jilles Tjoelker', | |
contact => 'gxti@partiallystapled.com', | |
name => 'cap_sasl.pl', | |
description => 'Implements PLAIN SASL authentication mechanism for use with charybdis ircds, and enables CAP MULTI-PREFIX', | |
license => 'GNU General Public License', | |
url => 'http://ircv3.atheme.org/extensions/sasl-3.1', | |
); | |
my %sasl_auth = (); | |
my %mech = (); | |
sub timeout; | |
sub server_connected { | |
my $server = shift; | |
$server->send_raw_now("CAP LS"); | |
} | |
sub event_cap { | |
my ($server, $args, $nick, $address) = @_; | |
my ($subcmd, $caps, $tosend); | |
$tosend = ''; | |
if ($args =~ /^\S+ (\S+) :(.*)$/) { | |
$subcmd = uc $1; | |
$caps = ' '.$2.' '; | |
if ($subcmd eq 'LS') { | |
$tosend .= ' multi-prefix' if $caps =~ / multi-prefix /i; | |
$tosend .= ' sasl' if $caps =~ / sasl /i && defined($sasl_auth{$server->{tag}}); | |
$tosend =~ s/^ //; | |
$server->print('', "CLICAP: supported by server:$caps"); | |
if (!$server->{connected}) { | |
if ($tosend eq '') { | |
$server->send_raw_now("CAP END"); | |
} else { | |
$server->print('', "CLICAP: requesting: $tosend"); | |
$server->send_raw_now("CAP REQ :$tosend"); | |
} | |
} | |
Irssi::signal_stop(); | |
} elsif ($subcmd eq 'ACK') { | |
$server->print('', "CLICAP: now enabled:$caps"); | |
if ($caps =~ / sasl /i) { | |
$sasl_auth{$server->{tag}}{buffer} = ''; | |
if($mech{$sasl_auth{$server->{tag}}{mech}}) { | |
$server->send_raw_now("AUTHENTICATE " . $sasl_auth{$server->{tag}}{mech}); | |
Irssi::timeout_add_once(5000, \&timeout, $server->{tag}); | |
}else{ | |
$server->print('', 'SASL: attempted to start unknown mechanism "' . $sasl_auth{$server->{tag}}{mech} . '"'); | |
} | |
} | |
elsif (!$server->{connected}) { | |
$server->send_raw_now("CAP END"); | |
} | |
Irssi::signal_stop(); | |
} elsif ($subcmd eq 'NAK') { | |
$server->print('', "CLICAP: refused:$caps"); | |
if (!$server->{connected}) { | |
$server->send_raw_now("CAP END"); | |
} | |
Irssi::signal_stop(); | |
} elsif ($subcmd eq 'LIST') { | |
$server->print('', "CLICAP: currently enabled:$caps"); | |
Irssi::signal_stop(); | |
} | |
} | |
} | |
sub event_authenticate { | |
my ($server, $args, $nick, $address) = @_; | |
my $sasl = $sasl_auth{$server->{tag}}; | |
return unless $sasl && $mech{$sasl->{mech}}; | |
$sasl->{buffer} .= $args; | |
return if length($args) == 400; | |
my $data = $sasl->{buffer} eq '+' ? '' : decode_base64($sasl->{buffer}); | |
my $out = $mech{$sasl->{mech}}($sasl, $data); | |
$out = '' unless defined $out; | |
$out = $out eq '' ? '+' : encode_base64($out, ''); | |
while(length $out >= 400) { | |
my $subout = substr($out, 0, 400, ''); | |
$server->send_raw_now("AUTHENTICATE $subout"); | |
} | |
if(length $out) { | |
$server->send_raw_now("AUTHENTICATE $out"); | |
}else{ # Last piece was exactly 400 bytes, we have to send some padding to indicate we're done | |
$server->send_raw_now("AUTHENTICATE +"); | |
} | |
$sasl->{buffer} = ''; | |
Irssi::signal_stop(); | |
} | |
sub event_saslend { | |
my ($server, $args, $nick, $address) = @_; | |
my $data = $args; | |
$data =~ s/^\S+ :?//; | |
# need this to see it, ?? -- jilles | |
$server->print('', $data); | |
if (!$server->{connected}) { | |
$server->send_raw_now("CAP END"); | |
} | |
} | |
sub timeout { | |
my $tag = shift; | |
my $server = Irssi::server_find_tag($tag); | |
if(!$server->{connected}) { | |
$server->print('', "SASL: authentication timed out"); | |
$server->send_raw_now("CAP END"); | |
} | |
} | |
sub cmd_sasl { | |
my ($data, $server, $item) = @_; | |
if ($data ne '') { | |
Irssi::command_runsub ('sasl', $data, $server, $item); | |
} else { | |
cmd_sasl_show(@_); | |
} | |
} | |
sub cmd_sasl_set { | |
my ($data, $server, $item) = @_; | |
if (my($net, $u, $p, $m) = $data =~ /^(\S+) (\S+) (\S+) (\S+)$/) { | |
if($mech{uc $m}) { | |
$sasl_auth{$net}{user} = $u; | |
$sasl_auth{$net}{password} = $p; | |
$sasl_auth{$net}{mech} = uc $m; | |
Irssi::print("SASL: added $net: [$m] $sasl_auth{$net}{user} *"); | |
}else{ | |
Irssi::print("SASL: unknown mechanism $m"); | |
} | |
} elsif ($data =~ /^(\S+)$/) { | |
$net = $1; | |
if (defined($sasl_auth{$net})) { | |
delete $sasl_auth{$net}; | |
Irssi::print("SASL: deleted $net"); | |
} else { | |
Irssi::print("SASL: no entry for $net"); | |
} | |
} else { | |
Irssi::print("SASL: usage: /sasl set <net> <user> <password or keyfile> <mechanism>"); | |
} | |
} | |
sub cmd_sasl_show { | |
#my ($data, $server, $item) = @_; | |
my $net; | |
my $count = 0; | |
foreach $net (keys %sasl_auth) { | |
Irssi::print("SASL: $net: [$sasl_auth{$net}{mech}] $sasl_auth{$net}{user} *"); | |
$count++; | |
} | |
Irssi::print("SASL: no networks defined") if !$count; | |
} | |
sub cmd_sasl_save { | |
#my ($data, $server, $item) = @_; | |
my $file = Irssi::get_irssi_dir()."/sasl.auth"; | |
open FILE, "> $file" or return; | |
chmod(0600, $file); | |
foreach my $net (keys %sasl_auth) { | |
printf FILE ("%s\t%s\t%s\t%s\n", $net, $sasl_auth{$net}{user}, $sasl_auth{$net}{password}, $sasl_auth{$net}{mech}); | |
} | |
close FILE; | |
Irssi::print("SASL: auth saved to $file"); | |
} | |
sub cmd_sasl_load { | |
#my ($data, $server, $item) = @_; | |
my $file = Irssi::get_irssi_dir()."/sasl.auth"; | |
open FILE, "< $file" or return; | |
%sasl_auth = (); | |
while (<FILE>) { | |
chomp; | |
my ($net, $u, $p, $m) = split (/\t/, $_, 4); | |
$m ||= "PLAIN"; | |
if($mech{uc $m}) { | |
$sasl_auth{$net}{user} = $u; | |
$sasl_auth{$net}{password} = $p; | |
$sasl_auth{$net}{mech} = uc $m; | |
}else{ | |
Irssi::print("SASL: unknown mechanism $m"); | |
} | |
} | |
close FILE; | |
Irssi::print("SASL: auth loaded from $file"); | |
} | |
sub cmd_sasl_mechanisms { | |
Irssi::print("SASL: mechanisms supported: " . join(" ", keys %mech)); | |
} | |
Irssi::signal_add_first('server connected', \&server_connected); | |
Irssi::signal_add('event cap', \&event_cap); | |
Irssi::signal_add('event authenticate', \&event_authenticate); | |
Irssi::signal_add('event 903', 'event_saslend'); | |
Irssi::signal_add('event 904', 'event_saslend'); | |
Irssi::signal_add('event 905', 'event_saslend'); | |
Irssi::signal_add('event 906', 'event_saslend'); | |
Irssi::signal_add('event 907', 'event_saslend'); | |
Irssi::command_bind('sasl', \&cmd_sasl); | |
Irssi::command_bind('sasl load', \&cmd_sasl_load); | |
Irssi::command_bind('sasl save', \&cmd_sasl_save); | |
Irssi::command_bind('sasl set', \&cmd_sasl_set); | |
Irssi::command_bind('sasl show', \&cmd_sasl_show); | |
Irssi::command_bind('sasl mechanisms', \&cmd_sasl_mechanisms); | |
$mech{PLAIN} = sub { | |
my($sasl, $data) = @_; | |
my $u = $sasl->{user}; | |
my $p = $sasl->{password}; | |
join("\0", $u, $u, $p); | |
}; | |
eval { | |
require Crypt::OpenSSL::Bignum; | |
require Crypt::Blowfish; | |
require Math::BigInt; | |
eval { | |
require Crypt::DH::GMP; | |
require Crypt::DH::GMP::Compat; | |
$::compute_secret = sub { Math::BigInt->new((shift)->compute_secret(@_)) }; | |
}; | |
# Any compilation errors are likely because | |
if ($@) { | |
Irssi::print($@); | |
Irssi::print("WARN: Crypt::DH::GMP is recommended, but unable to be used. Trying old Crypt::DH"); | |
require Crypt::DH; | |
$::compute_secret = sub { (shift)->compute_secret(@_) }; | |
} | |
sub bin2bi { return Crypt::OpenSSL::Bignum->new_from_bin(shift)->to_decimal } # binary to BigInt | |
sub bi2bin { return Crypt::OpenSSL::Bignum->new_from_decimal((shift)->bstr)->to_bin } # BigInt to binary | |
$mech{'DH-BLOWFISH'} = sub { | |
my($sasl, $data) = @_; | |
my $u = $sasl->{user}; | |
my $pass = $sasl->{password}; | |
# Generate private key and compute secret key | |
my($p, $g, $y) = unpack("(n/a*)3", $data); | |
my $dh = Crypt::DH->new(p => bin2bi($p), g => bin2bi($g)); | |
$dh->generate_keys; | |
my $secret = bi2bin(&compute_secret($dh, bin2bi($y))); | |
my $pubkey = bi2bin($dh->pub_key); | |
# Pad the password to the nearest multiple of blocksize and encrypt | |
$pass .= "\0"; | |
$pass .= chr(rand(256)) while length($pass) % 8; | |
my $cipher = Crypt::Blowfish->new($secret); | |
my $crypted = ''; | |
while(length $pass) { | |
my $clear = substr($pass, 0, 8, ''); | |
$crypted .= $cipher->encrypt($clear); | |
} | |
pack("n/a*Z*a*", $pubkey, $u, $crypted); | |
}; | |
}; | |
Irssi::print($@) if $@; | |
cmd_sasl_load(); | |
# vim: ts=4 |
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