fhem-mirror/FHEM/98_GoogleAuth.pm
betateilchen 7e0eb947c1 98_GoogleAuth.pm: commandref updated
git-svn-id: https://svn.fhem.de/fhem/trunk/fhem@23628 2b470e98-0d58-463d-a4d8-8e2adae1ed80
2021-01-27 17:59:58 +00:00

403 lines
13 KiB
Perl

# $Id$
# License & technical informations
=for comment
#
################################################################
#
# This script is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# The GNU General Public License can be found at
# http://www.gnu.org/copyleft/gpl.html.
# A copy is found in the textfile GPL.txt and important notices to the license
# from the author is found in LICENSE.txt distributed with these scripts.
#
# This script is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# This copyright notice MUST APPEAR in all copies of the script!
#
# Homepage: http://www.fhem.de
#
################################################################
#
# Module 98_GoogleAuth.pm
# written by pandabaer_de, revised by betateilchen
#
# based on informations from this website
# https://blog.darkpan.com/article/6/Perl-and-Google-Authenticator.html
#
# requires additional perl modules
# Convert::Base32 Authen::OATH Crypt::URandom
#
# on Debian systems, use apt-get to install appropriate packages
# libconvert-base32-perl libauthen-oath-perl libcrypt-urandom-perl
#
################################################################
#
=cut
# Development history
=for comment
#
# 2017-01-15 - first commit to ./contrib
#
# 2017-01-15 - added: direct QR display after set
# added: attribute ga_qrSize
# added: FW_detailFn
# added: attribute ga_labelName
# added: reading lastCheck
# removed: reading qr_url
# added: show link to qrcode and key for manual use
# in device details
# added: set command "revoke" to prevent overwrite
# of existing key
# added: attribute ga_showKey
# attribute ga_showLink
# added: function gAuth(<device>,<token>) for easy use
# added: FW_summaryFn
# added: commandref documentation EN
#
# 2017-01-15 - published to FHEM
# fixed: problem on iOS if label contains spaces
# added: issuer=FHEM in qr-code
#
# 2017-01-16 - added: attributes ga_showQR, ga_strictCheck
# removed: FW_summaryFn (not really useful)
#
# 2020-03-31 - changed: remove prototyping and undef results
#
# 2021-01-26 - changed: rework code to use own package
#
=cut
package FHEM::GoogleAuth; ## no critic
use strict;
use warnings;
use Convert::Base32;
use Authen::OATH;
use URI::Escape;
use Crypt::URandom qw( urandom );
use GPUtils qw(GP_Import GP_Export);
## Import der FHEM Funktionen
BEGIN {
# Import from main context
GP_Import(
qw( AttrVal
Debug
Log3
defs
readingFnAttributes
readingsSingleUpdate
setKeyValue
getKeyValue )
);
#-- Export to main context with different name
GP_Export(
qw( Initialize )
);
}
sub Initialize {
my ($hash) = @_;
$hash->{DefFn} = \&Define;
$hash->{DeleteFn} = \&Delete;
$hash->{SetFn} = \&Set;
$hash->{GetFn} = \&Get;
$hash->{FW_detailFn} = \&Detail;
$hash->{AttrList} = "ga_labelName ".
"ga_qrSize:100x100,200x200,300x300,400x400 ".
"ga_showKey:0,1 ga_showLink:0,1 ga_showQR:1,0 ".
"ga_strictCheck:0,1 ".
"$readingFnAttributes";
}
sub Define {
my ($hash, $def) = @_;
my $name = $hash->{NAME};
my @a = split("[ \t][ \t]*", $def);
return "Usage: Use Google Authenticator" if(@a != 2);
Log3($hash,4,"googleAuth $name: defined");
readingsSingleUpdate($hash,'state','defined',1);
return;
}
sub Delete {
my ($hash,$name) = @_;
setKeyValue("googleAuth$name",undef);
}
sub Set {
my ($hash, $name, $cmd, @args) = @_;
my $usage = "Unknown argument, choose one of new:noArg revoke:noArg";
if($cmd eq "new") {
#SOURCE: https://blog.darkpan.com/article/6/Perl-and-Google-Authenticator.html
return "Please revoke existing key first!" if defined(getKeyValue("googleAuth$name"));
my $secret_bytes = urandom(50);
my $secret_base32 = encode_base32( $secret_bytes );
Log3($hash,5,"googleAuth $name: secret_bytes=$secret_bytes");
Log3($hash,5,"googleAuth $name: set secret_base32=$secret_base32");
setKeyValue("googleAuth$name",$secret_base32); # write to fhem keystore
readingsSingleUpdate($hash,'state','active',1);
} elsif ($cmd eq "revoke") {
setKeyValue("googleAuth$name",undef);
readingsSingleUpdate($hash,'state','defined',1);
} else {
return $usage
}
return;
}
sub Get {
my ($hash, $name, $cmd, $given_token) = @_;
my $usage = "Unknown argument, choose one of check";
if ($cmd eq "check") {
return "Token missing!" unless (defined($given_token) && $given_token);
$given_token = _ga_make_token_6($given_token);
Log3($hash,4,"googleAuth $name: given: $given_token");
my $secret_base32 = getKeyValue("googleAuth$name"); # read from fhem keystore
Log3($hash,5,"googleAuth $name: get secret_base32=$secret_base32");
$secret_base32 = decode_base32($secret_base32);
Log3($hash,5,"googleAuth $name: secret_bytes=$secret_base32");
my $oath = Authen::OATH->new;
my @possible;
if (AttrVal($name,'ga_strictCheck',0) == 1) {
@possible = _ga_make_token_6($oath->totp($secret_base32));
} else {
@possible = map { _ga_make_token_6($oath->totp($secret_base32, $_)) } time-30, time, time+30;
}
Log3($hash,4,"googleAuth $name: possible: ".join ' ',@possible);
my $result = (grep /^$given_token$/, @possible) ? 1 : -1;
readingsSingleUpdate($hash,'lastResult',$result,0);
Log3($hash,4,"googleAuth $name: result: $result");
return $result;
}
return $usage;
}
sub Detail {
my ($FW_wname, $name, $room, $pageHash) = @_;
my $qr_url = _ga_make_url($name);
my $secret_base32 = getKeyValue("googleAuth$name"); # read from fhem keystore
return unless defined($qr_url);
my $ret = "<table>";
$ret .= "<tr><td rowspan=2>";
$ret .= "<a href=\"$qr_url\"><img src=\"$qr_url\"><\/a>"
if AttrVal($name,'ga_showQR',1);
$ret .= "</td>";
$ret .= "<td><br>&nbsp;<a href=\"$qr_url\">Link to QR code<\/a><\/td>"
if AttrVal($name,'ga_showLink',0);
$ret .= "</tr>";
$ret .= "<tr><td>&nbsp;Key (for manual use):<br>&nbsp;$secret_base32</td><tr>"
if AttrVal($name,'ga_showKey',0);
$ret .= "</table>";
return $ret;
}
# helper functions
sub _ga_make_url {
my ($name) = @_;
my $label = AttrVal($name,'ga_labelName',"FHEM Authentication $name");
$label =~ s/\s/\%20/g;
my $qrsize = AttrVal($name,'ga_qrSize','200x200');
my $secret_base32 = getKeyValue("googleAuth$name");
return unless defined($secret_base32);
my $url = "otpauth://totp/$label?secret=$secret_base32&issuer=FHEM";
my $qr_url = "https://chart.googleapis.com/chart?cht=qr&chs=$qrsize"."&chl=";
$qr_url .= uri_escape($url);
return $qr_url;
}
sub _ga_make_token_6 {
my $token = shift;
while (length $token < 6) {
$token = "0$token";
}
return $token;
}
package main;
sub gAuth {
my($name,$token,$aDev) = @_;
return "missing name!" unless $name;
return "missing $token!" unless $token;
$aDev //= '';
my $myHash = $defs{$name};
if (exists $myHash->{helper}{$token}
&& $myHash->{helper}{$token} - gettimeofday() > 0
&& defined($aDev)
&& exists $defs{$aDev}
&& $defs{$aDev}{TYPE} eq 'allowed') {
return 1;
} else {
delete $myHash->{helper}{$token} if defined($myHash->{helper}{$token});
my $result = FHEM::GoogleAuth::Get($myHash,$name,'check',$token);
if ($result == 1) {$myHash->{helper}{$token} = gettimeofday()+DAYSECONDS};
return $result;
}
}
1;
=pod
=item helper
=item summary Module to use GoogleAuthenticator
=item summary_DE Modul zur Nutzung von GoogleAuthenticator
=begin html
<a name="GoogleAuth"></a>
<h3>GoogleAuth</h3>
<ul>
GoogleAuthenticator provides two-factor-authentication using one-time-passwords (token).<br/>
These tokens are generated using the mobile app „Google Authenticator“ for example on a smartphone.<br/>
See <a href="https://en.wikipedia.org/wiki/Google_Authenticator">https://en.wikipedia.org/wiki/Google_Authenticator</a>
for more informations.<br/>
<br/>
<br/>
<b>Prerequesits</b><br/>
<br/>
<li>The fhem implementation of the Google Authenticator is credited to the following publication:<br/>
<a href="https://blog.darkpan.com/article/6/Perl-and-Google-Authenticator.html">https://blog.darkpan.com/article/6/Perl-and-Google-Authenticator.html</a></li>
<br/>
<li>Module uses following additional Perl modules:<br/>
<br/>
<ul><code>Convert::Base32 Authen::OATH Crypt::URandom</code></ul>
<br/>
If not already installed in your environment, please install them using appropriate commands from your environment.<br/>
<br/>
Package installation in debian environments:<br/>
<br/>
<ul><code>apt-get install libconvert-base32-perl libauthen-oath-perl libcrypt-urandom-perl</code></ul></li>
<br/>
<br/>
<a name="GoogleAuthdefine"></a>
<b>Define</b><br/><br/>
<ul>
<code>define &lt;name&gt; GoogleAuth</code><br/>
<br/>
Example:<br/><br/>
<ul><code>define googleAuth GoogleAuth</code><br/></ul>
</ul>
<br/>
<br/>
<a name="GoogleAuthset"></a>
<b>Set Commands</b><br/><br/>
<ul>
<li><code>set &lt;name&gt; new</code><br/>
<br/>
Generates a new secret key and displays the corresponding QR image.<br/>
Using the photo function of the Google Authenticator app,<br/>
this QR image can be used to transfer the secret key to the app.
</li>
<br/>
<li><code>set &lt;name&gt; revoke</code><br/>
<br/>
Remove existing key.<br/>
<b>You can not create a new key before</b> an existing key was deleted.<br/>
</li>
</ul>
<br/>
<br/>
<a name="GoogleAuthget"></a>
<b>Get Commands</b><br/><br/>
<ul>
<li><code>get &lt;name&gt; check &lt;token&gt;</code><br/>
<br/>
Check the validity of a given token; return value is 1 for a valid token, otherwise -1.<br/>
<ul>
<li>Token always consists of six numerical digits and will change every 30 seconds.</li>
<li>Token is valid if it matches one of three tokens calculated by FHEM<br/>
using three timestamps: -30 seconds, now and +30 seconds.<br/>
This behavior can be changed by attribute ga_strictCheck.</li>
</ul>
</li>
</ul>
<br/>
<br/>
<a name="GoogleAuthattr"></a>
<b>Attributes</b><br/><br/>
<ul>
<li><b>ga_labelName</b> - define a Name to identify PassCode inside the app.<br/>
<b>Do not use any special characters,</b> except SPACE, in this attribute!</li>
<li><b>ga_qrSize</b> - select image size of qr code</li>
<li><b>ga_showKey</b> - show key for manual use if set to 1</li>
<li><b>ga_showLink</b> - show link to qr code if set to 1</li>
<li><b>ga_showQR</b> - show qr code if set to 1</li>
<li><b>ga_strictCheck</b><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;AttrVal = 1 : check given token against one token<br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;AttrVal = 0 : check given token against three tokens(default)</li>
</ul>
<br/>
<br/>
<a name="GoogleAuthreadings"></a>
<b>Generated Readings/Events</b><br/><br/>
<ul>
<li><b>lastResult</b> - contains result from last token check</li>
<li><b>state</b> - "active" if a key is set, otherwise "defined"</li>
</ul>
<br/>
<br/>
<b>Integration with gAuth()</b><br/><br/>
<ul>
<li><code>gAuth(&lt;name&gt;,&lt;token&gt;)</code><br/>
<br/>
For easy use in your own scenarios you can call function gAuth(),<br/>
which will return same result codes as the "get" command.
</li>
<br/>
<li>Usage of gAuth() for login to FHEM<br/>
<br/>
A device of TYPE=allowed can be used to secure login to FHEM via basicAuth.<br/>
<code>attr &lt;deviceName&gt; basicAuth { "$user" eq "xxx" &amp;&amp; gAuth("GoogleAuth","$password","&lt;deviceName&gt;") == 1 }</code><br/>
<br/>
In both cases &lt;deviceName&gt; has to be the name of the allowed-TYPE device.<br/>
The authenticated login will be cached for this device for a maximum period of 86400 seconds.<br/>
Do not use basicAuthExpiry in this scenario!<br/>
The cache will be lost after FHEM restart or after any invalid token checked by the named allowed-TYPE device.<br/>
</li>
</ul>
<br/>
<br/>
</ul>
=end html
=begin html_DE
<a name="GoogleAuth"></a>
<h3>GoogleAuth</h3>
<ul>
Sorry, keine deutsche Dokumentation vorhanden.<br/><br/>
Die englische Doku gibt es hier: <a href='commandref.html#GoogleAuth'>GoogleAuth</a><br/>
</ul>
=end html_DE
=cut