1 package Koha::XSLT::Security;
3 # Copyright 2019 Prosentient Systems, Rijksmuseum
5 # This file is part of Koha.
7 # Koha is free software; you can redistribute it and/or modify it
8 # under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 3 of the License, or
10 # (at your option) any later version.
12 # Koha is distributed in the hope that it will be useful, but
13 # WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with Koha; if not, see <http://www.gnu.org/licenses>.
22 Koha::XSLT::Security - Add security features to Koha::XSLT::Base
26 use Koha::XSLT::Security;
27 my $secu = Koha::XSLT::Security->new;
28 $secu->register_callbacks;
29 $secu->set_parser_options($parser);
33 This object allows you to apply security options to Koha::XSLT::Base.
34 It looks for parser options in koha-conf.xml.
42 use base qw(Class::Accessor);
48 Creates object, checks if koha-conf.xml contains additional configuration
49 options, and checks if XML::LibXSLT::Security is present.
57 $self->{_options} = {};
58 my $conf = C4::Context->config('koha_xslt_security');
59 if( $conf && ref($conf) eq 'HASH' ) {
60 $self->{_options} = $conf;
63 my $security = eval { XML::LibXSLT::Security->new };
65 $self->{_security_obj} = $security;
67 warn "No XML::LibXSLT::Security object: $@"; #TODO Move to about ?
70 return bless $self, $class;
73 =head2 register_callbacks
75 Register LibXSLT security callbacks
79 sub register_callbacks {
82 my $security = $self->{_security_obj};
85 $security->register_callback( read_file => sub {
86 warn "read_file called in XML::LibXSLT";
87 #i.e. when using the exsl:document() element or document() function (to read a XML file)
88 my ($tctxt,$value) = @_;
91 $security->register_callback( write_file => sub {
92 warn "write_file called in XML::LibXSLT";
93 #i.e. when using the exsl:document element (or document() function?) (to write an output file of many possible types)
95 #<exsl:document href="file:///tmp/breached.txt">
96 # <xsl:text>breached!</xsl:text>
98 my ($tctxt,$value) = @_;
101 $security->register_callback( read_net => sub {
102 warn "read_net called in XML::LibXSLT";
103 #i.e. when using the document() function (to read XML from the network)
104 #e.g. <xsl:copy-of select="document('http://localhost')" />
105 my ($tctxt,$value) = @_;
108 $security->register_callback( write_net => sub {
109 warn "write_net called in XML::LibXSLT";
110 #NOTE: it's unknown how one would invoke this, but covering our bases anyway
111 my ($tctxt,$value) = @_;
118 my $xslt = XML::LibXSLT->new;
119 $security->set_callbacks( $xslt );
121 Apply registered callbacks to a specific xslt instance.
126 my ($self, $xslt) = @_;
128 my $security = $self->{_security_obj};
129 return if !$security;
130 $xslt->security_callbacks( $security );
133 =head2 set_parser_options
135 $security->set_parser_options($parser);
137 If koha-conf.xml includes koha_xslt_security options, set them.
138 We start with implementing expand_entities.
142 sub set_parser_options {
143 my ($self, $parser) = @_;
144 my $conf = $self->{_options};
146 if( $conf->{expand_entities_unsafe} ) { # NOT recommended
147 _set_option($parser, 'expand_entities', 1);
149 # If not explicitly set, we should disable expanding for security
150 _set_option($parser, 'expand_entities', 0);
155 my ($parser, $option_name, $value) = @_;
156 if( $parser->option_exists($option_name) ) {
157 $parser->set_option($option_name, $value);
159 #TODO Should we warn if it does not exist?
164 David Cook, Prosentient Systems
165 Marcel de Rooy, Rijksmuseum Netherlands