1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
package MooseX::Storage::Base::WithChecksum;
use Moose::Role;
with 'MooseX::Storage::Basic';
use Digest ();
use Data::Dumper ();
our $VERSION = '0.31';
our $AUTHORITY = 'cpan:STEVAN';
our $DIGEST_MARKER = '__DIGEST__';
around pack => sub {
my $orig = shift;
my $self = shift;
my @args = @_;
my $collapsed = $self->$orig( @args );
$collapsed->{$DIGEST_MARKER} = $self->_digest_packed($collapsed, @args);
return $collapsed;
};
around unpack => sub {
my ($orig, $class, $data, @args) = @_;
# check checksum on data
my $old_checksum = delete $data->{$DIGEST_MARKER};
my $checksum = $class->_digest_packed($data, @args);
($checksum eq $old_checksum)
|| confess "Bad Checksum got=($checksum) expected=($old_checksum)";
$class->$orig( $data, @args );
};
sub _digest_packed {
my ( $self, $collapsed, @args ) = @_;
my $d = $self->_digest_object(@args);
{
local $Data::Dumper::Indent = 0;
local $Data::Dumper::Sortkeys = 1;
local $Data::Dumper::Terse = 1;
local $Data::Dumper::Useqq = 0;
local $Data::Dumper::Deparse = 0; # FIXME?
my $str = Data::Dumper::Dumper($collapsed);
# NOTE:
# Canonicalize numbers to strings even if it
# mangles numbers inside strings. It really
# does not matter since its just the checksum
# anyway.
# - YK/SL
$str =~ s/(?<! ['"] ) \b (\d+) \b (?! ['"] )/'$1'/gx;
$d->add( $str );
}
return $d->hexdigest;
}
sub _digest_object {
my ( $self, %options ) = @_;
my $digest_opts = $options{digest};
$digest_opts = [ $digest_opts ]
if !ref($digest_opts) or ref($digest_opts) ne 'ARRAY';
my ( $d, @args ) = @$digest_opts;
if ( ref $d ) {
if ( $d->can("clone") ) {
return $d->clone;
}
elsif ( $d->can("reset") ) {
$d->reset;
return $d;
}
else {
die "Can't clone or reset digest object: $d";
}
}
else {
return Digest->new($d || "SHA-1", @args);
}
}
no Moose::Role;
1;
__END__
=pod
=head1 NAME
MooseX::Storage::Base::WithChecksum - A more secure serialization role
=head1 DESCRIPTION
This is an early implementation of a more secure Storage role,
which does integrity checks on the data. It is still being
developed so I recommend using it with caution.
Any thoughts, ideas or suggestions on improving our technique
are very welcome.
=head1 METHODS
=over 4
=item B<pack (?$salt)>
=item B<unpack ($data, ?$salt)>
=back
=head2 Introspection
=over 4
=item B<meta>
=back
=head1 BUGS
All complex software has bugs lurking in it, and this module is no
exception. If you find a bug please either email me, or add the bug
to cpan-RT.
=head1 AUTHOR
Stevan Little E<lt>stevan.little@iinteractive.comE<gt>
Yuval Kogman
=head1 COPYRIGHT AND LICENSE
Copyright 2007-2008 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut
|
