1 files changed, 153 insertions, 0 deletions
diff --git a/fml/lib/FML/String/Random.pm b/fml/lib/FML/String/Random.pm
new file mode 100644
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+++ b/fml/lib/FML/String/Random.pm
@@ -0,0 +1,153 @@
+#-*- perl -*-
+#
+#  Copyright (C) 2008 Ken'ichi Fukamachi
+#   All rights reserved. This program is free software; you can
+#   redistribute it and/or modify it under the same terms as Perl itself.
+#
+# $FML: @template.pm,v 1.12 2008/08/24 08:28:36 fukachan Exp $
+#
+
+package FML::String::Random;
+use strict;
+use vars qw(@ISA @EXPORT @EXPORT_OK $AUTOLOAD);
+use Carp;
+
+=head1 NAME
+
+FML::String::Random - create a random string.
+
+=head1 SYNOPSIS
+
+    my $random = new FML::String::Random;
+    my $magic = $random->magic_string();
+    my $id    = $random->identifier($magic);
+
+=head1 DESCRIPTION
+
+This class generates a magic string and the identifier used for the
+session ID.
+
+=head1 METHODS
+
+=head2 new()
+
+constructor.
+
+=cut
+
+
+# Descriptions: constructor.
+#    Arguments: OBJ($self)
+# Side Effects: none
+# Return Value: OBJ
+sub new
+{
+    my ($self) = @_;
+    my ($type) = ref($self) || $self;
+    my $me     = {};
+    return bless $me, $type;
+}
+
+
+=head2 magic_string()
+
+generate a random magic string.
+
+Currently, the string is a combination of
+
+    qw(a b c d e f g h k m n p r s t x y z 2 3 4 5 6 8);
+
+letters.
+
+=cut
+
+
+# Descriptions: generate a random magic string.
+#    Arguments: OBJ($self)
+# Side Effects: none
+# Return Value: STR
+sub magic_string
+{
+    my ($self) = @_;
+
+    # XXX Crypt::RandPasswd may be too slow sometimes.
+
+    my (@string) = qw(a b c d e f g h k m n p r s t x y z 2 3 4 5 6 8);
+    my ($strlen) = $#string;
+    my (@result) = ();
+
+    srand(time|$$);
+    for (my $i = 0; $i < 8; $i++) {
+	my $j = int(rand($strlen));
+	$result[ $i ] = $string[ $j ];
+    }
+
+    return join("", @result);
+}
+
+
+=head2 identifier($buf)
+
+generate an identifier from $buf. It is used for the session ID.
+
+=cut
+
+
+# Descriptions: generate an identifier from $buf.
+#    Arguments: OBJ($self) STR($buf)
+# Side Effects: none
+# Return Value: STR
+sub identifier
+{
+    my ($self, $buf) = @_;
+
+    my ($id_01) = sprintf("%s %s %s", rand(time), $$, $buf);
+    my ($id_02) = sprintf("%s %s %s", $$, $buf, rand(time));
+
+    use Mail::Message::Checksum;
+    my $cksum  = new Mail::Message::Checksum;
+    my $sum    = $cksum->md5( \$id_01 );
+    my $sum_ya = $cksum->md5( \$id_02 );
+    my $pebot  = int(rand(32));
+    my $sum_l  = substr($sum, 0, $pebot -1);
+    my $sum_r  = substr($sum, $pebot + 1, 32 - $pebot);
+    return sprintf("%s%s%s", $sum_r, $sum_ya, $sum_l);
+}
+
+
+#
+# DEBUG
+#
+if ($0 eq __FILE__) {
+    my $random = new FML::String::Random;
+    my $magic = $random->magic_string();
+    my $id    = $random->identifier($magic);
+    printf("magic string = %s\n", $magic);
+    printf("identifier   = %s\n", $id);
+}
+
+
+=head1 CODING STYLE
+
+See C<http://www.fml.org/software/FNF/> on fml coding style guide.
+
+=head1 AUTHOR
+
+Ken'ichi Fukamachi
+
+=head1 COPYRIGHT
+
+Copyright (C) 2008 Ken'ichi Fukamachi
+
+All rights reserved. This program is free software; you can
+redistribute it and/or modify it under the same terms as Perl itself.
+
+=head1 HISTORY
+
+FML::String::Random appeared in fml8 mailing list driver package.
+See C<http://www.fml.org/> for more details.
+
+=cut
+
+
+1;