Added test modules for mode 20, 21 and 23

tools/test_modules/m00020.pm

@@ -0,0 +1,44 @@
+#!/usr/bin/env perl
+
+##
+## Author......: See docs/credits.txt
+## License.....: MIT
+##
+
+use strict;
+use warnings;
+
+use Digest::MD5 qw (md5_hex);
+
+sub module_generate_hash
+{
+  my $word = shift;
+  my $salt = shift // random_numeric_string (random_count (15));
+
+  my $hash = md5_hex ($salt . $word) . ":$salt";
+
+  return $hash;
+}
+
+sub module_verify_hash
+{
+  my $line = shift;
+
+  my ($hash, $salt, $word) = split (':', $line);
+
+  return unless defined $hash;
+  return unless defined $salt;
+  return unless defined $word;
+
+  $word = pack_if_HEX_notation ($word);
+
+  my $new_hash = module_generate_hash ($word, $salt);
+
+  return unless defined $new_hash;
+
+  return unless $new_hash eq "$hash:$salt";
+
+  return $new_hash;
+}
+
+1;

tools/test_modules/m00021.pm

@@ -0,0 +1,44 @@
+#!/usr/bin/env perl
+
+##
+## Author......: See docs/credits.txt
+## License.....: MIT
+##
+
+use strict;
+use warnings;
+
+use Digest::MD5 qw (md5_hex);
+
+sub module_generate_hash
+{
+  my $word = shift;
+  my $salt = shift // random_hex_string (2);
+
+  my $hash = md5_hex ($salt . $word) . ":$salt";
+
+  return $hash;
+}
+
+sub module_verify_hash
+{
+  my $line = shift;
+
+  my ($hash, $salt, $word) = split (':', $line);
+
+  return unless defined $hash;
+  return unless defined $salt;
+  return unless defined $word;
+
+  $word = pack_if_HEX_notation ($word);
+
+  my $new_hash = module_generate_hash ($word, $salt);
+
+  return unless defined $new_hash;
+
+  return unless $new_hash eq "$hash:$salt";
+
+  return $new_hash;
+}
+
+1;

tools/test_modules/m00023.pm

@@ -0,0 +1,44 @@
+#!/usr/bin/env perl
+
+##
+## Author......: See docs/credits.txt
+## License.....: MIT
+##
+
+use strict;
+use warnings;
+
+use Digest::MD5 qw (md5_hex);
+
+sub module_generate_hash
+{
+  my $word = shift;
+  my $salt = shift // random_hex_string (2);
+
+  my $hash = md5_hex ($salt . "\nskyper\n" . $word) . ":$salt";
+
+  return $hash;
+}
+
+sub module_verify_hash
+{
+  my $line = shift;
+
+  my ($hash, $salt, $word) = split (':', $line);
+
+  return unless defined $hash;
+  return unless defined $salt;
+  return unless defined $word;
+
+  $word = pack_if_HEX_notation ($word);
+
+  my $new_hash = module_generate_hash ($word, $salt);
+
+  return unless defined $new_hash;
+
+  return unless $new_hash eq "$hash:$salt";
+
+  return $new_hash;
+}
+
+1;