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package Data::Password::zxcvbn::Match::Repeat;
use Moo;
with 'Data::Password::zxcvbn::Match';
our $VERSION = '1.1.2'; # VERSION
# ABSTRACT: match class for repetitions of other matches
has repeat_count => (is => 'ro', default => 1);
has base_token => ( is => 'ro', required => 1 );
has base_guesses => ( is => 'ro', default => 1 );
has base_matches => ( is => 'ro', default => sub { [] } );
my $GREEDY_RE = qr{\G.*? ((.+) \2+)}x;
my $LAZY_RE = qr{\G.*? ((.+?) \2+)}x;
my $LAZY_ANCHORED_RE = qr{\A ((.+?) \2+) \z}x;
sub make {
my ($class, $password, $opts) = @_;
my $length = length($password);
return [] if $length <= 1;
my @matches;
my $last_index = 0;
while ($last_index < $length) {
# make the regex matches start at $last_index
pos($password) = $last_index;
my @greedy_match = $password =~ $GREEDY_RE
or last;
my @greedy_idx = ($-[1],$+[1]-1);
pos($password) = $last_index;
my @lazy_match = $password =~ $LAZY_RE;
my @lazy_idx = ($-[1],$+[1]-1);
my (@token,$i,$j);
if (length($greedy_match[0]) > length($lazy_match[0])) {
# greedy beats lazy for 'aabaab'
# greedy: [aabaab, aab]
# lazy: [aa, a]
($i,$j) = @greedy_idx;
# greedy's repeated string might itself be repeated, eg.
# aabaab in aabaabaabaab.
# run an anchored lazy match on greedy's repeated string
# to find the shortest repeated string
@token = $greedy_match[0] =~ $LAZY_ANCHORED_RE;
}
else {
($i,$j) = @lazy_idx;
@token = @lazy_match;
}
require Data::Password::zxcvbn::MatchList;
my $base_analysis = Data::Password::zxcvbn::MatchList->omnimatch(
$token[1],
$opts,
)->most_guessable_match_list;
push @matches, $class->new({
i => $i, j => $j,
token => $token[0],
base_token => $token[1],
repeat_count => length($token[0]) / length($token[1]),
base_guesses => $base_analysis->guesses,
base_matches => $base_analysis->matches,
});
$last_index = $j + 1;
}
return \@matches;
}
sub estimate_guesses {
my ($self) = @_;
return $self->base_guesses * $self->repeat_count;
}
sub feedback_warning {
my ($self) = @_;
return length($self->base_token) == 1
? 'Repeats like "aaa" are easy to guess'
: 'Repeats like "abcabcabc" are only slightly harder to guess than "abc"'
;
}
sub feedback_suggestions {
return [ 'Avoid repeated words and characters' ];
}
around fields_for_json => sub {
my ($orig,$self) = @_;
( $self->$orig(), qw(repeat_count base_guesses base_token base_matches) )
};
1;
__END__
=pod
=encoding UTF-8
=head1 NAME
Data::Password::zxcvbn::Match::Repeat - match class for repetitions of other matches
=head1 VERSION
version 1.1.2
=head1 DESCRIPTION
This class represents the guess that a certain substring of a password
is a repetition of some other kind of match.
=head1 ATTRIBUTES
=head2 C<repeat_count>
integer, how many time the L<< /C<base_token> >> is repeated
=head2 C<base_token>
the match that is repeated; this will be an instance of some other
C<Data::Password::zxcvbn::Match::*> class
=head2 C<base_guesses>
the minimal estimate of the attempts needed to guess the L<<
/C<base_token> >>
=head2 C<base_matches>
the list of patterns that L<< /C<base_guesses> >> is based on
=head1 METHODS
=head2 C<make>
my @matches = @{ Data::Password::zxcvbn::Match::Repeat->make(
$password, \%opts,
) };
Scans the C<$password> for repeated substrings, then recursively
analyses them like the main L<< C<password_strength>
function|Data::Password::zxcvbn/password_strength >> would do:
password_strength($substring,\%opts);
L<< /C<base_guesses> >> and L<< /C<base_matches> >> come from that
recursive call.
=head2 C<estimate_guesses>
The number of guesses is the L<< /C<base_guesses> >> times the L<<
/C<repeat_count> >>.
=head2 C<feedback_warning>
=head2 C<feedback_suggestions>
This class suggests not to repeat substrings.
=head2 C<fields_for_json>
The JSON serialisation for matches of this class will contain C<token
i j guesses guesses_log10 repeat_count base_guesses base_token
base_matches>.
=head1 AUTHOR
Gianni Ceccarelli <gianni.ceccarelli@broadbean.com>
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2022 by BroadBean UK, a CareerBuilder Company.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut
|
