File Coverage

blib/lib/Crypt/OpenPGP/CFB.pm

Criterion	Covered	Total	%
statement	47	48	97.9
branch	2	4	50.0
condition	3	7	42.8
subroutine	5	6	83.3
pod	0	5	0.0
total	57	70	81.4

# This code based slightly on the Systemics Crypt::CFB.
# Parts Copyright (C) 1995, 1996 Systemics Ltd (http://www.systemics.com/)
# All rights reserved.

package Crypt::OpenPGP::CFB;
use strict;

sub new {
    my $class = shift;
    my $c = bless { }, $class;
    $c->init(@_);
}

sub init {
    my $c = shift;
    my($cipher, $iv) = @_;
    $c->{cipher} = $cipher;
    $c->{blocksize} = $cipher->blocksize;
    $c->{iv} = $iv || "\0" x $c->{blocksize};
    $c;
}

sub sync { $_[0]->{unused} = '' }

sub encrypt {
    my $c = shift;
    my($data) = @_;
    my $ret = '';
    my $iv = $c->{iv};
    my $out = $c->{unused} || '';
    my $size = length $out;
    while ($data) {
        unless ($size) {
            $out = $c->{cipher}->encrypt($iv);
            $size = $c->{blocksize};
        }
        my $in = substr $data, 0, $size, '';
        $size -= (my $got = length $in);
        $iv .= ($in ^= substr $out, 0, $got, '');
        substr $iv, 0, $got, '';
        $ret .= $in;
    }
    $c->{unused} = $out;
    $c->{iv} = $iv;
    $ret;
}

sub decrypt {
    my $c = shift;
    my($data) = @_;
    my $ret = '';
    my $iv = $c->{iv};
    my $out = $c->{unused} || '';
    my $size = length $out;
    while ($data) {
        unless ($size) {
            $out = $c->{cipher}->encrypt($iv);
            $size = $c->{blocksize};
        }
        my $in = substr $data, 0, $size, '';
        $size -= (my $got = length $in);
        substr $iv .= $in, 0, $got, '';
        $ret .= ($in ^= substr $out, 0, $got, '');
    }
    $c->{unused} = $out;
    $c->{iv} = $iv;
    $ret;
}

1;
__END__