File Coverage

blib/lib/Crypt/OpenPGP/SKSessionKey.pm

Criterion	Covered	Total	%
statement	62	66	93.9
branch	5	8	62.5
condition	4	9	44.4
subroutine	12	12	100.0
pod	4	5	80.0
total	87	100	87.0

package Crypt::OpenPGP::SKSessionKey;
use strict;
use warnings;

our $VERSION = '1.19'; # VERSION

use Crypt::OpenPGP::Constants qw( DEFAULT_CIPHER );
use Crypt::OpenPGP::Buffer;
use Crypt::OpenPGP::S2k;
use Crypt::OpenPGP::ErrorHandler;
use base qw( Crypt::OpenPGP::ErrorHandler );

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

sub init {
    my $key = shift;
    my %param = @_;
    $key->{version} = 4;
    if ((my $sym_key = $param{SymKey}) && (my $pass = $param{Passphrase})) {
        my $alg = $param{Cipher} || DEFAULT_CIPHER;
        my $cipher = Crypt::OpenPGP::Cipher->new($alg);
        my $keysize = $cipher->keysize;
        $key->{s2k_ciph} = $cipher->alg_id;
        $key->{s2k} = $param{S2k} || Crypt::OpenPGP::S2k->new('Salt_Iter');
        $sym_key = substr $sym_key, 0, $keysize;
        my $s2k_key = $key->{s2k}->generate($pass, $keysize);
        $cipher->init($s2k_key);
    }
    $key;
}

sub parse {
    my $class = shift;
    my($buf) = @_;
    my $key = $class->new;
    $key->{version} = $buf->get_int8;
    return $class->error("Unsupported version ($key->{version})")
        unless $key->{version} == 4;
    $key->{s2k_ciph} = $buf->get_int8;
    $key->{s2k} = Crypt::OpenPGP::S2k->parse($buf);
    if ($buf->offset < $buf->length) {
        $key->{encrypted} = $buf->get_bytes( $buf->length - $buf->offset );
    }
    $key;
}

sub save {
    my $key = shift;
    my $buf = Crypt::OpenPGP::Buffer->new;
    $buf->put_int8($key->{version});
    $buf->put_int8($key->{s2k_ciph});
    $buf->put_bytes( $key->{s2k}->save );
    $buf->bytes;
}

sub decrypt {
    my $key = shift;
    my($passphrase) = @_;
    my $cipher = Crypt::OpenPGP::Cipher->new($key->{s2k_ciph});
    my $keysize = $cipher->keysize;
    my $s2k_key = $key->{s2k}->generate($passphrase, $keysize);
    my($sym_key, $alg);
    if ($key->{encrypted}) {
        $cipher->init($s2k_key);
        $sym_key = $cipher->decrypt($key->{encrypted});
        $alg = ord substr $sym_key, 0, 1, '';
    } else {
        $sym_key = $s2k_key;
        $alg = $cipher->alg_id;
    }
    ($sym_key, $alg);
}

1;
__END__