libcryptx-perl/lib/Crypt/AuthEnc/ChaCha20Poly1305.pm
2018-03-22 15:51:09 +01:00

165 lines
4.4 KiB
Perl

package Crypt::AuthEnc::ChaCha20Poly1305;
use strict;
use warnings;
our $VERSION = '0.048';
use base qw(Crypt::AuthEnc Exporter);
our %EXPORT_TAGS = ( all => [qw( chacha20poly1305_encrypt_authenticate chacha20poly1305_decrypt_verify )] );
our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
our @EXPORT = qw();
use CryptX;
sub new { my $class = shift; _new(@_) }
sub chacha20poly1305_encrypt_authenticate {
my $key = shift;
my $iv = shift;
my $adata = shift;
my $plaintext = shift;
my $m = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);
$m->adata_add(defined $adata ? $adata : ''); #XXX-TODO if no aad we have to pass empty string
my $ct = $m->encrypt_add($plaintext);
my $tag = $m->encrypt_done;
return ($ct, $tag);
}
sub chacha20poly1305_decrypt_verify {
my $key = shift;
my $iv = shift;
my $adata = shift;
my $ciphertext = shift;
my $tag = shift;
my $m = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);
$m->adata_add(defined $adata ? $adata : ''); #XXX-TODO if no aad we have to pass empty string
my $ct = $m->decrypt_add($ciphertext);
return $m->decrypt_done($tag) ? $ct : undef;
}
1;
=pod
=head1 NAME
Crypt::AuthEnc::ChaCha20Poly1305 - Authenticated encryption in ChaCha20Poly1305 mode
=head1 SYNOPSIS
### OO interface
use Crypt::AuthEnc::ChaCha20Poly1305;
# encrypt and authenticate
my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);
$ae->aad_add('additional_authenticated_data1');
$ae->aad_add('additional_authenticated_data2');
$ct = $ae->encrypt_add('data1');
$ct = $ae->encrypt_add('data2');
$ct = $ae->encrypt_add('data3');
$tag = $ae->encrypt_done();
# decrypt and verify
my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);
$ae->aad_add('additional_authenticated_data1');
$ae->aad_add('additional_authenticated_data2');
$pt = $ae->decrypt_add('ciphertext1');
$pt = $ae->decrypt_add('ciphertext2');
$pt = $ae->decrypt_add('ciphertext3');
$tag = $ae->decrypt_done();
die "decrypt failed" unless $tag eq $expected_tag;
#or
my $result = $ae->decrypt_done($expected_tag) die "decrypt failed";
### functional interface
use Crypt::AuthEnc::ChaCha20Poly1305 qw(chacha20poly1305_encrypt_authenticate chacha20poly1305_decrypt_verify);
my ($ciphertext, $tag) = chacha20poly1305_encrypt_authenticate($key, $iv, $adata, $plaintext);
my $plaintext = chacha20poly1305_decrypt_verify($key, $iv, $adata, $ciphertext, $tag);
=head1 DESCRIPTION
Provides encryption and authentication based on ChaCha20 + Poly1305 as defined in RFC 7539 - L<https://tools.ietf.org/html/rfc7539>
=head1 EXPORT
Nothing is exported by default.
You can export selected functions:
use Crypt::AuthEnc::ChaCha20Poly1305 qw(chacha20poly1305_encrypt_authenticate chacha20poly1305_decrypt_verify);
=head1 FUNCTIONS
=head2 chacha20poly1305_encrypt_authenticate
my ($ciphertext, $tag) = chacha20poly1305_encrypt_authenticate($key, $iv, $adata, $plaintext);
# $key ..... key of proper length (128 or 256 bits / 16 or 32 bytes)
# $iv ...... initialization vector (64 or 96 bits / 8 or 12 bytes)
# $adata ... additional authenticated data (optional)
=head2 chacha20poly1305_decrypt_verify
my $plaintext = chacha20poly1305_decrypt_verify($key, $iv, $adata, $ciphertext, $tag);
# on error returns undef
=head1 METHODS
=head2 new
my $ae = Crypt::AuthEnc::ChaCha20Poly1305->new($key, $iv);
# $key ..... encryption key of proper length (128 or 256 bits / 16 or 32 bytes)
# $iv ...... initialization vector (64 or 96 bits / 8 or 12 bytes)
=head2 aad_add
Can be called before the first C<encrypt_add> or C<decrypt_add>;
$ae->aad_add($aad_data); #can be called multiple times
=head2 encrypt_add
$ciphertext = $ae->encrypt_add($data); #can be called multiple times
=head2 encrypt_done
$tag = $ae->encrypt_done();
=head2 decrypt_add
$plaintext = $ae->decrypt_add($ciphertext); #can be called multiple times
=head2 decrypt_done
my $result = $ae->decrypt_done($tag); # returns 1 (success) or 0 (failure)
#or
my $tag = $ae->decrypt_done; # returns $tag value
=head2 clone
my $ae_new = $ae->clone;
=head2 set_iv
$ae->set_iv($iv);
=head2 set_iv_rfc7905
$ae->set_iv_rfc7905($iv, $seqnum);
=head1 SEE ALSO
=over
=item * L<CryptX|CryptX>, L<Crypt::AuthEnc::GCM|Crypt::AuthEnc::GCM>, L<Crypt::AuthEnc::CCM|Crypt::AuthEnc::CCM>, L<Crypt::AuthEnc::EAX|Crypt::AuthEnc::EAX>, L<Crypt::AuthEnc::OCB|Crypt::AuthEnc::OCB>
=item * L<https://tools.ietf.org/html/rfc7539>
=back