view release on metacpan or  search on metacpan

lib/Crypt/ECDSA/Blind.pm  view on Meta::CPAN

sub from_hex {
  bless {d => Math::BigInt->from_hex(shift)}, 'Crypt::ECDSA::Blind::SecKey';
}

sub write {
  1;
}

sub d {
  shift->{d};
}

1; # End of Crypt::ECDSA::Blind::SecKey

package Crypt::ECDSA::Blind::Signature;

sub s {
  Math::BigInt->from_hex(shift->{'s'});
}

sub R {
  Crypt::ECDSA::Blind::_point_from_hex(shift->{R});
}

sub is_valid {
  my $self = shift;
  $self->{R} =~ /^[0-9a-f]+$/ and $self->{s} =~ /^[0-9a-f]+$/;
}

1; # End of Crypt::ECDSA::Blind::Signature

__END__

=head1 NAME

Crypt::ECDSA::Blind - Blind ECDSA Signatures

=head1 VERSION

 $Revision: 1.015 $
 $Date: Tue Oct 16 22:40:55 PDT 2018 $

=head1 SYNOPSIS

This module implements the blind ECDSA signature protocol outlined in
[1].

    use Crypt::ECDSA::Blind;

    my $ecdsab = new Crypt::ECDSA::Blind;

    my ($pubkey, $seckey) = $ecdsab->keygen;

    my $msg = 'Hello, world!';

    my $init = $ecdsab->init;

    my $req = $ecdsab->request( Key => $pubkey, Init => $init,
                                Message => $msg );

    my $blindsig = $ecdsab->sign( Key => $seckey, Init => $init,
                                  Plaintext => $req );

    my $sig = $ecdsab->unblind( Key => $pubkey, Init => $init,
                                Signature => $blindsig );

    print "Verified\n" if $ecdsab->verify( Key => $pubkey, Message => $msg,
                                           Signature => $sig );

=head1 METHODS

=head2 new

Creates and returns a new Crypt::ECDSA::Blind object. The following
optional named parameters can be provided:

=over

DB - Full pathname of a file to use for the database of initialization
vectors. This can also be the special filename ':memory:' in which
case the database will be in RAM rather than on a disk file. The
default is '/tmp/ceb.db'.

=back

=head2 keygen

Generates and returns an ECDSA key-pair for blind signing.

=head2 init

Generates and returns an initialization vector for blind signing. The
initialization vector should be passed in to the request(), sign() and
unblind() methods in the Init named parameter.

=head2 preinit

Generates and saves an initialization vector for later retrieval by
init. Keeping pre-prepared initialization vectors available for use on
demand will speed up calls to init.

=head2 request

Generates and returns a blind signing request. The following named
parameters are required:

=over

Init - The initialization vector from init()

Key - The public key of the signer

Message - The message to be blind signed

=back

=head2 sign

Generates and returns a blind signature. The following named
parameters are required:

=over

Init - The initialization vector from init()