package Crypt::Perl::RSA::KeyBase;
use strict;
use warnings;
use parent qw(
Class::Accessor::Fast
Crypt::Perl::KeyBase
);
use Module::Load ();
use Crypt::Perl::BigInt ();
use Crypt::Perl::X ();
BEGIN {
__PACKAGE__->mk_ro_accessors('modulus');
__PACKAGE__->mk_ro_accessors('publicExponent');
*N = \&modulus;
*E = \&publicExponent;
}
use constant _JWK_THUMBPRINT_JSON_ORDER => qw( e kty n );
sub new {
my ($class, @args) = @_;
my $self = $class->SUPER::new(@args);
$self->{'publicExponent'} = Crypt::Perl::BigInt->new( $self->{'publicExponent'} );
return $self;
}
sub to_pem {
my ($self) = @_;
require Crypt::Format;
return Crypt::Format::der2pem( $self->to_der(), $self->_PEM_HEADER() );
}
#i.e., modulus length, in bits
sub size {
my ($self) = @_;
return length( $self->modulus()->as_bin() ) - 2;
}
sub modulus_byte_length {
my ($self) = @_;
return length $self->N()->as_bytes();
#return( ( length( $self->N()->as_hex() ) - 2 ) / 2 );
}
sub verify_RS256 {
my ($self, $msg, $sig) = @_;
return $self->_verify($msg, $sig, 'Digest::SHA', 'sha256', 'PKCS1_v1_5');
}
sub verify_RS384 {
my ($self, $msg, $sig) = @_;
return $self->_verify($msg, $sig, 'Digest::SHA', 'sha384', 'PKCS1_v1_5');
}
sub verify_RS512 {
my ($self, $msg, $sig) = @_;
return $self->_verify($msg, $sig, 'Digest::SHA', 'sha512', 'PKCS1_v1_5');
}
sub encrypt_raw {
my ($self, $bytes) = @_;
return Crypt::Perl::BigInt->from_bytes($bytes)->bmodpow($self->{'publicExponent'}, $self->{'modulus'})->as_bytes();
}
sub to_der {
my ($self) = @_;
return $self->_to_der($self->_ASN1_MACRO());
}
sub algorithm_identifier {
my ($self) = @_;
return {
algorithm => OID_rsaEncryption(),
parameters => Crypt::Perl::ASN1::NULL(),
};
}
use constant OID_rsaEncryption => '1.2.840.113549.1.1.1';
sub _to_subject_public_der {
my ($self) = @_;
my $asn1 = $self->_asn1_find('SubjectPublicKeyInfo');
return $asn1->encode( {
algorithm => $self->algorithm_identifier(),
subjectPublicKey => $self->_to_der('RSAPublicKey'),
} );
}
sub get_struct_for_public_jwk {
my ($self) = @_;
require MIME::Base64;
return {
kty => 'RSA',
n => MIME::Base64::encode_base64url($self->N()->as_bytes()),
e => MIME::Base64::encode_base64url($self->E()->as_bytes()),
}
}
#----------------------------------------------------------------------
sub _asn1_find {
my ($self, $macro) = @_;
require Crypt::Perl::ASN1;
require Crypt::Perl::RSA::Template;
my $asn1 = Crypt::Perl::ASN1->new()->prepare(
Crypt::Perl::RSA::Template::get_template('INTEGER'),
);
return $asn1->find($macro);
}
sub _to_der {
my ($self, $macro) = @_;
return $self->_asn1_find($macro)->encode( { %$self } );
}
sub _verify {
my ($self, $message, $signature, $hash_module, $hasher, $scheme) = @_;
Module::Load::load($hash_module);
my $digest = $hash_module->can($hasher)->($message);
my $y = Crypt::Perl::BigInt->from_hex( unpack 'H*', $signature );
#This modifies $y, but it doesn’t matter here.
my $x = $y->bmodpow( $self->E(), $self->N() );
#Math::BigInt will strip off the leading zero that PKCS1_v1_5 requires,
#so let’s put it back first of all.
my $octets = "\0" . $x->as_bytes();
#printf "OCTETS - %v02x\n", $octets;
if ($scheme eq 'PKCS1_v1_5') {
my $key_bytes_length = $self->modulus_byte_length();
if (length($octets) != $key_bytes_length) {
my $err = sprintf( "Invalid PKCS1_v1_5 length: %d (should be %d)", length($octets), $key_bytes_length );
die Crypt::Perl::X::create('Generic', $err);
}
require Crypt::Perl::RSA::PKCS1_v1_5;
return $digest eq Crypt::Perl::RSA::PKCS1_v1_5::decode($octets, $hasher);
}
die Crypt::Perl::X::create('Generic', "Unknown signature scheme: “$scheme”");
}
1;