package PerlCryptLib;

use 5.008;
use strict;
use warnings;
use Carp;

require Exporter;
use AutoLoader;

our $VERSION = '1.04';


#############################################################################
# PRIVATE SUB
#############################################################################

	##### Returns list containing constants and enumerated constants
	sub __symbolList($;$) {
		my $pkg = shift;
		my $filter = shift || '^.*?$';
		my @list = ();
		$pkg = eval('*{' . $pkg . '::}');
		my $count = 0;
		foreach my $key ( sort keys %{$pkg} ) {
			if ($key =~ /$filter/) { 
				push @list, $key;
			}
		}
		return @list;
	}


#############################################################################
# Includes 'cryptlib' constants and enumarations porting definitions
#############################################################################

	require 'PerlCryptLib.ph';


#############################################################################
# Perl posrting for 'cryptlib' macros to examine return values
#############################################################################

	sub cryptStatusError($) {
		my $status = shift;
		return ( $status < &CRYPT_OK );
	}

	sub cryptStatusOK($) {
		my $status = shift;
		return ( $status == &CRYPT_OK );
	}


#############################################################################
# Perl porting for 'cryptlib' macros to manage low-level components
#############################################################################

	sub cryptInitComponents(;$$@) {
		die "Usage: cryptInitComponents(\$componentInfo, \$componentKeyType)\n" if scalar(@_) != 2;
		my ($componentInfo, $componentKeyType) = @_;
		$componentInfo->{isPublicKey} = ( $componentKeyType == &CRYPT_KEYTYPE_PUBLIC ? 1 : 0 );
		return &CRYPT_OK;
	}

	sub cryptDestroyComponents(;$@) {
		die "Usage: cryptDestroyComponents(\$componentInfo)\n" if scalar(@_) != 1;
		my $componentInfo = shift;
		undef $componentInfo;
		return &CRYPT_OK;
	}

	sub cryptSetComponent(;$$$$@) {
		die "Usage: cryptSetComponent(\$componentInfo, \$element, \$source, \$length)\nFor more info see README file." if scalar(@_) != 4;
		my ($componentInfo, $element, $source, $length) = @_;
		$componentInfo->{$element} = join('', $source, ("\0" x (&CRYPT_MAX_PKCSIZE - length($source))) );
		$componentInfo->{$element.'Len'} = $length;
		return &CRYPT_OK;
	}

	sub cryptFinalizeComponents(;$\$\$@) {
		die "Usage: cryptFinalizeComponents(\$componentInfo, \$blob, \$size)\nFor more info see README file." if scalar(@_) != 3;
		my ($componentInfo, $blob, $size) = @_;
		my @rsaFields = qw(isPublicKey n nLen e eLen d dLen p pLen q qLen u uLen e1 e1Len e2 e2Len);
	}


#############################################################################
# SYMBOL PACKAGE EXPORT
#############################################################################

	##### Array for cryptlib's constant names export
	my @CONSTANTS = __symbolList(__PACKAGE__, '^CRYPT_');

	##### Array for cryptlib's function names export
	my @FUNCTIONS = qw	(
							cryptStatusError cryptStatusOK
							cryptInitComponents cryptDestroyComponents cryptSetComponent cryptFinalizeComponents
							cryptInit cryptEnd 
							cryptQueryCapability 
							cryptCreateContext cryptDestroyContext cryptDestroyObject 
							cryptGenerateKey cryptGenerateKeyAsync cryptAsyncQuery cryptAsyncCancel 
							cryptEncrypt cryptDecrypt 
							cryptSetAttribute cryptSetAttributeString cryptGetAttribute cryptGetAttributeString cryptDeleteAttribute 
							cryptAddRandom 
							cryptQueryObject 
							cryptExportKey cryptExportKeyEx cryptImportKey cryptImportKeyEx 
							cryptCreateSignature cryptCreateSignatureEx cryptCheckSignature cryptCheckSignatureEx 
							cryptKeysetOpen cryptKeysetClose cryptGetPublicKey cryptGetPrivateKey cryptAddPublicKey cryptAddPrivateKey cryptDeleteKey 
							cryptCreateCert cryptDestroyCert cryptGetCertExtension cryptAddCertExtension cryptDeleteCertExtension cryptSignCert cryptCheckCert cryptImportCert cryptExportCert 
							cryptCAAddItem cryptCAGetItem cryptCADeleteItem cryptCACertManagement 
							cryptCreateEnvelope cryptDestroyEnvelope 
							cryptCreateSession cryptDestroySession 
							cryptPushData cryptFlushData cryptPopData 
							cryptDeviceOpen cryptDeviceClose cryptDeviceQueryCapability cryptDeviceCreateContext 
							cryptLogin cryptLogout 
						);


	# Esportazione costanti e funzioni
	our @ISA = qw(Exporter);
	our @EXPORT_OK = ( @CONSTANTS , @FUNCTIONS );
	our @EXPORT = ();
	our %EXPORT_TAGS =	( 
							all			=> [ @CONSTANTS , @FUNCTIONS ] ,
							constants	=> [ @CONSTANTS ] ,
							functions	=> [ @FUNCTIONS ]
						);


sub AUTOLOAD {
    # This AUTOLOAD is used to 'autoload' constants from the constant()
    # XS function.

    my $constname;
    our $AUTOLOAD;
    ($constname = $AUTOLOAD) =~ s/.*:://;
    croak "&PerlCryptLib::constant not defined" if $constname eq 'constant';
    my ($error, $val) = constant($constname);
    if ($error) { croak $error; }
    {
	no strict 'refs';
	# Fixed between 5.005_53 and 5.005_61
#XXX	if ($] >= 5.00561) {
#XXX	    *$AUTOLOAD = sub () { $val };
#XXX	}
#XXX	else {
	    *$AUTOLOAD = sub { $val };
#XXX	}
    }
    goto &$AUTOLOAD;
}

require XSLoader;
XSLoader::load('PerlCryptLib', $VERSION);

if ( __FILE__ eq "$0" ) {
	# TEST PACKAGE SPACE
}

1;
__END__


=head1 NAME

PerlCryptLib - Perl interface to Peter Guttman's cryptlib API

=head1 DESCRIPTION

PerlCryptLib is an interface module to access cryptlib API.

=over 8

cryptlib (Copyright 1992-2005 Peter Gutmann. All rights reserved.) is a powerful 
encryption and security software toolkit that allows even inexperienced 
crypto-programmers to easily add world-leading encryption and authentication 
services to their software.

For more information about cryptlib features and state-of-the-art, please visit
its official web-site at:

=over 4

=item * http://www.cs.auckland.ac.nz/~pgut001/cryptlib

=back

=back

=head1 INSTALLATION

Starting from version 1.04, PerlCryptLib has the ablility to match the correct 
version of the 'cryptlib' library used by your system. 
This is done translating on-the-fly the cryptlib.h header file into a 
correspondent Perl header file (named PerlCryptLib.ph) that will be used by
the main module.
To do that, you simply have to suggest the full-path to the cryptlib.h header 
file when prompted by the configuration utility:

 ./configure

After the configuration you can build, test and install as usual:

 perl Makefile.PL
 make
 make test TEST_VERBOSE=1  # or, simply, the canonical  make test
 make install

=head1 SYNOPSIS

 use PerlCryptLib qw(:all);

 my $envelope = CRYPT_ENVELOPE;
 if ( cryptInit() == CRYPT_OK ) {
   if ( cryptCreateEnvelope($envelope, 
                            CRYPT_UNUSED, 
                            CRYPT_FORMAT_CRYPTLIB) == CRYPT_OK ) {

     # set some attributes with cryptSetAttribute() or cryptSetAttributeString()
     # set some other crypto-stuff
     # push or pop data with cryptPushData() and cryptPopData()

     cryptDestroyEnvelope($envelope);
   }
   cryptEnd();
 }

=head2 Notes

cryptUIDisplayCert() and cryptUIGenerateKey() cryptlib functions are 
not implemented.

=head1 EXPORT/IMPORT

PerlCryptLib doesn't export anything by default.
You can choose to explicitly import specifics exported tags:

=over 4

=item :constants

all of the CRYPT_* cryptlib constants

=item :functions

all of the crypt* cryptlib functions

=item :all

all of the cryptlib constants and functions

=back

For example, to import only functions name:

 use PerlCryptLib ':functions';

Alternatively, you can import such functions or constants by specifying each
of them in the 'use' statement:

 use PerlCryptLib qw(cryptInit cryptEnd CRYPT_OK);

=head1 CONVENTIONS

=head2 Object-type declaration

=over 4

cryptlib object-handles MUST BE INITIALIZED with the appropriated object-type 
constant (CRYPT_CERTIFICATE, CRYPT_CONTEXT, CRYPT_DEVICE, CRYPT_ENVELOPE, 
CRYPT_KEYSET, CRYPT_SESSION, CRYPT_USER, CRYPT_HANDLE) or, at least, with a
numeric value (generally 0).

So, using

 my $envelope = CRYPT_ENVELOPE;
 my $context = CRYPT_CONTEXT;
 my $certificate = CRYPT_CERTIFICATE;
 
is the same as using

 my $envelope = 0;
 my $context = 0;
 my $certificate = 0;

but is much more comprehensive.

=back

=head2 Pass-by-reference

=over 4

To pass-by-reference cryptlib object-handles, as shown in the above 
example in SYNOPSIS section, it's not necessary to use the 'back-slash' 
reference operator ('\').

=back

=head2 Buffers

=over 4

To handle binary buffers (i.e., while enveloping data), you need to initialize 
them "allocating" the needed space, for example using:
 
 my $maxLength = 1024;
 my $key = ' ' x $maxLength;
 cryptExportKey($key, $maxLength, $keyLength, $context, $cert);

=back

=head2 NULL values

=over 4

NULL values can be handled in different ways:

 # Those three calls are all valid calls
 use constant NULL => 0x0;
 $null = 0x0;
 cryptGetPublicKey($cryptKeyset, $cert, CRYPT_KEYID_NONE, 0);
 cryptGetPublicKey($cryptKeyset, $cert, CRYPT_KEYID_NONE, NULL);
 cryptGetPublicKey($cryptKeyset, $cert, CRYPT_KEYID_NONE, $null); 

However, when used in pass-by-reference calls, MUST be declared as 0x0 
scalar values:

 $null = 0x0;
 cryptExportKey($null, 0, $maxLength, $context, $cert);

=back

=head2 Accessing low-level components

=over 4

In order to allow the access to low-level components, I've made some small 
changes to the cryptlib macro cryptSetComponent(), for which Perl syntax became:
 
 cryptSetComponent($componentInfo, $element, $source, $length)
 
where $componentInfo is the data-structure itself and $element is the 
data-structure element-name to set.
In addition I've added a NEW low-level macro to retrieve data-structure in
the appropriated format:

 cryptFinalizeComponents($componentInfo, $blob, $size)
  
Here is an example "translated" in PerlCryptLib:
  
 ##### Create objects
 $cryptContext = CRYPT_CONTEXT;
 $rsaKey = CRYPT_PKCINFO_RSA;

 ##### Initialize objects
 cryptCreateContext($cryptContext, $cryptUser, CRYPT_ALGO_RSA);
 cryptSetAttributeString($cryptContext, CRYPT_CTXINFO_LABEL, "RSA key", 7);
 cryptInitComponents($rsaKey, CRYPT_KEYTYPE_PRIVATE);

 ##### Set data-structure elements: note arguments syntax
 cryptSetComponent($rsaKey, 'n', $modulus, 2048);
 cryptSetComponent($rsaKey, 'e', $pubExponent, 17);
 cryptSetComponent($rsaKey, 'd', $privExponent, 2047);
 cryptSetComponent($rsaKey, 'p', $primeFactor1, 1024);
 cryptSetComponent($rsaKey, 'q', $primeFactor2, 1024);
 cryptSetComponent($rsaKey, 'u', $multInverse, 1020);
 cryptSetComponent($rsaKey, 'e1', $privExponent1, 1024);
 cryptSetComponent($rsaKey, 'e2', $privExponent2, 1019);
 
 ##### Finalize component to retrieve data to pass to cryptSetAttributeString
 $rsaKeyBlob = '';
 $rsaKeyBlobSize = 0;
 cryptFinalizeComponents($rsaKey, $rsaKeyBlob, $rsaKeyBlobSize);
 cryptSetAttributeString($cryptContext, CRYPT_CTXINFO_KEY_COMPONENTS,
                         $rsaKeyBlob, $rsaKeyBlobSize );
 
 ##### Destroy objects
 cryptDestroyComponents($rsaKey);
 cryptDestroyContext($cryptContext);

Note: to access single data-structure elements (if really needed) you can do 
as follow:

 print "rsaKey modulus length: ", $rsaKey->{nLen}, "\n";

=back

=head2 Querying objects

=over 4

To query objects such exported keys, signatures or cryptlib capabilities,
you can use standard functions cryptQueryObject() and cryptQueryCapability() 
as follow:

 $cryptObjectInfo = CRYPT_OBJECT_INFO;
 cryptQueryObject($encryptedKey, $encryptedKeyLength, $cryptObjectInfo);
 if ( $cryptObjectInfo->{objectType} == CRYPT_OBJECT_ENCRYPTED_KEY ) {
     warn "Import the key using conventional encryption!", "\n";
 }

 $cryptQueryInfo = CRYPT_QUERY_INFO;
 cryptQueryCapability(CRYPT_ALGO_3DES, $cryptQueryInfo);
 print "Algo-name: ", $cryptQueryInfo->{algoName}, "\n";

=back

=head1 PREREQUIREMENT

=over 4

=item * cryptlib v. 3.2.2 (or later)

CRYPTLIB Security Toolkit(c) by Peter Guttman

=back

=head1 SEE ALSO

See Peter Guttman's cryptlib web site:

=over 4

=item * http://www.cs.auckland.ac.nz/~pgut001/cryptlib/

=back

and cryptlib official mailing-list:

=over 4

=item * http://news.gmane.org/gmane.comp.encryption.cryptlib

=back

=head1 BUGS AND REQUESTS

Please report any bugs or feature requests to perlcryptlib@gmail.com, or 
through the web interface at http://rt.cpan.org/Public/.
I will be notified, and then you'll automatically be notified of progress on 
your bug as I make changes.

=head1 AUTHOR

Alvaro Livraghi, <perlcryptlib@gmail.com>

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2006-2007 Alvaro Livraghi. All Rights Reserved.

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself. 

=cut

