VOMS::Lite::ASN1Helper

VOMS::Lite::ASN1Helper - Perl extension for basic ASN.1 encoding and decoding. There is no OO in this module, it's a very basic straightforward implementation of ASN.1.

SYNOPSIS

use VOMS::Lite::ASN1Helper qw( Hex DecToHex ASN1BitStr ASN1Wrap ASN1UnwrapHex ASNLenStr ASN1Index ASN1Unwrap ASN1OIDtoOID);

# To convert a binary string, $data, to padded hex i.e. ([0-9a-f]{2})*
my $hexstr=Hex($data);

# To convert an integer to a padded string of hex values
my $hexint=DecToHex($int);

# To convert ASN1 represeantation of an OID to a dot representation e.g. 1.2.840.113549.1.9.1
my $OIDstr=ASN1OIDtoOID($data);

# To convert a dot representation of an OID (e.g. 1.2.840.113549.1.9.1) to an ASN1 represeantation 
my $ASN1str=OIDtoASN1OID($oid);

# To convert a hex representation of a N*8 bit bytestring into an ASN1 bitstring
my $hexbitstr=ASN1BitStr($hexstr);
my $hexbitstr=ASN1BitStr($hexstr,$lengthinbits);

# To wrap a hex string into an ASN.1 Primative
my $objectstr=30; #30 denotes a SEQUENCE
my $asn1prim=ASN1Wrap($hexstr);

# To unwrap a chunk of BER encoded ASN.1
my $contents=ASN1Unwrap($data);
my $contentshex=ASN1UnwrapHex($data);
# or
my ($headerLength,$dataLength,$class,$constructed,$tag,$contents)=ASN1Unwrap($data);

# To return the ASN.1 length header for a hex representation of some data
my $LenghtHeaderHex=ASNLenStr($hexstr);

# To index an ASN.1 string
foreach ASN1Index($data) {
  my ($class,$constructed,$tag,$position,$headLength,$dataLength)=@$_;
  ...
}

DESCRIPTION

VOMS::Lite::ASN1Helper is designed to provide simple ASN.1 encoding decoding methods for VOMS::Lite.

EXPORT

None by default.

By EXPORT_OK the following functions: Hex DecToHex ASN1BitStr ASN1Wrap ASN1UnwrapHex ASNLenStr ASN1Index ASN1Unwrap ASN1OIDtoOID OIDtoASN1OID

SEE ALSO

The X.680 and X.690 specifications: http://www.itu.int/ITU-T/studygroups/com17/languages/

This module was originally designed for the SHEBANGS project at The University of Manchester. http://www.mc.manchester.ac.uk/projects/shebangs/ now http://www.rcs.manchester.ac.uk/research/shebangs/

Mailing list, shebangs@listserv.manchester.ac.uk Mailing list, voms-lite@listserv.manchester.ac.uk

If you have a mailing list set up for your module, mention it here.

If you have a web site set up for your module, mention it here.

AUTHOR

Mike Jones <mike.jones@manchester.ac.uk>

COPYRIGHT AND LICENSE

Copyright (C) 2006 by Mike Jones

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.3 or, at your option, any later version of Perl 5 you may have available.