NAME
   Authen::ModAuthPubTkt - Generate Tickets (Signed HTTP Cookies) for
   mod_auth_pubtkt protected websites.

VERSION
   version 0.1.1

SYNOPSIS
   On the command-line, generate the public + private keys: (More details
   available at <https://neon1.net/mod_auth_pubtkt/install.html>)

           $ openssl genrsa -out key.priv.pem 1024
           $ openssl rsa -in key.priv.pem -out key.pub.pem -pubout

   Then in your perl script (which is probably the your custom login
   website), use the following code to issue tickets:

           use Authen::ModAuthPubTkt;

           my $ticket = pubtkt_generate(
                   privatekey => "key.priv.pem",
                   keytype    => "rsa",
                   clientip   => undef,  # or a valid IP address
                   userid     => "102",  # or any ID that makes sense to your application, e.g. email
                   validuntil => time() + 86400, # valid for one day
                   graceperiod=> 3600,   # grace period of an hour
                   tokens     => undef,  # comma separated string of tokens.
                   userdata   => undef   # any application specific data to pass.
           );

           ## $ticket string will look something like:
           ## "uid=102;validuntil=1337899939;graceperiod=1337896339;tokens=;udata=;sig=h5qR" \
           ## "yZZDl8PfW8wNxPYkcOMlAxtWuEyU5bNAwEFT9lztN3I7V13SaGOHl+U6wB+aMkvvLQiaAfD2xF/Hl" \
           ## "+QmLDEvpywp98+5nRS+GeihXTvEMRaA4YVyxb4NnZujCZgX8IBhP6XBlw3s7180jxE9I8DoDV8bDV" \
           ## "k/2em7yMEzLns="

   To verify a ticket, use the following code:

           my $ok = pubtkt_verify (
                   publickey => "key.pub.pem",
                   keytype   => "rsa",
                   ticket    => $ticket
           );
           die "Ticket verification failed.\n" if not $ok;

   To extract items from a ticket, use the following code:

           my %items = pubtkt_parse($ticket);

           ## %items will be something like:
           ## {
           ##    'uid' => 102,
           ##    'validuntil' => 1337899939,
           ##    'graceperiod => 1337896339,
           ##    'tokens' => "",
           ##    'udata'  => "",
           ##    'sig'    => 'h5qRyZZDl8PfW8wNxPYkcOMlAxtWuEyU5bNAwEFT9lztN3 (....)'
           ## }

   Also, a command-line utility ("mod_auth_pubtkt.pl") will be installed,
   and can be used to generate/verify keys:

           $ mod_auth_pubtkt.pl --generate --private-key key.priv.pem --rsa
           $ mod_auth_pubtkt.pl --verify --public-key key.pub.pem --rsa
           $ mod_autH_pubtkt.pl --help

DESCRIPTION
   This module generates and verify a mod_auth_pubtkt-compatible ticket
   string, which should be used as a cookie with the rest of the
   mod_auth_pubtkt ( <https://neon1.net/mod_auth_pubtkt/> ) system.

  Common scenario:
   1. On the login server side, write perl code to authenticate users
   (using Apache's authenetication, LDAP, DB, etc.).
   2. Once the user is authenticated, call "pubtkt_generate" to generate a
   ticket, and send it back to the user as a cookie.
   3. Redirect the user back to the server he/she came from.

Working Example
   A working (but minimal) perl login example is available at
   <https://github.com/manuelkasper/mod_auth_pubtkt/blob/master/perl-login/
   minimal_cgi/login.pl>

METHODS
 pubtkt_generate
   Generates a signed ticket.

   If successful, returns a signed ticket string (to be sent back to the
   user as a cookie).

   On any failure (bad key, failure to run "openssl", etc.) returns
   "undef".

   Accepts a hash of parameters:

   privatekey
       String containing the private key filename (full path). The key can
       be either DSA or RSA key (see keytype).

   keytype
       either "rsa" or "dsa" - depending on how you created the
       private/public key files.

   userid
       String containing the user ID. No specific format is enforced: can
       by a number, a string, an email address, etc. It will be encoded as
       "uid=XXXX" in the signed ticket.

   validuntil
       Numeric value, containing the validity period, in seconds since
       epoch (use "time()" function).

   graceperiod
       Optional. Numeric value. If given, will be added to the signed
       ticket string.

   clientip
       Optional. A string with an IP address. If given. will be added to
       the signed ticket string.

   token
       Optional. Any textual string. If given. will be added to the signed
       ticket string.

   userdata
       Optional. Any textual string. If given. will be added to the signed
       ticket string.

 pubtkt_verify
   Verifies a signed ticket string.

   If successful (i.e. the ticket's signature is valid), returns TRUE (=1).

   On any failure (bad key, failure to run "openssl", etc.) returns
   "undef".

   NOTE: This function checks ONLY THE SIGNATURE, based on the public key
   file. It is the caller's resposibility to check the expiration date.
   That is: The function will return TRUE if the ticket is properly signed,
   but possibly expired.

   Accepts a hash of parameters:

   publickey
       String containing the public key filename (full path). The key can
       be either DSA or RSA key (see keytype).

   keytype
       either "rsa" or "dsa" - depending on how you created the
       private/public key files.

   ticket
       The string of the ticket (such as returned by "pubtkt_generate").

 pubtkt_parse($ticket)
   Utility function to parse a ticket string into a Perl hash.

   NOTE: No validation is performed. The given ticket might be expired, or
   even forged.

PREREQUISITES
   openssl must be installed (and available on the $PATH).

   IPC::Run3 is required to run the openssl executables.

BUGS
   Probably many.

TODO
   Use Perl's Crypt::OpenSSL::RSA and Crypt::OpenSSL::DSA instead of the
   running "openssl" executable.

   Don't assume "openssl" binary is on the $PATH.

   Refactor into OO interface.

LICENSE
   Copyright (C) 2012 A. Gordon ( gordon at cshl dot edu ).

   Apache License, same as the rest of mod_auth_pubtkt

AUTHORS
   A. Gordon, heavily based on the PHP code from mod_auth_pubtkt.

SEE ALSO
   ModAuthPubTkt main website: <https://neon1.net/mod_auth_pubtkt/>

   ModAuthPubTkt github repository:
   <https://github.com/manuelkasper/mod_auth_pubtkt>

   This module's github repository:
   <https://github.com/agordon/Authen-ModAuthPubTkt>

   Examples in the "./eg" directory:

   generate_rsa_keys.sh
       Generates a pair of RSA key files.

   generate_dsa_keys.sh
       Generates a pair of DSA key files.

   mod_auth_pubtkt.pl
       A command-line utility to generate/verify tickets.