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Net::OpenID::Consumer - library for consumers of OpenID identities


  use Net::OpenID::Consumer;

  my $csr = Net::OpenID::Consumer->new(
    ua    => LWPx::ParanoidAgent->new,
    cache => Some::Cache->new,
    args  => $cgi,
    consumer_secret => ...,
    required_root => "",

  # a user entered, say, "" as their identity.  The first
  # step is to fetch that page, parse it, and get a
  # Net::OpenID::ClaimedIdentity object:

  my $claimed_identity = $csr->claimed_identity("");

  # now your app has to send them at their identity server's endpoint
  # to get redirected to either a positive assertion that they own
  # that identity, or where they need to go to login/setup trust/etc.

  my $check_url = $claimed_identity->check_url(
    return_to  => "",
    trust_root => "",

  # so you send the user off there, and then they come back to
  #, then you see what the identity server said.

  # Either use callback-based API (recommended)...
      not_openid => sub {
          die "Not an OpenID message";
      setup_required => sub {
          my $setup_url = shift;
          # Redirect the user to $setup_url
      cancelled => sub {
          # Do something appropriate when the user hits "cancel" at the OP
      verified => sub {
          my $vident = shift;
          # Do something with the VerifiedIdentity object $vident
      error => sub {
          my $err = shift;

  # ... or handle the various cases yourself
  if (my $setup_url = $csr->user_setup_url) {
       # redirect/link/popup user to $setup_url
  } elsif ($csr->user_cancel) {
       # restore web app state to prior to check_url
  } elsif (my $vident = $csr->verified_identity) {
       my $verified_url = $vident->url;
       print "You are $verified_url !";
  } else {
       die "Error validating identity: " . $csr->err;


This is the Perl API for (the consumer half of) OpenID, a distributed identity system based on proving you own a URL, which is then your identity. More information is available at:



my $csr = Net::OpenID::Consumer->new([ %opts ]);

You can set the ua, cache, consumer_secret, required_root, minimum_version and args in the constructor. See the corresponding method descriptions below.



Getter/setter for the LWP::UserAgent (or subclass) instance which will be used when web donwloads are needed. It's highly recommended that you use LWPx::ParanoidAgent, or at least read its documentation so you're aware of why you should care.


Getter/setter for the optional (but recommended!) cache instance you want to use for storing fetched parts of pages. (identity server public keys, and the <head> section of user's HTML pages)

The $cache object can be anything that has a ->get($key) and ->set($key,$value) methods. See URI::Fetch for more information. This cache object is just passed to URI::Fetch directly.

$code = $nos->consumer_secret; ($secret) = $code->($time);

The consumer secret is used to generate self-signed nonces for the return_to URL, to prevent spoofing.

In the simplest (and least secure) form, you configure a static secret value with a scalar. If you use this method and change the scalar value, any outstanding requests from the last 30 seconds or so will fail.

The more robust (but more complicated) form is to supply a subref that returns a secret based on the provided $time, a unix timestamp. And if one doesn't exist for that time, create, store and return it (with appropriate locking so you never return different secrets for the same time.)

Your secret may not exceed 255 characters.


Get or set the minimum OpenID protocol version supported. Currently the only useful value you can set here is 2, which will cause 1.1 identifiers to fail discovery with the error protocol_version_incorrect.

In most cases you'll want to allow both 1.1 and 2.0 identifiers, which is the default. If you want, you can set this property to 1 to make this behavior explicit.


Obtain a value from the message contained in the request arguments with the given key. This can only be used to obtain core arguments, not extension arguments.

Call this method without a $key argument to get a Net::OpenID::IndirectMessage object representing the message.


Can be used in 1 of 3 ways:

1. Setting the way which the Consumer instances obtains GET parameters:

$csr->args( $reference )

Where $reference is either a HASH ref, CODE ref, Apache $r, Apache::Request $apreq, or $cgi. If a CODE ref, the subref must return the value given one argument (the parameter to retrieve)

If you pass in an Apache $r object, you must not have already called $r->content as the consumer module will want to get the request arguments out of here in the case of a POST request.

2. Get a paramater:

my $foo = $csr->args("foo");

When given an unblessed scalar, it retrieves the value. It croaks if you haven't defined a way to get at the parameters.

Most callers should instead use the message method above, which abstracts away the need to understand OpenID's message serialization.

3. Get the getter:

my $code = $csr->args;

Without arguments, returns a subref that returns the value given a parameter name.

Most callers should instead use the message method above with no arguments, which returns an object from which extension attributes can be obtained by their documented namespace URI.

$url_prefix = $nos->required_root

If provided, this is the required string that all return_to URLs must start with. If it doesn't match, it'll be considered invalid (spoofed from another site)


Given a user-entered $url (which could be missing http://, or have extra whitespace, etc), returns either a Net::OpenID::ClaimedIdentity object, or undef on failure.

Note that this identity is NOT verified yet. It's only who the user claims they are, but they could be lying.

If this method returns undef, you can rely on the following errors codes (from $csr->errcode) to decide what to present to the user:

$csr->handle_server_response( %callbacks );

When a request comes in that contains a response from an OpenID provider, figure out what it means and dispatch to an appropriate callback to handle the request. This is the callback-based alternative to explicitly calling the methods below in the correct sequence, and is recommended unless you need to do something strange.

Anything you return from the selected callback function will be returned by this method verbatim. This is useful if the caller needs to return something different in each case.

The available callbacks are:

not_openid - the request isn't an OpenID response after all.
setup_required($setup_url) - the provider needs to present some UI to the user before it can respond. Send the user to the given URL by some means.
cancelled - the user cancelled the authentication request from the provider's UI
verified($verified_identity) - the user's identity has been successfully verified. A Net::OpenID::VerifiedIdentity object is passed in.
error($errcode, $errmsg) - an error has occured. An error code and message are provided.
$csr->user_setup_url( [ %opts ] )

Returns the URL the user must return to in order to login, setup trust, or do whatever the identity server needs them to do in order to make the identity assertion which they previously initiated by entering their claimed identity URL. Returns undef if this setup URL isn't required, in which case you should ask for the verified_identity.

The base URL this this function returns can be modified by using the following options in %opts:


What you're asking the identity server to do with the user after they setup trust. Can be either return or close to return the user back to the return_to URL, or close the browser window with JavaScript. If you don't specify, the behavior is undefined (probably the user gets a dead-end page with a link back to the return_to URL). In any case, the identity server can do whatever it wants, so don't depend on this.


Returns true if the user declined to share their identity, false otherwise. (This function is literally one line: returns true if "openid.mode" eq "cancel")

It's then your job to restore your app to where it was prior to redirecting them off to the user_setup_url, using the other query parameters that you'd sent along in your return_to URL.

$csr->verified_identity( [ %opts ] )

Returns a Net::OpenID::VerifiedIdentity object, or undef. Verification includes double-checking the reported identity URL declares the identity server, verifying the signature, etc.

The options in %opts may contain:


Sets the required_root just for this request. Values returns to its previous value afterwards.


Returns the last error, in form "errcode: errtext"


Returns the last error code.


Returns the last error text.


Returns the last error code/text in JSON format.


This module is Copyright (c) 2005 Brad Fitzpatrick. All rights reserved.

You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file. If you need more liberal licensing terms, please contact the maintainer.




The Net::OpenID family of modules has a mailing list powered by Google Groups. For more information, see .


OpenID website:

Net::OpenID::ClaimedIdentity -- part of this module

Net::OpenID::VerifiedIdentity -- part of this module

Net::OpenID::Server -- another module, for acting like an OpenID server


Brad Fitzpatrick <>

Tatsuhiko Miyagawa <>

Martin Atkins <>