AnyEvent::Yubico - AnyEvent based Perl extension for validating YubiKey OTPs. Though AnyEvent is used

       Dain Nilsson, <dain@yubico.com>

       Copyright (C) 2013 Yubico AB All rights reserved.

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perl v5.26.2                                       2018-05-21                              AnyEvent::Yubico(3pm)

       Validates a YubiKey OTP (One Time Password) using the YKVAL 2.0 protocol as defined here:
       https://github.com/Yubico/yubikey-val/wiki/ValidationProtocolV20

       To use this module, an API key is required, which can be requested here:
       https://upgrade.yubico.com/getapikey/

       When creating the AnyEvent::Yubico instance, the following arguments can be passed:

       client_id = $id_int
           Required. The client ID corresponding to the API key.

       api_key => $api_key_string
           Optional.  The  API  key used to sign requests and verify responses. Without this response signatures
           won't be verified.

       urls => $array_of_urls
           Optional. Defines which validation server URLs to  query.  The  default  uses  the  public  YubiCloud
           validation servers. Must support version 2.0 of the validation protocol.

           Example:

             $yk = AnyEvent::Yubico->new({
                 client_id => ...,
                 api_key => ...,
                 urls => [
                     "http://example.com/wsapi/2.0/verify",
                     "http://127.0.0.1/wsapi/2.0/verify"
                 ]
             });

       sign_requests => $enable
           Optional.  When  enabled  (enabled  by  default)  requests will be signed, as long as api_key is also
           provided.

       timeout => $seconds
           Optional. Timeout parameter sent to the server, see the protocol details for more information.

       sl => $level
           Optional. Security level parameter sent to the server, see the protocol details for more information.

       timestamp => $enable
           Optional. When enabled, sends the timestamp parameter to the  server,  causing  YubiKey  counter  and
           timestamp information to be returned in the response.

       local_timeout => $seconds
           Optional.  Sets the local timeout for how long the verify method will wait until failing. The default
           is 30 seconds.

       AnyEvent::Yubico - AnyEvent based Perl extension for validating YubiKey OTPs.  Though AnyEvent is used
       internally, the module does not impose any particular coding style on the caller. Provides both blocking
       and non-blocking methods of OTP verification.

       The            Yubico            Validation            Protocol            2.0             specification:
       https://github.com/Yubico/yubikey-val/wiki/ValidationProtocolV20

       More information about the YubiKey: http://www.yubico.com

         use AnyEvent::Yubico;

         $yk = AnyEvent::Yubico->new({ client_id => 4711, api_key => '<your API key here>' });

         $result = $yk->verify('<YubiKey OTP here>');
         if($result) ...

       For more details about the response, instead call verify_sync($otp), which returns a hash containing all
       the parameters that were in the response.

         $result_details = $yk->verify_sync('<YubiKey OTP here>');
         if($result_details->{status} == 'OK') ...

       As an alternative, you can call verify_async, which will return a condition variable immediately. This
       can be used if your application already uses an asynchronous model. You can also pass a callback as a
       second parameter to verify as well as verify_async, which will be invoked once validation has completed,
       with the result.

         $result_cv = $yk->verify_async('<YubiKey OTP here>', sub {
             #Callback invoked when verification is done
             $result_details = shift;
             if($result_details->{status} eq 'OK') ...
         });

         #Wait for the result (blocking, same as calling verify directly).
         $result_details = $result_cv->recv;