plugin.php

<?php
/*
Plugin Name: reCaptcha
Plugin URI: https://github.com/spbriggs/recaptcha-plugin/
Description: Implement reCaptcha on public submission page
Version: 1.1
Author: Simon Briggs
Author URI: https://github.com/spbriggs/
*/

function spb_recaptcha_check_Captcha($value, $url, $keyword, $title)
{
	// If the user is logged in then we don't need to process the captcha
	if (yourls_is_valid_user()===true)
	{
		return false;
	}
	$captchaType = $_POST['spb_recaptcha_captchatype'];
	if (empty($captchaType)) {$response['message'] ="Sorry, but you didn't pass the reCaptcha test";return $response;}
	switch($captchaType)
	{
		case 'recaptcha':
			return spb_recaptcha_dorecaptcha();
			break;
		case 'solvemedia':
			return spb_recaptcha_dosolvemedia();
			break;
		default:
			$response['message'] ="Sorry, but you didn't pass the reCaptcha test";
			return $response;
	}
}

function spb_recaptcha_dorecaptcha()
{
	$recaptcha=$_POST['g-recaptcha-response'];
	if(!empty($recaptcha))
	{
	    $privkey = yourls_get_option( 'spb_recaptcha_priv_key', "" );

		$google_url="https://www.google.com/recaptcha/api/siteverify";
		$secret=$privkey;
		$ip=$_SERVER['REMOTE_ADDR'];
		$url=$google_url."?secret=".$secret."&response=".$recaptcha."&remoteip=".$ip;
		$res=spb_recaptcha_getCurlData($url);
		$res= json_decode($res, true);
		//reCaptcha success check 
		if($res['success'])
		{
			return false;
		}
		else
		{
			$response['message'] ="Sorry, but you didn't pass the reCaptcha test";
			return $response;
		}
	}
	else
	{
		$response['message'] ="Sorry, but you didn't pass the reCaptcha test";
		return $response;
	}
}

function spb_recaptcha_dosolvemedia()
{
	require_once("solvemedialib.php");
	$privkey=yourls_get_option( 'spb_recaptcha_solvemediaVKey', "" );
	$hashkey=yourls_get_option( 'spb_recaptcha_solvemediaHKey', "" );
	$solvemedia_response = solvemedia_check_answer($privkey,
						$_SERVER["REMOTE_ADDR"],
						$_POST["adcopy_challenge"],
						$_POST["adcopy_response"],
						$hashkey);
	if (!$solvemedia_response->is_valid) {
		//handle incorrect answer
		$response['message'] = "Error: ".$solvemedia_response->error;
		return $response;
	}
	else {
		return false;
	}

}

function spb_recaptcha_getCurlData($url)
{
	$curl = curl_init();
	curl_setopt($curl, CURLOPT_URL, $url);
	curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($curl, CURLOPT_TIMEOUT, 10);
	curl_setopt($curl, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.16) Gecko/20110319 Firefox/3.6.16");
	$curlData = curl_exec($curl);
	curl_close($curl);
	return $curlData;
	}

function spb_recaptcha_add_Captcha_Script()
{
	$pubkey = yourls_get_option( 'spb_recaptcha_pub_key', "" );
	if (!(yourls_is_valid_user()===true))
	{
		echo ("<script src='https://www.google.com/recaptcha/api.js'></script>");
		echo("<div class='g-recaptcha' data-sitekey='" . $pubkey . "'></div>");
		echo("<input type='hidden' id='spb_recaptcha_captchatype' name='spb_recaptcha_captchatype' value='recaptcha'/>");
	}
}

function spb_recaptcha_add_SolveMedia_Script()
{
	$challengeKey = yourls_get_option( 'spb_recaptcha_solvemediaCKey', "" );
	if (!(yourls_is_valid_user()===true))
	{	
		require_once(dirname(__FILE__) . "/solvemedialib.php");			//include the Solve Media library 
		echo solvemedia_get_html($challengeKey);	//outputs the widget
	}
	echo("<input type='hidden' id='spb_recaptcha_captchatype' name='spb_recaptcha_captchatype' value='solvemedia'/>");
}

function spb_recaptcha_plugin_init() {
    yourls_register_plugin_page( 'spb_recaptcha', 'reCaptcha settings', 'spb_recaptcha_configpage_display' );
}

// The function that will draw the admin page
function spb_recaptcha_configpage_display() {
	 if( isset( $_POST['spb_recaptcha_public_key'] ) ) {
	        yourls_verify_nonce( 'spb_recaptcha_nonce' );
	        spb_recaptcha_save_admin();
	    }
    
    $nonce = yourls_create_nonce( 'spb_recaptcha_nonce' );
    $pubkey = yourls_get_option( 'spb_recaptcha_pub_key', "" );
    $privkey = yourls_get_option( 'spb_recaptcha_priv_key', "" );
    $solvemediaCKey = yourls_get_option( 'spb_recaptcha_solvemediaCKey', "" );
    $solvemediaVKey = yourls_get_option( 'spb_recaptcha_solvemediaVKey', "" );
    $solvemediaHKey = yourls_get_option( 'spb_recaptcha_solvemediaHKey', "" );


    echo '<h2>reCaptcha plugin settings</h2>';
    echo '<form method="post">';
    echo '<input type="hidden" name="nonce" value="' . $nonce . '" />';
    echo '<p><label for="spb_recaptcha_public_key">reCaptcha site key: </label>';
    echo '<input type="text" id="spb_recaptcha_public_key" name="spb_recaptcha_public_key" value="' . $pubkey . '"></p>';  
    echo '<p><label for="spb_recaptcha_private_key">reCaptcha secret key: </label>';
    echo '<input type="text" id="spb_recaptcha_private_key" name="spb_recaptcha_private_key" value="' . $privkey . '"></p>';

    echo '<hr/>';

    echo '<p><label for="spb_recaptcha_solvemediaCKey">Solve Media Challenge Key (C-key): </label>';
    echo '<input type="text" id="spb_recaptcha_solvemediaCKey" name="spb_recaptcha_solvemediaCKey" value="' . $solvemediaCKey . '"></p>';  
    echo '<p><label for="spb_recaptcha_solvemediaVKey">Solve Media Verification Key (V-key): </label>';
    echo '<input type="text" id="spb_recaptcha_solvemediaVKey" name="spb_recaptcha_solvemediaVKey" value="' . $solvemediaVKey . '"></p>';
    echo '<p><label for="spb_recaptcha_solvemediaHKey">Solve Media Authentication Hash Key (H-key): </label>';
    echo '<input type="text" id="spb_recaptcha_solvemediaHKey" name="spb_recaptcha_solvemediaHKey" value="' . $solvemediaHKey . '"></p>';
   
    echo '<input type="submit"/>';
    echo '</form>';
}

function spb_recaptcha_save_admin()
{
	$pubkey = $_POST['spb_recaptcha_public_key'];
	$privkey = $_POST['spb_recaptcha_private_key'];
	$solvemediaCKey = $_POST['spb_recaptcha_solvemediaCKey'];
	$solvemediaVKey = $_POST['spb_recaptcha_solvemediaVKey'];
	$solvemediaHKey = $_POST['spb_recaptcha_solvemediaHKey'];

	 if ( yourls_get_option( 'spb_recaptcha_pub_key' ) !== false ) {
        yourls_update_option( 'spb_recaptcha_pub_key', $pubkey );
    } else {
        yourls_add_option( 'spb_recaptcha_pub_key', $pubkey );
    }
	 if ( yourls_get_option( 'spb_recaptcha_priv_key' ) !== false ) {
        yourls_update_option( 'spb_recaptcha_priv_key', $privkey );
    } else {
        yourls_add_option( 'spb_recaptcha_priv_key', $privkey );
    }

    if ( yourls_get_option( 'spb_recaptcha_solvemediaCKey' ) !== false ) {
        yourls_update_option( 'spb_recaptcha_solvemediaCKey', $solvemediaCKey );
    } else {
        yourls_add_option( 'spb_recaptcha_solvemediaCKey', $solvemediaCKey );
    }
    if ( yourls_get_option( 'spb_recaptcha_solvemediaVKey' ) !== false ) {
        yourls_update_option( 'spb_recaptcha_solvemediaVKey', $solvemediaVKey );
    } else {
        yourls_add_option( 'spb_recaptcha_solvemediaVKey', $solvemediaVKey );
    }
    if ( yourls_get_option( 'spb_recaptcha_solvemediaHKey' ) !== false ) {
        yourls_update_option( 'spb_recaptcha_solvemediaHKey', $solvemediaHKey );
    } else {
        yourls_add_option( 'spb_recaptcha_solvemediaHKey', $solvemediaHKey );
    }
    echo "Saved";
}

yourls_add_action( 'plugins_loaded', 'spb_recaptcha_plugin_init' );
yourls_add_filter( 'shunt_add_new_link', 'spb_recaptcha_check_Captcha' );

?>