weforms / includes / library / reCaptcha / recaptchalib.php

recaptchalib.php in weForms – Easy Drag & Drop Contact Form Builder For WordPress 1.5.4, at includes/library/reCaptcha/recaptchalib.php

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1	<?php
2	/*
3	* This is a PHP library that handles calling reCAPTCHA.
4	* - Documentation and latest version
5	* http://recaptcha.net/plugins/php/
6	* - Get a reCAPTCHA API Key
7	* https://www.google.com/recaptcha/admin/create
8	* - Discussion group
9	* http://groups.google.com/group/recaptcha
10	*
11	* Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net
12	* AUTHORS:
13	* Mike Crawford
14	* Ben Maurer
15	*
16	* Permission is hereby granted, free of charge, to any person obtaining a copy
17	* of this software and associated documentation files (the "Software"), to deal
18	* in the Software without restriction, including without limitation the rights
19	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
20	* copies of the Software, and to permit persons to whom the Software is
21	* furnished to do so, subject to the following conditions:
22	*
23	* The above copyright notice and this permission notice shall be included in
24	* all copies or substantial portions of the Software.
25	*
26	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
29	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
30	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
31	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
32	* THE SOFTWARE.
33	*/
34
35	/**
36	* The reCAPTCHA server URL's
37	*/
38	define("RECAPTCHA_API_SERVER", "http://www.google.com/recaptcha/api");
39	define("RECAPTCHA_API_SECURE_SERVER", "https://www.google.com/recaptcha/api");
40	define("RECAPTCHA_VERIFY_SERVER", "www.google.com");
41
42	/**
43	* Encodes the given data into a query string format
44	* @param $data - array of string elements to be encoded
45	* @return string - encoded request
46	*/
47	function _recaptcha_qsencode ($data) {
48	$req = "";
49	foreach ( $data as $key => $value )
50	$req .= $key . '=' . urlencode( stripslashes($value) ) . '&';
51
52	// Cut the last '&'
53	$req=substr($req,0,strlen($req)-1);
54	return $req;
55	}
56
57
58
59	/**
60	* Submits an HTTP POST to a reCAPTCHA server
61	* @param string $host
62	* @param string $path
63	* @param array $data
64	* @param int port
65	* @return array response
66	*/
67	function _recaptcha_http_post($host, $path, $data, $port = 80) {
68
69	$req = _recaptcha_qsencode ($data);
70
71	$http_request = "POST $path HTTP/1.0\r\n";
72	$http_request .= "Host: $host\r\n";
73	$http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
74	$http_request .= "Content-Length: " . strlen($req) . "\r\n";
75	$http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
76	$http_request .= "\r\n";
77	$http_request .= $req;
78
79	$response = '';
80	if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
81	die ('Could not open socket');
82	}
83
84	fwrite($fs, $http_request);
85
86	while ( !feof($fs) )
87	$response .= fgets($fs, 1160); // One TCP-IP packet
88	fclose($fs);
89	$response = explode("\r\n\r\n", $response, 2);
90
91	return $response;
92	}
93
94
95
96	/**
97	* Gets the challenge HTML (javascript and non-javascript version).
98	* This is called from the browser, and the resulting reCAPTCHA HTML widget
99	* is embedded within the HTML form it was called from.
100	* @param string $pubkey A public key for reCAPTCHA
101	* @param string $error The error given by reCAPTCHA (optional, default is null)
102	* @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)
103
104	* @return string - The HTML to be embedded in the user's form.
105	*/
106	function recaptcha_get_html ($pubkey, $enable_no_captcha = false, $error = null, $use_ssl = false)
107	{
108	if ($pubkey == null \|\| $pubkey == '') {
109	die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
110	}
111
112	if ($use_ssl) {
113	$server = RECAPTCHA_API_SECURE_SERVER;
114	} else {
115	$server = RECAPTCHA_API_SERVER;
116	}
117
118	$errorpart = "";
119	if ($error) {
120	$errorpart = "&error=" . $error;
121	}
122
123
124	if ( $enable_no_captcha == true ) {
125	$return_var = '<div class="g-recaptcha" data-sitekey="'.$pubkey.'"></div><script src="https://www.google.com/recaptcha/api.js"></script>';
126	} else {
127	$return_var = '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script>';
128	}
129
130	return $return_var.'
131
132	<noscript>
133	<iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/>
134	<textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
135	<input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
136	</noscript>';
137	}
138
139
140
141
142	/**
143	* A ReCaptchaResponse is returned from recaptcha_check_answer()
144	*/
145	if ( !class_exists( 'ReCaptchaResponse' ) ) {
146	class ReCaptchaResponse {
147	var $is_valid;
148	var $error;
149	}
150	}
151
152
153
154	/**
155	* Calls an HTTP POST function to verify if the user's guess was correct
156	* @param string $privkey
157	* @param string $remoteip
158	* @param string $challenge
159	* @param string $response
160	* @param array $extra_params an array of extra variables to post to the server
161	* @return ReCaptchaResponse
162	*/
163	function recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array())
164	{
165	if ($privkey == null \|\| $privkey == '') {
166	die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
167	}
168
169	if ($remoteip == null \|\| $remoteip == '') {
170	die ("For security reasons, you must pass the remote ip to reCAPTCHA");
171	}
172
173
174
175	//discard spam submissions
176	if ($challenge == null \|\| strlen($challenge) == 0 \|\| $response == null \|\| strlen($response) == 0) {
177	$recaptcha_response = new ReCaptchaResponse();
178	$recaptcha_response->is_valid = false;
179	$recaptcha_response->error = 'incorrect-captcha-sol';
180	return $recaptcha_response;
181	}
182
183	$response = _recaptcha_http_post (RECAPTCHA_VERIFY_SERVER, "/recaptcha/api/verify",
184	array (
185	'privatekey' => $privkey,
186	'remoteip' => $remoteip,
187	'challenge' => $challenge,
188	'response' => $response
189	) + $extra_params
190	);
191
192	$answers = explode ("\n", $response [1]);
193	$recaptcha_response = new ReCaptchaResponse();
194
195	if (trim ($answers [0]) == 'true') {
196	$recaptcha_response->is_valid = true;
197	}
198	else {
199	$recaptcha_response->is_valid = false;
200	$recaptcha_response->error = $answers [1];
201	}
202	return $recaptcha_response;
203
204	}
205
206	/**
207	* gets a URL where the user can sign up for reCAPTCHA. If your application
208	* has a configuration page where you enter a key, you should provide a link
209	* using this function.
210	* @param string $domain The domain where the page is hosted
211	* @param string $appname The name of your application
212	*/
213	function recaptcha_get_signup_url ($domain = null, $appname = null) {
214	return "https://www.google.com/recaptcha/admin/create?" . _recaptcha_qsencode (array ('domains' => $domain, 'app' => $appname));
215	}
216
217	function _recaptcha_aes_pad($val) {
218	$block_size = 16;
219	$numpad = $block_size - (strlen ($val) % $block_size);
220	return str_pad($val, strlen ($val) + $numpad, chr($numpad));
221	}
222
223	/* Mailhide related code */
224
225	function _recaptcha_aes_encrypt($val,$ky) {
226	if (! function_exists ("mcrypt_encrypt")) {
227	die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed.");
228	}
229	$mode=MCRYPT_MODE_CBC;
230	$enc=MCRYPT_RIJNDAEL_128;
231	$val=_recaptcha_aes_pad($val);
232	return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
233	}
234
235
236	function _recaptcha_mailhide_urlbase64 ($x) {
237	return strtr(base64_encode ($x), '+/', '-_');
238	}
239
240	/* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
241	function recaptcha_mailhide_url($pubkey, $privkey, $email) {
242	if ($pubkey == '' \|\| $pubkey == null \|\| $privkey == "" \|\| $privkey == null) {
243	die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " .
244	"you can do so at <a href='http://www.google.com/recaptcha/mailhide/apikey'>http://www.google.com/recaptcha/mailhide/apikey</a>");
245	}
246
247
248	$ky = pack('H*', $privkey);
249	$cryptmail = _recaptcha_aes_encrypt ($email, $ky);
250
251	return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . _recaptcha_mailhide_urlbase64 ($cryptmail);
252	}
253
254	/**
255	* gets the parts of the email to expose to the user.
256	* eg, given johndoe@example,com return ["john", "example.com"].
257	* the email is then displayed as john...@example.com
258	*/
259	function _recaptcha_mailhide_email_parts ($email) {
260	$arr = preg_split("/@/", $email );
261
262	if (strlen ($arr[0]) <= 4) {
263	$arr[0] = substr ($arr[0], 0, 1);
264	} else if (strlen ($arr[0]) <= 6) {
265	$arr[0] = substr ($arr[0], 0, 3);
266	} else {
267	$arr[0] = substr ($arr[0], 0, 4);
268	}
269	return $arr;
270	}
271
272	/**
273	* Gets html to display an email address given a public an private key.
274	* to get a key, go to:
275	*
276	* http://www.google.com/recaptcha/mailhide/apikey
277	*/
278	function recaptcha_mailhide_html($pubkey, $privkey, $email) {
279	$emailparts = _recaptcha_mailhide_email_parts ($email);
280	$url = recaptcha_mailhide_url ($pubkey, $privkey, $email);
281
282	return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) .
283	"' onclick=\"window.open('" . htmlentities ($url) . "', '', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=500,height=300'); return false;\" title=\"Reveal this e-mail address\">...</a>@" . htmlentities ($emailparts [1]);
284
285	}
286
287
288	?>
289