$value )
$req .= $key . '=' . urlencode( stripslashes( $value ) ) . '&';
// Cut the last '&'
$req = substr( $req, 0, strlen( $req ) -1 );
return $req;
}
/**
* Submits an HTTP POST to a reCAPTCHA server
* @param string $host
* @param string $path
* @param array $data
* @param int port
* @return array response
*/
function _recaptcha_http_post( $host, $path, $data, $port = 80 ) {
$req = _recaptcha_qsencode ( $data );
$http_request = "POST $path HTTP/1.0\r\n";
$http_request .= "Host: $host\r\n";
$http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
$http_request .= "Content-Length: " . strlen( $req ) . "\r\n";
$http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
$http_request .= "\r\n";
$http_request .= $req;
$response = '';
if ( false == ( $fs = @fsockopen( $host, $port, $errno, $errstr, 10 ) ) ) {
die ( 'Could not open socket' );
}
fwrite( $fs, $http_request );
while ( !feof( $fs ) )
$response .= fgets( $fs, 1160 ); // One TCP-IP packet
fclose( $fs );
$response = explode( "\r\n\r\n", $response, 2 );
return $response;
}
/**
* Gets the challenge HTML (javascript and non-javascript version).
* This is called from the browser, and the resulting reCAPTCHA HTML widget
* is embedded within the HTML form it was called from.
* @param string $pubkey A public key for reCAPTCHA
* @param string $error The error given by reCAPTCHA (optional, default is null)
* @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)
* @return string - The HTML to be embedded in the user's form.
*/
function recaptcha_get_html ( $pubkey, $error = null, $use_ssl = false )
{
if ( $pubkey == null || $pubkey == '' ) {
die ( "To use reCAPTCHA you must get an API key from https://www.google.com/recaptcha/admin/create" );
}
if ( $use_ssl ) {
$server = RECAPTCHA_API_SECURE_SERVER;
} else {
$server = RECAPTCHA_API_SERVER;
}
$errorpart = "";
if ( $error ) {
$errorpart = "&error=" . $error;
}
return '
';
}
/**
* A ReCaptchaResponse is returned from recaptcha_check_answer()
*/
class ReCaptchaResponse {
public $is_valid;
public $error;
}
/**
* Calls an HTTP POST function to verify if the user's guess was correct
* @param string $privkey
* @param string $remoteip
* @param string $challenge
* @param string $response
* @param array $extra_params an array of extra variables to post to the server
* @return ReCaptchaResponse
*/
function recaptcha_check_answer ( $privkey, $remoteip, $challenge, $response, $extra_params = array() )
{
if ( $privkey == null || $privkey == '' ) {
die ( "To use reCAPTCHA you must get an API key from https://www.google.com/recaptcha/admin/create" );
}
if ( $remoteip == null || $remoteip == '' ) {
die ( "For security reasons, you must pass the remote ip to reCAPTCHA" );
}
// discard spam submissions
if ( $challenge == null || strlen( $challenge ) == 0 || $response == null || strlen( $response ) == 0 ) {
$recaptcha_response = new ReCaptchaResponse();
$recaptcha_response->is_valid = false;
$recaptcha_response->error = 'incorrect-captcha-sol';
return $recaptcha_response;
}
$response = _recaptcha_http_post ( RECAPTCHA_VERIFY_SERVER, "/recaptcha/api/verify",
array (
'privatekey' => $privkey,
'remoteip' => $remoteip,
'challenge' => $challenge,
'response' => $response
) + $extra_params
);
$answers = explode ( "\n", $response [1] );
$recaptcha_response = new ReCaptchaResponse();
if ( trim ( $answers [0] ) == 'true' ) {
$recaptcha_response->is_valid = true;
}
else {
$recaptcha_response->is_valid = false;
$recaptcha_response->error = $answers [1];
}
return $recaptcha_response;
}
/**
* gets a URL where the user can sign up for reCAPTCHA. If your application
* has a configuration page where you enter a key, you should provide a link
* using this function.
* @param string $domain The domain where the page is hosted
* @param string $appname The name of your application
*/
function recaptcha_get_signup_url ( $domain = null, $appname = null ) {
return "https://www.google.com/recaptcha/admin/create?" . _recaptcha_qsencode ( array ( 'domains' => $domain, 'app' => $appname ) );
}
function _recaptcha_aes_pad( $val ) {
$block_size = 16;
$numpad = $block_size - ( strlen ( $val ) % $block_size );
return str_pad( $val, strlen ( $val ) + $numpad, chr( $numpad ) );
}
/* Mailhide related code */
function _recaptcha_aes_encrypt( $val, $ky ) {
if ( ! function_exists ( "mcrypt_encrypt" ) ) {
die ( "To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed." );
}
$mode = MCRYPT_MODE_CBC;
$enc = MCRYPT_RIJNDAEL_128;
$val = _recaptcha_aes_pad( $val );
return mcrypt_encrypt( $enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" );
}
function _recaptcha_mailhide_urlbase64 ( $x ) {
return strtr( base64_encode ( $x ), '+/', '-_' );
}
/* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
function recaptcha_mailhide_url( $pubkey, $privkey, $email ) {
if ( $pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null ) {
die ( "To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " .
"you can do so at http://www.google.com/recaptcha/mailhide/apikey" );
}
$ky = pack( 'H*', $privkey );
$cryptmail = _recaptcha_aes_encrypt ( $email, $ky );
return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . _recaptcha_mailhide_urlbase64 ( $cryptmail );
}
/**
* gets the parts of the email to expose to the user.
* eg, given johndoe@example,com return ["john", "example.com"].
* the email is then displayed as john...@example.com
*/
function _recaptcha_mailhide_email_parts ( $email ) {
$arr = preg_split( "/@/", $email );
if ( strlen ( $arr[0] ) <= 4 ) {
$arr[0] = substr ( $arr[0], 0, 1 );
} elseif ( strlen ( $arr[0] ) <= 6 ) {
$arr[0] = substr ( $arr[0], 0, 3 );
} else {
$arr[0] = substr ( $arr[0], 0, 4 );
}
return $arr;
}
/**
* Gets html to display an email address given a public an private key.
* to get a key, go to:
*
* http://www.google.com/recaptcha/mailhide/apikey
*/
function recaptcha_mailhide_html( $pubkey, $privkey, $email ) {
$emailparts = _recaptcha_mailhide_email_parts ( $email );
$url = recaptcha_mailhide_url ( $pubkey, $privkey, $email );
return htmlentities( $emailparts[0] ) . "...@" . htmlentities ( $emailparts [1] );
}