Source/SimpleBackRef.php
protected function checkCtrl()
    {
        $requestURL = substr($this->request, 0, -38); //the last 38 characters are the CTRL param
        $hashInput = strlen($requestURL) . $requestURL;
        $this->debugMessage[] = 'REQUEST URL: ' . $requestURL;
        $this->debugMessage[] = 'GET ctrl: ' . @$this->getData['ctrl'];
        $this->debugMessage[] = 'Calculated ctrl: ' . $this->hmac($this->secretKey, $hashInput);
        if (isset($this->getData['ctrl']) && $this->getData['ctrl'] == $this->hmac($this->secretKey, $hashInput)) {
            return true;
        }
        $this->errorMessage[] = 'HASH: Calculated hash is not valid!';
        $this->errorMessage[] = 'BACKREF ERROR: ' . @$this->getData['err'];
        return false;
    }
protected function checkCtrl()
    {
        $requestURL = substr($this->request, 0, -38); //the last 38 characters are the CTRL param
        $hashInput = strlen($requestURL) . $requestURL;
        $this->debugMessage[] = 'REQUEST URL: ' . $requestURL;
        $this->debugMessage[] = 'GET ctrl: ' . @$this->getData['ctrl'];
        $this->debugMessage[] = 'Calculated ctrl: ' . $this->hmac($this->secretKey, $hashInput);
        if (isset($this->getData['ctrl']) && $this->getData['ctrl'] == $this->hmac($this->secretKey, $hashInput)) {
            return true;
        }
        $this->errorMessage[] = 'HASH: Calculated hash is not valid!';
        $this->errorMessage[] = 'BACKREF ERROR: ' . @$this->getData['err'];
        return false;
    }
protected function checkCtrl ( ) { $ requestURL = substr ( $ this -> request , 0 , - 38 ) ; //the last 38 characters are the CTRL param $ hashInput = strlen ( $ requestURL ) . $ requestURL ; $ this -> debugMessage [ ] = 'REQUEST URL: ' . $ requestURL ; $ this -> debugMessage [ ] = 'GET ctrl: ' . @ $ this -> getData [ 'ctrl' ] ; $ this -> debugMessage [ ] = 'Calculated ctrl: ' . $ this -> hmac ( $ this -> secretKey , $ hashInput ) ; if ( isset ( $ this -> getData [ 'ctrl' ] ) && $ this -> getData [ 'ctrl' ] == $ this -> hmac ( $ this -> secretKey , $ hashInput ) ) { return true ; } $ this -> errorMessage [ ] = 'HASH: Calculated hash is not valid!' ; $ this -> errorMessage [ ] = 'BACKREF ERROR: ' . @ $ this -> getData [ 'err' ] ; return false ; }
Validates CTRL variable

@return boolean
Validates CTRL variable