encryptResource() public static method

Takes two resource handles and encrypts the contents of the first, writing the ciphertext into the second.
public static encryptResource ( resource $inputHandle, resource $outputHandle, Defuse\Crypto\Key $key )
$inputHandle resource
$outputHandle resource
$key Defuse\Crypto\Key
 /**
  * Encrypts a stream.
  *
  * @param resource $resource The stream to encrypt.
  *
  * @return resource The encrypted stream.
  */
 private function encryptStream($resource)
 {
     $out = fopen('php://temp', 'r+b');
     File::encryptResource($resource, $out, $this->key());
     rewind($out);
     return $out;
 }
 /**
  * Encrypts a string.
  *
  * @param string $contents The string to encrypt.
  *
  * @return string The encrypted string.
  */
 protected function encrypt($contents)
 {
     $resource = fopen('php://memory', 'r+b');
     File::writeBytes($resource, $contents);
     rewind($resource);
     $out = fopen('php://memory', 'r+b');
     File::encryptResource($resource, $out, $this->key);
     rewind($out);
     return stream_get_contents($out);
 }