/**
  * @param string $fingerprint
  * @throws ConfigurationException
  */
 public function __construct($fingerprint)
 {
     $gpg = new \gnupg();
     if (!$gpg->addencryptkey($fingerprint)) {
         throw ConfigurationException::failedToAddEncryptKey($fingerprint, $gpg->geterror());
     }
     if (!$this->addencryptkey($fingerprint)) {
         throw ConfigurationException::failedToAddEncryptKey($fingerprint, $this->geterror());
     }
     $this->ability |= EncryptionAbility::ENCRYPT;
 }