code: function (data, scheme) {
        // scheme = RSA-OAEP, RSAES-PKCS1-V1_5
        scheme = scheme || SCHEME;
        return forge.util.encode64(this._cert.publicKey.encrypt(data, scheme));
      }
docs: Encrypt data using RSA public key inside the X.509 certificate
  @param {String} data The data to encrypt
  @param {String} [scheme='RSA-OAEP'] The scheme to be used in encryption.
  Use 'RSAES-PKCS1-V1_5' in legacy applications.
  @return {String} The RSA encryption result in Base64