*   ...,
   *   [[2: publicKey        [1] PublicKey OPTIONAL ]],
   *   ...
   * }
   *
   * PrivateKeyInfo ::= OneAsymmetricKey
   * ```
   */
  internal val privateKeyInfo: BasicDerAdapter<PrivateKeyInfo> =
    Adapters.sequence(
      "PrivateKeyInfo",
      Adapters.INTEGER_AS_LONG,
      algorithmIdentifier,
      Adapters.OCTET_STRING,
      decompose = {
        listOf(

      encodeBase64Lines(pkcs1Bytes())
      append("-----END RSA PRIVATE KEY-----\n")
    }
  }

  private fun pkcs1Bytes(): ByteString {
    val decoded = CertificateAdapters.privateKeyInfo.fromDer(keyPair.private.encoded.toByteString())
    return decoded.privateKey
  }

  /** Build a held certificate with reasonable defaults. */
  class Builder {
    private var notBefore = -1L