internal data class BasicConstraints(
  /** True if this certificate can be used as a Certificate Authority (CA). */
  val ca: Boolean,
  /** The maximum number of intermediate CAs between this and leaf certificates. */
  val maxIntermediateCas: Long?,
)

/** A private key. Note that this class doesn't support attributes or an embedded public key. */
internal data class PrivateKeyInfo(
  // v1(0), v2(1).
  val version: Long,