KeyStoreWrapper.kt

private fun initGeneratorWithKeyPairGeneratorSpec(generator: KeyPairGenerator, alias: String) {
    val startDate = Calendar.getInstance()
    val endDate = Calendar.getInstance()
    endDate.add(Calendar.YEAR, 20)

    val builder = KeyPairGeneratorSpec.Builder(context)
          .setAlias(alias)
          .setSerialNumber(BigInteger.ONE)
          .setSubject(X500Principal("CN=${alias} CA Certificate"))
          .setStartDate(startDate.time)
          .setEndDate(endDate.time)

    generator.initialize(builder.build())
}