import java.security.spec.X509EncodedKeySpec
import java.text.SimpleDateFormat
import java.util.Date
import java.util.TimeZone
import okhttp3.tls.HeldCertificate
import okhttp3.tls.decodeCertificatePem
import okhttp3.tls.internal.der.ObjectIdentifiers.BASIC_CONSTRAINTS
import okhttp3.tls.internal.der.ObjectIdentifiers.COMMON_NAME
import okhttp3.tls.internal.der.ObjectIdentifiers.ORGANIZATIONAL_UNIT_NAME

      return decode(certificatePem, pkcs8Base64)
    }

    private fun decode(
      certificatePem: String,
      pkcs8Base64Text: String,
    ): HeldCertificate {
      val certificate = certificatePem.decodeCertificatePem()

      val pkcs8Bytes =
        pkcs8Base64Text.decodeBase64()
          ?: throw IllegalArgumentException("failed to decode private key")