CertificateAdapters.subjectPublicKeyInfo.fromDer(
          subjectKeyPair.public.encoded.toByteString(),
        )
      val subject: List<List<AttributeTypeAndValue>> = subject()

      // Issuer/signer keys & identity. May be the subject if it is self-signed.
      val issuerKeyPair: KeyPair
      val issuer: List<List<AttributeTypeAndValue>>
      if (signedBy != null) {
        issuerKeyPair = signedBy!!.keyPair