for (caCert in caCerts) {
      map.getOrPut(caCert.subjectX500Principal) { mutableSetOf() }.add(caCert)
    }
    this.subjectToCaCerts = map
  }

  override fun findByIssuerAndSignature(cert: X509Certificate): X509Certificate? {
    val issuer = cert.issuerX500Principal
    val subjectCaCerts = subjectToCaCerts[issuer] ?: return null

    return subjectCaCerts.firstOrNull {
      try {