docs: public static X509Certificate getCertfromPEM(InputStream certStream)
              throws IOException, CertificateException, NoSuchProviderException {
  
          String beginKey = "-----BEGIN CERTIFICATE-----";
          String endKey = "-----END CERTIFICATE-----";
          BufferedReader bufRdr = new BufferedReader(new InputStreamReader(certStream));
          ByteArrayOutputStream ostr = new ByteArrayOutputStream();
          PrintStream opstr = new PrintStream(ostr);
          String temp;
          while ((temp = bufRdr.readLine()) != null && !temp.equals(beginKey))
              continue;
          if (temp == null)
              throw new IOException("Error in " + certStream.toString() + ", missing " + beginKey + " boundary");
          while ((temp = bufRdr.readLine()) != null && !temp.equals(endKey))
              opstr.print(temp);
          if (temp == null)
              throw new IOException("Error in " + certStream.toString() + ", missing " + endKey + " boundary");
          opstr.close();
  
          byte[] certbuf = Base64.decode(ostr.toByteArray());
  
          // X509Certificate object
          CertificateFactory cf = CertificateFactory.getInstance("X.509", "SC");
          X509Certificate x509cert = (X509Certificate) cf.generateCertificate(new ByteArrayInputStream(certbuf));
          return x509cert;
      }