private static void test(PrivateKey privateKey, PublicKey publicKey) throws Exception {
   testSignature("MD2withRSA", privateKey, publicKey);
   testSignature("MD5withRSA", privateKey, publicKey);
   testSignature("SHA1withRSA", privateKey, publicKey);
   testSignature("SHA224withRSA", privateKey, publicKey);
   testSignature("SHA256withRSA", privateKey, publicKey);
   RSAPublicKey rsaKey = (RSAPublicKey) publicKey;
   if (rsaKey.getModulus().bitLength() > 512) {
     // for SHA384 and SHA512 the data is too long for 512 bit keys
     testSignature("SHA384withRSA", privateKey, publicKey);
     testSignature("SHA512withRSA", privateKey, publicKey);
   }
 }
  /**
   * Appends an HTML representation of the given X509Certificate.
   *
   * @param sb StringBuilder to append to
   * @param certificate to print
   */
  private void renderX509(StringBuilder sb, X509Certificate certificate) {
    X500Principal issuer = certificate.getIssuerX500Principal();
    X500Principal subject = certificate.getSubjectX500Principal();

    sb.append("<table cellspacing='1' cellpadding='1'>\n");

    // subject
    addTitle(sb, R.getI18NString("service.gui.CERT_INFO_ISSUED_TO"));
    try {
      for (Rdn name : new LdapName(subject.getName()).getRdns()) {
        String nameType = name.getType();
        String lblKey = "service.gui.CERT_INFO_" + nameType;
        String lbl = R.getI18NString(lblKey);

        if ((lbl == null) || ("!" + lblKey + "!").equals(lbl)) lbl = nameType;

        final String value;
        Object nameValue = name.getValue();

        if (nameValue instanceof byte[]) {
          byte[] nameValueAsByteArray = (byte[]) nameValue;

          value = getHex(nameValueAsByteArray) + " (" + new String(nameValueAsByteArray) + ")";
        } else value = nameValue.toString();

        addField(sb, lbl, value);
      }
    } catch (InvalidNameException ine) {
      addField(sb, R.getI18NString("service.gui.CERT_INFO_CN"), subject.getName());
    }

    // issuer
    addTitle(sb, R.getI18NString("service.gui.CERT_INFO_ISSUED_BY"));
    try {
      for (Rdn name : new LdapName(issuer.getName()).getRdns()) {
        String nameType = name.getType();
        String lblKey = "service.gui.CERT_INFO_" + nameType;
        String lbl = R.getI18NString(lblKey);

        if ((lbl == null) || ("!" + lblKey + "!").equals(lbl)) lbl = nameType;

        final String value;
        Object nameValue = name.getValue();

        if (nameValue instanceof byte[]) {
          byte[] nameValueAsByteArray = (byte[]) nameValue;

          value = getHex(nameValueAsByteArray) + " (" + new String(nameValueAsByteArray) + ")";
        } else value = nameValue.toString();

        addField(sb, lbl, value);
      }
    } catch (InvalidNameException ine) {
      addField(sb, R.getI18NString("service.gui.CERT_INFO_CN"), issuer.getName());
    }

    // validity
    addTitle(sb, R.getI18NString("service.gui.CERT_INFO_VALIDITY"));
    addField(
        sb,
        R.getI18NString("service.gui.CERT_INFO_ISSUED_ON"),
        certificate.getNotBefore().toString());
    addField(
        sb,
        R.getI18NString("service.gui.CERT_INFO_EXPIRES_ON"),
        certificate.getNotAfter().toString());

    addTitle(sb, R.getI18NString("service.gui.CERT_INFO_FINGERPRINTS"));
    try {
      String sha1String = getThumbprint(certificate, "SHA1");
      String md5String = getThumbprint(certificate, "MD5");

      addField(sb, "SHA1:", sha1String);
      addField(sb, "MD5:", md5String);
    } catch (CertificateException e) {
      // do nothing as we cannot show this value
    }

    addTitle(sb, R.getI18NString("service.gui.CERT_INFO_CERT_DETAILS"));

    addField(
        sb,
        R.getI18NString("service.gui.CERT_INFO_SER_NUM"),
        certificate.getSerialNumber().toString());

    addField(
        sb, R.getI18NString("service.gui.CERT_INFO_VER"), String.valueOf(certificate.getVersion()));

    addField(
        sb,
        R.getI18NString("service.gui.CERT_INFO_SIGN_ALG"),
        String.valueOf(certificate.getSigAlgName()));

    addTitle(sb, R.getI18NString("service.gui.CERT_INFO_PUB_KEY_INFO"));

    addField(
        sb,
        R.getI18NString("service.gui.CERT_INFO_ALG"),
        certificate.getPublicKey().getAlgorithm());

    if (certificate.getPublicKey().getAlgorithm().equals("RSA")) {
      RSAPublicKey key = (RSAPublicKey) certificate.getPublicKey();

      addField(
          sb,
          R.getI18NString("service.gui.CERT_INFO_PUB_KEY"),
          R.getI18NString(
              "service.gui.CERT_INFO_KEY_BYTES_PRINT",
              new String[] {
                String.valueOf(key.getModulus().toByteArray().length - 1),
                key.getModulus().toString(16)
              }));

      addField(
          sb, R.getI18NString("service.gui.CERT_INFO_EXP"), key.getPublicExponent().toString());

      addField(
          sb,
          R.getI18NString("service.gui.CERT_INFO_KEY_SIZE"),
          R.getI18NString(
              "service.gui.CERT_INFO_KEY_BITS_PRINT",
              new String[] {String.valueOf(key.getModulus().bitLength())}));
    } else if (certificate.getPublicKey().getAlgorithm().equals("DSA")) {
      DSAPublicKey key = (DSAPublicKey) certificate.getPublicKey();

      addField(sb, "Y:", key.getY().toString(16));
    }

    addField(
        sb,
        R.getI18NString("service.gui.CERT_INFO_SIGN"),
        R.getI18NString(
            "service.gui.CERT_INFO_KEY_BYTES_PRINT",
            new String[] {
              String.valueOf(certificate.getSignature().length), getHex(certificate.getSignature())
            }));

    sb.append("</table>\n");
  }