code: @AssertTrue(message = "the provided certificate passphrase does not match with the uploaded certificate")
      public boolean isCertificatePassphraseValid() {
          try {
              PKCS12.validate(certificate, passphrase);
              return true;
          } catch (Exception e) {
              return false;
          }
      }
docs: Validates whether the certificate/passphrase pair
  is valid, and does not contain any bogus content.
  
  @return true if valid, otherwise false