Alias[] aliases = this.request.getAliases();
boolean valid = true;
for (Alias alias : aliases) {
PrivateKeyEntry privateKeyEntry = (PrivateKeyEntry) store.get(alias, StoreEntryType.PRIVATE_KEY);
Certificate[] chain = privateKeyEntry.getChain();
X509Certificate certificate = (X509Certificate) chain[0];
PublicKey publicKey = certificate.getPublicKey();
ByteArrayInputStream inputStream = new ByteArrayInputStream(signature);
Document document = this.documentBuilderFactory.newDocumentBuilder().parse(inputStream);