public class SignCryptoPro {
	
	// Path to PDF files
	final static String PREFIX_PDF_DIR = "dir/";
	// Path to certificate, CRL, CA, key store
	final static String PREFIX_KEY_DIR = "dir/";             //dailybuilds/CSPbuild/rtests/cades/

	// Alias of key in client store
	final static String ALIAS = "Test1";
	// Password to client store
	final static char[] PASSWORD = null;
	
	// Alias of CA certificate in trusted store
	final static String CA_ALIAS = "name.cer";         //cert.cer
	// Password to trusted store
	final static char[] CA_PASSWORD = "13564877".toCharArray();
	// CA file
	final static String CA_FILENAME =  "name.cer";     //certstore.crs
	// PDF file
	final static String PDF_FILENAME = "test.pdf";
		
	/**
	 * Loads key store.
	 * @param storeFile - key store file.
	 * @param password - password to store.
	 * @return opened key store.
	 * @throws KeyStoreException
	 * @throws NoSuchProviderException
	 * @throws NoSuchAlgorithmException
	 * @throws CertificateException
	 * @throws IOException
	 */
	private static KeyStore loadKeyStore(String storeFile, char[] password) throws KeyStoreException, NoSuchProviderException, 
	NoSuchAlgorithmException, CertificateException, IOException {
            
		KeyStore keyStore = KeyStore.getInstance("HDImageStore","JCP");
		keyStore.load( (storeFile == null) ? null : new FileInputStream(storeFile), password);
		
		return keyStore;
	}
	
	/**
	 * Signs PDF file (CryptoPro PDF / PKCS7 DETACHED) and saves it.
	 * @param fileToSign - source PDF file.
	 * @param signedFile - signed PDF file.
	 * @param signStore - store containing key to sign file.
	 * @param trustedStore - store containing trusted CA certificate.
	 * @throws IOException
	 * @throws DocumentException
	 * @throws KeyStoreException
	 * @throws NoSuchProviderException
	 * @throws NoSuchAlgorithmException
	 * @throws CertificateException
	 * @throws UnrecoverableKeyException
	 */
	public static void signPDF(String fileToSign, String signedFile, KeyStore signStore, KeyStore trustedStore) throws IOException, 
	DocumentException, KeyStoreException, NoSuchProviderException, NoSuchAlgorithmException, CertificateException, 
	UnrecoverableKeyException {
		
		// Get key and certificates
		PrivateKey key = (PrivateKey)signStore.getKey(ALIAS, PASSWORD);
		
		int chainLength = (trustedStore == null) ? 1 : 2;
		
		Certificate[] chain = new Certificate[chainLength];
		chain[0] = signStore.getCertificate(ALIAS);
		
		if (trustedStore != null) {
			chain[1] = trustedStore.getCertificate(CA_ALIAS);
		}
		
		// Load PDF
		PdfReader reader = new PdfReader(fileToSign);
		FileOutputStream fout = new FileOutputStream(signedFile);
		PdfStamper stp = PdfStamper.createSignature(reader, fout, '\0');
		
		// Sign document
		PdfSignatureAppearance sap = stp.getSignatureAppearance();
		sap.setProvider("JCP");
		sap.setCrypto(key, chain, null, PdfSignatureAppearance.CRYPTOPRO_SIGNED);
		sap.setReason("I'm the signer");
		sap.setLocation("CryptoPro");
		stp.close();
	}
	
	
	/**
	 * @param args
	 * @throws NoSuchProviderException 
	 * @throws KeyStoreException 
	 * @throws IOException 
	 * @throws CertificateException 
	 * @throws NoSuchAlgorithmException 
	 * @throws UnrecoverableKeyException 
	 * @throws DocumentException 
	 * @throws SignatureException 
	 * @throws CRLException 
	 */
	public static void main(String[] args) throws KeyStoreException, NoSuchProviderException, NoSuchAlgorithmException, 
	CertificateException, IOException, UnrecoverableKeyException, DocumentException, SignatureException, CRLException {

		// Trusted store (CA) to build chain
		KeyStore trustedStore = null;
		
		// Key store containing trusted certificate to build chain
		if (CA_FILENAME != null) {
			trustedStore = loadKeyStore(PREFIX_KEY_DIR + CA_FILENAME, CA_PASSWORD);
		}
		
		// Key store containing client key to sign document
		final KeyStore clientStore = loadKeyStore(null, PASSWORD);
		
		// Sign PDF
		signPDF(PREFIX_PDF_DIR + PDF_FILENAME, 
				PREFIX_PDF_DIR + "signed_" + PDF_FILENAME, clientStore, trustedStore );

	}
}