Security.insertProviderAt(new BouncyCastleProvider(),1);

		Provider[] prvs=Security.getProviders();
		for(Provider prv:prvs){
			System.out.println(prv);
		}

		FileInputStream fis = new FileInputStream(sign_path);
		CertificateFactory cf = CertificateFactory.getInstance("X.509");
		Collection c = cf.generateCertificates(fis);
		Iterator i = c.iterator();
		X509Certificate cert=null;
		if (i.hasNext()) {
			cert = (X509Certificate) i.next();
			System.out.println(cert);
		}
		fis.close();

		PublicKey publicKey=cert.getPublicKey();

		Signature sig_bc=Signature.getInstance(cert.getSigAlgName(), BouncyCastleProvider.PROVIDER_NAME);
		sig_bc.initVerify(publicKey);
		System.out.println(sig_bc);

		FileInputStream my_file=new FileInputStream(file_path);
		while(my_file.available()>0){
			byte symb=(byte)my_file.read();
			sig_bc.update(symb);
		}
		System.out.println();
		my_file.close();

		sig_bc.verify(cert.getSignature());