package chapter4;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.SignatureException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.Date;

import org.bouncycastle.jce.X509Principal;
import org.bouncycastle.x509.X509V3CertificateGenerator;

class CertGenerator {
	public static void main(String[] args) throws NoSuchAlgorithmException,
			InvalidKeyException, SecurityException, SignatureException,
			KeyStoreException, CertificateException, FileNotFoundException,
			IOException {
		CertGenerator d = new CertGenerator();
		KeyPair caPair = d.generateKeyPair();
		X509Certificate generateCertWithKeypair = d
				.generateCertWithKeypair(caPair);
		storeTheFileWithKeyStore(generateCertWithKeypair, caPair);
	}

	private static void storeTheFileWithKeyStore(X509Certificate cert,
			KeyPair caPair) throws KeyStoreException, NoSuchAlgorithmException,
			CertificateException, FileNotFoundException, IOException {
		KeyStore keyStore = KeyStore.getInstance("RSA");
		keyStore.load(null, null);
		keyStore.setKeyEntry("certificatename", caPair.getPrivate(),
				"mysecretpassword".toCharArray(),
				new java.security.cert.Certificate[] { cert });
		File file = new File(".", "keystore.test");
		keyStore.store(new FileOutputStream(file),
				"mysecretpassword".toCharArray());

	}

	KeyPair generateKeyPair() throws NoSuchAlgorithmException {

		KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
		keyPairGenerator.initialize(2048, new SecureRandom());
		KeyPair keyPair = keyPairGenerator.generateKeyPair();
		return keyPair;
	}

	public X509Certificate generateCertWithKeypair(KeyPair caPair)
			throws InvalidKeyException, SecurityException, SignatureException {
		X509V3CertificateGenerator v3CertGen = new X509V3CertificateGenerator();
		v3CertGen
				.setSerialNumber(BigInteger.valueOf(System.currentTimeMillis()));
		v3CertGen
				.setIssuerDN(new X509Principal("CN=cn, O=o, L=L, ST=il, C= c"));
		v3CertGen.setNotBefore(new Date(System.currentTimeMillis() - 1000L * 60
				* 60 * 24));
		v3CertGen.setNotAfter(new Date(System.currentTimeMillis()
				+ (1000L * 60 * 60 * 24 * 365 * 10)));
		v3CertGen
				.setSubjectDN(new X509Principal("CN=cn, O=o, L=L, ST=il, C= c"));
		v3CertGen.setPublicKey(caPair.getPublic());
		v3CertGen.setSignatureAlgorithm("SHA1WithRSAEncryption");
		X509Certificate generateX509Certificate = v3CertGen
				.generateX509Certificate(caPair.getPrivate());
		return generateX509Certificate;
	}

}