Use BC to generate certificate

Question

Hello, everyone,
I am trying to generate my own certificate instead of asking it from a CA such as verisign.com. And I know that the provider from Sun can not do that. So, I turned to BC provider. But, I really have no idea about how to generate my certificate programmablely. Is there any tutorial or sample code talking about how to do that using BC? Or, is there any other method to learn how to do that?
Your help is highly appreciated!
Regards

Answer 1

X509V3CertificateGenerator certificateGenerator = new X509V3CertificateGenerator();
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA"); // key pair algorithm
keyPairGenerator.initialize(1024); // key size
KeyPair keyPair = keyPairGenerator.generateKeyPair(); // generate keys
int usage = X509KeyUsage.digitalSignature | X509KeyUsage.dataEncipherment; // set key usage, it's optional
X509KeyUsage keyUsage = new X509KeyUsage(usage);
certificateGenerator.addExtension("2.5.29.15", false, keyUsage);
certificateGenerator.setSerialNumber(BigInteger.ONE); // set serial number
String x509Name = "CN=SomeName";
certificateGenerator.setIssuerDN(new X509Name(x509Name));
certificateGenerator.setSubjectDN(new X509Name(x509Name));
Calendar nextYearDate = Calendar.getInstance();
nextYearDate.add(Calendar.YEAR, 1); // Valid for 1 year
certificateGenerator.setNotAfter(nextYearDate.getTime());
certificateGenerator.setNotBefore(Calendar.getInstance().getTime());
certificateGenerator.setSignatureAlgorithm("SHA1withRSA");
certificateGenerator.setPublicKey(keyPair.getPublic());
String alias = Long.toHexString(SecureRandom.getInstance("SHA1PRNG").nextLong());
X509Certificate certificate = certificateGenerator.generateX509Certificate(keyPair.getPrivate());