import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.math.BigInteger;
import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.Security;
import java.security.SignatureException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import javax.security.auth.x500.X500Principal;
import org.bouncycastle.x509.X509V1CertificateGenerator;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
KeyPair pair = generateRSAKeyPair();
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
bOut.write(generateV1Certificate(pair).getEncoded());
bOut.close();
InputStream in = new ByteArrayInputStream(bOut.toByteArray());
CertificateFactory fact = CertificateFactory.getInstance("X.509", "BC");
X509Certificate x509Cert;
Collection collection = new ArrayList();
while ((x509Cert = (X509Certificate) fact.generateCertificate(in)) != null) {
collection.add(x509Cert);
}
Iterator it = collection.iterator();
while (it.hasNext()) {
System.out.println("version: " + ((X509Certificate) it.next()).getVersion());
}
}
public static X509Certificate generateV1Certificate(KeyPair pair) throws InvalidKeyException,
NoSuchProviderException, SignatureException {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
X509V1CertificateGenerator certGen = new X509V1CertificateGenerator();
certGen.setSerialNumber(BigInteger.valueOf(System.currentTimeMillis()));
certGen.setIssuerDN(new X500Principal("CN=Test Certificate"));
certGen.setNotBefore(new Date(System.currentTimeMillis() - 10000));
certGen.setNotAfter(new Date(System.currentTimeMillis() + 10000));
certGen.setSubjectDN(new X500Principal("CN=Test Certificate"));
certGen.setPublicKey(pair.getPublic());
certGen.setSignatureAlgorithm("SHA256WithRSAEncryption");
return certGen.generateX509Certificate(pair.getPrivate(), "BC");
}
public static KeyPair generateRSAKeyPair() throws Exception {
KeyPairGenerator kpGen = KeyPairGenerator.getInstance("RSA", "BC");
kpGen.initialize(1024, new SecureRandom());
return kpGen.generateKeyPair();
}
}