MainClass.java Source code

Introduction

Here is the source code for MainClass.java

Source

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.Date;

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 = (X509Certificate) fact.generateCertificate(in);
        System.out.println("issuer: " + x509Cert.getIssuerX500Principal());
    }

    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();
    }
}