programmatically import .cer certificate into keystore

Question

How can I import a .p12 certificate from the classpath into the java keystore? First I used the InstallCert https://code.google.com/p/java-use-examples/source/browse/trunk/src/com/aw/ad/util/InstallCert.java and did some changes so the server certificate will be imported into the keystore in the java install directory. This works fine but now I want to load a certificate from my classpath.

EDIT: I just use a .cer certificate, see next answer

Answer 1

The answer:

    InputStream certIn = ClassLoader.class.getResourceAsStream("/package/myCert.cer");

    final char sep = File.separatorChar;
    File dir = new File(System.getProperty("java.home") + sep + "lib" + sep + "security");
    File file = new File(dir, "cacerts");
    InputStream localCertIn = new FileInputStream(file);

    KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
    keystore.load(localCertIn, passphrase);
    if (keystore.containsAlias("myAlias")) {
        certIn.close();
        localCertIn.close();
        return;
    }
    localCertIn.close();

    BufferedInputStream bis = new BufferedInputStream(certIn);
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    while (bis.available() > 0) {
        Certificate cert = cf.generateCertificate(bis);
        keystore.setCertificateEntry("myAlias", cert);
    }

    certIn.close();

    OutputStream out = new FileOutputStream(file);
    keystore.store(out, passphrase);
    out.close();

For Java Web Start dont use the ClassLoader, use the Class itselfe:

InputStream certIn = Certificates.class.getResourceAsStream("/package/myCert.cer");