Java.security.KeyStoreException: Cannot store non-PrivateKeys

Question

I have been getting this exception:
Exception in thread "main" java.security.KeyStoreException: Cannot store non-PrivateKeys
     at sun.security.provider.JavaKeyStore.engineSetKeyEntry(Unknown Source)
     at java.security.KeyStore.setKeyEntry(Unknown Source)
     at KeyStoreExample.encrypt(KeyStoreExample.java:89)
     at KeyStoreExample.main(KeyStoreExample.java:39)
while running this code:
private static void encrypt(char[] password, String plaintext)
  throws Exception
    System.out.println("Generating a TripleDES key...");
    // Create a Blowfish key
    KeyGenerator keyGenerator = KeyGenerator.getInstance("TripleDES");
    keyGenerator.init(168);
    Key key = keyGenerator.generateKey();
    System.out.println("Done generating the key.");
    // Create a cipher using that key to initialize it
    Cipher cipher = Cipher.getInstance("TripleDES/ECB/PKCS5Padding");
    cipher.init(Cipher.ENCRYPT_MODE, key);
    byte[] plaintextBytes = plaintext.getBytes();
    // Perform the actual encryption
    byte[] cipherText = cipher.doFinal(plaintextBytes);
    // Now we need to Base64-encode it for ascii display
    BASE64Encoder encoder = new BASE64Encoder();
    String output = encoder.encode(cipherText);
    System.out.println("Ciphertext: "+output);
    /* Create a keystore and place the key in it
     * We're using a jceks keystore, which is provided by Sun's JCE.
     * If you don't have the JCE installed, you can use "JKS",
     * which is the default keystore. It doesn't provide
     * the same level of protection however.
    KeyStore keyStore = KeyStore.getInstance("JKS", "SUN");
    // This initializes a blank keystore
    keyStore.load(null, null);
    // Now we add the key to the keystore, protected
    // by the password.
    keyStore.setKeyEntry("LuisTest", key, password, null);
    // Store the password to the filesystem, protected
    // by the same password.
    FileOutputStream fos = new FileOutputStream(FILENAME);
    keyStore.store(fos, password);
    fos.close();The error fires when it gets to this line
    keyStore.setKeyEntry("LuisTest", key, password, null);

Answer 1

Maybe you should try defining the type of entry that
you want stored into the KeyStore, i.e. privateKey,
SecretKey, TrustedCertificateEntry. The setKeyEntry
method that you're using expects a certificate chain
to accompany the Key if it is used as a private key.
If you don't want to use the key as one of the
available types, perhaps you need to use the
CertStore object as opposed to the KeyStore object.Hi,
I've got the same exception althought I specified the type of entry. Here is my test code :
public void createKeyStore() {
     try {
          KeyGenerator keyGen = KeyGenerator.getInstance("DES");
          SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");
          keyGen.init(56, random);
          SecretKey secretKey = keyGen.generateKey();
          KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
          char password[] = {'j', 's', 'd', '4', '9', '4' };
          // Create an empty keystore
          ks.load(null, password);
          KeyStore.SecretKeyEntry skEntry = new KeyStore.SecretKeyEntry(secretKey);
          ks.setEntry("symKey", skEntry, new KeyStore.PasswordProtection(password));
          // store away the keystore
          java.io.FileOutputStream fos =
               new java.io.FileOutputStream("mystore");
          ks.store(fos, password);
          fos.close();
     } catch (NoSuchAlgorithmException nsaex) {
          nsaex.printStackTrace(System.err);
     } catch (NoSuchProviderException nspex) {
          nspex.printStackTrace(System.err);
     } catch (KeyStoreException ksex) {
          ksex.printStackTrace(System.err);
     } catch (CertificateException cex) {
          cex.printStackTrace(System.err);
     } catch (IOException ioex) {
          ioex.printStackTrace(System.err);
} ... and what I don't understand is that the main idea of this code is taken from the Java API documentation itself. See this url for reference
http://java.sun.com/j2se/1.5.0/docs/api/java/security/KeyStore.html