KeyPairGenerator 不可用

Question

我正在创建一个程序来生成密钥对，但出现以下错误：

Exception in thread "main" java.lang.NullPointerException
at generateAESKey.main(generateAESKey.java:43)

这就是我目前的工作。

key.getEncoded());

未读。

public class generateAESKey {
    public static void main(String[] args) throws Exception {
        generateAESKey generatekey = new generateAESKey();    
        KeyGenerator keyGen = KeyGenerator.getInstance("AES");
        keyGen.init(256);
        SecretKey skey = keyGen.generateKey();
        byte[] raw = skey.getEncoded();
        FileOutputStream fos2 = new FileOutputStream("C:\Users\win8.1\Desktop\AES\test.txt");
        fos2.write(raw);
        fos2.close();


        KeyPairGenerator keyGen1 = KeyPairGenerator.getInstance("RSA");
        SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");
        keyGen1.initialize(1024, random);
        KeyPair generatedKeyPair = keyGen1.genKeyPair();
        savePublicKey(generatedKeyPair.getPublic(), "C:\Users\win8.1\Desktop\AES\public");
        savePrivateKey(generatedKeyPair.getPrivate(), "C:\Users\win8.1\Desktop\AES\private");


        PublicKey key = null;

        X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(
        key.getEncoded());
        FileOutputStream fos3 = new FileOutputStream("C:\Users\win8.1\Desktop\AES\public.txt");
        fos3.write(x509EncodedKeySpec.getEncoded());
        fos3.close();

        PrivateKey key1 = null;
        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(
        key1.getEncoded());
        FileOutputStream fos4 = new FileOutputStream("C:\Users\win8.1\Desktop\AES\private.txt");
        fos4.write(pkcs8EncodedKeySpec.getEncoded());
        fos4.close();
        System.out.println("SAVE");

    }
        private static void savePrivateKey(PrivateKey private1, String string) {
        // TODO Auto-generated method stub

    }
        private static void savePublicKey(PublicKey public1, String string) {
        // TODO Auto-generated method stub

    }

        public SecretKeySpec getKeySpec() throws IOException, NoSuchAlgorithmException {
            byte[] bytes = new byte[16];
            File f = new File("aes.key");
            SecretKey key = null;
            SecretKeySpec spec = null;
            if (f.exists()) {
              new FileInputStream(f).read(bytes);
            } else {
               KeyGenerator kgen = KeyGenerator.getInstance("AES");
               kgen.init(256);  //128 kalagay
               key = kgen.generateKey();
               bytes = key.getEncoded();
               new FileOutputStream(f).write(bytes);
            }
            spec = new SecretKeySpec(bytes,"AES");
            return spec;
          }
}

任何帮助将不胜感激。谢谢。

我已经编辑过了。

Answer 1

这一行是错误的：

KeyPairGenerator keyGen1 = KeyPairGenerator.getInstance("ALGORITHM");

您必须提供要使用的算法的名称，例如：

KeyPairGenerator keyGen1 = KeyPairGenerator.getInstance("RSA");

Answer 2

第一个错误: KeyPairGenerator.getInstance(String algorithm) 只能处理以下输入 Strings:

迪菲赫尔曼
动态搜索广告
RSA
EC

更多信息请看in the docs

可能来电 KeyPairGenerator.getInstance("RSA");

第二个错误 (nullptr): 你必须创建一个PublicKey！你正在做 PublicKey key = null; 然后你跌倒：

X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(
key.getEncoded());//key is null so nullpointer will occur

您必须为 key 变量赋值。我假设你想使用你创建的 PublicKey 所以这样做： PublicKey key = generatedKeyPair.getPublic();

KeyPairGenerator 不可用

KeyPairGenerator not available

java

public-key

private-key