在 BlackBerry 上使用 RSA 加密时出错

Question

我正在尝试在 Blackberry 上通过其原生 API 使用 RSA 加密。我在 Java 中制作了一个公钥/私钥对，并将密钥的模数和指数保存为字符串，这样我就可以从中生成密钥以进行加密和解密。以下代码来自客户端，我得到一个InvalidKeyException 并且回溯为空，所以我不知道发生了什么：

public byte[] Encrypt(byte[] data)
  {
      try {
            RSACryptoSystem cryptoSystem = new RSACryptoSystem(1024);
            RSAPublicKey publicKey = new RSAPublicKey(cryptoSystem, _publicKeyExponent.getBytes(), _publicKeyModulus.getBytes());
            RSAEncryptorEngine encryptorEngine = new RSAEncryptorEngine(publicKey);

            PKCS5FormatterEngine formatterEngine = new PKCS5FormatterEngine( encryptorEngine );

            ByteArrayOutputStream output = new ByteArrayOutputStream();
            BlockEncryptor encryptor = new BlockEncryptor( formatterEngine, output );

            encryptor.write(data);
            encryptor.close();
            output.close();

            return output.toByteArray();
        } catch (InvalidKeyException e) {
            // TODO Auto-generated catch block
            System.out.println();
            e.printStackTrace();
        } catch (CryptoTokenException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (CryptoUnsupportedOperationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (UnsupportedCryptoSystemException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
      return null;
  } 

这就是我在服务器端生成密钥的操作：

try {
            keyPairGenerator = KeyPairGenerator.getInstance("RSA");
            keyPairGenerator.initialize(1024);
            keyFactory = KeyFactory.getInstance("RSA");
        } catch (NoSuchAlgorithmException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        }

        keyPair = keyPairGenerator.generateKeyPair();
        publicKey = keyPair.getPublic();
        privateKey = keyPair.getPrivate();

        try {
            publicKeySpec = keyFactory.getKeySpec(publicKey, RSAPublicKeySpec.class);
            privateKeySpec = keyFactory.getKeySpec(privateKey, RSAPrivateKeySpec.class);
        } catch (InvalidKeySpecException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        }

        privateKeyModulus = privateKeySpec.getModulus().toString();
        privateKeyExponent = privateKeySpec.getPrivateExponent().toString();

        publicKeyModulus = publicKeySpec.getModulus().toString();
        publicKeyExponent = publicKeySpec.getPublicExponent().toString();

有什么想法吗？

编辑：我尝试通过加密和解密在服务器上进行简单测试，当我尝试解密时，我得到一个IllegalBlockSizeException 这些是我的加密和解密方法（服务器端）：

public byte[] Decrypt(byte[] data)
    {
        try {
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] cipherData = cipher.doFinal(data);
            return cipherData;
        } catch (NoSuchAlgorithmException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch (NoSuchPaddingException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch(IllegalBlockSizeException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch(InvalidKeyException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch(BadPaddingException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        }

        return null;
    }

    public byte[] Encrypt(byte[] data)
    {
        try {
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            byte[] cipherData = cipher.doFinal(data);
            return cipherData;
        } catch (NoSuchAlgorithmException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch (NoSuchPaddingException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch(IllegalBlockSizeException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch(InvalidKeyException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        } catch(BadPaddingException ex) {
            Logger.getLogger(EncryptorDecryptor.class.getName()).log(Level.SEVERE, null, ex);
        }

        return null;
    }

这是我正在尝试的简单测试：

userName = Base64.encode(encryptorDecryptor.Encrypt(userName.getBytes()));
password = Base64.encode(encryptorDecryptor.Encrypt(password.getBytes()));

userName = new String(encryptorDecryptor.Decrypt(Base64.decode(userName)));
password = new String(encryptorDecryptor.Decrypt(Base64.decode(password)));

Answer 1

1. 使用 String 作为任意随机字节的容器是一个错误，例如userName = new String(encryptorDecryptor.Encrypt(userName.getBytes())); 错了。
2. 我不熟悉 Blackberry 的 Java API，但通常你不能使用 RSA 加密多个块
3. 数组上的 toString() 方法（例如publicKeySpec.getModulus().toString()）不会返回任何有用的东西。您应该能够通过查看数据来解决这个问题。这确实是一个初学者的 Java 错误，而不是密码学问题。
4. 不要为 String 构造函数和 String.getBytes() 方法使用默认字符集。始终指定一个字符集，通常“UTF-8”是完美的。

这就是我的耐心。