Question

我无法捕获此代码的异常。查看代码注释中的线索。显然序列化工作正常，所以我不会粘贴序列化方法代码。

public class NewCipher {

    private static final String password = "somestatickey";
    private Cipher desCipher;
    private SecretKey secretKey;
    private Context ctx;

    public NewCipher(Context ctx) throws Exception {

        this.ctx = ctx;
        // Create Key
        byte key[] = password.getBytes();
        DESKeySpec desKeySpec = new DESKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        secretKey = keyFactory.generateSecret(desKeySpec);

        // Create Cipher
        desCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

    }

棘手的部分从这里开始：

public ArrayList<Category> loadCategories(){
    try {
        try {
            // Change cipher mode
            desCipher.init(Cipher.DECRYPT_MODE, secretKey); //some uncatchable exception seems to be appearing here

            // Create stream                
            FileInputStream fis;
            fis = ctx.openFileInput("categories.des");          
            BufferedInputStream bis = new BufferedInputStream(fis);
            CipherInputStream cis = new CipherInputStream(bis, desCipher);
            ObjectInputStream ois = new ObjectInputStream(cis);

            try {
                // Read objects         
                ArrayList<Category> categories = (ArrayList<Category>) ois.readObject(); //however the debugger goes right to this line and then goes to the finally, and then straight to final catch block
                return categories; //not beeing executed

            }
            finally {
                ois.close(); //debugger does a step here and then jumps to the end
            }   
        }
        catch(GeneralSecurityException ex) {
            Log.v("Debug", "Some message", ex); //not beeing executed
            return null; //not beeing executed  
        }           

    } catch (Exception e) {
        Log.v("Debug", "Some message", e); //not beeing executed
        return null; //actually the debugger jumps right here avoiding the log line above
    }
}

我如何知道问题在desCipher.init(Cipher.DECRYPT_MODE, secretKey);行？我一个接一个地删除行，并且总是得到相同的结果。第一行肯定发生了一些错误。

不幸的是，我无法抓住它，并且由于某种原因，代码正在尝试进一步执行。我在这里完全糊涂了。我尝试IOException和IllegalStateException代替GeneralSecurityException。还试图抛出BadPaddingException。虽然没有日志。

拜托，我需要帮助。

Answer 1

您的密钥大小不正确，代码应抛出InvalidKeyException，其类型为GeneralSecurityException。在调试之前，请确保您的代码编译并与生成的类文件保持同步。

请注意，永远不要使用String作为密码，不应该使用getBytes（）而不指定编码，不应该使用DES，不应该使用ECB模式（等等）。

反序列化加密的ObjectList

1 个答案: