在Android上加密文件AES [英] Encrypting files with AES on Android

问题描述

所以我工作的一个个人项目，我自己，我想我的手机上的文件进行加密。这些文件可以是任何东西，如文档，照片等。现在，我试图让这个工作正常。当过我运行加密它似乎正常工作和加密文件。当我运行解密，有时它工作和其他时候也不能。当它失败我一般得到一个错误而最终确定的密码，垫块损坏错误。我也没有使用不同的测试文件，因此它不像一些文件工作和别人不一样。这是同样的两个文件我尝试每一次。

So I am working on a personal project for myself, and I am trying to encrypt files on my phone. These files can be anything i.e Documents, photos, etc. Right now I am trying to get this working properly. When ever I run the encryption it seems to work properly and encrypt the files. When I run the decrypt, sometimes it works and other times it doesn't. When it fails I generally get a "Error while finalizing cipher, pad block corrupted" error. I'm also not using different test files, so it isn't like some files work and others don't. It's the same two files I try each time.

public static void encryptfile(String path,String Pass) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
    FileInputStream fis = new FileInputStream(path);
    FileOutputStream fos = new FileOutputStream(path.concat(".crypt"));
    byte[] key = (salt + Pass).getBytes("UTF-8");
    MessageDigest sha = MessageDigest.getInstance("SHA-1");
    key = sha.digest(key);
    key = Arrays.copyOf(key,16);
    SecretKeySpec sks = new SecretKeySpec(key, "AES");
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, sks);
    CipherOutputStream cos = new CipherOutputStream(fos, cipher);
    int b;
    byte[] d = new byte[8];
    while((b = fis.read(d)) != -1) {
        cos.write(d, 0, b);
    }
    cos.flush();
    cos.close();
    fis.close();
}

public static void decrypt(String path,String Pass) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
    FileInputStream fis = new FileInputStream(path);
    FileOutputStream fos = new FileOutputStream(path.replace(".crypt",""));
    byte[] key = (salt + Pass).getBytes("UTF-8");
    MessageDigest sha = MessageDigest.getInstance("SHA-1");
    key = sha.digest(key);
    key = Arrays.copyOf(key,16);
    SecretKeySpec sks = new SecretKeySpec(key, "AES");
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, sks);
    CipherInputStream cis = new CipherInputStream(fis, cipher);
    int b;
    byte[] d = new byte[8];
    while((b = cis.read(d)) != -1) {
        fos.write(d, 0, b);
    }
    fos.flush();
    fos.close();
    cis.close();
}

目前的盐和密码是静态的，不用于测试目的改变。仍然得到大约一半的时间错误。

Currently the Salt and Password are static and do not change for testing purposes. Still get errors about half the time.

有没有人对为什么出现这种情况的任何想法？我一直在寻找周围，我已经找到了两件事情来尝试，其中没有工作。我已经经历了一些解决方案如下问题看：

Does anyone have any ideas on why this happens? I have been searching around and I have found a couple things to try, none of which worked. I have looked through some of the following questions for solutions:

<一个href="http://stackoverflow.com/questions/26426151/android-decryption-error-while-finalizing-cipher">Android解密：错误而最终确定密码

<一个href="http://stackoverflow.com/questions/12799726/last-block-incomplete-with-cipherinputstream-cipheroutputstream-even-with-paddi">last不完全阻塞与CipherInputStream / CipherOutputStream，即使填充AES / CBC / PKCS5Padding

在Android 4.2加密错误

<一个href="http://stackoverflow.com/questions/11503157/decrypting-error-no-iv-set-when-one-expected">Decrypting错误：＆QUOT;当一个预期＆QUOT没有四集;

<一个href="http://stackoverflow.com/questions/4598873/how-to-handle-last-block-incomplete-in-decryption">How处理＆QUOT;最后一个数据块不完整的解密＆QUOT;

<一个href="http://stackoverflow.com/questions/12136558/encryption-and-decryption-of-image-file">Encryption和图像文件解密

<一个href="http://stackoverflow.com/questions/13527521/tips-on-encryption-decryption-of-images-in-java-using-aes">Tips使用AES 在java中的图像加密/解密

Tips on encryption/decryption of images in java using AES

任何帮助是极大AP preciated！我想，我只是简单的东西...

Any help is greatly appreciated! I think I am just missing something simple...

更新！

人们都权当它是盐。当我删除了盐，问题解决了......难道一点挖，原来盐+通行证是问题，但由于盐是一个byte []和通是一个字符串。我改变盐的字符串，然后用salt.concat（通行证），问题解决了！

People were right when it was the salt. When I removed the salt, the problem was solved... Did a little more digging, turns out salt+Pass was the issues, but because the salt was a byte[] and Pass was a string. I changed salt to String and then used salt.concat(Pass) and the problem was solved!

推荐答案

也许我失去了一些东西，但在我的身边它的工作原理没有问题。 你可以试试下面的类简单地改变fileToBeCrypted，fileToBeDecrypted和fileDecryptedOutput变量？

maybe I'm missing something but on my side it works without a problem. Can you try the following class simply changing the fileToBeCrypted, fileToBeDecrypted and fileDecryptedOutput variables?

package test;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

public class TestCrypt{

    private static final String salt = "t784";
    private static final String cryptPassword = "873147cbn9x5'2 79'79314";
    private static final String fileToBeCrypted = "c:\\Temp\\sampleFile.conf";
    private static final String fileToBeDecrypted = "c:\\Temp\\sampleFile.conf.crypt";
    private static final String fileDecryptedOutput = "c:\\Temp\\sampleFile.conf.decrypted";

    public static void main(String[] args) throws Exception
    {
        for (int i=0; i<100; i++)
        {
            encryptfile(fileToBeCrypted, cryptPassword);
            decrypt(fileToBeDecrypted, cryptPassword, fileDecryptedOutput);
            System.out.println(i);
        }
    }

    public static void encryptfile(String path,String password) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
        FileInputStream fis = new FileInputStream(path);
        FileOutputStream fos = new FileOutputStream(path.concat(".crypt"));
        byte[] key = (salt + password).getBytes("UTF-8");
        MessageDigest sha = MessageDigest.getInstance("SHA-1");
        key = sha.digest(key);
        key = Arrays.copyOf(key,16);
        SecretKeySpec sks = new SecretKeySpec(key, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, sks);
        CipherOutputStream cos = new CipherOutputStream(fos, cipher);
        int b;
        byte[] d = new byte[8];
        while((b = fis.read(d)) != -1) {
            cos.write(d, 0, b);
        }
        cos.flush();
        cos.close();
        fis.close();
    }

    public static void decrypt(String path,String password, String outPath) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
        FileInputStream fis = new FileInputStream(path);
        FileOutputStream fos = new FileOutputStream(outPath);
        byte[] key = (salt + password).getBytes("UTF-8");
        MessageDigest sha = MessageDigest.getInstance("SHA-1");
        key = sha.digest(key);
        key = Arrays.copyOf(key,16);
        SecretKeySpec sks = new SecretKeySpec(key, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, sks);
        CipherInputStream cis = new CipherInputStream(fis, cipher);
        int b;
        byte[] d = new byte[8];
        while((b = cis.read(d)) != -1) {
            fos.write(d, 0, b);
        }
        fos.flush();
        fos.close();
        cis.close();
    }

}

我可以重复很多次没有一个错误！ 我使用的Oracle JDK 1.8，但在1.7兼容模式下运行。

I can iterate many times without an error! I'm using Oracle JDK 1.8 but running in 1.7 compatibility mode.

希望这有助于你。

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