在Android上使用AES加密文件 [英] Encrypting files with AES on Android
问题描述
所以我正在为自己的个人项目工作，我正在尝试加密手机上的文件。这些文件可以是文件，照片等。现在我正在努力使其正常工作。当我运行加密时，它似乎正常工作并加密文件。当我运行解密时，有时它工作，其他时候它不。当它失败时，我通常会得到一个错误，而最终确定密码，垫块损坏错误。我也没有使用不同的测试文件，所以它不像一些文件工作，而其他文件没有。这是我每次尝试的两个文件。
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，Salt和Password是静态的，为了测试目的不改变。有一半的时间仍然收到错误。
Currently the Salt and Password are static and do not change for testing purposes. Still get errors about half the time.
有没有人有什么想法为什么会发生这种情况？我一直在寻找，我已经找到了几件事情尝试，没有一个工作。我查看了以下解决方案的一些问题：
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:
任何帮助都非常感谢！我想我只是想念简单的一些...
Any help is greatly appreciated! I think I am just missing something simple...
更新！
盐是正确的人。当我删除盐，问题解决了...再多挖一下，结果salt + pass是问题，但因为salt是一个字节[]，而Pass是一个字符串。我把salt改成String，然后用salt.concat（Pass），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
一些东西，但在我身边它没有问题。
你可以尝试以下类，只需更改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();
}
}
我可以迭代很多次没有错误！
我正在使用Oracle JDK 1.8，但是以1.7兼容模式运行。
I can iterate many times without an error! I'm using Oracle JDK 1.8 but running in 1.7 compatibility mode.
希望这有助于您。
Bye
皮耶罗
Bye Piero
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