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Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded

Posted on 2012-05-19 13:19 IceWee 閱讀(30904) 評(píng)論(3) 編輯收藏所屬分類(lèi): Java 、加解密

本工具類(lèi)經(jīng)過(guò)測(cè)試可用，之前寫(xiě)的沒(méi)有使用CipherInputStream和CipherOutputStream，生成的加密文件與源文件大小不一致，加密時(shí)沒(méi)有問(wèn)題，解密時(shí)總是拋出如下異常：

Exception in thread "main" javax.crypto.BadPaddingException: Given final block not properly padded

at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)

at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13*..)

at javax.crypto.Cipher.doFinal(DashoA13*..)

其中BASE64底層依賴(lài)庫(kù)沒(méi)有使用SUN的，而是下載的“javabase64-1.3.1.jar”

DESUtils.java

package demo.security;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.OutputStream;

import java.security.Key;

import java.security.SecureRandom;

import javax.crypto.Cipher;

import javax.crypto.CipherInputStream;

import javax.crypto.CipherOutputStream;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

/**

*

* DES加密解密工具包

*

* @author IceWee

* @date 2012-5-19

* @version 1.0

public class DESUtils {

private static final String ALGORITHM = "DES";

private static final int CACHE_SIZE = 1024;

/**

*

* 生成隨機(jī)密鑰

*

* @return

* @throws Exception

public static String getSecretKey() throws Exception {

return getSecretKey(null);

}

/**

*

* 生成密鑰

*

* @param seed 密鑰種子

* @return

* @throws Exception

public static String getSecretKey(String seed) throws Exception {

SecureRandom secureRandom;

if (seed != null && !"".equals(seed))

secureRandom = new SecureRandom(seed.getBytes());

else

secureRandom = new SecureRandom();

KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM);

keyGenerator.init(secureRandom);

SecretKey secretKey = keyGenerator.generateKey();

return Base64Utils.encode(secretKey.getEncoded());

}

/**

*

* 加密

*

* @param data

* @param key

* @return

* @throws Exception

public static byte[] encrypt(byte[] data, String key) throws Exception {

Key k = toKey(Base64Utils.decode(key));

Cipher cipher = Cipher.getInstance(ALGORITHM);

cipher.init(Cipher.ENCRYPT_MODE, k);

return cipher.doFinal(data);

}

/**

*

* 文件加密

*

* @param key

* @param sourceFilePath

* @param destFilePath

* @throws Exception

public static void encryptFile(String key, String sourceFilePath, String destFilePath) throws Exception {

File sourceFile = new File(sourceFilePath);

File destFile = new File(destFilePath);

if (sourceFile.exists() && sourceFile.isFile()) {

if (!destFile.getParentFile().exists()) {

destFile.getParentFile().mkdirs();

}

destFile.createNewFile();

InputStream in = new FileInputStream(sourceFile);

OutputStream out = new FileOutputStream(destFile);

Key k = toKey(Base64Utils.decode(key));

Cipher cipher = Cipher.getInstance(ALGORITHM);

cipher.init(Cipher.ENCRYPT_MODE, k);

CipherInputStream cin = new CipherInputStream(in, cipher);

byte[] cache = new byte[CACHE_SIZE];

int nRead = 0;

while ((nRead = cin.read(cache)) != -1) {

out.write(cache, 0, nRead);

out.flush();

}

out.close();

cin.close();

in.close();

}

/**

*

* 解密

*

* @param data

* @param key

* @return

* @throws Exception

public static byte[] decrypt(byte[] data, String key) throws Exception {

Key k = toKey(Base64Utils.decode(key));

Cipher cipher = Cipher.getInstance(ALGORITHM);

cipher.init(Cipher.DECRYPT_MODE, k);

return cipher.doFinal(data);

}

/**

*

* 文件解密

*

* @param key

* @param sourceFilePath

* @param destFilePath

* @throws Exception

public static void decryptFile(String key, String sourceFilePath, String destFilePath) throws Exception {

File sourceFile = new File(sourceFilePath);

File destFile = new File(destFilePath);

if (sourceFile.exists() && sourceFile.isFile()) {

if (!destFile.getParentFile().exists()) {

destFile.getParentFile().mkdirs();

}

destFile.createNewFile();

InputStream in = new FileInputStream(sourceFile);

OutputStream out = new FileOutputStream(destFile);

Key k = toKey(Base64Utils.decode(key));

Cipher cipher = Cipher.getInstance(ALGORITHM);

cipher.init(Cipher.DECRYPT_MODE, k);

CipherOutputStream cout = new CipherOutputStream(out, cipher);

byte[] cache = new byte[CACHE_SIZE];

int nRead = 0;

while ((nRead = in.read(cache)) != -1) {

cout.write(cache, 0, nRead);

cout.flush();

}

cout.close();

out.close();

in.close();

}

/**

*

* 轉(zhuǎn)換密鑰

*

* @param key

* @return

* @throws Exception

private static Key toKey(byte[] key) throws Exception {

DESKeySpec dks = new DESKeySpec(key);

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);

SecretKey secretKey = keyFactory.generateSecret(dks);

return secretKey;

}

Base64Utils.java

package demo.security;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.OutputStream;

import it.sauronsoftware.base64.Base64;

/**

*

* BASE64編碼解碼工具包

*

*

* 依賴(lài)javabase64-1.3.1.jar

*

* @author IceWee

* @date 2012-5-19

* @version 1.0

public class Base64Utils {

/**

* 文件讀取緩沖區(qū)大小

private static final int CACHE_SIZE = 1024;

/**

*

* BASE64字符串解碼為二進(jìn)制數(shù)據(jù)

*

* @param base64

* @return

* @throws Exception

public static byte[] decode(String base64) throws Exception {

return Base64.decode(base64.getBytes());

}

/**

*

* 二進(jìn)制數(shù)據(jù)編碼為BASE64字符串

*

* @param bytes

* @return

* @throws Exception

public static String encode(byte[] bytes) throws Exception {

return new String(Base64.encode(bytes));

}

/**

*

* 將文件編碼為BASE64字符串

*

*

* 大文件慎用，可能會(huì)導(dǎo)致內(nèi)存溢出

*

* @param filePath 文件絕對(duì)路徑

* @return

* @throws Exception

public static String encodeFile(String filePath) throws Exception {

byte[] bytes = fileToByte(filePath);

return encode(bytes);

}

/**

*

* BASE64字符串轉(zhuǎn)回文件

*

* @param filePath 文件絕對(duì)路徑

* @param base64 編碼字符串

* @throws Exception

public static void decodeToFile(String filePath, String base64) throws Exception {

byte[] bytes = decode(base64);

byteArrayToFile(bytes, filePath);

}

/**

*

* 文件轉(zhuǎn)換為二進(jìn)制數(shù)組

*

* @param filePath 文件路徑

* @return

* @throws Exception

public static byte[] fileToByte(String filePath) throws Exception {

byte[] data = new byte[0];

File file = new File(filePath);

if (file.exists()) {

FileInputStream in = new FileInputStream(file);

ByteArrayOutputStream out = new ByteArrayOutputStream(2048);

byte[] cache = new byte[CACHE_SIZE];

int nRead = 0;

while ((nRead = in.read(cache)) != -1) {

out.write(cache, 0, nRead);

out.flush();

}

out.close();

in.close();

data = out.toByteArray();

}

return data;

}

/**

*

* 二進(jìn)制數(shù)據(jù)寫(xiě)文件

*

* @param bytes 二進(jìn)制數(shù)據(jù)

* @param filePath 文件生成目錄

public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception {

InputStream in = new ByteArrayInputStream(bytes);

File destFile = new File(filePath);

if (!destFile.getParentFile().exists()) {

destFile.getParentFile().mkdirs();

}

destFile.createNewFile();

OutputStream out = new FileOutputStream(destFile);

byte[] cache = new byte[CACHE_SIZE];

int nRead = 0;

while ((nRead = in.read(cache)) != -1) {

out.write(cache, 0, nRead);

out.flush();

}

out.close();

in.close();

}

DESTester.java

package demo.security;

public class DESTester {

static String key;

static {

try {

key = DESUtils.getSecretKey();

} catch (Exception e) {

e.printStackTrace();

}

public static void main(String[] args) throws Exception {

long begin = System.currentTimeMillis();

encryptFile();

decryptFile();

test();

long end = System.currentTimeMillis();

System.err.println("耗時(shí)：" + (end-begin)/1000 + "秒

");

}

static void encryptFile() throws Exception {

String sourceFilePath = "D:/demo.mp4";

String destFilePath = "D:/demo_encrypted.mp4";

DESUtils.encryptFile(key, sourceFilePath, destFilePath);

}

static void decryptFile() throws Exception {

String sourceFilePath = "D:/demo_encrypted.mp4";

String destFilePath = "D:/demo_decrypted.mp4";

DESUtils.decryptFile(key, sourceFilePath, destFilePath);

}

static void test() throws Exception {

String source = "這是一行測(cè)試DES加密/解密的文字，你看完也等于沒(méi)看，是不是?。?！";

System.err.println("原文:\t" + source);

byte[] inputData = source.getBytes();

inputData = DESUtils.encrypt(inputData, key);

System.err.println("加密后:\t" + Base64Utils.encode(inputData));

byte[] outputData = DESUtils.decrypt(inputData, key);

String outputStr = new String(outputData);

System.err.println("解密后:\t" + outputStr);

}

Feedback

# re: Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded 回復(fù) 更多評(píng)論

2012-09-04 22:09 by yaray

str.getBytes();
調(diào)用此方法時(shí)，凡是未指定具體字符編碼的程序，均依賴(lài)于JRE所在操作系統(tǒng)的默認(rèn)編碼類(lèi)型，因此類(lèi)似的加解密程序均是不完全可靠的。解決辦法：調(diào)用此方法時(shí)指定為 UTF-8 編碼，即：str.getBytes("UTF-8");

# re: Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded 回復(fù) 更多評(píng)論

2012-09-05 09:07 by IceWee

@yaray
感謝回復(fù)，可能我系統(tǒng)上的文字都用的UTF-8編碼吧，Eclipse的編碼也用的UTF-8，所以沒(méi)有測(cè)試到這個(gè)bug。

# re: Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded 回復(fù) 更多評(píng)論

2013-01-10 20:34 by free4wp

SecureRandom 實(shí)現(xiàn)完全隨操作系統(tǒng)本身的內(nèi)部狀態(tài)，除非調(diào)用方在調(diào)用 getInstance 方法之后又調(diào)用了 setSeed 方法；該實(shí)現(xiàn)在 windows 上每次生成的 key 都相同，但是在 solaris 或部分 linux 系統(tǒng)上則不同。
正確的解決方法：
http://free4wp.com/%e8%a7%a3%e5%86%b3linux%e6%93%8d%e4%bd%9c%e7%b3%bb%e7%bb%9f%e4%b8%8baes%e8%a7%a3%e5%af%86%e5%a4%b1%e8%b4%a5%e7%9a%84%e9%97%ae%e9%a2%98.html

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Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded

Feedback

# re: Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded 回復(fù) 更多評(píng)論

# re: Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded 回復(fù) 更多評(píng)論

# re: Java DES文件加密解密 javax.crypto.BadPaddingException: Given final block not properly padded 回復(fù) 更多評(píng)論