在对安全性要求比较高的报文做加密的时候，算法有很多种，我这里主要用到的就是AES加密算法。由于在国内使用，所以不可避免的要对中文进行加密和解密，而在这个过程中，发现，如果不做处理，很容易会出现中文乱码。
下面是常见的情况：
一、中文乱码
不对密码进行编码处理
byte[] decryptResult = decrypt(encryptResult, password);
System.out.println("解密后：" + new String(decryptResult));
运行后
加密前：我是shoneworn
解密后：鎴戞槸shoneworn
二、对文字进行编码处理，但是在传输过程中草率的将byte[]转成String, String code = new String(bytes); 由于AES加密算法要求密文是16位的倍数。所以，这么处理，在解密的时候，就会报各种错。比如下面的。
String code = new String(encryptResult);
byte[] decryptResult = decrypt(code.getBytes(), password);
结果就.........
加密前：我是shoneworn
javax.crypto.BadPaddingException: Given final block not properly padded
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:966)
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:824)
at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:436)
at javax.crypto.Cipher.doFinal(Cipher.java:2165)
at com.ailin.test.AES.decrypt(AES.java:72)
at com.ailin.test.AES.main(AES.java:173)
Exception in thread "main" java.lang.NullPointerException
at java.lang.String.<init>(Unknown Source)
at com.ailin.test.AES.main(AES.java:174)
三、给功能正常的，能传中文的，不报错的AES加密加密算法源码
package com.ailin.test;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
public class AES {
/**
* 加密
*
* @param content
* 需要加密的内容
* @param password
* 加密密码
* @return
*/
public static byte[] encrypt(String content, String password) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(password.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
byte[] byteContent = content.getBytes("utf-8");
cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
byte[] result = cipher.doFinal(byteContent);
return result; // 加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}
/**
* 解密
*
* @param content
* 待解密内容
* @param password
* 解密密钥
* @return
*/
public static byte[] decrypt(byte[] content, String password) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(password.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
byte[] result = cipher.doFinal(content);
return result; // 加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}
/**
* 将二进制转换成16进制
*
* @param buf
* @return
*/
public static String parseByte2HexStr(byte buf[]) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < buf.length; i++) {
String hex = Integer.toHexString(buf[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
sb.append(hex.toUpperCase());
}
return sb.toString();
}
/**
* 将16进制转换为二进制
*
* @param hexStr
* @return
*/
public static byte[] parseHexStr2Byte(String hexStr) {
if (hexStr.length() < 1)
return null;
byte[] result = new byte[hexStr.length() / 2];
for (int i = 0; i < hexStr.length() / 2; i++) {
int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
result[i] = (byte) (high * 16 + low);
}
return result;
}
/**
* 加密
*
* @param content
* 需要加密的内容
* @param password
* 加密密码
* @return
*/
public static byte[] encrypt2(String content, String password) {
try {
SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding");
byte[] byteContent = content.getBytes("utf-8");
cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
byte[] result = cipher.doFinal(byteContent);
return result; // 加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}
public static void main(String[] args) throws UnsupportedEncodingException {
String content = "我是shoneworn";
String password = "12345678";
// 加密
System.out.println("加密前：" + content);
byte[] encode = encrypt(content, password);
//传输过程,不转成16进制的字符串，就等着程序崩溃掉吧
String code = parseByte2HexStr(encode);
System.out.println("密文字符串：" + code);
byte[] decode = parseHexStr2Byte(code);
// 解密
byte[] decryptResult = decrypt(decode, password);
System.out.println("解密后：" + new String(decryptResult, "UTF-8")); //不转码会乱码
}
}
