java中rsa乱码介绍

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。（推荐：java视频教程）

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);

AES加密时会将被加密数据转换成编码格式的字节数组也就是String.getBytes()方法，当getBytes方法不设置参数时，默认使用本机默认编码格式，改成String.getBytes(“utf-8”)问题解决。

使用rsa加密解密示例：

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 {    
    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;
    }    
    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;
    }    
    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();
    }    
    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;
    }    
    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            
         }
}

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