AES加密解密算法 2015.03.14

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.SecureRandom;
 
/**
 * AES加解密算法
 */
public class AesUtils {
    //用于加密的密钥
    private static final String PASSWORD_AES_KEY="123456789";
 
    /**
     * 将url传递的参数用AES方式加密
     * @param url
     * @return
     */
    public static String aesEncryptUrl(String url){
        try{
            if(StringUtils.isEmpty(url)){
                return null;
            }
            return parseByte2HexStr(encrypt(url,PASSWORD_AES_KEY));
        }catch(Exception ex){
            if(StringUtils.isEmpty(url)){
                return null;
            }
        }
        return null;
    }
    /**
     * 将url传递的参数用AES方式解密
     * @param url
     * @return
     */
    public static String aesDecrypt(String url){
        try{
            if(StringUtils.isEmpty(url)){
                return null;
            }
            byte[] decryptFrom=parseHexStr2Byte(url);
            System.out.println("decryptFrom"+decryptFrom.length);
            byte[] deryptResult=decrypt(decryptFrom,PASSWORD_AES_KEY);
            System.out.println(deryptResult);
            return new String(deryptResult);
        }catch(Exception ex){
 
        }
        return null;
    }
    /**
     * 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");
            SecureRandom secureRandom=SecureRandom.getInstance("SHA1PRNG");
            secureRandom.setSeed(password.getBytes("UTF-8"));
            kgen.init(128, secureRandom);
            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 (Exception 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");
            SecureRandom secureRandom=SecureRandom.getInstance("SHA1PRNG");
            secureRandom.setSeed(password.getBytes("UTF-8"));
            kgen.init(128, secureRandom);
            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 (Exception 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;
    }
}