Encryption

创建时间:2016/9/14 18:48
更新时间:2018/1/9 14:33
标签:util

package jinri;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class Encryption {
       // 加密
       public static String Encrypt(String sSrc, String sKey, byte[] ivKey)
                     throws Exception {
              if (ivKey == null) {
                     System.out.print("ivKey为空null");
                     return null;
              }
              // 判断ivKey是否为16位
              if (ivKey.length != 16) {
                     System.out.print("ivKey长度不是16位");
                     return null;
              }
              if (sKey == null) {
                     System.out.print("Key为空null");
                     return null;
              }
              // 判断Key是否为16位
              if (sKey.length() != 16) {
                     System.out.print("Key长度不是16位");
                     return null;
              }
              SecretKeySpec skeySpec = new SecretKeySpec(sKey.getBytes(), "AES");
              Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
              // "算法/模式/补码方式"
              IvParameterSpec iv = new IvParameterSpec(ivKey);
              // 使用CBC模式,需要一个向量iv,可增加加密算法的强度
              cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
              byte[] encrypted = cipher.doFinal(sSrc.getBytes());
              return new BASE64Encoder().encode(encrypted);
              // 此处使用BASE64做转码功能,同时能起到2次加密的作用。
       }
       // 解密
       public static String Decrypt(String sSrc, String sKey, byte[] ivKey)
                     throws Exception {
              try {
                     // 判断Key是否正确
                     if (sKey == null) {
                           System.out.print("Key为空null");
                           return null;
                     }
                     // 判断Key是否为16位
                     if (sKey.length() != 16) {
                           System.out.print("Key长度不是16位");
                           return null;
                     }
                     byte[] raw = sKey.getBytes("ASCII");
                     SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
                     Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
                     IvParameterSpec iv = new IvParameterSpec(ivKey);
                     cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
                     byte[] encrypted1 = new BASE64Decoder().decodeBuffer(sSrc);
                     // 先用base64解密
                     try {
                           byte[] original = cipher.doFinal(encrypted1);
                           String originalString = new String(original);
                           return originalString;
                     } catch (Exception e) {
                           System.out.println(e.toString());
                           return null;
                     }
              } catch (Exception ex) {
                     System.out.println(ex.toString());
                     return null;
              }
       }
       public static void main(String[] args) throws Exception {
              
              /*
               *  加密用的Key 可以用26个字母和数字组成 ,最好不要用保留字符 ,虽然不会错,至于怎么裁决 ,个人看情况而定  此处使用AES
               *  使用CBC模式,需要一个向量iv,可增加加密算法的强度
               * -128-CBC加密模式 ,key需要为16位。
               */
              
              String cKey = "1234567890123456";
              byte[] ivKey = new byte[16];
              // 需要加密的字串
              String cSrc = "abcdefghigklmnopqrstuvwxyz0123456789";
              System.out.println(cSrc);
              // 加密
              long lStart = System.currentTimeMillis();
              String enString = Encryption.Encrypt(cSrc, cKey,ivKey);
              System.out.println("加密后的字串是:" + enString);
              long lUseTime = System.currentTimeMillis() - lStart;
              System.out.println("加密耗时:" + lUseTime + "毫秒");
              // 解密 lStart = System.currentTimeMillis();
              String DeString = Encryption.Decrypt(enString, cKey,ivKey);
              System.out.println("解密后的字串是:" + DeString);
              lUseTime = System.currentTimeMillis() - lStart;
              System.out.println("解密耗时:" + lUseTime + "毫秒");
       }
}