MD5Test加密解密加盐

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MD5Test加密解密加盐

package com.app.scmaTest;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Random;import org.apachemons.codec.binary.Hex;public class MD5Test {//生成普通的MD5码public static String MD5(String input) {MessageDigest md5 = null;try {md5 = MessageDigest.getInstance("MD5");} catch (NoSuchAlgorithmException e) {return "check jdk";} catch (Exception e) {e.printStackTrace();return "";}char[] charArray = input.toCharArray();byte[] byteArray = new byte[charArray.length];for (int i = 0; i < charArray.length; i++)byteArray[i] = (byte) charArray[i];byte[] md5Bytes = md5.digest(byteArray);StringBuffer hexValue = new StringBuffer();for (int i = 0; i < md5Bytes.length; i++) {int val = ((int) md5Bytes[i]) & 0xff;if (val < 16)hexValue.append("0");hexValue.append(Integer.toHexString(val));}return hexValue.toString();}//生成“盐”和加盐后的MD5码，并将盐混入到MD5码中public static String generate(String password) {//生成一个16位的随机数，也就是所谓的“盐”Random r = new Random();StringBuilder sb = new StringBuilder(16);sb.append(r.nextInt(99999999)).append(r.nextInt(99999999));int len = sb.length();if (len < 16) {for (int i = 0; i < 16 - len; i++) {sb.append("0");}}String salt = sb.toString();//将“盐”加到明文中，并生成新的MD5码password = md5Hex(password + salt);//将“盐”混到新生成的MD5码中，之所以这样做是为了后期更方便的校验明文和秘文，也可以不用这么做，不过要将“盐”单独存下来，不推荐这种方式char[] cs = new char[48];for (int i = 0; i < 48; i += 3) {cs[i] = password.charAt(i / 3 * 2);char c = salt.charAt(i / 3);cs[i + 1] = c;cs[i + 2] = password.charAt(i / 3 * 2 + 1);}return new String(cs);}//验证明文和加盐后的MD5码是否匹配public static boolean verify(String password, String md5) {//先从MD5码中取出之前加的“盐”和加“盐”后生成的MD5码char[] cs1 = new char[32];char[] cs2 = new char[16];for (int i = 0; i < 48; i += 3) {cs1[i / 3 * 2] = md5.charAt(i);cs1[i / 3 * 2 + 1] = md5.charAt(i + 2);cs2[i / 3] = md5.charAt(i + 1);}String salt = new String(cs2);//比较二者是否相同return md5Hex(password + salt).equals(new String(cs1));}//生成MD5private static String md5Hex(String src) {try {MessageDigest md5 = MessageDigest.getInstance("MD5");byte[] bs = md5.digest(src.getBytes());return new String(new Hex().encode(bs));} catch (Exception e) {return null;}}public static void main(String args[]) {String plaintext = "junfan";System.out.println("明文：" + plaintext);System.out.println("普通MD5码：" + MD5(plaintext));// 获取加盐后的MD5值String ciphertext = generate(plaintext);System.out.println("加盐后MD5码：" + ciphertext);System.out.println("是否是同一字符串:" + verify(plaintext, ciphertext));}}