import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.apache.commons.codec.binary.Hex;
/**
* MD5加密解密工具类
*/
public class MD5Util {
public static String md5for3(String password) {
String get = MD5Util.getStrMD5(password);
String strMD5 = MD5Util.getStrMD5(get);
String str = MD5Util.getStrMD5(strMD5);
return str;
}
/**
* 普通MD5加密 01
*/
public static String getStrMD5(String inStr) {
// 获取MD5实例
MessageDigest md5 = null;
try {
md5 = MessageDigest.getInstance("MD5");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
System.out.println(e.toString());
return "";
}
// 将加密字符串转换为字符数组
char[] charArray = inStr.toCharArray();
byte[] byteArray = new byte[charArray.length];
// 开始加密
for (int i = 0; i < charArray.length; i++)
byteArray[i] = (byte) charArray[i];
byte[] digest = md5.digest(byteArray);
StringBuilder sb = new StringBuilder();
for (int i = 0; i < digest.length; i++) {
int var = digest[i] & 0xff;
if (var < 16)
sb.append("0");
sb.append(Integer.toHexString(var));
}
return sb.toString();
}
/**
* 普通MD5加密 02
*/
public static String getStrrMD5(String password) {
char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
try {
byte strTemp[] = password.getBytes("UTF-8");
MessageDigest mdTemp = MessageDigest.getInstance("MD5");
mdTemp.update(strTemp);
byte md[] = mdTemp.digest();
int j = md.length;
char str[] = new char[j * 2];
int k = 0;
for (int i = 0; i < j; i++) {
byte byte0 = md[i];
str[k++] = hexDigits[byte0 >>> 4 & 15];
str[k++] = hexDigits[byte0 & 15];
}
return new String(str);
} catch (Exception e) {
return null;
}
}
/**
* MD5双重解密
*/
public static String getconvertMD5(String inStr) {
char[] charArray = inStr.toCharArray();
for (int i = 0; i < charArray.length; i++) {
charArray[i] = (char) (charArray[i] ^ 't');
}
String str = String.valueOf(charArray);
return str;
}
/**
* 使用Apache的Hex类实现Hex(16进制字符串和)和字节数组的互转
*/
@SuppressWarnings("unused")
private static String md5Hex(String str) {
try {
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] digest = md.digest(str.getBytes());
return new String(new Hex().encode(digest));
} catch (Exception e) {
e.printStackTrace();
System.out.println(e.toString());
return "";
}
}
/**
* 加盐MD5加密
*/
public static String getSaltMD5(String username,String password) {
/* // 生成一个16位的随机数
Random random = new Random();
StringBuilder sBuilder = new StringBuilder(16);
sBuilder.append(random.nextInt(99999999)).append(random.nextInt(99999999));
int len = sBuilder.length();
if (len < 16) {
for (int i = 0; i < 16 - len; i++) {
sBuilder.append("0");
}
}
// 生成最终的加密盐
String Salt = sBuilder.toString();*/
StringBuffer s = new StringBuffer();
s.append(username);
s.append("qaz");
int len=s.length();
if (len < 16) {
for (int i = 0; i < 16 - len; i++) {
s.append("0");
}
}
String Salt = s.toString();
password = md5Hex(password + Salt);
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 String.valueOf(cs);
}
/**
* 验证加盐后是否和原文一致
*/
public static boolean getSaltverifyMD5(String password, String md5str) {
char[] cs1 = new char[32];
char[] cs2 = new char[16];
for (int i = 0; i < 48; i += 3) {
cs1[i / 3 * 2] = md5str.charAt(i);
cs1[i / 3 * 2 + 1] = md5str.charAt(i + 2);
cs2[i / 3] = md5str.charAt(i + 1);
}
String Salt = new String(cs2);
return md5Hex(password + Salt).equals(String.valueOf(cs1));
}
public static void main(String[] args) {
MD5Util md = new MD5Util();
String username="a123456";
String pass = "6294018299c3094d3dc3405598783406";
String saltMD5 = md.md5for3(username);
System.out.println(saltMD5);
}
/*public static void main(String[] args) {
MD5Util md = new MD5Util();
String strMD5 = new String("root");
System.out.println("原始：" + strMD5);
System.out.println("东东的：" + md.getStrrMD5(strMD5));
System.out.println("MD5后：" + md.getStrMD5(strMD5));
System.out.println("加密的：" + md.getconvertMD5(strMD5));
System.out.println("解密的：" + md.getconvertMD5(md.getconvertMD5(strMD5)));
// 原文
String plaintext = "root";
// plaintext = "123456";
System.out.println("原始：" + plaintext);
System.out.println("普通MD5后：" + MD5Util.getStrMD5(plaintext));
// 获取加盐后的MD5值
String ciphertext = MD5Util.getSaltMD5("root",plaintext);
System.out.println("加盐后MD5：" + ciphertext);
System.out.println("是否是同一字符串:" + MD5Util.getSaltverifyMD5(plaintext, ciphertext));
String[] tempSalt = { "810e1ee9ee5e28188658f431451a29c2d81048de6a108e8a",
"66db82d9da2e35c95416471a147d12e46925d38e1185c043",
"61a718e4c15d914504a41d95230087a51816632183732b5a" };
for (String temp : tempSalt) {
System.out.println("是否是同一字符串:" + MD5Util.getSaltverifyMD5(plaintext, temp));
}
}
*/
}
在做注册时可以对密码加密，登录时对传过来的密码加密然后和数据库的做比较。我们在项目中是对密码进行了三次加密，调用了三次getStrMD5( )方法
