Java使用MD5加盐对密码进行加密处理,附注册和登录加密解密处理

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
 
public class PasswordHelper {
 
    private static final String MD5 = "MD5";
    private static final String HEX_NUMS_STR = "0123456789ABCDEF";
    private static final int COUNT_BITS = 128;
 
    public static void main(String[] args) {
        // 测试注册
        String password = "user_password";
        String salt = register(password);
        System.out.println("注册生成的盐值：" + salt);
        String encryptedPassword = encrypt(password, salt);
        System.out.println("注册生成的密码：" + encryptedPassword);
 
        // 测试登录
        boolean loginSuccess = login(password, salt, encryptedPassword);
        System.out.println("登录结果：" + (loginSuccess ? "成功" : "失败"));
    }
 
    public static String register(String password) {
        SecureRandom random = new SecureRandom();
        byte[] salt = new byte[COUNT_BITS / 8];
        random.nextBytes(salt);
        return encryptToHex(salt);
    }
 
    public static String encrypt(String password, String salt) {
        return md5(password + salt, MD5);
    }
 
    public static boolean login(String password, String salt, String encryptedPassword) {
        String encryptedPasswordFromDb = encrypt(password, salt);
        return encryptedPasswordFromDb.equals(encryptedPassword);
    }
 
    private static String md5(String input, String algorithm) {
        try {
            MessageDigest messageDigest = MessageDigest.getInstance(algorithm);
            byte[] inputByteArray = input.getBytes();
            messageDigest.update(inputByteArray);
            byte[] resultByteArray = messageDigest.digest();
            return encryptToHex(resultByteArray);
        } catch (NoSuchAlgorithmException e) {
            return null;
        }
    }
 
    private static String encryptToHex(byte[] input) {
        StringBuilder hexBuilder = new StringBuilder();
        for (byte b : input) {
            hexBuilder.append(byteToHex(b));
        }
        return hexBuilder.toString();
    }
 
    private static String byteToHex(byte b) {
        int val = b & 0xff;
        return HEX_NUMS_STR.charAt(val >> 4) + "" + HEX_NUMS_STR.charAt(val & 0x0f);
    }
}

这段代码提供了一个简单的密码加盐和验证流程。register方法生成盐值，encrypt方法使用盐值对密码进行加密，而login方法则用于验证登录信息。这里使用MD5作为散列函数，并将其输出转化为十六进制字符串。注意，在实际应用中应该使用更安全的加密算