关于 Spring Security 5 默认使用 Password Hash 算法

账户密码存储的安全性是一个很老的话题，但还是会频频发生，一般的做法是 SHA256(userInputpwd+globalsalt+usersalt) 并设置密码时时要求长度与大小写组合，一般这样设计可以满足绝大部分的安全性需求。更复杂一些的方案有组合算法签名(比如：SHA256 + BCRYPT 组合 ) , 两步认证，Password Hash 等。

在之前集成  spring-security-oauth2 搭建 OAuth2.0 服务,依赖项 Spring Security 5 默认引入了更安全的加/解密机制，如果之前程序使用纯文本的方式存储用户密码与 Client 的密钥或低版本升级到 Spring Security 5 后可能会出现如下错误。

Encoded password does not look like BCrypt
java.lang.IllegalArgumentException: There is no PasswordEncoder mapped for the id "null"
    at org.springframework.security.crypto.password.DelegatingPasswordEncoder$UnmappedIdPasswordEncoder.matches(DelegatingPasswordEncoder.java:233)
    at org.springframework.security.crypto.password.DelegatingPasswordEncoder.matches(DelegatingPasswordEncoder.java:196)

Spring Security 5 对 PasswordEncoder 做了相关的重构，提供了 Password Hash 算法的实现(bCrypt, PBKDF2, SCrypt 等是最常用的几种密码 Hash 算法)，将密码编码之后的 hash 值和加密方式一起存储,原先默认配置的 PlainTextPasswordEncoder 明文密码被移除了(本身明文存储密码也是不合适的一种方式，只适用与测试环境)。

@Bean
public static NoOpPasswordEncoder passwordEncoder() {
    return NoOpPasswordEncoder.getInstance();
}

createDelegatingPasswordEncoder 方法定义了众多密码密码编码方式的集合,可以通过使用 PasswordEncoderFactories 类创建一个 DelegatingPasswordEncoder 的方式来解决这个问题。

Reverting to NoOpPasswordEncoder is not considered to be secure. You should instead migrate to using DelegatingPasswordEncoder to support secure password encoding. https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#troubleshooting

/**
 * Used for creating {@link PasswordEncoder} instances
 * @author Rob Winch
 * @since 5.0
 */
public class PasswordEncoderFactories {

    /**
     * Creates a {@link DelegatingPasswordEncoder} with default mappings. Additional
     * mappings may be added and the encoding will be updated to conform with best
     * practices. However, due to the nature of {@link DelegatingPasswordEncoder} the
     * updates should not impact users. The mappings current are:
     *
     * <ul>
     * <li>bcrypt - {@link BCryptPasswordEncoder} (Also used for encoding)</li>
     * <li>ldap - {@link LdapShaPasswordEncoder}</li>
     * <li>MD4 - {@link Md4PasswordEncoder}</li>
     * <li>MD5 - {@code new MessageDigestPasswordEncoder("MD5")}</li>
     * <li>noop - {@link NoOpPasswordEncoder}</li>
     * <li>pbkdf2 - {@link Pbkdf2PasswordEncoder}</li>
     * <li>scrypt - {@link SCryptPasswordEncoder}</li>
     * <li>SHA-1 - {@code new MessageDigestPasswordEncoder("SHA-1")}</li>
     * <li>SHA-256 - {@code new MessageDigestPasswordEncoder("SHA-256")}</li>
     * <li>sha256 - {@link StandardPasswordEncoder}</li>
     * </ul>
     *
     * @return the {@link PasswordEncoder} to use
     */
    public static PasswordEncoder createDelegatingPasswordEncoder() {
        String encodingId = "bcrypt";
        Map<String, PasswordEncoder> encoders = new HashMap<>();
        encoders.put(encodingId, new BCryptPasswordEncoder());
        encoders.put("ldap", new LdapShaPasswordEncoder());
        encoders.put("MD4", new Md4PasswordEncoder());
        encoders.put("MD5", new MessageDigestPasswordEncoder("MD5"));
        encoders.put("noop", NoOpPasswordEncoder.getInstance());
        encoders.put("pbkdf2", new Pbkdf2PasswordEncoder());
        encoders.put("scrypt", new SCryptPasswordEncoder());
        encoders.put("SHA-1", new MessageDigestPasswordEncoder("SHA-1"));
        encoders.put("SHA-256", new MessageDigestPasswordEncoder("SHA-256"));
        encoders.put("sha256", new StandardPasswordEncoder());

        return new DelegatingPasswordEncoder(encodingId, encoders);
    }

    private PasswordEncoderFactories() {}
}

Password Encoding

使用 BCryptPasswordEncoder 编码（默认）

//    @Bean
//    public PasswordEncoder passwordEncoder(){
//        return new BCryptPasswordEncoder();
//    }

    @Bean
    PasswordEncoder passwordEncoder(){
        return PasswordEncoderFactories.createDelegatingPasswordEncoder();
    }

    /**
     * 配置授权的用户信息
     * @param authenticationManagerBuilder
     * @throws Exception
     */
    @Override
    protected void configure(AuthenticationManagerBuilder authenticationManagerBuilder) throws Exception {

//        authenticationManagerBuilder.inMemoryAuthentication()
//                .withUser("irving")
//                .password(passwordEncoder().encode("123456"))
//                .roles("read");

        authenticationManagerBuilder.userDetailsService(userDetailService).passwordEncoder(passwordEncoder());
    }

使用 PasswordEncoderFactories 类提供的默认编码器，存储密码的格式如下所示( {id}encodedPassword )，然后在加密后的密码前添加 Password Encoder 各自的标识符

{bcrypt}$2a$10$oenCzSR.yLibYMDwVvuCaeIlSIqsx0TBY1094.jQ3wgPEXzTrA52.

public class TestBCryptPwd {

    @Bean
    PasswordEncoder passwordEncoder(){
        return PasswordEncoderFactories.createDelegatingPasswordEncoder();
    }

    @Bean
    public PasswordEncoder bcryptPasswordEncoder(){
        return new BCryptPasswordEncoder();
    }

    @Bean
    public PasswordEncoder pbkdf2PasswordEncoder(){
        return new Pbkdf2PasswordEncoder();
    }

    @Bean
    public PasswordEncoder scryptPasswordEncoder(){
        return new SCryptPasswordEncoder();
    }

    @Test
    public void testPasswordEncoder() {
        String pwd = passwordEncoder().encode("123456");
        String bcryptPassword = bcryptPasswordEncoder().encode("123456");
        String pbkdf2Password = pbkdf2PasswordEncoder().encode("123456");
        String scryptPassword = scryptPasswordEncoder().encode("123456");
        System.out.println(pwd  +"\n"+bcryptPassword +"\n"+pbkdf2Password+"\n"+scryptPassword);

        /*
            {bcrypt}$2a$10$dXJ3SW6G7P50lGmMkkmwe.20cQQubK3.HZWzG3YB1tlRy.fqvM/BG 1
            {noop}password 2
            {pbkdf2}5d923b44a6d129f3ddf3e3c8d29412723dcbde72445e8ef6bf3b508fbf17fa4ed4d6b99ca763d8dc 3
            {scrypt}$e0801$8bWJaSu2IKSn9Z9kM+TPXfOc/9bdYSrN1oD9qfVThWEwdRTnO7re7Ei+fUZRJ68k9lTyuTeUp4of4g24hHnazw==$OAOec05+bXxvuu/1qZ6NUR+xQYvYv7BeL1QxwRpY5Pc=  4
            {sha256}97cde38028ad898ebc02e690819fa220e88c62e0699403e94fff291cfffaf8410849f27605abcbc0 5
        */
    }
}

Password Matching

BCryptPasswordEncoder encoder = new BCryptPasswordEncoder;
String result = encoder.encode("123456");
assertTrue(encoder.matches("123456", result));
Pbkdf2PasswordEncoder encoder = new Pbkdf2PasswordEncoder();
String result = encoder.encode("123456");
assertTrue(encoder.matches("123456", result));
SCryptPasswordEncoder encoder = new SCryptPasswordEncoder();
String result = encoder.encode("123456");
assertTrue(encoder.matches("123456", result));

示列

    /**
     * 修改用户密码
     *
     * @param oldPwd
     * @param newPwd
     * @param userName
     * @return
     */
    @Override
    public Users modifyPwd(String oldPwd, String newPwd, String userName) {
        Users user = this.userRepository.findByUsername(userName);
        //验证用户是否存在
        if (user == null) {
            throw new UserFriendlyException("用户不存在!");
        }
        //验证原密码是否正确
        if (!passwordEncoder.matches(oldPwd, user.getPassword())) {
            throw new UserFriendlyException("原密码不正确!");
        }
        //修改密码
        user.setPassword(passwordEncoder.encode(newPwd));
        return this.userRepository.save(user);
    }

应该使用哪一种Password Hash？[引用]

PBKDF2、BCRYPT、SCRYPT 曾经是最常用的三种密码Hash算法，至于哪种算法最好，多年以来密码学家们并无定论。但可以确定的是，这三种算法都不完美，各有缺点。其中PBKDF2因为计算过程需要内存少所以可被GPU/ASIC加速，BCRYPT不支持内存占用调整且容易被FPGA加速，而SCRYPT不支持单独调整内存或计算时间占用且可能被ASIC加速并有被旁路攻击的可能。

2013年NIST（美国国家标准与技术研究院）邀请了一些密码学家一起，举办了密码hash算法大赛（Password Hashing Competition），意在寻找一种标准的用来加密密码的hash算法，并借此在业界宣传加密存储用户密码的重要性。大赛列出了参赛算法可能面临的攻击手段：

• [X] 加密算法破解（原值还原、哈希碰撞等，即应满足Cryptographic Hash的第2、3、4条特性）;

• [X] 查询表/彩虹表攻击；
• [X] CPU优化攻击；
• [X] GPU、FPGA、ASIC等专用硬件攻击；
• [X] 旁路攻击;

最终在2015年7月，Argon2算法赢得了这项竞赛，被NIST认定为最好的密码hash算法。不过因为算法过新，目前还没听说哪家大公司在用Argon2做密码加密。

REFER:
https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#core-services-password-encoding
https://stackoverflow.com/questions/49582971/encoded-password-does-not-look-like-bcrypt
https://www.baeldung.com/spring-security-5-default-password-encoder
https://www.cnkirito.moe/spring-security-6/
https://stackoverflow.com/questions/6832445/how-can-bcrypt-have-built-in-salts
https://www.cnblogs.com/xinzhao/p/6035847.html
http://www.cnblogs.com/cnblogsfans/p/5112167.html
https://github.com/KaiZhang890/store-password-safely