UsernamePasswordAuthenticationFilter

这个需求应该扩展spring security。主要扩展以下类：
UsernamePasswordAuthenticationFilter类的attemptAuthentication方法，主要获取request传递的参数；
UsernamePasswordAuthenticationToken类，主要用于增加认证所用到的额外参数；
DaoAuthenticationProvider类的retrieveUser方法，主要把UsernamePasswordAuthenticationToken扩展类的额外参数传递给UserDetailsService；
UserDetailsService实现类的loadUserByUsername方法。主用使用额外参数及账号、密码等多个参数进行验证。

当然，扩展完成后，需要对spring security的配置文件进行修改。修改的主要目标就是替换掉原来的bean。如果我说的还不够明确，可参

SpringSecurity自定义UsernamePasswordAuthenticationFilter UsernamePasswordAuthenticationFilter介绍

UsernamePasswordAuthenticationFilter是AbstractAuthenticationProcessingFilter针对使用用户名和密码进行身份验证而定制化的一个过滤器。其添加是在调用http.formLogin()时作用，默认的登录请求pattern为"/login"，并且为POST请求。当我们登录的时候，也就是匹配到loginProcessingUrl，这个过滤器就会委托认证管理器authenticationManager来验证登录。

自定义UsernamePasswordAuthenticationFilter

这里我的需求是通过自定义UsernamePasswordAuthenticationFilter实现对前端传过来的密码进行RSA私钥解密，并且因为登录地址不是"/login"，所以继承的是AbstractAuthenticationProcessingFilter，如果登录地址为默认，那么可直接继承UsernamePasswordAuthenticationFilter重写attemptAuthentication方法即可。

public class MyUsernamePasswordAuthenticationFilter extends AbstractAuthenticationProcessingFilter {
    public static final String SPRING_SECURITY_FORM_USERNAME_KEY = "username";
    public static final String SPRING_SECURITY_FORM_PASSWORD_KEY = "password";
    private String usernameParameter = SPRING_SECURITY_FORM_USERNAME_KEY;
    private String passwordParameter = SPRING_SECURITY_FORM_PASSWORD_KEY;
    private boolean postonly = true;
    private String privateKey = "xxxxxxxxxxxxxxxxxxx";
    
    public MyUsernamePasswordAuthenticationFilter() {
        super(new AntPathRequestMatcher("/oauth/token", "POST"));
    }

    public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response)
            throws AuthenticationException {
        if (postonly && !request.getMethod().equals("POST")) {
            throw new AuthenticationServiceException("Authentication method not supported: " + request.getMethod());
        }
        String username = obtainUsername(request);
        String password = obtainPassword(request);
        try {
            password = RSAUtil.decrypt(password, privateKey);
        } catch (Exception e) {
            e.printStackTrace();
        }

        if (username == null) {
            username = "";
        }
        
        if (password == null) {
            password = "";
        }

        username = username.trim();

        UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(username, password);

        // Allow subclasses to set the "details" property
        setDetails(request, authRequest);

        return super.getAuthenticationManager().authenticate(authRequest);
    }

    public void setAuthenticationManager(AuthenticationManager authenticationManager) {
        super.setAuthenticationManager(authenticationManager);
    }
    
    protected String obtainPassword(HttpServletRequest request) {
        return request.getParameter(passwordParameter).replaceAll(" ", "+");
    }

    protected String obtainUsername(HttpServletRequest request) {
        return request.getParameter(usernameParameter);
    }

    protected void setDetails(HttpServletRequest request,
            UsernamePasswordAuthenticationToken authRequest) {
        authRequest.setDetails(authenticationDetailsSource.buildDetails(request));
    }

    public void setUsernameParameter(String usernameParameter) {
        Assert.hasText(usernameParameter, "Username parameter must not be empty or null");
        this.usernameParameter = usernameParameter;
    }

    public void setPasswordParameter(String passwordParameter) {
        Assert.hasText(passwordParameter, "Password parameter must not be empty or null");
        this.passwordParameter = passwordParameter;
    }
    
    public void setPostonly(boolean postOnly) {
        this.postonly = postOnly;
    }

    public final String getUsernameParameter() {
        return usernameParameter;
    }

    public final String getPasswordParameter() {
        return passwordParameter;
    }

}

把自定义 MyUsernamePasswordAuthenticationFilter 添加到 Filter Chain 过滤器链中

在 SpringSecurity 的配置类中使用 http.addFilterAt(myAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class) 把自定义的过滤器放在UsernamePasswordAuthenticationFilter 的位置，并为其设置认证成功和失败的处理方法以及认证管理器AuthenticationManager

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    
    @Autowired
    private AuthenticationSuccessHandler appLoginInSuccessHandler;
    
    @Bean
    @Override
    public AuthenticationManager authenticationManagerBean() throws Exception {
        AuthenticationManager manager = super.authenticationManagerBean();
        return manager;
    }
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().anyRequest().authenticated()
                .and().httpBasic().and()
                .cors().disable().headers().frameOptions().sameOrigin();// 解决iframe无法访问
        http.addFilterAt(myAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class);
    }

    @Bean
MyUsernamePasswordAuthenticationFilter myAuthenticationFilter() throws Exception {
        MyUsernamePasswordAuthenticationFilter filter = new MyUsernamePasswordAuthenticationFilter();
        filter.setAuthenticationManager(authenticationManagerBean());
        filter.setAuthenticationSuccessHandler(appLoginInSuccessHandler);
        filter.setAuthenticationFailureHandler(new AuthenticationFailureHandler() {
            @Override
            public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException e) throws IOException, ServletException {
                response.setContentType("application/json;charset=utf-8");
                response.getWriter().write(JSON.toJSonString(Respon.failed("登录失败!")));
            }
        });
        return filter;
    }
}

自定义UsernamePasswordAuthenticationFilter的运用

除了上面的例子，还常用于修改表单登录变为使用Json格式登录,登录验证码等等，需要注意的地方是UsernamePasswordAuthenticationFilter的默认登录地址为