spring security登录认证流程解析

转 https://blog.csdn.net/qq_37142346/article/details/80032336

1.说明

1. 用户认证流程
2. 认证结果如何在多个请求之间共享
3. 获取认证用户信息、用户认证流程

Spring Security核心就是一系列的过滤器链，当一个请求来的时候，首先要通过过滤器链的校验，校验通过之后才会访问用户各种信息。
 

2.当用户发送登录请求的时候，首先进入到UsernamePasswordAuthenticationFilter中进行校验。

2.1UsernamePasswordAuthenticationFilter部分源码

package org.springframework.security.web.authentication;

import org.springframework.security.authentication.AuthenticationServiceException;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
import org.springframework.util.Assert;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class UsernamePasswordAuthenticationFilter extends
        AbstractAuthenticationProcessingFilter {
    // ~ Static fields/initializers
    // =====================================================================================

    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;

    // ~ Constructors
    // ===================================================================================================

    public UsernamePasswordAuthenticationFilter() {
        super(new AntPathRequestMatcher("/login", "POST"));
    }

    // ~ Methods
    // ========================================================================================================

    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);

        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 this.getAuthenticationManager().authenticate(authRequest);
    }

}

　它继承了AbstractAuthenticationProcessingFilter

2.2AbstractAuthenticationProcessingFilter部分源码

package org.springframework.security.web.authentication;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.context.MessageSource;
import org.springframework.context.MessageSourceAware;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.security.authentication.AuthenticationDetailsSource;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.InternalAuthenticationServiceException;
import org.springframework.security.authentication.event.InteractiveAuthenticationSuccessEvent;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.SpringSecurityMessageSource;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.session.NullAuthenticatedSessionStrategy;
import org.springframework.security.web.authentication.session.SessionAuthenticationStrategy;
import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
import org.springframework.security.web.util.matcher.RequestMatcher;
import org.springframework.util.Assert;
import org.springframework.web.filter.GenericFilterBean;

public abstract class AbstractAuthenticationProcessingFilter extends GenericFilterBean
        implements ApplicationEventPublisherAware, MessageSourceAware {

    protected ApplicationEventPublisher eventPublisher;
    protected AuthenticationDetailsSource<HttpServletRequest, ?> authenticationDetailsSource = new WebAuthenticationDetailsSource();
    private AuthenticationManager authenticationManager;
    protected MessageSourceAccessor messages = SpringSecurityMessageSource.getAccessor();
    private RememberMeServices rememberMeServices = new NullRememberMeServices();

    private RequestMatcher requiresAuthenticationRequestMatcher;

    private boolean continueChainBeforeSuccessfulAuthentication = false;

    private SessionAuthenticationStrategy sessionStrategy = new NullAuthenticatedSessionStrategy();

    private boolean allowSessionCreation = true;

    private AuthenticationSuccessHandler successHandler = new SavedRequestAwareAuthenticationSuccessHandler();
    private AuthenticationFailureHandler failureHandler = new SimpleUrlAuthenticationFailureHandler();

    protected AbstractAuthenticationProcessingFilter(String defaultFilterProcessesUrl) {
        setFilterProcessesUrl(defaultFilterProcessesUrl);
    }

    protected AbstractAuthenticationProcessingFilter(
            RequestMatcher requiresAuthenticationRequestMatcher) {
        Assert.notNull(requiresAuthenticationRequestMatcher,
                "requiresAuthenticationRequestMatcher cannot be null");
        this.requiresAuthenticationRequestMatcher = requiresAuthenticationRequestMatcher;
    }

    @Override
    public void afterPropertiesSet() {
        Assert.notNull(authenticationManager, "authenticationManager must be specified");
    }

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;

        if (!requiresAuthentication(request, response)) {  //是否需要校验
            chain.doFilter(request, response);

            return;
        }

        if (logger.isDebugEnabled()) {
            logger.debug("Request is to process authentication");
        }

        Authentication authResult;

        try {
            authResult = attemptAuthentication(request, response);  //调用attemptAuthentication方法
            if (authResult == null) {
                // return immediately as subclass has indicated that it hasn't completed
                // authentication
                return;
            }
            sessionStrategy.onAuthentication(authResult, request, response);
        }
        catch (InternalAuthenticationServiceException failed) {
            logger.error(
                    "An internal error occurred while trying to authenticate the user.",
                    failed);
            unsuccessfulAuthentication(request, response, failed);

            return;
        }
        catch (AuthenticationException failed) {
            // Authentication failed
            unsuccessfulAuthentication(request, response, failed);

            return;
        }

        // Authentication success
        if (continueChainBeforeSuccessfulAuthentication) {
            chain.doFilter(request, response);
        }

        successfulAuthentication(request, response, chain, authResult);
    }
}

2.2.1关键方法doFilter(ServletRequest req, ServletResponse res, FilterChain chain)

　　打断点发送登录请求进入源码中，我们会发现它会进入到UsernamePasswordAuthenticationFilter的attemptAuthentication这个方法中

　　会获取用户的username以及password参数的信息，然后使用构造器new
UsernamePasswordAuthenticationToken(username,
password)封装为一个UsernamePasswordAuthenticationToken对象，在这个构造器内部会将对应的信息赋值给各自的本地变量，并且会调用父类AbstractAuthenticationToken构造器（这个父类的构造器后面会介绍到），传一个null值进去，为什么是null呢？因为刚开始并没有认证，因此用户没有任何权限，并且设置没有认证的信息（setAuthenticated(false)）

2.2.2在　attemptAuthentication方法末尾调用了return this.getAuthenticationManager().authenticate(authRequest);

　　ProviderManager部分源码

package org.springframework.security.authentication;

import java.util.Collections;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.MessageSource;
import org.springframework.context.MessageSourceAware;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.CredentialsContainer;
import org.springframework.security.core.SpringSecurityMessageSource;
import org.springframework.util.Assert;

public class ProviderManager implements AuthenticationManager, MessageSourceAware,
        InitializingBean {

    private static final Log logger = LogFactory.getLog(ProviderManager.class);

    private AuthenticationEventPublisher eventPublisher = new NullEventPublisher();
    private List<AuthenticationProvider> providers = Collections.emptyList();
    protected MessageSourceAccessor messages = SpringSecurityMessageSource.getAccessor();
    private AuthenticationManager parent;
    private boolean eraseCredentialsAfterAuthentication = true;

    public ProviderManager(List<AuthenticationProvider> providers) {
        this(providers, null);
    }

    public ProviderManager(List<AuthenticationProvider> providers,
            AuthenticationManager parent) {
        Assert.notNull(providers, "providers list cannot be null");
        this.providers = providers;
        this.parent = parent;
        checkState();
    }

    public Authentication authenticate(Authentication authentication)
            throws AuthenticationException {
        Class<? extends Authentication> toTest = authentication.getClass();
        AuthenticationException lastException = null;
        AuthenticationException parentException = null;
        Authentication result = null;
        Authentication parentResult = null;
        boolean debug = logger.isDebugEnabled();

        for (AuthenticationProvider provider : getProviders()) {
            if (!provider.supports(toTest)) {
                continue;
            }

            if (debug) {
                logger.debug("Authentication attempt using "
                        + provider.getClass().getName());
            }

            try {
                result = provider.authenticate(authentication);

                if (result != null) {
                    copyDetails(authentication, result);
                    break;
                }
            }
            catch (AccountStatusException e) {
                prepareException(e, authentication);
                // SEC-546: Avoid polling additional providers if auth failure is due to
                // invalid account status
                throw e;
            }
            catch (InternalAuthenticationServiceException e) {
                prepareException(e, authentication);
                throw e;
            }
            catch (AuthenticationException e) {
                lastException = e;
            }
        }

        if (result == null && parent != null) {
            // Allow the parent to try.
            try {
                result = parentResult = parent.authenticate(authentication);
            }
            catch (ProviderNotFoundException e) {
                // ignore as we will throw below if no other exception occurred prior to
                // calling parent and the parent
                // may throw ProviderNotFound even though a provider in the child already
                // handled the request
            }
            catch (AuthenticationException e) {
                lastException = parentException = e;
            }
        }

        if (result != null) {
            if (eraseCredentialsAfterAuthentication
                    && (result instanceof CredentialsContainer)) {
                // Authentication is complete. Remove credentials and other secret data
                // from authentication
                ((CredentialsContainer) result).eraseCredentials();
            }

            // If the parent AuthenticationManager was attempted and successful then it will publish an AuthenticationSuccessEvent
            // This check prevents a duplicate AuthenticationSuccessEvent if the parent AuthenticationManager already published it
            if (parentResult == null) {
                eventPublisher.publishAuthenticationSuccess(result);
            }
            return result;
        }

        // Parent was null, or didn't authenticate (or throw an exception).

        if (lastException == null) {
            lastException = new ProviderNotFoundException(messages.getMessage(
                    "ProviderManager.providerNotFound",
                    new Object[] { toTest.getName() },
                    "No AuthenticationProvider found for {0}"));
        }

        // If the parent AuthenticationManager was attempted and failed then it will publish an AbstractAuthenticationFailureEvent
        // This check prevents a duplicate AbstractAuthenticationFailureEvent if the parent AuthenticationManager already published it
        if (parentException == null) {
            prepareException(lastException, authentication);
        }

        throw lastException;
    }

}

　　在ProviderManager这个实现类中，它会调用AuthenticationProvider接口的实现类获取用户的信息，用户的信息权限的验证就在该类中校验。进入ProviderManager类中调用authenticate(Authentication authentication)方法，它通过AuthenticationProvider实现类获取用户的登录的方式后会有一个for循环遍历它是否支持这种登录方式，具体的登录方式有表单登录，qq登录，微信登录等。如果都不支持它会结束for循环，如果支持则会进入AuthenticationProvider接口的抽象实现类AbstractUserDetailsAuthenticationProvider中调用 authenticate(Authentication authentication)方法对用户的身份进入校验。

2.2.3provider.authenticate(authentication)---调用AuthenticationProvider接口的抽象实现类AbstractUserDetailsAuthenticationProvider中的 authenticate(Authentication authentication)方法对用户的身份进入校验

　　AbstractUserDetailsAuthenticationProvider部分源码

package org.springframework.security.authentication.dao;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.security.authentication.AccountExpiredException;
import org.springframework.security.authentication.AuthenticationProvider;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.authentication.CredentialsExpiredException;
import org.springframework.security.authentication.DisabledException;
import org.springframework.security.authentication.LockedException;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.SpringSecurityMessageSource;
import org.springframework.security.core.authority.mapping.GrantedAuthoritiesMapper;
import org.springframework.security.core.authority.mapping.NullAuthoritiesMapper;
import org.springframework.security.core.userdetails.UserCache;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsChecker;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.security.core.userdetails.cache.NullUserCache;

import org.springframework.beans.factory.InitializingBean;

import org.springframework.context.MessageSource;
import org.springframework.context.MessageSourceAware;
import org.springframework.context.support.MessageSourceAccessor;

import org.springframework.util.Assert;

public abstract class AbstractUserDetailsAuthenticationProvider implements
        AuthenticationProvider, InitializingBean, MessageSourceAware {

    protected final Log logger = LogFactory.getLog(getClass());

    protected MessageSourceAccessor messages = SpringSecurityMessageSource.getAccessor();
    private UserCache userCache = new NullUserCache();
    private boolean forcePrincipalAsString = false;
    protected boolean hideUserNotFoundExceptions = true;
    private UserDetailsChecker preAuthenticationChecks = new DefaultPreAuthenticationChecks();
    private UserDetailsChecker postAuthenticationChecks = new DefaultPostAuthenticationChecks();
    private GrantedAuthoritiesMapper authoritiesMapper = new NullAuthoritiesMapper();
public Authentication authenticate(Authentication authentication)
            throws AuthenticationException {
        Assert.isInstanceOf(UsernamePasswordAuthenticationToken.class, authentication,
                () -> messages.getMessage(
                        "AbstractUserDetailsAuthenticationProvider.onlySupports",
                        "Only UsernamePasswordAuthenticationToken is supported"));

        // Determine username
        String username = (authentication.getPrincipal() == null) ? "NONE_PROVIDED"
                : authentication.getName();

        boolean cacheWasUsed = true;
        UserDetails user = this.userCache.getUserFromCache(username);

        if (user == null) {
            cacheWasUsed = false;

            try {
                user = retrieveUser(username,
                        (UsernamePasswordAuthenticationToken) authentication);
            }
            catch (UsernameNotFoundException notFound) {
                logger.debug("User '" + username + "' not found");

                if (hideUserNotFoundExceptions) {
                    throw new BadCredentialsException(messages.getMessage(
                            "AbstractUserDetailsAuthenticationProvider.badCredentials",
                            "Bad credentials"));
                }
                else {
                    throw notFound;
                }
            }

            Assert.notNull(user,
                    "retrieveUser returned null - a violation of the interface contract");
        }

        try {
            preAuthenticationChecks.check(user);
            additionalAuthenticationChecks(user,
                    (UsernamePasswordAuthenticationToken) authentication);
        }
        catch (AuthenticationException exception) {
            if (cacheWasUsed) {
                // There was a problem, so try again after checking
                // we're using latest data (i.e. not from the cache)
                cacheWasUsed = false;
                user = retrieveUser(username,
                        (UsernamePasswordAuthenticationToken) authentication);
                preAuthenticationChecks.check(user);
                additionalAuthenticationChecks(user,
                        (UsernamePasswordAuthenticationToken) authentication);
            }
            else {
                throw exception;
            }
        }

        postAuthenticationChecks.check(user);

        if (!cacheWasUsed) {
            this.userCache.putUserInCache(user);
        }

        Object principalToReturn = user;

        if (forcePrincipalAsString) {
            principalToReturn = user.getUsername();
        }

        return createSuccessAuthentication(principalToReturn, authentication, user);
    }


    protected Authentication createSuccessAuthentication(Object principal,
            Authentication authentication, UserDetails user) {

        UsernamePasswordAuthenticationToken result = new UsernamePasswordAuthenticationToken(
                principal, authentication.getCredentials(),
                authoritiesMapper.mapAuthorities(user.getAuthorities()));
        result.setDetails(authentication.getDetails());

        return result;
    }
}

　　进入抽象类AbstractUserDetailsAuthenticationProvider的内部的authenticate方法之后，先会判断user是否为空，这个user是UserDetail的对象，如果为空，表示还没有认证，就需要调用retrieveUser方法去获取用户的信息，这个方法是抽象类AbstractUserDetailsAuthenticationProvider的扩展类DaoAuthenticationProvider的一个方法。

2.2.4 user = retrieveUser(username, (UsernamePasswordAuthenticationToken) authentication)调用DaoAuthenticationProvider的retrieveUser方法

　　在该扩展类的retrieveUser方法中调用UserDetailsService这个接口的实现类的loadUserByUsername方法去获取用户信息，而这里我自己编写了实现类MyUserDetail类，在这个实现类中，我们可以编写自己的逻辑，从数据库中获取用户密码等权限信息返回。

在拿到用户的信息后，返回到AbstractUserDetailsAuthenticationProvider类中调用createSuccessAuthentication(principalToReturn,
authentication,
user)方法，在该方法中会调用三个参数的UsernamePasswordAuthenticationToken构造器，不同于前面调用两个参数的，因为这里已经验证了用户的信息和权限，因此不再是给父类构造器中传null值了，而是用户的权限集合，并且设置认证通过（setAuthenticated(true)），

2.2.5return createSuccessAuthentication(principalToReturn, authentication, user);调用AbstractUserDetailsAuthenticationProvider的createSuccessAuthentication方法

2.2.6 身份认证成功后，AbstractAuthenticationProcessingFilter类中调用successfulAuthentication方法

　　这个方法它会调用SecurityContext，最后将认证的结果放入SecurityContextHolder中，SecurityContext类很简单，重写了equals方法和hascode方法，保证了authentication的唯一性。SecurityContextHolder类实际上对ThreadLocal的一个封装，可以在不同方法之间进行通信。

　　

　　最后会被SecurityContextPersistenceFilter过滤器使用，这个过滤器的作用是什么呢？当一个请求来的时候，它会将session中的值传入到该线程中，当请求返回的时候，它会判断该请求线程是否有SecurityContext，如果有它会将其放入到session中，因此保证了请求结果可以在不同的请求之间共享。