注:分析的Springsecurity版本是4.3.x,源碼可自行到github上去下載。
先上一張圖,如下圖1.1所示:
圖1.1 Springsecurity認證的時序圖
1.AuthenticationManager
AuthenticationManager的實現類ProviderManager的實現如下:
List-1.1 ProviderManager的authenticate方法
public class ProviderManager implements AuthenticationManager, MessageSourceAware,
InitializingBean {
private List<AuthenticationProvider> providers = Collections.emptyList();
private AuthenticationManager parent;
public Authentication authenticate(Authentication authentication)
throws AuthenticationException {
Class<? extends Authentication> toTest = authentication.getClass();
AuthenticationException lastException = null;
Authentication result = null;
boolean debug = logger.isDebugEnabled();
for (AuthenticationProvider provider : getProviders()) {
//調用supports方法
if (!provider.supports(toTest)) {
continue;
}
if (debug) {
logger.debug("Authentication attempt using "
+ provider.getClass().getName());
}
try {
//調用provider的authenticate方法
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 {
//如果result爲null且parent不爲null,那麼調用parent的authenticate方法
result = 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 = e;
}
}
}
...
- 遍歷AuthenticationProvider,調用provider的supports方法,如果返回爲true,那麼執行後面的流程。
- 之後調用AuthenticationProvider的authenticate方法,如果返回的result不爲null,那麼跳出循環。
- 如果遍歷完了AuthenticationProvider,result的值還是null且parent不爲null,那麼調用parent的authenticate方法。
- 如果得到的result值不爲null,那麼返回這個result給調用者。
2.AuthenticationProvider
AuthenticationProvider是個接口,如下List-2.1所示:
List-2.1 AuthenticationProvider的接口定義
/**
* Indicates a class can process a specific
* {@link org.springframework.security.core.Authentication} implementation.
*
* @author Ben Alex
*/
public interface AuthenticationProvider {
Authentication authenticate(Authentication authentication)
throws AuthenticationException;
boolean supports(Class<?> authentication);
}
以DaoAuthenticationProvider爲例,它的繼承圖如下所示:
圖2.1 DaoAuthenticationProvider的繼承圖
AbstractUserDetailsAuthenticationProvider中的authenticate方法中,定義了主要的模板,即它裏面使用了Template方法。如下List-2.2所示:
List-2.2 AbstractUserDetailsAuthenticationProvider的authenticate方法
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 {
//retrieveUser方法是抽象的,它由子類來實現
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方法是抽象的,由子類來實現。
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);
}
retrieveUser和additionalAuthenticationChecks由子類DaoAuthenticationProvider來實現。DaoAuthenticationProvider中的retrieveUser方法,涉及UserDetailsService。
3.UserDetailsService
它的實現如下List-3.1所示:
List-3.1 UserDetailsService定義
public interface UserDetailsService {
UserDetails loadUserByUsername(String username) throws UsernameNotFoundException;
}
這個接口的有個實現類JdbcUserDetailsManager,它實現了接口UserDetailsManager,這個接口定義的是對用戶信息管理的接口。
參考:
- http://niocoder.com/2018/01/02/Spring-Security%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%E4%B8%80-Spring-Security%E8%AE%A4%E8%AF%81%E8%BF%87%E7%A8%8B/
- https://github.com/longfeizheng/logback