shiro认证代码流程

发表于   |   分类于   |  

认证流程

  1. subject提交认证，传过去token参数
  2. DelegatingSubject代理类调用securityManager.login(this,token)，此方法会通过token查询，获取到一个subject，接下来会对这个subject进行检查，如果没有问题，就把subject的内容塞入到this中，也就是当前调用认证方法的那个subject中，完成副作用。
  3. DefaultSecurityManager的login方法拿到subject和token参数后，调用父类的方法：authenticate(token)来获取到一个认证信息AuthenticationInfo。接下来会调用createSubject方法，把AuthenticationInfo、token和subject重新组装成一个新的subject，返回。
  4. AuthenticatingSecurityManager方法中的authenticate(token)方法接收到token后，执行操作，return this.authenticator.authenticate(token)。authenticator在new的时候就自动创建完成，为ModularAuthenticator，返回一个认证信息AuthenticationInfo。
  5. AbstractAuthenticator方法中会有一个方法info = doAuthenticate(token)，来获取认证信息，ModularAuthenticator方法中写了这个。
  6. ModularAuthenticator方法继承了抽象类AbstractAuthenticator，拿到token后去realm里查询用户的认证信息，自定义的realm就在这里的集合中，通过注入的方式加入集合，也可以配置认证的三个策略。自定义的realm覆盖重写doGetAuthenticationInfo方法。

subject.login(token)

1
2
3
4
5
6
7
// 执行认证的提交
try {
    subject.login(token);
} catch (AuthenticationException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

DelegatingSubject

subject的代理类。

1
2
3
public class DelegatingSubject implements Subject {
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
public void login(AuthenticationToken token) throws AuthenticationException {
    clearRunAsIdentitiesInternal();
    // subject是返回的已经认证处理过的，根据token去查询出来的subject对象
    Subject subject = securityManager.login(this, token);
    // 用户的身份凭证信息
    PrincipalCollection principals;
    String host = null;
    // 把subject中获取到的凭证信息放进去
    if (subject instanceof DelegatingSubject) {
        DelegatingSubject delegating = (DelegatingSubject) subject;
        //we have to do this in case there are assumed identities - we don't want to lose the 'real' principals:
        principals = delegating.principals;
        host = delegating.host;
    } else {
        principals = subject.getPrincipals();
    }
    // 如果凭证信息为空，就是没有有效的用户认证信息返回，就抛出异常
    if (principals == null || principals.isEmpty()) {
        String msg = "Principals returned from securityManager.login( token ) returned a null or " +
                "empty value.  This value must be non null and populated with one or more elements.";
        throw new IllegalStateException(msg);
    }
    
    // 有合法的凭证信息，就全部塞到调用login的那个subject中，完成副作用
    this.principals = principals;
    this.authenticated = true;
    if (token instanceof HostAuthenticationToken) {
        host = ((HostAuthenticationToken) token).getHost();
    }
    if (host != null) {
        this.host = host;
    }
    Session session = subject.getSession(false);
    if (session != null) {
        this.session = decorate(session);
    } else {
        this.session = null;
    }
}

DefaultSecurityManager

这是一个默认的安全管理器。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
public Subject login(Subject subject, AuthenticationToken token) throws AuthenticationException {
    AuthenticationInfo info;
    try {
        // 根据token去进行认证，返回一个认证信息，authenticationInfo
        info = authenticate(token);
    } catch (AuthenticationException ae) {
        try {
            // 认证失败就抛出认证失败的异常
            onFailedLogin(token, ae, subject);
        } catch (Exception e) {
            if (log.isInfoEnabled()) {
                log.info("onFailedLogin method threw an " +
                        "exception.  Logging and propagating original AuthenticationException.", e);
            }
        }
        throw ae; //propagate
    }
    // 如果到这步，说明认证成功，把认证信息、令牌等全部组装成一个新的subject，返回这个已经通过认证的，已登录的subject
    Subject loggedIn = createSubject(token, info, subject);
    onSuccessfulLogin(token, info, loggedIn);
    return loggedIn;
}

AuthenticatingSecurityManager

1
2
3
4
public AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {
    // 值得一提的是这个authenticator是默认的new的一个ModularRealmAuthenticator
    return this.authenticator.authenticate(token);
}

AbstractAuthenticator

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
public final AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {
    if (token == null) {
        throw new IllegalArgumentException("Method argumet (authentication token) cannot be null.");
    }
    log.trace("Authentication attempt received for token [{}]", token);
    AuthenticationInfo info;
    try {
        // 进行认证，认证信息放到info中，否则抛异常
        info = doAuthenticate(token);
        if (info == null) {
            String msg = "No account information found for authentication token [" + token + "] by this " +
                    "Authenticator instance.  Please check that it is configured correctly.";
            throw new AuthenticationException(msg);
        }
    } catch (Throwable t) {
        AuthenticationException ae = null;
        if (t instanceof AuthenticationException) {
            ae = (AuthenticationException) t;
        }
        if (ae == null) {
            //Exception thrown was not an expected AuthenticationException.  Therefore it is probably a little more
            //severe or unexpected.  So, wrap in an AuthenticationException, log to warn, and propagate:
            String msg = "Authentication failed for token submission [" + token + "].  Possible unexpected " +
                    "error? (Typical or expected login exceptions should extend from AuthenticationException).";
            ae = new AuthenticationException(msg, t);
        }
        try {
            notifyFailure(token, ae);
        } catch (Throwable t2) {
            if (log.isWarnEnabled()) {
                String msg = "Unable to send notification for failed authentication attempt - listener error?.  " +
                        "Please check your AuthenticationListener implementation(s).  Logging sending exception " +
                        "and propagating original AuthenticationException instead...";
                log.warn(msg, t2);
            }
        }
        throw ae;
    }
    log.debug("Authentication successful for token [{}].  Returned account [{}]", token, info);
    notifySuccess(token, info);
    return info;
}

ModularRealmAuthenticator

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
protected AuthenticationInfo doAuthenticate(AuthenticationToken authenticationToken) throws AuthenticationException {
    assertRealmsConfigured();
    Collection<Realm> realms = getRealms();
    // 判断多个realm还是单个realm
    if (realms.size() == 1) {
        return doSingleRealmAuthentication(realms.iterator().next(), authenticationToken);
    } else {
        return doMultiRealmAuthentication(realms, authenticationToken);
    }
}
// 单个realm进行认证 
protected AuthenticationInfo doSingleRealmAuthentication(Realm realm, AuthenticationToken token) {
    if (!realm.supports(token)) {
        String msg = "Realm [" + realm + "] does not support authentication token [" +
                token + "].  Please ensure that the appropriate Realm implementation is " +
                "configured correctly or that the realm accepts AuthenticationTokens of this type.";
        throw new UnsupportedTokenException(msg);
    }
    // 这个get方法就是我们自定义realm的时候override的方法
    AuthenticationInfo info = realm.getAuthenticationInfo(token);
    if (info == null) {
        String msg = "Realm [" + realm + "] was unable to find account data for the " +
                "submitted AuthenticationToken [" + token + "].";
        throw new UnknownAccountException(msg);
    }
    return info;
}

注意的是，ModularRealmAuthenticator中的realm，是有set方法的，在spring中直接通过配置文件注入的方式set进来即可。

多个realm的配置方法

其中也有三种不同的realm认证策略，基本上都是针对多个realm配置的情况。

1
2
3
4
5
6
// 配置认证策略
DefaultSecurityManager securityManager = new DefaultSecurityManager();
ModularRealmAuthenticator authenticator = new ModularRealmAuthenticator();
authenticator.setAuthenticationStrategy(new AllSuccessfulStrategy());
securityManager.setAuthenticator(authenticator);

ini配置方法

1
2
3
4
5
6
[main]
#authenticator
authenticator=org.apache.shiro.authc.pam.ModularRealmAuthenticator
authenticationStrategy=org.apache.shiro.authc.pam.AtLeastOneSuccessfulStrategy
authenticator.authenticationStrategy=$authenticationStrategy
securityManager.authenticator=$authenticator

spring注入的方法

1
2
3
4
<!-- 配置认证策略 -->
<property name="authenticator.authenticationStrategy">
    <bean class="org.apache.shiro.authc.pam.FirstSuccessfulStrategy" />
</property>