realm
Realm：Shiro 从 Realm 获取安全数据（如用户、角色、权限），就是说 SecurityManager要验证用户身份，那么它需要从 Realm 获取相应的用户进行比较以确定用户身份是否合法，也需要从 Realm 得到用户相应的角色/权限进行验证用户是否能进行操作。
可以配置多个但最少得有一个
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从shiro 的顶级架构图中就可以看出realm的地位
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relam中有很多一般 继承 AuthorizingRealm 也可根据需求自己继承其他的 realm 类
public class MyRealm extends AuthorizingRealm {
/**
* 授权
*
* @param principals
* @return
*/
@Override
protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
return null;
}
/**
* 认证
*
* @param token
* @return
* @throws AuthenticationException
*/
@Override
protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
return null;
}
}
认证：简单理解就是登录 那shiro是如何进行登录的? （mindmanager 思维导图）连接地址
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简单说一下登录流程：
点击登录以后会提交 用户名 密码 给controller中
Subject subject = SecurityUtils.getSubject();
UsernamePasswordToken token = new UsernamePasswordToken(username, password);
subject.login(token);`
调用DelegatingSubject.login
public class DelegatingSubject implements Subject
public void login(AuthenticationToken token) throws AuthenticationException {
clearRunAsIdentitiesInternal();
// 调用securityManager.login(this, token);
Subject subject = securityManager.login(this, token);
PrincipalCollection principals;
String host = null;
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();
}
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);
}
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;
}
}
调用 DefaultSecurityManager .login
public class DefaultSecurityManager extends SessionsSecurityManager
public Subject login(Subject subject, AuthenticationToken token) throws AuthenticationException {
AuthenticationInfo info;
try {
info = authenticate(token);
} catch (AuthenticationException ae) {
try {
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
}
Subject loggedIn = createSubject(token, info, subject);
onSuccessfulLogin(token, info, loggedIn);
return loggedIn;
}
/**
* Delegates to the wrapped {@link org.apache.shiro.authc.Authenticator Authenticator} for authentication.
*/
public AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {
return this.authenticator.authenticate(token);
}
AuthenticatingSecurityManager.authenticate
public abstract class AuthenticatingSecurityManager extends RealmSecurityManager {
private Authenticator authenticator;
/**
* Default no-arg constructor that initializes its internal
* <code>authenticator</code> instance to a
* {@link org.apache.shiro.authc.pam.ModularRealmAuthenticator ModularRealmAuthenticator}.
*/
public AuthenticatingSecurityManager() {
super();
this.authenticator = new ModularRealmAuthenticator();
}
/**
* Delegates to the wrapped {@link org.apache.shiro.authc.Authenticator Authenticator} for authentication.
*/
public AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {
return this.authenticator.authenticate(token);
}
}
AbstractAuthenticator .authenticate
public abstract class AbstractAuthenticator implements Authenticator, LogoutAware {
public final AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {
if (token == null) {
throw new IllegalArgumentException("Method argument (authentication token) cannot be null.");
}
log.trace("Authentication attempt received for token [{}]", token);
AuthenticationInfo info;
try {
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);
if (log.isWarnEnabled())
log.warn(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;
}
protected abstract AuthenticationInfo doAuthenticate(AuthenticationToken token)
throws AuthenticationException;
}
ModularRealmAuthenticator.doAuthenticate
public class ModularRealmAuthenticator extends AbstractAuthenticator {
protected AuthenticationInfo doAuthenticate(AuthenticationToken authenticationToken) throws AuthenticationException {
assertRealmsConfigured();
Collection<Realm> realms = getRealms();
if (realms.size() == 1) {
return doSingleRealmAuthentication(realms.iterator().next(), authenticationToken);
} else {
return doMultiRealmAuthentication(realms, authenticationToken);
}
}
}
shiro判断配置的realm是一个还是多个 调用不同的方法就行认证 但都会调用
AuthenticatingRealm.getAuthenticationInfo
public abstract class AuthenticatingRealm extends CachingRealm implements Initializable {
public final AuthenticationInfo getAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
AuthenticationInfo info = getCachedAuthenticationInfo(token);
if (info == null) {
//otherwise not cached, perform the lookup:
info = doGetAuthenticationInfo(token);
log.debug("Looked up AuthenticationInfo [{}] from doGetAuthenticationInfo", info);
if (token != null && info != null) {
cacheAuthenticationInfoIfPossible(token, info);
}
} else {
log.debug("Using cached authentication info [{}] to perform credentials matching.", info);
}
if (info != null) {
// 密码比较的 主要看密码加密
assertCredentialsMatch(token, info);
} else {
log.debug("No AuthenticationInfo found for submitted AuthenticationToken [{}]. Returning null.", token);
}
return info;
}
protected abstract AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException;
自定义realm
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public class MyRealm extends AuthorizingRealm {
//public class MyRealm extends AuthenticatingRealm {
/**
* 认证
*
* @param token
* @return
* @throws AuthenticationException
*/
@Override
protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
UsernamePasswordToken usernamePasswordToken = (UsernamePasswordToken) token;
String username = usernamePasswordToken.getUsername();
String password = String.valueOf(usernamePasswordToken.getPassword());
ByteSource solt = ByteSource.Util.bytes(username);
if (username.equals("username") && password.equals("password")) {
return new SimpleAuthenticationInfo(username, password, getName());
}
return null;
}
}
这里面涉及到 一个realm 和多个realm 请看 ModularRealmAuthenticator 的源码分析和配置
