jaasrealm.java

业界著名的tomcat服务器的最新6.0的源代码。

     * configuration file), it will parse the class names and store the resulting
     * string(s) into the <code>ArrayList</code> field </code>userClasses</code>.
     */
    public void setUserClassNames(String userClassNames) {
        this.userClassNames = userClassNames;
        userClasses.clear();
        String temp = this.userClassNames;
        if (temp == null) {
            return;
        }
        while (true) {
            int comma = temp.indexOf(',');
            if (comma < 0) {
                break;
            }
            userClasses.add(temp.substring(0, comma).trim());
            temp = temp.substring(comma + 1);
        }
        temp = temp.trim();
        if (temp.length() > 0) {
            userClasses.add(temp);
        }
    }


    // --------------------------------------------------------- Public Methods


    /**
     * Return the <code>Principal</code> associated with the specified username and
     * credentials, if there is one; otherwise return <code>null</code>.
     *
     * If there are any errors with the JDBC connection, executing
     * the query or anything we return null (don't authenticate). This
     * event is also logged, and the connection will be closed so that
     * a subsequent request will automatically re-open it.
     *
     * @param username Username of the <code>Principal</code> to look up
     * @param credentials Password or other credentials to use in
     *  authenticating this username
     */
    public Principal authenticate(String username, String credentials) {

        // Establish a LoginContext to use for authentication
        try {
        LoginContext loginContext = null;
        if( appName==null ) appName="Tomcat";

        if( log.isDebugEnabled())
            log.debug(sm.getString("jaasRealm.beginLogin", username, appName));

        // What if the LoginModule is in the container class loader ?
        ClassLoader ocl = null;

        if (isUseContextClassLoader()) {
          ocl=Thread.currentThread().getContextClassLoader();
          Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
        }

        try {
            loginContext = new LoginContext
                (appName, new JAASCallbackHandler(this, username,
                                                  credentials));
        } catch (Throwable e) {
            log.error(sm.getString("jaasRealm.unexpectedError"), e);
            return (null);
        } finally {
            if( isUseContextClassLoader()) {
              Thread.currentThread().setContextClassLoader(ocl);
            }
        }

        if( log.isDebugEnabled())
            log.debug("Login context created " + username);

        // Negotiate a login via this LoginContext
        Subject subject = null;
        try {
            loginContext.login();
            subject = loginContext.getSubject();
            if (subject == null) {
                if( log.isDebugEnabled())
                    log.debug(sm.getString("jaasRealm.failedLogin", username));
                return (null);
            }
        } catch (AccountExpiredException e) {
            if (log.isDebugEnabled())
                log.debug(sm.getString("jaasRealm.accountExpired", username));
            return (null);
        } catch (CredentialExpiredException e) {
            if (log.isDebugEnabled())
                log.debug(sm.getString("jaasRealm.credentialExpired", username));
            return (null);
        } catch (FailedLoginException e) {
            if (log.isDebugEnabled())
                log.debug(sm.getString("jaasRealm.failedLogin", username));
            return (null);
        } catch (LoginException e) {
            log.warn(sm.getString("jaasRealm.loginException", username), e);
            return (null);
        } catch (Throwable e) {
            log.error(sm.getString("jaasRealm.unexpectedError"), e);
            return (null);
        }

        if( log.isDebugEnabled())
            log.debug(sm.getString("jaasRealm.loginContextCreated", username));

        // Return the appropriate Principal for this authenticated Subject
        Principal principal = createPrincipal(username, subject);
        if (principal == null) {
            log.debug(sm.getString("jaasRealm.authenticateFailure", username));
            return (null);
        }
        if (log.isDebugEnabled()) {
            log.debug(sm.getString("jaasRealm.authenticateSuccess", username));
        }

        return (principal);
        } catch( Throwable t) {
            log.error( "error ", t);
            return null;
        }
    }
     

    // -------------------------------------------------------- Package Methods


    // ------------------------------------------------------ Protected Methods


    /**
     * Return a short name for this <code>Realm</code> implementation.
     */
    protected String getName() {

        return (name);

    }


    /**
     * Return the password associated with the given principal's user name.
     */
    protected String getPassword(String username) {

        return (null);

    }


    /**
     * Return the <code>Principal</code> associated with the given user name.
     */
    protected Principal getPrincipal(String username) {

        return (null);

    }


    /**
     * Identify and return a <code>java.security.Principal</code> instance
     * representing the authenticated user for the specified <code>Subject</code>.
     * The Principal is constructed by scanning the list of Principals returned
     * by the JAASLoginModule. The first <code>Principal</code> object that matches
     * one of the class names supplied as a "user class" is the user Principal.
     * This object is returned to tha caller.
     * Any remaining principal objects returned by the LoginModules are mapped to  
     * roles, but only if their respective classes match one of the "role class" classes. 
     * If a user Principal cannot be constructed, return <code>null</code>.
     * @param subject The <code>Subject</code> representing the logged-in user
     */
    protected Principal createPrincipal(String username, Subject subject) {
        // Prepare to scan the Principals for this Subject
        String password = null; // Will not be carried forward

        List roles = new ArrayList();
        Principal userPrincipal = null;

        // Scan the Principals for this Subject
        Iterator principals = subject.getPrincipals().iterator();
        while (principals.hasNext()) {
            Principal principal = (Principal) principals.next();

            String principalClass = principal.getClass().getName();

            if( log.isDebugEnabled() ) {
                log.debug(sm.getString("jaasRealm.checkPrincipal", principal, principalClass));
            }

            if (userPrincipal == null && userClasses.contains(principalClass)) {
                userPrincipal = principal;
                if( log.isDebugEnabled() ) {
                    log.debug(sm.getString("jaasRealm.userPrincipalSuccess", principal.getName()));
                }
            }
            
            if (roleClasses.contains(principalClass)) {
                roles.add(principal.getName());
                if( log.isDebugEnabled() ) {
                    log.debug(sm.getString("jaasRealm.rolePrincipalAdd", principal.getName()));
                }
            }
        }

        // Print failure message if needed
        if (userPrincipal == null) {
            if (log.isDebugEnabled()) {
                log.debug(sm.getString("jaasRealm.userPrincipalFailure"));
                log.debug(sm.getString("jaasRealm.rolePrincipalFailure"));
            }
        } else {
            if (roles.size() == 0) {
                if (log.isDebugEnabled()) {
                    log.debug(sm.getString("jaasRealm.rolePrincipalFailure"));
                }
            }
        }

        // Return the resulting Principal for our authenticated user
        return new GenericPrincipal(this, username, null, roles, userPrincipal);
    }

     /**
      * Ensure the given name is legal for JAAS configuration.
      * Added for Bugzilla 30869, made protected for easy customization
      * in case my implementation is insufficient, which I think is
      * very likely.
      *
      * @param src The name to validate
      * @return A string that's a valid JAAS realm name
      */
     protected String makeLegalForJAAS(final String src) {
         String result = src;
         
         // Default name is "other" per JAAS spec
         if(result == null) {
             result = "other";
         }

         // Strip leading slash if present, as Sun JAAS impl
         // barfs on it (see Bugzilla 30869 bug report).
         if(result.startsWith("/")) {
             result = result.substring(1);
         }

         return result;
     }


    // ------------------------------------------------------ Lifecycle Methods


    /**
     *
     * Prepare for active use of the public methods of this <code>Component</code>.
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that prevents it from being started
     */
    public void start() throws LifecycleException {

        // Perform normal superclass initialization
        super.start();

    }


    /**
     * Gracefully shut down active use of the public methods of this <code>Component</code>.
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that needs to be reported
     */
    public void stop() throws LifecycleException {

        // Perform normal superclass finalization
        super.stop();

    }


}