/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.shiro.cas;
  
  import org.apache.shiro.authc.AuthenticationException;
  import org.apache.shiro.authc.AuthenticationInfo;
  import org.apache.shiro.authc.AuthenticationToken;
  import org.apache.shiro.authc.SimpleAuthenticationInfo;
  import org.apache.shiro.authz.AuthorizationInfo;
  import org.apache.shiro.authz.SimpleAuthorizationInfo;
  import org.apache.shiro.realm.AuthorizingRealm;
  import org.apache.shiro.subject.PrincipalCollection;
  import org.apache.shiro.subject.SimplePrincipalCollection;
  import org.apache.shiro.util.CollectionUtils;
  import org.apache.shiro.util.StringUtils;
  import org.jasig.cas.client.authentication.AttributePrincipal;
  import org.jasig.cas.client.validation.*;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  /**
   * This realm implementation acts as a CAS client to a CAS server for authentication and basic authorization.
   * <p/>
   * This realm functions by inspecting a submitted {@link org.apache.shiro.cas.CasToken CasToken} (which essentially 
   * wraps a CAS service ticket) and validates it against the CAS server using a configured CAS
   * {@link org.jasig.cas.client.validation.TicketValidator TicketValidator}.
   * <p/>
   * The {@link #getValidationProtocol() validationProtocol} is {@code CAS} by default, which indicates that a
   * a {@link org.jasig.cas.client.validation.Cas20ServiceTicketValidator Cas20ServiceTicketValidator}
   * will be used for ticket validation.  You can alternatively set
   * or {@link org.jasig.cas.client.validation.Saml11TicketValidator Saml11TicketValidator} of CAS client. It is based on
   * {@link AuthorizingRealm AuthorizingRealm} for both authentication and authorization. User id and attributes are retrieved from the CAS
   * service ticket validation response during authentication phase. Roles and permissions are computed during authorization phase (according
   * to the attributes previously retrieved).
   *
   * @since 1.2
   * @see <a href="https://github.com/bujiio/buji-pac4j">buji-pac4j</a>
   * @deprecated replaced with Shiro integration in <a href="https://github.com/bujiio/buji-pac4j">buji-pac4j</a>.
   */
  @Deprecated
  public class CasRealm extends AuthorizingRealm {
  
      // default name of the CAS attribute for remember me authentication (CAS 3.4.10+)
      public static final String DEFAULT_REMEMBER_ME_ATTRIBUTE_NAME = "longTermAuthenticationRequestTokenUsed";
      public static final String DEFAULT_VALIDATION_PROTOCOL = "CAS";
      
      private static Logger log = LoggerFactory.getLogger(CasRealm.class);
      
      // this is the url of the CAS server (example : http://host:port/cas)
      private String casServerUrlPrefix;
      
      // this is the CAS service url of the application (example : http://host:port/mycontextpath/shiro-cas)
      private String casService;
      
      /* CAS protocol to use for ticket validation : CAS (default) or SAML :
         - CAS protocol can be used with CAS server version < 3.1 : in this case, no user attributes can be retrieved from the CAS ticket validation response (except if there are some customizations on CAS server side)
         - SAML protocol can be used with CAS server version >= 3.1 : in this case, user attributes can be extracted from the CAS ticket validation response
      */
      private String validationProtocol = DEFAULT_VALIDATION_PROTOCOL;
      
      // default name of the CAS attribute for remember me authentication (CAS 3.4.10+)
      private String rememberMeAttributeName = DEFAULT_REMEMBER_ME_ATTRIBUTE_NAME;
      
      // this class from the CAS client is used to validate a service ticket on CAS server
      private TicketValidator ticketValidator;
      
      // default roles to applied to authenticated user
      private String defaultRoles;
      
      // default permissions to applied to authenticated user
      private String defaultPermissions;
      
      // names of attributes containing roles
      private String roleAttributeNames;
      
      // names of attributes containing permissions
      private String permissionAttributeNames;
      
      public CasRealm() {
         setAuthenticationTokenClass(CasToken.class);
     }
 
     @Override
     protected void onInit() {
         super.onInit();
         ensureTicketValidator();
     }
 
     protected TicketValidator ensureTicketValidator() {
         if (this.ticketValidator == null) {
             this.ticketValidator = createTicketValidator();
         }
         return this.ticketValidator;
     }
     
     protected TicketValidator createTicketValidator() {
         String urlPrefix = getCasServerUrlPrefix();
         if ("saml".equalsIgnoreCase(getValidationProtocol())) {
             return new Saml11TicketValidator(urlPrefix);
         }
         return new Cas20ServiceTicketValidator(urlPrefix);
     }
     
     /**
      * Authenticates a user and retrieves its information.
      * 
      * @param token the authentication token
      * @throws AuthenticationException if there is an error during authentication.
      */
     @Override
     @SuppressWarnings("unchecked")
     protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
         CasToken./../../org/apache/shiro/cas/CasToken.html#CasToken">CasToken casToken = (CasToken) token;
         if (token == null) {
             return null;
         }
         
         String ticket = (String)casToken.getCredentials();
         if (!StringUtils.hasText(ticket)) {
             return null;
         }
         
         TicketValidator ticketValidator = ensureTicketValidator();
 
         try {
             // contact CAS server to validate service ticket
             Assertion casAssertion = ticketValidator.validate(ticket, getCasService());
             // get principal, user id and attributes
             AttributePrincipal casPrincipal = casAssertion.getPrincipal();
             String userId = casPrincipal.getName();
             log.debug("Validate ticket : {} in CAS server : {} to retrieve user : {}", new Object[]{
                     ticket, getCasServerUrlPrefix(), userId
             });
 
             Map<String, Object> attributes = casPrincipal.getAttributes();
             // refresh authentication token (user id + remember me)
             casToken.setUserId(userId);
             String rememberMeAttributeName = getRememberMeAttributeName();
             String rememberMeStringValue = (String)attributes.get(rememberMeAttributeName);
             boolean isRemembered = rememberMeStringValue != null && Boolean.parseBoolean(rememberMeStringValue);
             if (isRemembered) {
                 casToken.setRememberMe(true);
             }
             // create simple authentication info
             List<Object> principals = CollectionUtils.asList(userId, attributes);
             PrincipalCollection principalCollection = new SimplePrincipalCollection(principals, getName());
             return new SimpleAuthenticationInfo(principalCollection, ticket);
         } catch (TicketValidationException e) { 
             throw new CasAuthenticationException("Unable to validate ticket [" + ticket + "]", e);
         }
     }
     
     /**
      * Retrieves the AuthorizationInfo for the given principals (the CAS previously authenticated user : id + attributes).
      * 
      * @param principals the primary identifying principals of the AuthorizationInfo that should be retrieved.
      * @return the AuthorizationInfo associated with this principals.
      */
     @Override
     @SuppressWarnings("unchecked")
     protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
         // retrieve user information
         SimplePrincipalCollection principalCollection = (SimplePrincipalCollection) principals;
         List<Object> listPrincipals = principalCollection.asList();
         Map<String, String> attributes = (Map<String, String>) listPrincipals.get(1);
         // create simple authorization info
         SimpleAuthorizationInfoorizationInfo">SimpleAuthorizationInfo simpleAuthorizationInfo = new SimpleAuthorizationInfo();
         // add default roles
         addRoles(simpleAuthorizationInfo, split(defaultRoles));
         // add default permissions
         addPermissions(simpleAuthorizationInfo, split(defaultPermissions));
         // get roles from attributes
         List<String> attributeNames = split(roleAttributeNames);
         for (String attributeName : attributeNames) {
             String value = attributes.get(attributeName);
             addRoles(simpleAuthorizationInfo, split(value));
         }
         // get permissions from attributes
         attributeNames = split(permissionAttributeNames);
         for (String attributeName : attributeNames) {
             String value = attributes.get(attributeName);
             addPermissions(simpleAuthorizationInfo, split(value));
         }
         return simpleAuthorizationInfo;
     }
     
     /**
      * Split a string into a list of not empty and trimmed strings, delimiter is a comma.
      * 
      * @param s the input string
      * @return the list of not empty and trimmed strings
      */
     private List<String> split(String s) {
         List<String> list = new ArrayList<String>();
         String[] elements = StringUtils.split(s, ',');
         if (elements != null && elements.length > 0) {
             for (String element : elements) {
                 if (StringUtils.hasText(element)) {
                     list.add(element.trim());
                 }
             }
         }
         return list;
     }
     
     /**
      * Add roles to the simple authorization info.
      * 
      * @param simpleAuthorizationInfo
      * @param roles the list of roles to add
      */
     private void addRoles(SimpleAuthorizationInfo simpleAuthorizationInfo, List<String> roles) {
         for (String role : roles) {
             simpleAuthorizationInfo.addRole(role);
         }
     }
     
     /**
      * Add permissions to the simple authorization info.
      * 
      * @param simpleAuthorizationInfo
      * @param permissions the list of permissions to add
      */
     private void addPermissions(SimpleAuthorizationInfo simpleAuthorizationInfo, List<String> permissions) {
         for (String permission : permissions) {
             simpleAuthorizationInfo.addStringPermission(permission);
         }
     }
 
     public String getCasServerUrlPrefix() {
         return casServerUrlPrefix;
     }
 
     public void setCasServerUrlPrefix(String casServerUrlPrefix) {
         this.casServerUrlPrefix = casServerUrlPrefix;
     }
 
     public String getCasService() {
         return casService;
     }
 
     public void setCasService(String casService) {
         this.casService = casService;
     }
 
     public String getValidationProtocol() {
         return validationProtocol;
     }
 
     public void setValidationProtocol(String validationProtocol) {
         this.validationProtocol = validationProtocol;
     }
 
     public String getRememberMeAttributeName() {
         return rememberMeAttributeName;
     }
 
     public void setRememberMeAttributeName(String rememberMeAttributeName) {
         this.rememberMeAttributeName = rememberMeAttributeName;
     }
 
     public String getDefaultRoles() {
         return defaultRoles;
     }
 
     public void setDefaultRoles(String defaultRoles) {
         this.defaultRoles = defaultRoles;
     }
 
     public String getDefaultPermissions() {
         return defaultPermissions;
     }
 
     public void setDefaultPermissions(String defaultPermissions) {
         this.defaultPermissions = defaultPermissions;
     }
 
     public String getRoleAttributeNames() {
         return roleAttributeNames;
     }
 
     public void setRoleAttributeNames(String roleAttributeNames) {
         this.roleAttributeNames = roleAttributeNames;
     }
 
     public String getPermissionAttributeNames() {
         return permissionAttributeNames;
     }
 
     public void setPermissionAttributeNames(String permissionAttributeNames) {
         this.permissionAttributeNames = permissionAttributeNames;
     }
 }