/*
* 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
*/
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 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
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;
}
}