org.apache.wiki.auth

Class AuthorizationManager

java.lang.Object

org.apache.wiki.auth.AuthorizationManager

public class AuthorizationManager
extends Object

Manages all access control and authorization; determines what authenticated users are allowed to do.

Privileges in JSPWiki are expressed as Java-standard Permission classes. There are two types of permissions:

• WikiPermission - privileges that apply to an entire wiki instance: e.g., editing user profiles, creating pages, creating groups
• PagePermission - privileges that apply to a single wiki page or range of pages: e.g., reading, editing, renaming

Calling classes determine whether they are entitled to perform a particular action by constructing the appropriate permission first, then passing it and the current WikiSession to the checkPermission(WikiSession, Permission) method. If the session's Subject possesses the permission, the action is allowed.

For WikiPermissions, the decision criteria is relatively simple: the caller either possesses the permission, as granted by the wiki security policy -- or not.

For PagePermissions, the logic is exactly the same if the page being checked does not have an access control list. However, if the page does have an ACL, the authorization decision is made based the union of the permissions granted in the ACL and in the security policy. In other words, the user must be named in the ACL (or belong to a group or role that is named in the ACL) and be granted (at least) the same permission in the security policy. We do this to prevent a user from gaining more permissions than they already have, based on the security policy.

See the checkPermission(WikiSession, Permission) and hasRoleOrPrincipal(WikiSession, Principal) methods for more information on the authorization logic.

Since:

2.3

See Also:

AuthenticationManager

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_AUTHORIZER The default external Authorizer is the WebContainerAuthorizer
protected static String	DEFAULT_POLICY Name of the default security policy file, in WEB-INF.
protected static String	POLICY Property that supplies the security policy file name, in WEB-INF.
static String	PROP_AUTHORIZER The property name in jspwiki.properties for specifying the external Authorizer.

Constructor Summary

Constructors

Constructor and Description
AuthorizationManager() Constructs a new AuthorizationManager instance.

Method Summary

Modifier and Type	Method and Description
void	addWikiEventListener(WikiEventListener listener) Registers a WikiEventListener with this instance.
protected boolean	allowedByLocalPolicy(Principal[] principals, Permission permission) Checks to see if the local security policy allows a particular static Permission.
boolean	checkPermission(WikiSession session, Permission permission) Returns true or false, depending on whether a Permission is allowed for the Subject associated with a supplied WikiSession.
protected boolean	checkStaticPermission(WikiSession session, Permission permission) Determines whether a Subject possesses a given "static" Permission as defined in the security policy file.
protected void	fireEvent(int type, Principal user, Object permission) Fires a WikiSecurityEvent of the provided type, user, and permission to all registered listeners.
Authorizer	getAuthorizer() Returns the current external Authorizer in use.
boolean	hasAccess(WikiContext context, javax.servlet.http.HttpServletResponse response) Checks whether the current user has access to the wiki context, by obtaining the required Permission (WikiContext.requiredPermission()) and delegating the access check to checkPermission(WikiSession, Permission).
boolean	hasAccess(WikiContext context, javax.servlet.http.HttpServletResponse response, boolean redirect) Checks whether the current user has access to the wiki context (and optionally redirects if not), by obtaining the required Permission (WikiContext.requiredPermission()) and delegating the access check to checkPermission(WikiSession, Permission).
protected boolean	hasRoleOrPrincipal(WikiSession session, Principal principal) Determines if the Subject associated with a supplied WikiSession contains a desired user Principal or built-in Role principal, OR is a member a Group or external Role.
void	initialize(WikiEngine engine, Properties properties) Initializes AuthorizationManager with an engine and set of properties.
boolean	isUserInRole(WikiSession session, Principal principal) Determines if the Subject associated with a supplied WikiSession contains a desired Role or GroupPrincipal.
void	removeWikiEventListener(WikiEventListener listener) Un-registers a WikiEventListener with this instance.
Principal	resolvePrincipal(String name) Given a supplied string representing a Principal's name from an Acl, this method resolves the correct type of Principal (role, group, or user).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_AUTHORIZER

public static final String DEFAULT_AUTHORIZER

The default external Authorizer is the WebContainerAuthorizer

See Also:

Constant Field Values

POLICY

protected static final String POLICY

Property that supplies the security policy file name, in WEB-INF.

See Also:

Constant Field Values

DEFAULT_POLICY

protected static final String DEFAULT_POLICY

Name of the default security policy file, in WEB-INF.

See Also:

Constant Field Values

PROP_AUTHORIZER

public static final String PROP_AUTHORIZER

The property name in jspwiki.properties for specifying the external Authorizer.

See Also:

Constant Field Values

Constructor Detail

AuthorizationManager

public AuthorizationManager()

Constructs a new AuthorizationManager instance.

Method Detail

checkPermission

public boolean checkPermission(WikiSession session,
                               Permission permission)

Returns true or false, depending on whether a Permission is allowed for the Subject associated with a supplied WikiSession. The access control algorithm works this way:

1. The Acl for the page is obtained
2. The Subject associated with the current WikiSession is obtained
3. If the Subject's Principal set includes the Role Principal that is the administrator group, always allow the Permission
4. For all permissions, check to see if the Permission is allowed according to the default security policy. If it isn't, deny the permission and halt further processing.
5. If there is an Acl, get the list of Principals assigned this Permission in the Acl: these will be role, group or user Principals, or UnresolvedPrincipals (see below). Then iterate through the Subject's Principal set and determine whether the user (Subject) possesses any one of these specified Roles or Principals. The matching process delegates to hasRoleOrPrincipal(WikiSession, Principal).

Note that when iterating through the Acl's list of authorized Principals, it is possible that one or more of the Acl's Principal entries are of type UnresolvedPrincipal. This means that the last time the ACL was read, the Principal (user, built-in Role, authorizer Role, or wiki Group) could not be resolved: the Role was not valid, the user wasn't found in the UserDatabase, or the Group wasn't known to (e.g., cached) in the GroupManager. If an UnresolvedPrincipal is encountered, this method will attempt to resolve it first before checking to see if the Subject possesses this principal, by calling resolvePrincipal(String). If the (re-)resolution does not succeed, the access check for the principal will fail by definition (the Subject should never contain UnresolvedPrincipals).

If security not set to JAAS, will return true.

Parameters:

session - the current wiki session

permission - the Permission being checked

Returns:

the result of the Permission check

See Also:

hasRoleOrPrincipal(WikiSession, Principal)

isUserInRole

public boolean isUserInRole(WikiSession session,
                            Principal principal)

Determines if the Subject associated with a supplied WikiSession contains a desired Role or GroupPrincipal. The algorithm simply checks to see if the Subject possesses the Role or GroupPrincipal it in its Principal set. Note that any user (anonymous, asserted, authenticated) can possess a built-in role. But a user must be authenticated to possess a role other than one of the built-in ones. We do this to prevent privilege escalation.

For all other cases, this method returns false.

Note that this method does not consult the external Authorizer or GroupManager; it relies on the Principals that have been injected into the user's Subject at login time, or after group creation/modification/deletion.

Parameters:

session - the current wiki session, which must be non-null. If null, the result of this method always returns false

principal - the Principal (role or group principal) to look for, which must be non-null. If null, the result of this method always returns false

Returns:

true if the Subject supplied with the WikiContext posesses the Role or GroupPrincipal, false otherwise

getAuthorizer

public Authorizer getAuthorizer()
                         throws WikiSecurityException

Returns the current external Authorizer in use. This method is guaranteed to return a properly-initialized Authorizer, unless it could not be initialized. In that case, this method throws a WikiSecurityException.

Returns:

the current Authorizer

Throws:

WikiSecurityException - if the Authorizer could not be initialized

hasRoleOrPrincipal

protected boolean hasRoleOrPrincipal(WikiSession session,
                                     Principal principal)

Determines if the Subject associated with a supplied WikiSession contains a desired user Principal or built-in Role principal, OR is a member a Group or external Role. The rules are as follows:

1. First, if desired Principal is a Role or GroupPrincipal, delegate to isUserInRole(WikiSession, Principal) and return the result.
2. Otherwise, we're looking for a user Principal, so iterate through the Principal set and see if any share the same name as the one we are looking for.

Note: if the Principal parameter is a user principal, the session must be authenticated in order for the user to "possess it". Anonymous or asserted sessions will never posseess a named user principal.

Parameters:

session - the current wiki session, which must be non-null. If null, the result of this method always returns false

principal - the Principal (role, group, or user principal) to look for, which must be non-null. If null, the result of this method always returns false

Returns:

true if the Subject supplied with the WikiContext posesses the Role, GroupPrincipal or desired user Principal, false otherwise

hasAccess

public boolean hasAccess(WikiContext context,
                         javax.servlet.http.HttpServletResponse response)
                  throws IOException

Checks whether the current user has access to the wiki context, by obtaining the required Permission (WikiContext.requiredPermission()) and delegating the access check to checkPermission(WikiSession, Permission). If the user is allowed, this method returns true; false otherwise. If access is allowed, the wiki context will be added to the request as an attribute with the key name WikiTagBase.ATTR_CONTEXT. Note that this method will automatically redirect the user to a login or error page, as appropriate, if access fails. This is NOT guaranteed to be default behavior in the future.

Parameters:

context - wiki context to check if it is accesible

response - the http response

Returns:

the result of the access check

Throws:

IOException - In case something goes wrong

hasAccess

public boolean hasAccess(WikiContext context,
                         javax.servlet.http.HttpServletResponse response,
                         boolean redirect)
                  throws IOException

Checks whether the current user has access to the wiki context (and optionally redirects if not), by obtaining the required Permission (WikiContext.requiredPermission()) and delegating the access check to checkPermission(WikiSession, Permission). If the user is allowed, this method returns true; false otherwise. Also, the wiki context will be added to the request as attribute with the key name WikiTagBase.ATTR_CONTEXT.

Parameters:

context - wiki context to check if it is accesible

response - The servlet response object

redirect - If true, makes an automatic redirect to the response

Returns:

the result of the access check

Throws:

IOException - If something goes wrong

initialize

public void initialize(WikiEngine engine,
                       Properties properties)
                throws WikiException

Initializes AuthorizationManager with an engine and set of properties. Expects to find property 'jspwiki.authorizer' with a valid Authorizer implementation name to take care of role lookup operations.

Parameters:

engine - the wiki engine

properties - the set of properties used to initialize the wiki engine

Throws:

WikiException - if the AuthorizationManager cannot be initialized

allowedByLocalPolicy

protected boolean allowedByLocalPolicy(Principal[] principals,
                                       Permission permission)

Checks to see if the local security policy allows a particular static Permission. Do not use this method for normal permission checks; use checkPermission(WikiSession, Permission) instead.

Parameters:

principals - the Principals to check

permission - the Permission

Returns:

the result

checkStaticPermission

protected boolean checkStaticPermission(WikiSession session,
                                        Permission permission)

Determines whether a Subject possesses a given "static" Permission as defined in the security policy file. This method uses standard Java 2 security calls to do its work. Note that the current access control context's codeBase is effectively this class, not that of the caller. Therefore, this method will work best when what matters in the policy is who makes the permission check, not what the caller's code source is. Internally, this method works by executing Subject.doAsPrivileged with a privileged action that simply calls AccessController.checkPermission(Permission).

Parameters:

session - the WikiSession whose permission status is being queried

permission - the Permission the Subject must possess

Returns:

true if the Subject possesses the permission, false otherwise

See Also:

. A caught exception (or lack thereof) determines whether the privilege is absent (or present).

resolvePrincipal

public Principal resolvePrincipal(String name)

Given a supplied string representing a Principal's name from an Acl, this method resolves the correct type of Principal (role, group, or user). This method is guaranteed to always return a Principal. The algorithm is straightforward:

1. If the name matches one of the built-in Role names, return that built-in Role
2. If the name matches one supplied by the current Authorizer, return that Role
3. If the name matches a group managed by the current GroupManager, return that Group
4. Otherwise, assume that the name represents a user principal. Using the current UserDatabase, find the first user who matches the supplied name by calling UserDatabase.find(String).
5. Finally, if a user cannot be found, manufacture and return a generic UnresolvedPrincipal

Parameters:

name - the name of the Principal to resolve

Returns:

the fully-resolved Principal

addWikiEventListener

public void addWikiEventListener(WikiEventListener listener)

Registers a WikiEventListener with this instance.

Parameters:

listener - the event listener

removeWikiEventListener

public void removeWikiEventListener(WikiEventListener listener)

Un-registers a WikiEventListener with this instance.

Parameters:

listener - the event listener

fireEvent

protected void fireEvent(int type,
                         Principal user,
                         Object permission)

Fires a WikiSecurityEvent of the provided type, user, and permission to all registered listeners.

Parameters:

type - the event type to be fired

user - the user associated with the event

permission - the permission the subject must possess

See Also:

WikiSecurityEvent