Magnolia 5.3 reached end of life on June 30, 2017. This branch is no longer supported, see End-of-life policy.
Java filters were introduced in the Java Servlet specification version 2.3. A filter intercepts requests and responses to transform or use the information. Filters typically do not themselves create responses, but instead provide universal functions that can be "attached" to any type of servlet or JSP page.
Since the filter chain is responsible for request handling in Magnolia, the default chain illustrates how filters are used to process requests. This document provides minimal information on filters. For more, see Request processing and filters and the filters
package.
Don't change the filter order
Magnolia handles incoming requests to display a page through its own filter chain. Filters in the chain are executed in the order in which they are declared until a filter decides that it can fulfil the request.
Be careful
When editing properties in the filter chain be careful. Always test the changes on test environment before applying it to a productive system.
For instance - when adding a Voter entry to a filter with an erroneous regular expression - you won't access admin central anymore. (In such case you have to use Groovy Rescue App).
The first filter in the filter chain is
ContextFilter
. This filter initializes MgnlContext
and configures MDC logging. MgnlContext
is local to the request and available on every further filter. The context provides a lot of useful functions, see
MgnlContext
for details. Additionally the
AggregationState
is initialized and populated with:
The AggregationState
is accessible using MgnlContext.getAggregationState()
.
ContentTypeFilter is no more responsible for setting content type of the response. The filter sets some values onto the AggregationState and can be used to restrict responses to configured mime types.
Magnolia 5.3.11+
By default, Magnolia tries to respond to every request - even if the MIME type is not configured. To restrict responses to configured MIME types only, add a registeredExtensionsOnly
property to the contentType
filter configuration:
Node name | value |
---|---|
server | |
filters | |
contentType | |
class | info.magnolia.cms.filters.ContentTypeFilter |
enabled | true |
registeredExtensionsOnly | true |
When registeredExtensionsOnly
is true
Magnolia will respond with response code 400 to requests with extensions that are not registered in MIMEMapping.
If the request has no extension, Magnolia assumes it is html
.
Magnolia 5.3.12+
You can restrict responses to match content types with the validateContentType
property.
Example: If you request https://demopublic.magnolia-cms.com/travel.c, the HTML source is returned because of the text/plain
MIME mapping in /server/MIMEMapping/c
To force content type matching, add the validateContentType
property in server/filters/contentType
and set the value to true
.
Node name | value |
---|---|
server | |
filters | |
contentType | |
class | info.magnolia.cms.filters.ContentTypeFilter |
enabled | true |
registeredExtensionsOnly | true |
validateContentType | true |
When the validateContentType
property is set to true
, Magnolia will respond with response code 400 if the requested extension does not match the content type. This property essentially disables all unknown extensions.
Magnolia EE Pro 5.3+
DateDetectorFilter
is a simple date trait filter that stores current system time in the TraitCollector
.
Magnolia EE Pro 5.3+
CountryDetectorFilter
is a GeoIP trait filter that detects the user's country using the IP address of the request. It adds the country to the aggregation state as a trait. If a GET parameter
with an IP address is supplied, this address is used to resolve the country, which is stored in the Country#REQUEST_PARAMETER
TraitCollector
.
Magnolia EE Pro 5.3+
VisitorDetectorFilter
is a visitor trait filter that detects the type of visitor based on the current user and cookies. visitorCookies
can be configured for returning and registered users.
Node name | Value |
---|---|
visitor | |
visitorCookies | |
returning | returning |
level | 5 |
name | VISITOR |
value | returning |
registered | registered |
name | VISITOR |
value | registered |
byPasses | |
class | info.magnolia.personalization.visitor.VisitorDetectorFilter |
Magnolia EE Pro 5.3+
PreviewFilter
is a preview filter that takes preview parameters and sets them in the TraitCollector
.
DeviceDetectionFilter detects the type of device requesting content. Device detection is done using the Mobile Detect API.
CosMultipartRequestFilter checks to see if there are any binary uploads such as form attachments in the request, extracts the binaries and persists them in the JCR.
UnicodeNormalizationFilter normalizes the current URI to the NFC form that is used internally.
RegistrationFilter
checks the validity of the registration of an enterprise installation and delegates to the registration form so that the user can enter the license key. The license is also checked in other parts of the code such as in the STK.
Handles incoming login requests and delegates to login handlers. The handlers are configured under this filter. LoginFilter checks to verify that user credentials have been authenticated so that only authenticated users can be made active users. Magnolia uses JAAS for authentication. For more information see Security.
The activation filter handles incoming activation requests. This filter is the receiving part of the activation process.
The activation filter is implemented using
ReceiveFilter
from the Activation module. In the Enterprise Edition, XAReceiveFilter
(included in the Transactional Activation module) extends ReceiveFilter
to provide transaction related communications with syndicators.
Here's an example of how to use the bypass feature to avoid specific filters. This configuration will only handle requests where the URI starts with /.magnolia/activation
.
Node name | Value |
---|---|
activation | |
bypasses | |
allButActivationHandler | |
class | info.magnolia.voting.voters.URIStartsWithVoter |
not | true |
pattern | /.magnolia/activation |
class | info.magnolia.module.exchangetransactional.XAReceiveFilter |
To increase the performance of the site
GZipFilter
replaces text type responses with the gzipped response. The trick in this filter is that it passes a ResponseWrapper instead of the response object it got in the doFilter(..)
call to the filter chain. After all the following filters have been executed, content is extracted from the ResponseWrapper, gzipped and written to the original response.
MultiChannelFilter resolves the channel to use by considering variations of the set channel. Resulting site gets set in ExtendedAggregationState .
MultiSiteFilter
is an Enterprise Edition filter. It detects which site definition should be used. The filter makes site related properties available in the
AggregationState
.
The SiteMergeFilter merges channel variations with the site definition. The configuration under this filter overrides configuration done in the site definition. The filter sets the site definition in the aggregation state. In the Community Edition, this filter sets the site in the aggregation state. In the Enterprise Edition, the multisite filter can also set the site.
LogoutFilter
checks to see if the logout attribute mgnlLogout
is set as a request parameter. If this flag is found, the user will be logged out and the filter chain will restart with the first filter.
SecurityCallbackFilter
handles 401 and 403 HTTP response codes and AccessDeniedExceptions
. The filter renders an appropriate "login form" that can consist of a redirect or anything else.
Multiple HttpClientCallbacks
with different configuration and behavior can be configured for this filter.
Here are the client callback configurations for the demo-project members area redirect and login form.
Node name | Value |
---|---|
securityCallback | |
clientCallbacks | |
public | |
originalUrlPattern | |
class | info.magnolia.cms.security.auth.callback.RedirectClientCallback |
location | /demo-project/members-area/login.html |
form | |
class | info.magnolia.cms.security.auth.callback.FormClientCallback |
loginForm | /mgnl-resources/defaultLoginForm/login.html |
class | info.magnolia.cms.security.SecurityCallbackFilter |
Both callback classes implement the
HttpClientCallback
interface and support their own configuration properties. A custom callback should implement this interface.
Classes:
loginForm
.The AbstractHttpClientCallback class provides a number of filtering capabilities:
url
. Current request URL decoded and without the context path.urlPattern
originalUrl
. Original request URL decoded and without the context path, but not modified by any filter.originalUrlPattern
hostPattern
voters
For example, in a multisite installation for the request
http://demoauthor.magnolia-cms.com/demo-project/about.html:
url
is /about.html
originalUrl
is /demo-project/about.html
.The Multisite filter removes the first-level node name from the URL.
The methods provided by the AbstractHttpClientCallback
class are also provided by the utility class
UrlPatternDelegate
.
Magnolia 5.2.8+ / 5.3.2+
CsrfSecurityFilter checks the HTTP referer header to ensure that the request is not a cross-site request forgery attack. When a possible CSRF attack is detected the system serves a 400 Bad Request status to the browser. Magnolia also logs a security warning to the audit log.
If you access Magnolia with a script, set the referer header in your script to ensure the script can access Magnolia. Similarly, if you embed Magnolia content into a different website, disable the CSRF filter or add a voter (see below) that bypasses the CSRF filter for any requests coming from the trusted URL.
The CSRF security filter causes a request to fail if:
The referer header is empty
Host: mysite.com/.magnolia/pages/adminCentral.html Referer:
The host part of the referer header does not match the requested host.
Host: mysite.com/.magnolia/pages/adminCentral.html Referer: hackersite.io
You can bypass the CSRF security filter with a voter.
By default, the filter is bypassed if:
/.magnolia
. Only AdminCentral URLs are vulnerable to CSRF attacks. Other URLs are not checked. You can create your own whitelist of referrer domains or URIs using a voter. The filter is bypassed for the whitelisted referrers. In this example we bypass the filter for any requests referred by
http://www.trustedsite.com/
.
Node name | Value |
---|---|
csrfSecurity |
|
bypasses |
|
BypassWhenNotInAdminCentral |
|
BypassWhenNotAuthenticated |
|
BypassWhenNoQueryParameters |
|
BypassWhenVaadinRequest |
|
whitelist |
|
class | info.magnolia.voting.voters.RequestHeaderPatternSimpleVoter |
headerName | referer |
pattern | http://www.trustedsite.com |
class | info.magnolia.cms.security.CsrfSecurityFilter |
Voter properties:
<voter node>
: Voter parent node. You can name the node for example as whitelist
.class
: Fully-qualified voter class name. See examples below.headerName
: Header you are checking such as referer
. pattern
: Domain or URI pattern compliant to
SimpleUrlPattern
. The pattern must be present in the header for the filter to be bypassed. Use these voter classes:
info.magnolia.voting.voters.RequestHeaderPatternSimpleVoter
: Checks for a URL pattern compliant to
SimpleUrlPattern
such as http://www.trustedsite.*
. info.magnolia.voting.voters.RequestHeaderPatternRegexVoter
: Checks for a regular expression pattern.Some builds of Internet explorer don't send the HTTP request header referrer when submitting a form or when opening a pop up. If the referrer is not in the HTTP request header, CsrfSecurityFilter#handlePossibleCsrf
interprets the request as potential CSRF attack which forces the user to login on the pop up. (See
-
MAGNOLIA-6211Getting issue details...
STATUS
). To overcome this "issue", add voter class
UserAgentVoter
to bypass CsrfSecurityFilter for Internet Explorer.
Node name | Value |
---|---|
csrfSecurity |
|
bypasses |
|
userAgent |
|
allowed | |
IE6 | .*MSIE 6\.0.* |
IE11 | .*Trident/7.0; rv:11.0.* |
class | info.magnolia.voting.voters.UserAgentVoter |
Below the node allowed
you can add a list of regular expressions to match the HTTP header userAgent. In the example above we have bypassed Internet Explorer 6 and 11.
To ensure the filter is bypassed, make sure to have at least one property on the node allowed
with a value which will match the userAgent of the browser for which you want to bypass the filter. (For Internet Explorer 11, the userAgent is Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko.)
Always test changes on test environment before applying it to a productive system. When adding an erroneous regular expression - you won't access admin central anymore. (In such case you have to use Groovy Rescue App).
CrossSiteSecurityFilter
grants or denies permission to a site when the site is requested through a particular domain name. For example, if you only grant access to the demo-project site through www.demo-project.com
, no other URL can be used to access the content. When a user tries to access one site's content through another site's domain name, the system displays a HTTP 404 error (page not found). See Cross-site security
URISecurityFilter
checks to see if the active user has permission to access the requested URI. In the Enterprise Edition,
SiteUriSecurityFilter
(included in the Multisite module ) extends UriSecurityFilter
to provide site aware functionality.
The following constraints are considered in finding the permissions of the user:
If the user does not have the permission to access the URI then JAAS will provide a login form. This default behavior of the URI security filter can be changed in JAAS configuration.
You can configure your own login form in the URI security filter to replace the default Magnolia login form. The form is configured in /server/filters/securityCallback/clientCallbacks
. Here is an example of a custom form used to grant public users access to a restricted members area. Authentication is delegated to the custom form when a particular URI is accessed.
If you don't grant permission to the custom login form path then a standard Magnolia login form will be displayed, usually on author instance.
RangeSupportFilter adds support for ranged requests. Ranged requests is used by iPhone and some other clients to stream videos. In contrast to Android phones, iPhone does not support any other method of streaming videos.
I18nContentSupportFilter detects the requested locale and sets the locale in the aggregation state. The filter rewrites the internal current URI, whether virtual or not. It does not rewrite the URI displayed to the user, however. See Language.
CacheFilter manages the Magnolia cache.
The cache filter checks if a requested resource is already stored in the cache to avoid recreation of the resource. If the resource is in the cache, then it will be written to the response and the filter chain stops. If the resource is not found in the cache, then a ResponseWrapper
which not only writes to the "standard" response, but also saves the response, is passed to the chain. After the filters that follow have been executed (and the requested resource created), the content is extracted from the response wrapper and stored in the cache.
The cache filter is part of the Cache module and the respective configuration can be found in the cache module configuration.
VirtualUriFilter checks if the requested URI matches a configured URI pattern and executes the URI mapping.
The servlets configured in modules are installed in Magnolia's servlets filter chain using the
ServletDispatchingFilter
as the implementing filter class. If the servlet mapping matches the URI, then the service(..
) method of the servlet is called. See Registering a servlet for more.
Finally we arrive at the filter chain which does the page rendering and delivery. The filters are grouped in this filter chain so they share a co-bypass definition.
RepositoryMappingFilter
handles access to different workspaces. By default Magnolia is connected with the website
workspace. Therefore a request URI is interpreted as the path to a node in the website
workspace. If you want to address nodes in other workspaces you need to specify a repository mapping in /server/URI2RepositoryMapping
.
Whereas the URI security filter checks permissions on the URI, ContentSecurityFilter checks if the current user has permission to access the requested content resource. The following constraints are considered in finding the permissions of the user:
If the user does not have permission to the resource, then JAAS will provide a login form. This default behavior of the content security filter can be changed in JAAS configuration.
AggregatorFilter analyses the request and stores the results in the AggregationState . After this filter, every value the aggregation state can have is known.
Target | Collected information |
---|---|
Page |
|
NodeData |
|
Magnolia EE Pro 5.3+
VariantResolverFilter
is a personalization filter that wraps variant nodes. The filter tries to resolve a variant from the current node (from AggregationState
) using all available traits stored in the TraitCollector
and wraps it accordingly, if required. It only uses PersonalizationNodeWrapper
if a variant was resolved. Non-variants are not wrapped.
Magnolia 5.1+ deprecated. This filter is no longer used. It's function is now handled in part by the page editor and in part by the
MultiChannelFilter
.
InterceptFilter handles administrative requests from AdminCentral like
ModelExecutionFilter
executes the component model before template rendering. The filter looks for a request parameter containing the UUID of the component to execute. The model can send output in which case page rendering is skipped, or return a URI prefixed by redirect
, permanent
or forward
.
Finally, RenderingFilter is responsible for delivering the requested resource. If the requested resource is data, such as a file, then the data is just copied to the response.
The rendering filter is terminal, meaning it ends the filter chain and filtering process. If no filter before it has been able to fulfill the request and the rendering filter cannot find the page either, then a 404 "Page not found" error is returned. This is default behavior.
5.2.1+ You can change the behavior by adding a
terminateChain
property under the rendering filter and setting it to false
. When a request for a page such as /home/some/page
is received and no such page exists in the JCR, your own servlets can have a go at fulfilling the request. The default value for the terminateChain
property is true.