org.apache.catalina.filters

Class CsrfPreventionFilter

java.lang.Object

org.apache.catalina.filters.FilterBase

org.apache.catalina.filters.CsrfPreventionFilter

public class CsrfPreventionFilter
extends FilterBase

Provides basic CSRF protection for a web application. The filter assumes that:

• The filter is mapped to /*
• HttpServletResponse#encodeRedirectURL(String) and HttpServletResponse#encodeURL(String) are used to encode all URLs returned to the client

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	CsrfPreventionFilter.CsrfResponseWrapper

Field Summary

Fields inherited from class org.apache.catalina.filters.FilterBase

sm

Constructor Summary

Constructors

Constructor and Description
CsrfPreventionFilter()

Method Summary

Methods

Modifier and Type	Method and Description
void	doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
protected java.lang.String	generateNonce() Generate a once time token (nonce) for authenticating subsequent requests.
void	init(FilterConfig filterConfig)
void	setEntryPoints(java.lang.String entryPoints) Entry points are URLs that will not be tested for the presence of a valid nonce.
void	setNonceCacheSize(int nonceCacheSize) Sets the number of previously issued nonces that will be cached on a LRU basis to support parallel requests, limited use of the refresh and back in the browser and similar behaviors that may result in the submission of a previous nonce rather than the current one.
void	setRandomClass(java.lang.String randomClass) Specify the class to use to generate the nonces.

Methods inherited from class org.apache.catalina.filters.FilterBase

destroy

Methods inherited from class java.lang.Object

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

Constructor Detail

CsrfPreventionFilter

public CsrfPreventionFilter()

Method Detail

setEntryPoints

public void setEntryPoints(java.lang.String entryPoints)

Entry points are URLs that will not be tested for the presence of a valid nonce. They are used to provide a way to navigate back to a protected application after navigating away from it. Entry points will be limited to HTTP GET requests and should not trigger any security sensitive actions.

Parameters:

entryPoints - Comma separated list of URLs to be configured as entry points.

setNonceCacheSize

public void setNonceCacheSize(int nonceCacheSize)

Sets the number of previously issued nonces that will be cached on a LRU basis to support parallel requests, limited use of the refresh and back in the browser and similar behaviors that may result in the submission of a previous nonce rather than the current one. If not set, the default value of 5 will be used.

Parameters:

nonceCacheSize - The number of nonces to cache

setRandomClass

public void setRandomClass(java.lang.String randomClass)

Specify the class to use to generate the nonces. Must be in instance of Random.

Parameters:

randomClass - The name of the class to use

init

public void init(FilterConfig filterConfig)
          throws ServletException

Overrides:

init in class FilterBase

Throws:

ServletException

doFilter

public void doFilter(ServletRequest request,
            ServletResponse response,
            FilterChain chain)
              throws java.io.IOException,
                     ServletException

Throws:

java.io.IOException

ServletException

generateNonce

protected java.lang.String generateNonce()

Generate a once time token (nonce) for authenticating subsequent requests. This will also add the token to the session. The nonce generation is a simplified version of ManagerBase.generateSessionId().