org.springframework.security.web.csrf.LazyCsrfTokenRepository Maven / Gradle / Ivy
/*
* Copyright 2012-2016 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.security.web.csrf;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.util.Assert;
/**
* A {@link CsrfTokenRepository} that delays saving new {@link CsrfToken} until the
* attributes of the {@link CsrfToken} that were generated are accessed.
*
* @author Rob Winch
* @since 4.1
*/
public final class LazyCsrfTokenRepository implements CsrfTokenRepository {
/**
* The {@link HttpServletRequest} attribute name that the {@link HttpServletResponse}
* must be on.
*/
private static final String HTTP_RESPONSE_ATTR = HttpServletResponse.class.getName();
private final CsrfTokenRepository delegate;
/**
* Creates a new instance
* @param delegate the {@link CsrfTokenRepository} to use. Cannot be null
* @throws IllegalArgumentException if delegate is null.
*/
public LazyCsrfTokenRepository(CsrfTokenRepository delegate) {
Assert.notNull(delegate, "delegate cannot be null");
this.delegate = delegate;
}
/**
* Generates a new token
* @param request the {@link HttpServletRequest} to use. The
* {@link HttpServletRequest} must have the {@link HttpServletResponse} as an
* attribute with the name of HttpServletResponse.class.getName()
*/
@Override
public CsrfToken generateToken(HttpServletRequest request) {
return wrap(request, this.delegate.generateToken(request));
}
/**
* Does nothing if the {@link CsrfToken} is not null. Saving is done only when the
* {@link CsrfToken#getToken()} is accessed from
* {@link #generateToken(HttpServletRequest)}. If it is null, then the save is
* performed immediately.
*/
@Override
public void saveToken(CsrfToken token, HttpServletRequest request, HttpServletResponse response) {
if (token == null) {
this.delegate.saveToken(token, request, response);
}
}
/**
* Delegates to the injected {@link CsrfTokenRepository}
*/
@Override
public CsrfToken loadToken(HttpServletRequest request) {
return this.delegate.loadToken(request);
}
private CsrfToken wrap(HttpServletRequest request, CsrfToken token) {
HttpServletResponse response = getResponse(request);
return new SaveOnAccessCsrfToken(this.delegate, request, response, token);
}
private HttpServletResponse getResponse(HttpServletRequest request) {
HttpServletResponse response = (HttpServletResponse) request.getAttribute(HTTP_RESPONSE_ATTR);
Assert.notNull(response, () -> "The HttpServletRequest attribute must contain an HttpServletResponse "
+ "for the attribute " + HTTP_RESPONSE_ATTR);
return response;
}
private static final class SaveOnAccessCsrfToken implements CsrfToken {
private transient CsrfTokenRepository tokenRepository;
private transient HttpServletRequest request;
private transient HttpServletResponse response;
private final CsrfToken delegate;
SaveOnAccessCsrfToken(CsrfTokenRepository tokenRepository, HttpServletRequest request,
HttpServletResponse response, CsrfToken delegate) {
this.tokenRepository = tokenRepository;
this.request = request;
this.response = response;
this.delegate = delegate;
}
@Override
public String getHeaderName() {
return this.delegate.getHeaderName();
}
@Override
public String getParameterName() {
return this.delegate.getParameterName();
}
@Override
public String getToken() {
saveTokenIfNecessary();
return this.delegate.getToken();
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
SaveOnAccessCsrfToken other = (SaveOnAccessCsrfToken) obj;
if (this.delegate == null) {
if (other.delegate != null) {
return false;
}
}
else if (!this.delegate.equals(other.delegate)) {
return false;
}
return true;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((this.delegate == null) ? 0 : this.delegate.hashCode());
return result;
}
@Override
public String toString() {
return "SaveOnAccessCsrfToken [delegate=" + this.delegate + "]";
}
private void saveTokenIfNecessary() {
if (this.tokenRepository == null) {
return;
}
synchronized (this) {
if (this.tokenRepository != null) {
this.tokenRepository.saveToken(this.delegate, this.request, this.response);
this.tokenRepository = null;
this.request = null;
this.response = null;
}
}
}
}
}