--- /dev/null
+/*
+ * 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.catalina.filters;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.apache.catalina.filters.Constants;
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * <p>
+ * A {@link Filter} that enable client-side cross-origin requests by
+ * implementing W3C's CORS (<b>C</b>ross-<b>O</b>rigin <b>R</b>esource
+ * <b>S</b>haring) specification for resources. Each {@link HttpServletRequest}
+ * request is inspected as per specification, and appropriate response headers
+ * are added to {@link HttpServletResponse}.
+ * </p>
+ *
+ * <p>
+ * By default, it also sets following request attributes, that help to
+ * determine the nature of the request downstream.
+ * <ul>
+ * <li><b>cors.isCorsRequest:</b> Flag to determine if the request is a CORS
+ * request. Set to <code>true</code> if a CORS request; <code>false</code>
+ * otherwise.</li>
+ * <li><b>cors.request.origin:</b> The Origin URL, i.e. the URL of the page from
+ * where the request is originated.</li>
+ * <li>
+ * <b>cors.request.type:</b> Type of request. Possible values:
+ * <ul>
+ * <li>SIMPLE: A request which is not preceded by a pre-flight request.</li>
+ * <li>ACTUAL: A request which is preceded by a pre-flight request.</li>
+ * <li>PRE_FLIGHT: A pre-flight request.</li>
+ * <li>NOT_CORS: A normal same-origin request.</li>
+ * <li>INVALID_CORS: A cross-origin request which is invalid.</li>
+ * </ul>
+ * </li>
+ * <li><b>cors.request.headers:</b> Request headers sent as
+ * 'Access-Control-Request-Headers' header, for pre-flight request.</li>
+ * </ul>
+ * </p>
+ *
+ * @see <a href="http://www.w3.org/TR/cors/">CORS specification</a>
+ *
+ */
+public final class CorsFilter implements Filter {
+
+ private static final Log log = LogFactory.getLog(CorsFilter.class);
+
+ private static final StringManager sm =
+ StringManager.getManager(Constants.Package);
+
+
+ /**
+ * A {@link Collection} of origins consisting of zero or more origins that
+ * are allowed access to the resource.
+ */
+ private final Collection<String> allowedOrigins;
+
+ /**
+ * Determines if any origin is allowed to make request.
+ */
+ private boolean anyOriginAllowed;
+
+ /**
+ * A {@link Collection} of methods consisting of zero or more methods that
+ * are supported by the resource.
+ */
+ private final Collection<String> allowedHttpMethods;
+
+ /**
+ * A {@link Collection} of headers consisting of zero or more header field
+ * names that are supported by the resource.
+ */
+ private final Collection<String> allowedHttpHeaders;
+
+ /**
+ * A {@link Collection} of exposed headers consisting of zero or more header
+ * field names of headers other than the simple response headers that the
+ * resource might use and can be exposed.
+ */
+ private final Collection<String> exposedHeaders;
+
+ /**
+ * A supports credentials flag that indicates whether the resource supports
+ * user credentials in the request. It is true when the resource does and
+ * false otherwise.
+ */
+ private boolean supportsCredentials;
+
+ /**
+ * Indicates (in seconds) how long the results of a pre-flight request can
+ * be cached in a pre-flight result cache.
+ */
+ private long preflightMaxAge;
+
+ /**
+ * Determines if the request should be decorated or not.
+ */
+ private boolean decorateRequest;
+
+
+ public CorsFilter() {
+ this.allowedOrigins = new HashSet<String>();
+ this.allowedHttpMethods = new HashSet<String>();
+ this.allowedHttpHeaders = new HashSet<String>();
+ this.exposedHeaders = new HashSet<String>();
+ }
+
+
+ @Override
+ public void doFilter(final ServletRequest servletRequest,
+ final ServletResponse servletResponse, final FilterChain filterChain)
+ throws IOException, ServletException {
+ if (!(servletRequest instanceof HttpServletRequest) ||
+ !(servletResponse instanceof HttpServletResponse)) {
+ throw new ServletException(sm.getString("corsFilter.onlyHttp"));
+ }
+
+ // Safe to downcast at this point.
+ HttpServletRequest request = (HttpServletRequest) servletRequest;
+ HttpServletResponse response = (HttpServletResponse) servletResponse;
+
+ // Determines the CORS request type.
+ CorsFilter.CORSRequestType requestType = checkRequestType(request);
+
+ // Adds CORS specific attributes to request.
+ if (decorateRequest) {
+ CorsFilter.decorateCORSProperties(request, requestType);
+ }
+ switch (requestType) {
+ case SIMPLE:
+ // Handles a Simple CORS request.
+ this.handleSimpleCORS(request, response, filterChain);
+ break;
+ case ACTUAL:
+ // Handles an Actual CORS request.
+ this.handleSimpleCORS(request, response, filterChain);
+ break;
+ case PRE_FLIGHT:
+ // Handles a Pre-flight CORS request.
+ this.handlePreflightCORS(request, response, filterChain);
+ break;
+ case NOT_CORS:
+ // Handles a Normal request that is not a cross-origin request.
+ this.handleNonCORS(request, response, filterChain);
+ break;
+ default:
+ // Handles a CORS request that violates specification.
+ this.handleInvalidCORS(request, response, filterChain);
+ break;
+ }
+ }
+
+
+ @Override
+ public void init(final FilterConfig filterConfig) throws ServletException {
+ // Initialize defaults
+ parseAndStore(DEFAULT_ALLOWED_ORIGINS, DEFAULT_ALLOWED_HTTP_METHODS,
+ DEFAULT_ALLOWED_HTTP_HEADERS, DEFAULT_EXPOSED_HEADERS,
+ DEFAULT_SUPPORTS_CREDENTIALS, DEFAULT_PREFLIGHT_MAXAGE,
+ DEFAULT_DECORATE_REQUEST);
+
+ if (filterConfig != null) {
+ String configAllowedOrigins = filterConfig
+ .getInitParameter(PARAM_CORS_ALLOWED_ORIGINS);
+ String configAllowedHttpMethods = filterConfig
+ .getInitParameter(PARAM_CORS_ALLOWED_METHODS);
+ String configAllowedHttpHeaders = filterConfig
+ .getInitParameter(PARAM_CORS_ALLOWED_HEADERS);
+ String configExposedHeaders = filterConfig
+ .getInitParameter(PARAM_CORS_EXPOSED_HEADERS);
+ String configSupportsCredentials = filterConfig
+ .getInitParameter(PARAM_CORS_SUPPORT_CREDENTIALS);
+ String configPreflightMaxAge = filterConfig
+ .getInitParameter(PARAM_CORS_PREFLIGHT_MAXAGE);
+ String configDecorateRequest = filterConfig
+ .getInitParameter(PARAM_CORS_REQUEST_DECORATE);
+
+ parseAndStore(configAllowedOrigins, configAllowedHttpMethods,
+ configAllowedHttpHeaders, configExposedHeaders,
+ configSupportsCredentials, configPreflightMaxAge,
+ configDecorateRequest);
+ }
+ }
+
+
+ /**
+ * Handles a CORS request of type {@link CORSRequestType}.SIMPLE.
+ *
+ * @param request
+ * The {@link HttpServletRequest} object.
+ * @param response
+ * The {@link HttpServletResponse} object.
+ * @param filterChain
+ * The {@link FilterChain} object.
+ * @throws IOException
+ * @throws ServletException
+ * @see <a href="http://www.w3.org/TR/cors/#resource-requests">Simple
+ * Cross-Origin Request, Actual Request, and Redirects</a>
+ */
+ protected void handleSimpleCORS(final HttpServletRequest request,
+ final HttpServletResponse response, final FilterChain filterChain)
+ throws IOException, ServletException {
+
+ CorsFilter.CORSRequestType requestType = checkRequestType(request);
+ if (!(requestType == CorsFilter.CORSRequestType.SIMPLE ||
+ requestType == CorsFilter.CORSRequestType.ACTUAL)) {
+ throw new IllegalArgumentException(
+ sm.getString("corsFilter.wrongType2",
+ CorsFilter.CORSRequestType.SIMPLE,
+ CorsFilter.CORSRequestType.ACTUAL));
+ }
+
+ final String origin = request
+ .getHeader(CorsFilter.REQUEST_HEADER_ORIGIN);
+ final String method = request.getMethod();
+
+ // Section 6.1.2
+ if (!isOriginAllowed(origin)) {
+ handleInvalidCORS(request, response, filterChain);
+ return;
+ }
+
+ if (!allowedHttpMethods.contains(method)) {
+ handleInvalidCORS(request, response, filterChain);
+ return;
+ }
+
+ // Section 6.1.3
+ // Add a single Access-Control-Allow-Origin header.
+ if (anyOriginAllowed && !supportsCredentials) {
+ // If resource doesn't support credentials and if any origin is
+ // allowed
+ // to make CORS request, return header with '*'.
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN,
+ "*");
+ } else {
+ // If the resource supports credentials add a single
+ // Access-Control-Allow-Origin header, with the value of the Origin
+ // header as value.
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN,
+ origin);
+ }
+
+ // Section 6.1.3
+ // If the resource supports credentials, add a single
+ // Access-Control-Allow-Credentials header with the case-sensitive
+ // string "true" as value.
+ if (supportsCredentials) {
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_CREDENTIALS,
+ "true");
+ }
+
+ // Section 6.1.4
+ // If the list of exposed headers is not empty add one or more
+ // Access-Control-Expose-Headers headers, with as values the header
+ // field names given in the list of exposed headers.
+ if ((exposedHeaders != null) && (exposedHeaders.size() > 0)) {
+ String exposedHeadersString = join(exposedHeaders, ",");
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_EXPOSE_HEADERS,
+ exposedHeadersString);
+ }
+
+ // Forward the request down the filter chain.
+ filterChain.doFilter(request, response);
+ }
+
+
+ /**
+ * Handles CORS pre-flight request.
+ *
+ * @param request
+ * The {@link HttpServletRequest} object.
+ * @param response
+ * The {@link HttpServletResponse} object.
+ * @param filterChain
+ * The {@link FilterChain} object.
+ * @throws IOException
+ * @throws ServletException
+ */
+ protected void handlePreflightCORS(final HttpServletRequest request,
+ final HttpServletResponse response, final FilterChain filterChain)
+ throws IOException, ServletException {
+
+ CORSRequestType requestType = checkRequestType(request);
+ if (requestType != CORSRequestType.PRE_FLIGHT) {
+ throw new IllegalArgumentException(
+ sm.getString("corsFilter.wrongType1",
+ CORSRequestType.PRE_FLIGHT.name().toLowerCase()));
+ }
+
+ final String origin = request
+ .getHeader(CorsFilter.REQUEST_HEADER_ORIGIN);
+
+ // Section 6.2.2
+ if (!isOriginAllowed(origin)) {
+ handleInvalidCORS(request, response, filterChain);
+ return;
+ }
+
+ // Section 6.2.3
+ String accessControlRequestMethod = request.getHeader(
+ CorsFilter.REQUEST_HEADER_ACCESS_CONTROL_REQUEST_METHOD);
+ if (accessControlRequestMethod == null ||
+ !HTTP_METHODS.contains(accessControlRequestMethod.trim())) {
+ handleInvalidCORS(request, response, filterChain);
+ return;
+ } else {
+ accessControlRequestMethod = accessControlRequestMethod.trim();
+ }
+
+ // Section 6.2.4
+ String accessControlRequestHeadersHeader = request.getHeader(
+ CorsFilter.REQUEST_HEADER_ACCESS_CONTROL_REQUEST_HEADERS);
+ List<String> accessControlRequestHeaders = new LinkedList<String>();
+ if (accessControlRequestHeadersHeader != null &&
+ !accessControlRequestHeadersHeader.trim().isEmpty()) {
+ String[] headers = accessControlRequestHeadersHeader.trim().split(
+ ",");
+ for (String header : headers) {
+ accessControlRequestHeaders.add(header.trim().toLowerCase());
+ }
+ }
+
+ // Section 6.2.5
+ if (!allowedHttpMethods.contains(accessControlRequestMethod)) {
+ handleInvalidCORS(request, response, filterChain);
+ return;
+ }
+
+ // Section 6.2.6
+ if (!accessControlRequestHeaders.isEmpty()) {
+ for (String header : accessControlRequestHeaders) {
+ if (!allowedHttpHeaders.contains(header)) {
+ handleInvalidCORS(request, response, filterChain);
+ return;
+ }
+ }
+ }
+
+ // Section 6.2.7
+ if (supportsCredentials) {
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN,
+ origin);
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_CREDENTIALS,
+ "true");
+ } else {
+ if (anyOriginAllowed) {
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN,
+ "*");
+ } else {
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN,
+ origin);
+ }
+ }
+
+ // Section 6.2.8
+ if (preflightMaxAge > 0) {
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_MAX_AGE,
+ String.valueOf(preflightMaxAge));
+ }
+
+ // Section 6.2.9
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_METHODS,
+ accessControlRequestMethod);
+
+ // Section 6.2.10
+ if ((allowedHttpHeaders != null) && (!allowedHttpHeaders.isEmpty())) {
+ response.addHeader(
+ CorsFilter.RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_HEADERS,
+ join(allowedHttpHeaders, ","));
+ }
+
+ // Do not forward the request down the filter chain.
+ }
+
+
+ /**
+ * Handles a request, that's not a CORS request, but is a valid request i.e.
+ * it is not a cross-origin request. This implementation, just forwards the
+ * request down the filter chain.
+ *
+ * @param request
+ * The {@link HttpServletRequest} object.
+ * @param response
+ * The {@link HttpServletResponse} object.
+ * @param filterChain
+ * The {@link FilterChain} object.
+ * @throws IOException
+ * @throws ServletException
+ */
+ private void handleNonCORS(final HttpServletRequest request,
+ final HttpServletResponse response, final FilterChain filterChain)
+ throws IOException, ServletException {
+ // Let request pass.
+ filterChain.doFilter(request, response);
+ }
+
+
+ /**
+ * Handles a CORS request that violates specification.
+ *
+ * @param request
+ * The {@link HttpServletRequest} object.
+ * @param response
+ * The {@link HttpServletResponse} object.
+ * @param filterChain
+ * The {@link FilterChain} object.
+ */
+ private void handleInvalidCORS(final HttpServletRequest request,
+ final HttpServletResponse response, final FilterChain filterChain) {
+ String origin = request.getHeader(CorsFilter.REQUEST_HEADER_ORIGIN);
+ String method = request.getMethod();
+ String accessControlRequestHeaders = request.getHeader(
+ REQUEST_HEADER_ACCESS_CONTROL_REQUEST_HEADERS);
+
+ response.setContentType("text/plain");
+ response.setStatus(HttpServletResponse.SC_FORBIDDEN);
+ response.resetBuffer();
+
+ if (log.isDebugEnabled()) {
+ // Debug so no need for i18n
+ StringBuilder message =
+ new StringBuilder("Invalid CORS request; Origin=");
+ message.append(origin);
+ message.append(";Method=");
+ message.append(method);
+ if (accessControlRequestHeaders != null) {
+ message.append(";Access-Control-Request-Headers=");
+ message.append(accessControlRequestHeaders);
+ }
+ log.debug(message.toString());
+ }
+ }
+
+
+ @Override
+ public void destroy() {
+ // NOOP
+ }
+
+
+ /**
+ * Decorates the {@link HttpServletRequest}, with CORS attributes.
+ * <ul>
+ * <li><b>cors.isCorsRequest:</b> Flag to determine if request is a CORS
+ * request. Set to <code>true</code> if CORS request; <code>false</code>
+ * otherwise.</li>
+ * <li><b>cors.request.origin:</b> The Origin URL.</li>
+ * <li><b>cors.request.type:</b> Type of request. Values:
+ * <code>simple</code> or <code>preflight</code> or <code>not_cors</code> or
+ * <code>invalid_cors</code></li>
+ * <li><b>cors.request.headers:</b> Request headers sent as
+ * 'Access-Control-Request-Headers' header, for pre-flight request.</li>
+ * </ul>
+ *
+ * @param request
+ * The {@link HttpServletRequest} object.
+ * @param corsRequestType
+ * The {@link CORSRequestType} object.
+ */
+ protected static void decorateCORSProperties(
+ final HttpServletRequest request,
+ final CORSRequestType corsRequestType) {
+ if (request == null) {
+ throw new IllegalArgumentException(
+ sm.getString("corsFilter.nullRequest"));
+ }
+
+ if (corsRequestType == null) {
+ throw new IllegalArgumentException(
+ sm.getString("corsFilter.nullRequestType"));
+ }
+
+ switch (corsRequestType) {
+ case SIMPLE:
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST,
+ Boolean.TRUE);
+ request.setAttribute(CorsFilter.HTTP_REQUEST_ATTRIBUTE_ORIGIN,
+ request.getHeader(CorsFilter.REQUEST_HEADER_ORIGIN));
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE,
+ corsRequestType.name().toLowerCase());
+ break;
+ case ACTUAL:
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST,
+ Boolean.TRUE);
+ request.setAttribute(CorsFilter.HTTP_REQUEST_ATTRIBUTE_ORIGIN,
+ request.getHeader(CorsFilter.REQUEST_HEADER_ORIGIN));
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE,
+ corsRequestType.name().toLowerCase());
+ break;
+ case PRE_FLIGHT:
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST,
+ Boolean.TRUE);
+ request.setAttribute(CorsFilter.HTTP_REQUEST_ATTRIBUTE_ORIGIN,
+ request.getHeader(CorsFilter.REQUEST_HEADER_ORIGIN));
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE,
+ corsRequestType.name().toLowerCase());
+ String headers = request.getHeader(
+ REQUEST_HEADER_ACCESS_CONTROL_REQUEST_HEADERS);
+ if (headers == null) {
+ headers = "";
+ }
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_REQUEST_HEADERS, headers);
+ break;
+ case NOT_CORS:
+ request.setAttribute(
+ CorsFilter.HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST,
+ Boolean.FALSE);
+ break;
+ default:
+ // Don't set any attributes
+ break;
+ }
+ }
+
+
+ /**
+ * Joins elements of {@link Set} into a string, where each element is
+ * separated by the provided separator.
+ *
+ * @param elements
+ * The {@link Set} containing elements to join together.
+ * @param joinSeparator
+ * The character to be used for separating elements.
+ * @return The joined {@link String}; <code>null</code> if elements
+ * {@link Set} is null.
+ */
+ protected static String join(final Collection<String> elements,
+ final String joinSeparator) {
+ String separator = ",";
+ if (elements == null) {
+ return null;
+ }
+ if (joinSeparator != null) {
+ separator = joinSeparator;
+ }
+ StringBuilder buffer = new StringBuilder();
+ boolean isFirst = true;
+ for (String element : elements) {
+ if (!isFirst) {
+ buffer.append(separator);
+ } else {
+ isFirst = false;
+ }
+
+ if (element != null) {
+ buffer.append(element);
+ }
+ }
+
+ return buffer.toString();
+ }
+
+
+ /**
+ * Determines the request type.
+ *
+ * @param request
+ */
+ protected CORSRequestType checkRequestType(final HttpServletRequest request) {
+ CORSRequestType requestType = CORSRequestType.INVALID_CORS;
+ if (request == null) {
+ throw new IllegalArgumentException(
+ sm.getString("corsFilter.nullRequest"));
+ }
+ String originHeader = request.getHeader(REQUEST_HEADER_ORIGIN);
+ // Section 6.1.1 and Section 6.2.1
+ if (originHeader != null) {
+ if (originHeader.isEmpty()) {
+ requestType = CORSRequestType.INVALID_CORS;
+ } else if (!isValidOrigin(originHeader)) {
+ requestType = CORSRequestType.INVALID_CORS;
+ } else {
+ String method = request.getMethod();
+ if (method != null && HTTP_METHODS.contains(method)) {
+ if ("OPTIONS".equals(method)) {
+ String accessControlRequestMethodHeader =
+ request.getHeader(
+ REQUEST_HEADER_ACCESS_CONTROL_REQUEST_METHOD);
+ if (accessControlRequestMethodHeader != null &&
+ !accessControlRequestMethodHeader.isEmpty()) {
+ requestType = CORSRequestType.PRE_FLIGHT;
+ } else if (accessControlRequestMethodHeader != null &&
+ accessControlRequestMethodHeader.isEmpty()) {
+ requestType = CORSRequestType.INVALID_CORS;
+ } else {
+ requestType = CORSRequestType.ACTUAL;
+ }
+ } else if ("GET".equals(method) || "HEAD".equals(method)) {
+ requestType = CORSRequestType.SIMPLE;
+ } else if ("POST".equals(method)) {
+ String contentType = request.getContentType();
+ if (contentType != null) {
+ contentType = contentType.toLowerCase().trim();
+ if (SIMPLE_HTTP_REQUEST_CONTENT_TYPE_VALUES
+ .contains(contentType)) {
+ requestType = CORSRequestType.SIMPLE;
+ } else {
+ requestType = CORSRequestType.ACTUAL;
+ }
+ }
+ } else if (COMPLEX_HTTP_METHODS.contains(method)) {
+ requestType = CORSRequestType.ACTUAL;
+ }
+ }
+ }
+ } else {
+ requestType = CORSRequestType.NOT_CORS;
+ }
+
+ return requestType;
+ }
+
+
+ /**
+ * Checks if the Origin is allowed to make a CORS request.
+ *
+ * @param origin
+ * The Origin.
+ * @return <code>true</code> if origin is allowed; <code>false</code>
+ * otherwise.
+ */
+ private boolean isOriginAllowed(final String origin) {
+ if (anyOriginAllowed) {
+ return true;
+ }
+
+ // If 'Origin' header is a case-sensitive match of any of allowed
+ // origins, then return true, else return false.
+ return allowedOrigins.contains(origin);
+ }
+
+
+ /**
+ * Parses each param-value and populates configuration variables. If a param
+ * is provided, it overrides the default.
+ *
+ * @param allowedOrigins
+ * A {@link String} of comma separated origins.
+ * @param allowedHttpMethods
+ * A {@link String} of comma separated HTTP methods.
+ * @param allowedHttpHeaders
+ * A {@link String} of comma separated HTTP headers.
+ * @param exposedHeaders
+ * A {@link String} of comma separated headers that needs to be
+ * exposed.
+ * @param supportsCredentials
+ * "true" if support credentials needs to be enabled.
+ * @param preflightMaxAge
+ * The amount of seconds the user agent is allowed to cache the
+ * result of the pre-flight request.
+ * @throws ServletException
+ */
+ private void parseAndStore(final String allowedOrigins,
+ final String allowedHttpMethods, final String allowedHttpHeaders,
+ final String exposedHeaders, final String supportsCredentials,
+ final String preflightMaxAge, final String decorateRequest)
+ throws ServletException {
+ if (allowedOrigins != null) {
+ if (allowedOrigins.trim().equals("*")) {
+ this.anyOriginAllowed = true;
+ } else {
+ this.anyOriginAllowed = false;
+ Set<String> setAllowedOrigins =
+ parseStringToSet(allowedOrigins);
+ this.allowedOrigins.clear();
+ this.allowedOrigins.addAll(setAllowedOrigins);
+ }
+ }
+
+ if (allowedHttpMethods != null) {
+ Set<String> setAllowedHttpMethods =
+ parseStringToSet(allowedHttpMethods);
+ this.allowedHttpMethods.clear();
+ this.allowedHttpMethods.addAll(setAllowedHttpMethods);
+ }
+
+ if (allowedHttpHeaders != null) {
+ Set<String> setAllowedHttpHeaders =
+ parseStringToSet(allowedHttpHeaders);
+ Set<String> lowerCaseHeaders = new HashSet<String>();
+ for (String header : setAllowedHttpHeaders) {
+ String lowerCase = header.toLowerCase();
+ lowerCaseHeaders.add(lowerCase);
+ }
+ this.allowedHttpHeaders.clear();
+ this.allowedHttpHeaders.addAll(lowerCaseHeaders);
+ }
+
+ if (exposedHeaders != null) {
+ Set<String> setExposedHeaders = parseStringToSet(exposedHeaders);
+ this.exposedHeaders.clear();
+ this.exposedHeaders.addAll(setExposedHeaders);
+ }
+
+ if (supportsCredentials != null) {
+ // For any value other then 'true' this will be false.
+ this.supportsCredentials = Boolean
+ .parseBoolean(supportsCredentials);
+ }
+
+ if (preflightMaxAge != null) {
+ try {
+ if (!preflightMaxAge.isEmpty()) {
+ this.preflightMaxAge = Long.parseLong(preflightMaxAge);
+ } else {
+ this.preflightMaxAge = 0L;
+ }
+ } catch (NumberFormatException e) {
+ throw new ServletException(
+ sm.getString("corsFilter.invalidPreflightMaxAge"), e);
+ }
+ }
+
+ if (decorateRequest != null) {
+ // For any value other then 'true' this will be false.
+ this.decorateRequest = Boolean.parseBoolean(decorateRequest);
+ }
+ }
+
+ /**
+ * Takes a comma separated list and returns a Set<String>.
+ *
+ * @param data
+ * A comma separated list of strings.
+ * @return Set<String>
+ */
+ private Set<String> parseStringToSet(final String data) {
+ String[] splits;
+
+ if (data != null && data.length() > 0) {
+ splits = data.split(",");
+ } else {
+ splits = new String[] {};
+ }
+
+ Set<String> set = new HashSet<String>();
+ if (splits.length > 0) {
+ for (String split : splits) {
+ set.add(split.trim());
+ }
+ }
+
+ return set;
+ }
+
+
+ /**
+ * Checks if a given origin is valid or not. Criteria:
+ * <ul>
+ * <li>If an encoded character is present in origin, it's not valid.</li>
+ * <li>Origin should be a valid {@link URI}</li>
+ * </ul>
+ *
+ * @param origin
+ * @see <a href="http://tools.ietf.org/html/rfc952">RFC952</a>
+ */
+ protected static boolean isValidOrigin(String origin) {
+ // Checks for encoded characters. Helps prevent CRLF injection.
+ if (origin.contains("%")) {
+ return false;
+ }
+
+ URI originURI;
+
+ try {
+ originURI = new URI(origin);
+ } catch (URISyntaxException e) {
+ return false;
+ }
+ // If scheme for URI is null, return false. Return true otherwise.
+ return originURI.getScheme() != null;
+
+ }
+
+
+ /**
+ * Determines if any origin is allowed to make CORS request.
+ *
+ * @return <code>true</code> if it's enabled; false otherwise.
+ */
+ public boolean isAnyOriginAllowed() {
+ return anyOriginAllowed;
+ }
+
+
+ /**
+ * Returns a {@link Set} of headers that should be exposed by browser.
+ */
+ public Collection<String> getExposedHeaders() {
+ return exposedHeaders;
+ }
+
+
+ /**
+ * Determines is supports credentials is enabled.
+ */
+ public boolean isSupportsCredentials() {
+ return supportsCredentials;
+ }
+
+
+ /**
+ * Returns the preflight response cache time in seconds.
+ *
+ * @return Time to cache in seconds.
+ */
+ public long getPreflightMaxAge() {
+ return preflightMaxAge;
+ }
+
+
+ /**
+ * Returns the {@link Set} of allowed origins that are allowed to make
+ * requests.
+ *
+ * @return {@link Set}
+ */
+ public Collection<String> getAllowedOrigins() {
+ return allowedOrigins;
+ }
+
+
+ /**
+ * Returns a {@link Set} of HTTP methods that are allowed to make requests.
+ *
+ * @return {@link Set}
+ */
+ public Collection<String> getAllowedHttpMethods() {
+ return allowedHttpMethods;
+ }
+
+
+ /**
+ * Returns a {@link Set} of headers support by resource.
+ *
+ * @return {@link Set}
+ */
+ public Collection<String> getAllowedHttpHeaders() {
+ return allowedHttpHeaders;
+ }
+
+
+ // -------------------------------------------------- CORS Response Headers
+ /**
+ * The Access-Control-Allow-Origin header indicates whether a resource can
+ * be shared based by returning the value of the Origin request header in
+ * the response.
+ */
+ public static final String RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN =
+ "Access-Control-Allow-Origin";
+
+ /**
+ * The Access-Control-Allow-Credentials header indicates whether the
+ * response to request can be exposed when the omit credentials flag is
+ * unset. When part of the response to a preflight request it indicates that
+ * the actual request can include user credentials.
+ */
+ public static final String RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_CREDENTIALS =
+ "Access-Control-Allow-Credentials";
+
+ /**
+ * The Access-Control-Expose-Headers header indicates which headers are safe
+ * to expose to the API of a CORS API specification
+ */
+ public static final String RESPONSE_HEADER_ACCESS_CONTROL_EXPOSE_HEADERS =
+ "Access-Control-Expose-Headers";
+
+ /**
+ * The Access-Control-Max-Age header indicates how long the results of a
+ * preflight request can be cached in a preflight result cache.
+ */
+ public static final String RESPONSE_HEADER_ACCESS_CONTROL_MAX_AGE =
+ "Access-Control-Max-Age";
+
+ /**
+ * The Access-Control-Allow-Methods header indicates, as part of the
+ * response to a preflight request, which methods can be used during the
+ * actual request.
+ */
+ public static final String RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_METHODS =
+ "Access-Control-Allow-Methods";
+
+ /**
+ * The Access-Control-Allow-Headers header indicates, as part of the
+ * response to a preflight request, which header field names can be used
+ * during the actual request.
+ */
+ public static final String RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_HEADERS =
+ "Access-Control-Allow-Headers";
+
+ // -------------------------------------------------- CORS Request Headers
+ /**
+ * The Origin header indicates where the cross-origin request or preflight
+ * request originates from.
+ */
+ public static final String REQUEST_HEADER_ORIGIN = "Origin";
+
+ /**
+ * The Access-Control-Request-Method header indicates which method will be
+ * used in the actual request as part of the preflight request.
+ */
+ public static final String REQUEST_HEADER_ACCESS_CONTROL_REQUEST_METHOD =
+ "Access-Control-Request-Method";
+
+ /**
+ * The Access-Control-Request-Headers header indicates which headers will be
+ * used in the actual request as part of the preflight request.
+ */
+ public static final String REQUEST_HEADER_ACCESS_CONTROL_REQUEST_HEADERS =
+ "Access-Control-Request-Headers";
+
+ // ----------------------------------------------------- Request attributes
+ /**
+ * The prefix to a CORS request attribute.
+ */
+ public static final String HTTP_REQUEST_ATTRIBUTE_PREFIX = "cors.";
+
+ /**
+ * Attribute that contains the origin of the request.
+ */
+ public static final String HTTP_REQUEST_ATTRIBUTE_ORIGIN =
+ HTTP_REQUEST_ATTRIBUTE_PREFIX + "request.origin";
+
+ /**
+ * Boolean value, suggesting if the request is a CORS request or not.
+ */
+ public static final String HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST =
+ HTTP_REQUEST_ATTRIBUTE_PREFIX + "isCorsRequest";
+
+ /**
+ * Type of CORS request, of type {@link CORSRequestType}.
+ */
+ public static final String HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE =
+ HTTP_REQUEST_ATTRIBUTE_PREFIX + "request.type";
+
+ /**
+ * Request headers sent as 'Access-Control-Request-Headers' header, for
+ * pre-flight request.
+ */
+ public static final String HTTP_REQUEST_ATTRIBUTE_REQUEST_HEADERS =
+ HTTP_REQUEST_ATTRIBUTE_PREFIX + "request.headers";
+
+ // -------------------------------------------------------------- Constants
+ /**
+ * Enumerates varies types of CORS requests. Also, provides utility methods
+ * to determine the request type.
+ */
+ protected static enum CORSRequestType {
+ /**
+ * A simple HTTP request, i.e. it shouldn't be pre-flighted.
+ */
+ SIMPLE,
+ /**
+ * A HTTP request that needs to be pre-flighted.
+ */
+ ACTUAL,
+ /**
+ * A pre-flight CORS request, to get meta information, before a
+ * non-simple HTTP request is sent.
+ */
+ PRE_FLIGHT,
+ /**
+ * Not a CORS request, but a normal request.
+ */
+ NOT_CORS,
+ /**
+ * An invalid CORS request, i.e. it qualifies to be a CORS request, but
+ * fails to be a valid one.
+ */
+ INVALID_CORS
+ }
+
+ /**
+ * {@link Collection} of HTTP methods. Case sensitive.
+ *
+ * @see <a href="http://tools.ietf.org/html/rfc2616#section-5.1.1"
+ * >http://tools.ietf.org/html/rfc2616#section-5.1.1</a>
+ *
+ */
+ public static final Collection<String> HTTP_METHODS =
+ new HashSet<String>(Arrays.asList("OPTIONS", "GET", "HEAD", "POST",
+ "PUT", "DELETE", "TRACE", "CONNECT"));
+ /**
+ * {@link Collection} of non-simple HTTP methods. Case sensitive.
+ */
+ public static final Collection<String> COMPLEX_HTTP_METHODS =
+ new HashSet<String>(Arrays.asList("PUT", "DELETE", "TRACE",
+ "CONNECT"));
+ /**
+ * {@link Collection} of Simple HTTP methods. Case sensitive.
+ *
+ * @see <a href="http://www.w3.org/TR/cors/#terminology"
+ * >http://www.w3.org/TR/cors/#terminology</a>
+ */
+ public static final Collection<String> SIMPLE_HTTP_METHODS =
+ new HashSet<String>(Arrays.asList("GET", "POST", "HEAD"));
+
+ /**
+ * {@link Collection} of Simple HTTP request headers. Case in-sensitive.
+ *
+ * @see <a href="http://www.w3.org/TR/cors/#terminology"
+ * >http://www.w3.org/TR/cors/#terminology</a>
+ */
+ public static final Collection<String> SIMPLE_HTTP_REQUEST_HEADERS =
+ new HashSet<String>(Arrays.asList("Accept", "Accept-Language",
+ "Content-Language"));
+
+ /**
+ * {@link Collection} of Simple HTTP request headers. Case in-sensitive.
+ *
+ * @see <a href="http://www.w3.org/TR/cors/#terminology"
+ * >http://www.w3.org/TR/cors/#terminology</a>
+ */
+ public static final Collection<String> SIMPLE_HTTP_RESPONSE_HEADERS =
+ new HashSet<String>(Arrays.asList("Cache-Control",
+ "Content-Language", "Content-Type", "Expires",
+ "Last-Modified", "Pragma"));
+
+ /**
+ * {@link Collection} of Simple HTTP request headers. Case in-sensitive.
+ *
+ * @see <a href="http://www.w3.org/TR/cors/#terminology"
+ * >http://www.w3.org/TR/cors/#terminology</a>
+ */
+ public static final Collection<String> SIMPLE_HTTP_REQUEST_CONTENT_TYPE_VALUES =
+ new HashSet<String>(Arrays.asList(
+ "application/x-www-form-urlencoded",
+ "multipart/form-data", "text/plain"));
+
+ // ------------------------------------------------ Configuration Defaults
+ /**
+ * By default, all origins are allowed to make requests.
+ */
+ public static final String DEFAULT_ALLOWED_ORIGINS = "*";
+
+ /**
+ * By default, following methods are supported: GET, POST, HEAD and OPTIONS.
+ */
+ public static final String DEFAULT_ALLOWED_HTTP_METHODS =
+ "GET,POST,HEAD,OPTIONS";
+
+ /**
+ * By default, time duration to cache pre-flight response is 30 mins.
+ */
+ public static final String DEFAULT_PREFLIGHT_MAXAGE = "1800";
+
+ /**
+ * By default, support credentials is turned on.
+ */
+ public static final String DEFAULT_SUPPORTS_CREDENTIALS = "true";
+
+ /**
+ * By default, following headers are supported:
+ * Origin,Accept,X-Requested-With, Content-Type,
+ * Access-Control-Request-Method, and Access-Control-Request-Headers.
+ */
+ public static final String DEFAULT_ALLOWED_HTTP_HEADERS =
+ "Origin,Accept,X-Requested-With,Content-Type," +
+ "Access-Control-Request-Method,Access-Control-Request-Headers";
+
+ /**
+ * By default, none of the headers are exposed in response.
+ */
+ public static final String DEFAULT_EXPOSED_HEADERS = "";
+
+ /**
+ * By default, request is decorated with CORS attributes.
+ */
+ public static final String DEFAULT_DECORATE_REQUEST = "true";
+
+ // ----------------------------------------Filter Config Init param-name(s)
+ /**
+ * Key to retrieve allowed origins from {@link FilterConfig}.
+ */
+ public static final String PARAM_CORS_ALLOWED_ORIGINS =
+ "cors.allowed.origins";
+
+ /**
+ * Key to retrieve support credentials from {@link FilterConfig}.
+ */
+ public static final String PARAM_CORS_SUPPORT_CREDENTIALS =
+ "cors.support.credentials";
+
+ /**
+ * Key to retrieve exposed headers from {@link FilterConfig}.
+ */
+ public static final String PARAM_CORS_EXPOSED_HEADERS =
+ "cors.exposed.headers";
+
+ /**
+ * Key to retrieve allowed headers from {@link FilterConfig}.
+ */
+ public static final String PARAM_CORS_ALLOWED_HEADERS =
+ "cors.allowed.headers";
+
+ /**
+ * Key to retrieve allowed methods from {@link FilterConfig}.
+ */
+ public static final String PARAM_CORS_ALLOWED_METHODS =
+ "cors.allowed.methods";
+
+ /**
+ * Key to retrieve preflight max age from {@link FilterConfig}.
+ */
+ public static final String PARAM_CORS_PREFLIGHT_MAXAGE =
+ "cors.preflight.maxage";
+
+ /**
+ * Key to determine if request should be decorated.
+ */
+ public static final String PARAM_CORS_REQUEST_DECORATE =
+ "cors.request.decorate";
+}
Code Review / controller.git / commitdiff