CrossOriginAccessControl.cpp [plain text]
#include "config.h"
#include "CrossOriginAccessControl.h"
#include "HTTPParsers.h"
#include "ResourceResponse.h"
#include "SecurityOrigin.h"
#include <wtf/Threading.h>
#include <wtf/text/AtomicString.h>
#include <wtf/text/StringBuilder.h>
namespace WebCore {
bool isOnAccessControlSimpleRequestMethodWhitelist(const String& method)
{
return method == "GET" || method == "HEAD" || method == "POST";
}
bool isOnAccessControlSimpleRequestHeaderWhitelist(const String& name, const String& value)
{
if (equalIgnoringCase(name, "accept")
|| equalIgnoringCase(name, "accept-language")
|| equalIgnoringCase(name, "content-language")
|| equalIgnoringCase(name, "origin")
|| equalIgnoringCase(name, "referer"))
return true;
if (equalIgnoringCase(name, "content-type")) {
String mimeType = extractMIMETypeFromMediaType(value);
return equalIgnoringCase(mimeType, "application/x-www-form-urlencoded")
|| equalIgnoringCase(mimeType, "multipart/form-data")
|| equalIgnoringCase(mimeType, "text/plain");
}
return false;
}
bool isSimpleCrossOriginAccessRequest(const String& method, const HTTPHeaderMap& headerMap)
{
if (!isOnAccessControlSimpleRequestMethodWhitelist(method))
return false;
HTTPHeaderMap::const_iterator end = headerMap.end();
for (HTTPHeaderMap::const_iterator it = headerMap.begin(); it != end; ++it) {
if (!isOnAccessControlSimpleRequestHeaderWhitelist(it->first, it->second))
return false;
}
return true;
}
static PassOwnPtr<HTTPHeaderSet> createAllowedCrossOriginResponseHeadersSet()
{
OwnPtr<HTTPHeaderSet> headerSet = adoptPtr(new HashSet<String, CaseFoldingHash>);
headerSet->add("cache-control");
headerSet->add("content-language");
headerSet->add("content-type");
headerSet->add("expires");
headerSet->add("last-modified");
headerSet->add("pragma");
return headerSet.release();
}
bool isOnAccessControlResponseHeaderWhitelist(const String& name)
{
AtomicallyInitializedStatic(HTTPHeaderSet*, allowedCrossOriginResponseHeaders = createAllowedCrossOriginResponseHeadersSet().leakPtr());
return allowedCrossOriginResponseHeaders->contains(name);
}
void updateRequestForAccessControl(ResourceRequest& request, SecurityOrigin* securityOrigin, StoredCredentials allowCredentials)
{
request.removeCredentials();
request.setAllowCookies(allowCredentials == AllowStoredCredentials);
request.setHTTPOrigin(securityOrigin->toString());
}
ResourceRequest createAccessControlPreflightRequest(const ResourceRequest& request, SecurityOrigin* securityOrigin)
{
ResourceRequest preflightRequest(request.url());
updateRequestForAccessControl(preflightRequest, securityOrigin, DoNotAllowStoredCredentials);
preflightRequest.setHTTPMethod("OPTIONS");
preflightRequest.setHTTPHeaderField("Access-Control-Request-Method", request.httpMethod());
preflightRequest.setPriority(request.priority());
const HTTPHeaderMap& requestHeaderFields = request.httpHeaderFields();
if (requestHeaderFields.size() > 0) {
StringBuilder headerBuffer;
HTTPHeaderMap::const_iterator it = requestHeaderFields.begin();
headerBuffer.append(it->first);
++it;
HTTPHeaderMap::const_iterator end = requestHeaderFields.end();
for (; it != end; ++it) {
headerBuffer.append(',');
headerBuffer.append(' ');
headerBuffer.append(it->first);
}
preflightRequest.setHTTPHeaderField("Access-Control-Request-Headers", headerBuffer.toString().lower());
}
return preflightRequest;
}
bool passesAccessControlCheck(const ResourceResponse& response, StoredCredentials includeCredentials, SecurityOrigin* securityOrigin, String& errorDescription)
{
AtomicallyInitializedStatic(AtomicString&, accessControlAllowOrigin = *new AtomicString("access-control-allow-origin"));
AtomicallyInitializedStatic(AtomicString&, accessControlAllowCredentials = *new AtomicString("access-control-allow-credentials"));
const String& accessControlOriginString = response.httpHeaderField(accessControlAllowOrigin);
if (accessControlOriginString == "*" && includeCredentials == DoNotAllowStoredCredentials)
return true;
if (securityOrigin->isUnique()) {
errorDescription = "Cannot make any requests from " + securityOrigin->toString() + ".";
return false;
}
if (accessControlOriginString != securityOrigin->toString()) {
if (accessControlOriginString == "*")
errorDescription = "Cannot use wildcard in Access-Control-Allow-Origin when credentials flag is true.";
else
errorDescription = "Origin " + securityOrigin->toString() + " is not allowed by Access-Control-Allow-Origin.";
return false;
}
if (includeCredentials == AllowStoredCredentials) {
const String& accessControlCredentialsString = response.httpHeaderField(accessControlAllowCredentials);
if (accessControlCredentialsString != "true") {
errorDescription = "Credentials flag is true, but Access-Control-Allow-Credentials is not \"true\".";
return false;
}
}
return true;
}
void parseAccessControlExposeHeadersAllowList(const String& headerValue, HTTPHeaderSet& headerSet)
{
Vector<String> headers;
headerValue.split(',', false, headers);
for (unsigned headerCount = 0; headerCount < headers.size(); headerCount++) {
String strippedHeader = headers[headerCount].stripWhiteSpace();
if (!strippedHeader.isEmpty())
headerSet.add(strippedHeader);
}
}
}