1/* 2 * Copyright (C) 2008, 2009 Apple Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 */ 26 27#include "config.h" 28#include "CrossOriginPreflightResultCache.h" 29 30#include "CrossOriginAccessControl.h" 31#include "ResourceResponse.h" 32#include <wtf/CurrentTime.h> 33#include <wtf/MainThread.h> 34#include <wtf/StdLibExtras.h> 35 36namespace WebCore { 37 38using namespace std; 39 40// These values are at the discretion of the user agent. 41static const unsigned defaultPreflightCacheTimeoutSeconds = 5; 42static const unsigned maxPreflightCacheTimeoutSeconds = 600; // Should be short enough to minimize the risk of using a poisoned cache after switching to a secure network. 43 44static bool parseAccessControlMaxAge(const String& string, unsigned& expiryDelta) 45{ 46 // FIXME: this will not do the correct thing for a number starting with a '+' 47 bool ok = false; 48 expiryDelta = string.toUIntStrict(&ok); 49 return ok; 50} 51 52template<class HashType> 53static void addToAccessControlAllowList(const String& string, unsigned start, unsigned end, HashSet<String, HashType>& set) 54{ 55 StringImpl* stringImpl = string.impl(); 56 if (!stringImpl) 57 return; 58 59 // Skip white space from start. 60 while (start <= end && isSpaceOrNewline((*stringImpl)[start])) 61 ++start; 62 63 // only white space 64 if (start > end) 65 return; 66 67 // Skip white space from end. 68 while (end && isSpaceOrNewline((*stringImpl)[end])) 69 --end; 70 71 set.add(string.substring(start, end - start + 1)); 72} 73 74template<class HashType> 75static bool parseAccessControlAllowList(const String& string, HashSet<String, HashType>& set) 76{ 77 unsigned start = 0; 78 size_t end; 79 while ((end = string.find(',', start)) != notFound) { 80 if (start != end) 81 addToAccessControlAllowList(string, start, end - 1, set); 82 start = end + 1; 83 } 84 if (start != string.length()) 85 addToAccessControlAllowList(string, start, string.length() - 1, set); 86 87 return true; 88} 89 90bool CrossOriginPreflightResultCacheItem::parse(const ResourceResponse& response, String& errorDescription) 91{ 92 m_methods.clear(); 93 if (!parseAccessControlAllowList(response.httpHeaderField("Access-Control-Allow-Methods"), m_methods)) { 94 errorDescription = "Cannot parse Access-Control-Allow-Methods response header field."; 95 return false; 96 } 97 98 m_headers.clear(); 99 if (!parseAccessControlAllowList(response.httpHeaderField("Access-Control-Allow-Headers"), m_headers)) { 100 errorDescription = "Cannot parse Access-Control-Allow-Headers response header field."; 101 return false; 102 } 103 104 unsigned expiryDelta; 105 if (parseAccessControlMaxAge(response.httpHeaderField("Access-Control-Max-Age"), expiryDelta)) { 106 if (expiryDelta > maxPreflightCacheTimeoutSeconds) 107 expiryDelta = maxPreflightCacheTimeoutSeconds; 108 } else 109 expiryDelta = defaultPreflightCacheTimeoutSeconds; 110 111 m_absoluteExpiryTime = currentTime() + expiryDelta; 112 return true; 113} 114 115bool CrossOriginPreflightResultCacheItem::allowsCrossOriginMethod(const String& method, String& errorDescription) const 116{ 117 if (m_methods.contains(method) || isOnAccessControlSimpleRequestMethodWhitelist(method)) 118 return true; 119 120 errorDescription = "Method " + method + " is not allowed by Access-Control-Allow-Methods."; 121 return false; 122} 123 124bool CrossOriginPreflightResultCacheItem::allowsCrossOriginHeaders(const HTTPHeaderMap& requestHeaders, String& errorDescription) const 125{ 126 HTTPHeaderMap::const_iterator end = requestHeaders.end(); 127 for (HTTPHeaderMap::const_iterator it = requestHeaders.begin(); it != end; ++it) { 128 if (!m_headers.contains(it->key) && !isOnAccessControlSimpleRequestHeaderWhitelist(it->key, it->value)) { 129 errorDescription = "Request header field " + it->key.string() + " is not allowed by Access-Control-Allow-Headers."; 130 return false; 131 } 132 } 133 return true; 134} 135 136bool CrossOriginPreflightResultCacheItem::allowsRequest(StoredCredentials includeCredentials, const String& method, const HTTPHeaderMap& requestHeaders) const 137{ 138 String ignoredExplanation; 139 if (m_absoluteExpiryTime < currentTime()) 140 return false; 141 if (includeCredentials == AllowStoredCredentials && m_credentials == DoNotAllowStoredCredentials) 142 return false; 143 if (!allowsCrossOriginMethod(method, ignoredExplanation)) 144 return false; 145 if (!allowsCrossOriginHeaders(requestHeaders, ignoredExplanation)) 146 return false; 147 return true; 148} 149 150CrossOriginPreflightResultCache& CrossOriginPreflightResultCache::shared() 151{ 152 DEFINE_STATIC_LOCAL(CrossOriginPreflightResultCache, cache, ()); 153 ASSERT(isMainThread()); 154 return cache; 155} 156 157void CrossOriginPreflightResultCache::appendEntry(const String& origin, const KURL& url, PassOwnPtr<CrossOriginPreflightResultCacheItem> preflightResult) 158{ 159 ASSERT(isMainThread()); 160 m_preflightHashMap.set(make_pair(origin, url), preflightResult); 161} 162 163bool CrossOriginPreflightResultCache::canSkipPreflight(const String& origin, const KURL& url, StoredCredentials includeCredentials, const String& method, const HTTPHeaderMap& requestHeaders) 164{ 165 ASSERT(isMainThread()); 166 CrossOriginPreflightResultHashMap::iterator cacheIt = m_preflightHashMap.find(make_pair(origin, url)); 167 if (cacheIt == m_preflightHashMap.end()) 168 return false; 169 170 if (cacheIt->value->allowsRequest(includeCredentials, method, requestHeaders)) 171 return true; 172 173 m_preflightHashMap.remove(cacheIt); 174 return false; 175} 176 177void CrossOriginPreflightResultCache::empty() 178{ 179 ASSERT(isMainThread()); 180 m_preflightHashMap.clear(); 181} 182 183} // namespace WebCore 184