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 "core/loader/CrossOriginPreflightResultCache.h" 29 30#include "core/fetch/FetchUtils.h" 31#include "platform/network/ResourceResponse.h" 32#include "wtf/CurrentTime.h" 33#include "wtf/MainThread.h" 34#include "wtf/StdLibExtras.h" 35 36namespace blink { 37 38// These values are at the discretion of the user agent. 39static const unsigned defaultPreflightCacheTimeoutSeconds = 5; 40static const unsigned maxPreflightCacheTimeoutSeconds = 600; // Should be short enough to minimize the risk of using a poisoned cache after switching to a secure network. 41 42static bool parseAccessControlMaxAge(const String& string, unsigned& expiryDelta) 43{ 44 // FIXME: this will not do the correct thing for a number starting with a '+' 45 bool ok = false; 46 expiryDelta = string.toUIntStrict(&ok); 47 return ok; 48} 49 50template<class HashType> 51static void addToAccessControlAllowList(const String& string, unsigned start, unsigned end, HashSet<String, HashType>& set) 52{ 53 StringImpl* stringImpl = string.impl(); 54 if (!stringImpl) 55 return; 56 57 // Skip white space from start. 58 while (start <= end && isSpaceOrNewline((*stringImpl)[start])) 59 ++start; 60 61 // only white space 62 if (start > end) 63 return; 64 65 // Skip white space from end. 66 while (end && isSpaceOrNewline((*stringImpl)[end])) 67 --end; 68 69 set.add(string.substring(start, end - start + 1)); 70} 71 72template<class HashType> 73static bool parseAccessControlAllowList(const String& string, HashSet<String, HashType>& set) 74{ 75 unsigned start = 0; 76 size_t end; 77 while ((end = string.find(',', start)) != kNotFound) { 78 if (start != end) 79 addToAccessControlAllowList(string, start, end - 1, set); 80 start = end + 1; 81 } 82 if (start != string.length()) 83 addToAccessControlAllowList(string, start, string.length() - 1, set); 84 85 return true; 86} 87 88bool CrossOriginPreflightResultCacheItem::parse(const ResourceResponse& response, String& errorDescription) 89{ 90 m_methods.clear(); 91 if (!parseAccessControlAllowList(response.httpHeaderField("Access-Control-Allow-Methods"), m_methods)) { 92 errorDescription = "Cannot parse Access-Control-Allow-Methods response header field."; 93 return false; 94 } 95 96 m_headers.clear(); 97 if (!parseAccessControlAllowList(response.httpHeaderField("Access-Control-Allow-Headers"), m_headers)) { 98 errorDescription = "Cannot parse Access-Control-Allow-Headers response header field."; 99 return false; 100 } 101 102 unsigned expiryDelta; 103 if (parseAccessControlMaxAge(response.httpHeaderField("Access-Control-Max-Age"), expiryDelta)) { 104 if (expiryDelta > maxPreflightCacheTimeoutSeconds) 105 expiryDelta = maxPreflightCacheTimeoutSeconds; 106 } else { 107 expiryDelta = defaultPreflightCacheTimeoutSeconds; 108 } 109 110 m_absoluteExpiryTime = currentTime() + expiryDelta; 111 return true; 112} 113 114bool CrossOriginPreflightResultCacheItem::allowsCrossOriginMethod(const String& method, String& errorDescription) const 115{ 116 if (m_methods.contains(method) || FetchUtils::isSimpleMethod(method)) 117 return true; 118 119 errorDescription = "Method " + method + " is not allowed by Access-Control-Allow-Methods."; 120 return false; 121} 122 123bool CrossOriginPreflightResultCacheItem::allowsCrossOriginHeaders(const HTTPHeaderMap& requestHeaders, String& errorDescription) const 124{ 125 HTTPHeaderMap::const_iterator end = requestHeaders.end(); 126 for (HTTPHeaderMap::const_iterator it = requestHeaders.begin(); it != end; ++it) { 127 if (!m_headers.contains(it->key) && !FetchUtils::isSimpleHeader(it->key, it->value) && !FetchUtils::isForbiddenHeaderName(it->key)) { 128 errorDescription = "Request header field " + it->key.string() + " is not allowed by Access-Control-Allow-Headers."; 129 return false; 130 } 131 } 132 return true; 133} 134 135bool CrossOriginPreflightResultCacheItem::allowsRequest(StoredCredentials includeCredentials, const String& method, const HTTPHeaderMap& requestHeaders) const 136{ 137 String ignoredExplanation; 138 if (m_absoluteExpiryTime < currentTime()) 139 return false; 140 if (includeCredentials == AllowStoredCredentials && m_credentials == DoNotAllowStoredCredentials) 141 return false; 142 if (!allowsCrossOriginMethod(method, ignoredExplanation)) 143 return false; 144 if (!allowsCrossOriginHeaders(requestHeaders, ignoredExplanation)) 145 return false; 146 return true; 147} 148 149CrossOriginPreflightResultCache& CrossOriginPreflightResultCache::shared() 150{ 151 DEFINE_STATIC_LOCAL(CrossOriginPreflightResultCache, cache, ()); 152 ASSERT(isMainThread()); 153 return cache; 154} 155 156void CrossOriginPreflightResultCache::appendEntry(const String& origin, const KURL& url, PassOwnPtr<CrossOriginPreflightResultCacheItem> preflightResult) 157{ 158 ASSERT(isMainThread()); 159 m_preflightHashMap.set(std::make_pair(origin, url), preflightResult); 160} 161 162bool CrossOriginPreflightResultCache::canSkipPreflight(const String& origin, const KURL& url, StoredCredentials includeCredentials, const String& method, const HTTPHeaderMap& requestHeaders) 163{ 164 ASSERT(isMainThread()); 165 CrossOriginPreflightResultHashMap::iterator cacheIt = m_preflightHashMap.find(std::make_pair(origin, url)); 166 if (cacheIt == m_preflightHashMap.end()) 167 return false; 168 169 if (cacheIt->value->allowsRequest(includeCredentials, method, requestHeaders)) 170 return true; 171 172 m_preflightHashMap.remove(cacheIt); 173 return false; 174} 175 176} // namespace blink 177