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/CrossOriginAccessControl.h" 31 #include "platform/network/ResourceResponse.h" 32 #include "wtf/CurrentTime.h" 33 #include "wtf/MainThread.h" 34 #include "wtf/StdLibExtras.h" 35 36 namespace WebCore { 37 38 // These values are at the discretion of the user agent. 39 static const unsigned defaultPreflightCacheTimeoutSeconds = 5; 40 static const unsigned maxPreflightCacheTimeoutSeconds = 600; // Should be short enough to minimize the risk of using a poisoned cache after switching to a secure network. 41 42 static 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 50 template<class HashType> 51 static 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 72 template<class HashType> 73 static 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 88 bool 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 m_absoluteExpiryTime = currentTime() + expiryDelta; 110 return true; 111 } 112 113 bool CrossOriginPreflightResultCacheItem::allowsCrossOriginMethod(const String& method, String& errorDescription) const 114 { 115 if (m_methods.contains(method) || isOnAccessControlSimpleRequestMethodWhitelist(method)) 116 return true; 117 118 errorDescription = "Method " + method + " is not allowed by Access-Control-Allow-Methods."; 119 return false; 120 } 121 122 bool CrossOriginPreflightResultCacheItem::allowsCrossOriginHeaders(const HTTPHeaderMap& requestHeaders, String& errorDescription) const 123 { 124 HTTPHeaderMap::const_iterator end = requestHeaders.end(); 125 for (HTTPHeaderMap::const_iterator it = requestHeaders.begin(); it != end; ++it) { 126 if (!m_headers.contains(it->key) && !isOnAccessControlSimpleRequestHeaderWhitelist(it->key, it->value)) { 127 errorDescription = "Request header field " + it->key.string() + " is not allowed by Access-Control-Allow-Headers."; 128 return false; 129 } 130 } 131 return true; 132 } 133 134 bool CrossOriginPreflightResultCacheItem::allowsRequest(StoredCredentials includeCredentials, const String& method, const HTTPHeaderMap& requestHeaders) const 135 { 136 String ignoredExplanation; 137 if (m_absoluteExpiryTime < currentTime()) 138 return false; 139 if (includeCredentials == AllowStoredCredentials && m_credentials == DoNotAllowStoredCredentials) 140 return false; 141 if (!allowsCrossOriginMethod(method, ignoredExplanation)) 142 return false; 143 if (!allowsCrossOriginHeaders(requestHeaders, ignoredExplanation)) 144 return false; 145 return true; 146 } 147 148 CrossOriginPreflightResultCache& CrossOriginPreflightResultCache::shared() 149 { 150 DEFINE_STATIC_LOCAL(CrossOriginPreflightResultCache, cache, ()); 151 ASSERT(isMainThread()); 152 return cache; 153 } 154 155 void CrossOriginPreflightResultCache::appendEntry(const String& origin, const KURL& url, PassOwnPtr<CrossOriginPreflightResultCacheItem> preflightResult) 156 { 157 ASSERT(isMainThread()); 158 m_preflightHashMap.set(std::make_pair(origin, url), preflightResult); 159 } 160 161 bool CrossOriginPreflightResultCache::canSkipPreflight(const String& origin, const KURL& url, StoredCredentials includeCredentials, const String& method, const HTTPHeaderMap& requestHeaders) 162 { 163 ASSERT(isMainThread()); 164 CrossOriginPreflightResultHashMap::iterator cacheIt = m_preflightHashMap.find(std::make_pair(origin, url)); 165 if (cacheIt == m_preflightHashMap.end()) 166 return false; 167 168 if (cacheIt->value->allowsRequest(includeCredentials, method, requestHeaders)) 169 return true; 170 171 m_preflightHashMap.remove(cacheIt); 172 return false; 173 } 174 175 } // namespace WebCore 176