1 /*
2  * Copyright (C) 2008 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 "CrossOriginAccessControl.h"
29 
30 #include "HTTPParsers.h"
31 #include "ResourceResponse.h"
32 #include "SecurityOrigin.h"
33 #include <wtf/HashSet.h>
34 #include <wtf/Threading.h>
35 #include <wtf/text/AtomicString.h>
36 
37 namespace WebCore {
38 
isOnAccessControlSimpleRequestMethodWhitelist(const String & method)39 bool isOnAccessControlSimpleRequestMethodWhitelist(const String& method)
40 {
41     return method == "GET" || method == "HEAD" || method == "POST";
42 }
43 
isOnAccessControlSimpleRequestHeaderWhitelist(const String & name,const String & value)44 bool isOnAccessControlSimpleRequestHeaderWhitelist(const String& name, const String& value)
45 {
46     if (equalIgnoringCase(name, "accept") || equalIgnoringCase(name, "accept-language") || equalIgnoringCase(name, "content-language"))
47         return true;
48 
49     // Preflight is required for MIME types that can not be sent via form submission.
50     if (equalIgnoringCase(name, "content-type")) {
51         String mimeType = extractMIMETypeFromMediaType(value);
52         return equalIgnoringCase(mimeType, "application/x-www-form-urlencoded")
53             || equalIgnoringCase(mimeType, "multipart/form-data")
54             || equalIgnoringCase(mimeType, "text/plain");
55     }
56 
57     return false;
58 }
59 
isSimpleCrossOriginAccessRequest(const String & method,const HTTPHeaderMap & headerMap)60 bool isSimpleCrossOriginAccessRequest(const String& method, const HTTPHeaderMap& headerMap)
61 {
62     if (!isOnAccessControlSimpleRequestMethodWhitelist(method))
63         return false;
64 
65     HTTPHeaderMap::const_iterator end = headerMap.end();
66     for (HTTPHeaderMap::const_iterator it = headerMap.begin(); it != end; ++it) {
67         if (!isOnAccessControlSimpleRequestHeaderWhitelist(it->first, it->second))
68             return false;
69     }
70 
71     return true;
72 }
73 
74 typedef HashSet<String, CaseFoldingHash> HTTPHeaderSet;
createAllowedCrossOriginResponseHeadersSet()75 static PassOwnPtr<HTTPHeaderSet> createAllowedCrossOriginResponseHeadersSet()
76 {
77     OwnPtr<HTTPHeaderSet> headerSet = adoptPtr(new HashSet<String, CaseFoldingHash>);
78 
79     headerSet->add("cache-control");
80     headerSet->add("content-language");
81     headerSet->add("content-type");
82     headerSet->add("expires");
83     headerSet->add("last-modified");
84     headerSet->add("pragma");
85 
86     return headerSet.release();
87 }
88 
isOnAccessControlResponseHeaderWhitelist(const String & name)89 bool isOnAccessControlResponseHeaderWhitelist(const String& name)
90 {
91     AtomicallyInitializedStatic(HTTPHeaderSet*, allowedCrossOriginResponseHeaders = createAllowedCrossOriginResponseHeadersSet().leakPtr());
92 
93     return allowedCrossOriginResponseHeaders->contains(name);
94 }
95 
passesAccessControlCheck(const ResourceResponse & response,bool includeCredentials,SecurityOrigin * securityOrigin,String & errorDescription)96 bool passesAccessControlCheck(const ResourceResponse& response, bool includeCredentials, SecurityOrigin* securityOrigin, String& errorDescription)
97 {
98     // A wildcard Access-Control-Allow-Origin can not be used if credentials are to be sent,
99     // even with Access-Control-Allow-Credentials set to true.
100     const String& accessControlOriginString = response.httpHeaderField("Access-Control-Allow-Origin");
101     if (accessControlOriginString == "*" && !includeCredentials)
102         return true;
103 
104     if (securityOrigin->isUnique()) {
105         errorDescription = "Cannot make any requests from " + securityOrigin->toString() + ".";
106         return false;
107     }
108 
109     // FIXME: Access-Control-Allow-Origin can contain a list of origins.
110     RefPtr<SecurityOrigin> accessControlOrigin = SecurityOrigin::createFromString(accessControlOriginString);
111     if (!accessControlOrigin->isSameSchemeHostPort(securityOrigin)) {
112         errorDescription = (accessControlOriginString == "*") ? "Cannot use wildcard in Access-Control-Allow-Origin when credentials flag is true."
113             : "Origin " + securityOrigin->toString() + " is not allowed by Access-Control-Allow-Origin.";
114         return false;
115     }
116 
117     if (includeCredentials) {
118         const String& accessControlCredentialsString = response.httpHeaderField("Access-Control-Allow-Credentials");
119         if (accessControlCredentialsString != "true") {
120             errorDescription = "Credentials flag is true, but Access-Control-Allow-Credentials is not \"true\".";
121             return false;
122         }
123     }
124 
125     return true;
126 }
127 
128 } // namespace WebCore
129