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 "AtomicString.h"

    31 #include "HTTPParsers.h"

    32 #include "ResourceResponse.h"

    33 #include "SecurityOrigin.h"

    34 #include <wtf/Threading.h>

    35 

    36 namespace WebCore {

    37 

    38 bool isOnAccessControlSimpleRequestMethodWhitelist(const String& method)

    39 {

    40     return method == "GET" || method == "HEAD" || method == "POST";

    41 }

    42 

    43 bool isOnAccessControlSimpleRequestHeaderWhitelist(const String& name, const String& value)

    44 {

    45     if (equalIgnoringCase(name, "accept") || equalIgnoringCase(name, "accept-language") || equalIgnoringCase(name, "content-language"))

    46         return true;

    47 

    48     // Preflight is required for MIME types that can not be sent via form submission.

    49     if (equalIgnoringCase(name, "content-type")) {

    50         String mimeType = extractMIMETypeFromMediaType(value);

    51         return equalIgnoringCase(mimeType, "application/x-www-form-urlencoded")

    52             || equalIgnoringCase(mimeType, "multipart/form-data")

    53             || equalIgnoringCase(mimeType, "text/plain");

    54     }

    55 

    56     return false;

    57 }

    58 

    59 bool isSimpleCrossOriginAccessRequest(const String& method, const HTTPHeaderMap& headerMap)

    60 {

    61     if (!isOnAccessControlSimpleRequestMethodWhitelist(method))

    62         return false;

    63 

    64     HTTPHeaderMap::const_iterator end = headerMap.end();

    65     for (HTTPHeaderMap::const_iterator it = headerMap.begin(); it != end; ++it) {

    66         if (!isOnAccessControlSimpleRequestHeaderWhitelist(it->first, it->second))

    67             return false;

    68     }

    69 

    70     return true;

    71 }

    72 

    73 typedef HashSet<String, CaseFoldingHash> HTTPHeaderSet;

    74 static HTTPHeaderSet* createAllowedCrossOriginResponseHeadersSet()

    75 {

    76     HTTPHeaderSet* headerSet = new HashSet<String, CaseFoldingHash>;

    77     

    78     headerSet->add("cache-control");

    79     headerSet->add("content-language");

    80     headerSet->add("content-type");

    81     headerSet->add("expires");

    82     headerSet->add("last-modified");

    83     headerSet->add("pragma");

    84 

    85     return headerSet;

    86 }

    87 

    88 bool isOnAccessControlResponseHeaderWhitelist(const String& name)

    89 {

    90     AtomicallyInitializedStatic(HTTPHeaderSet*, allowedCrossOriginResponseHeaders = createAllowedCrossOriginResponseHeadersSet());

    91 

    92     return allowedCrossOriginResponseHeaders->contains(name);

    93 }

    94 

    95 bool passesAccessControlCheck(const ResourceResponse& response, bool includeCredentials, SecurityOrigin* securityOrigin, String& errorDescription)

    96 {

    97     // A wildcard Access-Control-Allow-Origin can not be used if credentials are to be sent,

    98     // even with Access-Control-Allow-Credentials set to true.

    99     const String& accessControlOriginString = response.httpHeaderField("Access-Control-Allow-Origin");

   100     if (accessControlOriginString == "*" && !includeCredentials)

   101         return true;

   102 

   103     if (securityOrigin->isUnique()) {

   104         errorDescription = "Cannot make any requests from " + securityOrigin->toString() + ".";

   105         return false;

   106     }

   107 

   108     // FIXME: Access-Control-Allow-Origin can contain a list of origins.

   109     RefPtr<SecurityOrigin> accessControlOrigin = SecurityOrigin::createFromString(accessControlOriginString);

   110     if (!accessControlOrigin->isSameSchemeHostPort(securityOrigin)) {

   111         errorDescription = (accessControlOriginString == "*") ? "Cannot use wildcard in Access-Control-Allow-Origin when credentials flag is true."

   112             : "Origin " + securityOrigin->toString() + " is not allowed by Access-Control-Allow-Origin.";

   113         return false;

   114     }

   115 

   116     if (includeCredentials) {

   117         const String& accessControlCredentialsString = response.httpHeaderField("Access-Control-Allow-Credentials");

   118         if (accessControlCredentialsString != "true") {

   119             errorDescription = "Credentials flag is true, but Access-Control-Allow-Credentials is not \"true\".";

   120             return false;

   121         }

   122     }

   123 

   124     return true;

   125 }

   126 

   127 } // namespace WebCore