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      1 /*
      2  * Copyright (C) 2011 Adam Barth. 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 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 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 #ifndef XSSAuditor_h
     27 #define XSSAuditor_h
     28 
     29 #include "core/html/parser/HTMLToken.h"
     30 #include "platform/network/HTTPParsers.h"
     31 #include "platform/text/SuffixTree.h"
     32 #include "platform/weborigin/KURL.h"
     33 #include "wtf/PassOwnPtr.h"
     34 #include "wtf/text/TextEncoding.h"
     35 
     36 namespace WebCore {
     37 
     38 class Document;
     39 class HTMLDocumentParser;
     40 class HTMLSourceTracker;
     41 class XSSInfo;
     42 class XSSAuditorDelegate;
     43 
     44 struct FilterTokenRequest {
     45     FilterTokenRequest(HTMLToken& token, HTMLSourceTracker& sourceTracker, bool shouldAllowCDATA)
     46         : token(token)
     47         , sourceTracker(sourceTracker)
     48         , shouldAllowCDATA(shouldAllowCDATA)
     49     { }
     50 
     51     HTMLToken& token;
     52     HTMLSourceTracker& sourceTracker;
     53     bool shouldAllowCDATA;
     54 };
     55 
     56 class XSSAuditor {
     57     WTF_MAKE_NONCOPYABLE(XSSAuditor);
     58 public:
     59     XSSAuditor();
     60 
     61     void init(Document*, XSSAuditorDelegate*);
     62     void initForFragment();
     63 
     64     PassOwnPtr<XSSInfo> filterToken(const FilterTokenRequest&);
     65     bool isSafeToSendToAnotherThread() const;
     66 
     67 private:
     68     static const size_t kMaximumFragmentLengthTarget = 100;
     69 
     70     enum State {
     71         Uninitialized,
     72         FilteringTokens,
     73         PermittingAdjacentCharacterTokens,
     74         SuppressingAdjacentCharacterTokens
     75     };
     76 
     77     enum AttributeKind {
     78         NormalAttribute,
     79         SrcLikeAttribute,
     80         ScriptLikeAttribute
     81     };
     82 
     83     bool filterStartToken(const FilterTokenRequest&);
     84     void filterEndToken(const FilterTokenRequest&);
     85     bool filterCharacterToken(const FilterTokenRequest&);
     86     bool filterScriptToken(const FilterTokenRequest&);
     87     bool filterObjectToken(const FilterTokenRequest&);
     88     bool filterParamToken(const FilterTokenRequest&);
     89     bool filterEmbedToken(const FilterTokenRequest&);
     90     bool filterAppletToken(const FilterTokenRequest&);
     91     bool filterFrameToken(const FilterTokenRequest&);
     92     bool filterMetaToken(const FilterTokenRequest&);
     93     bool filterBaseToken(const FilterTokenRequest&);
     94     bool filterFormToken(const FilterTokenRequest&);
     95     bool filterInputToken(const FilterTokenRequest&);
     96     bool filterButtonToken(const FilterTokenRequest&);
     97 
     98     bool eraseDangerousAttributesIfInjected(const FilterTokenRequest&);
     99     bool eraseAttributeIfInjected(const FilterTokenRequest&, const QualifiedName&, const String& replacementValue = String(), AttributeKind treatment = NormalAttribute);
    100 
    101     String decodedSnippetForToken(const HTMLToken&);
    102     String decodedSnippetForName(const FilterTokenRequest&);
    103     String decodedSnippetForAttribute(const FilterTokenRequest&, const HTMLToken::Attribute&, AttributeKind treatment = NormalAttribute);
    104     String decodedSnippetForJavaScript(const FilterTokenRequest&);
    105 
    106     bool isContainedInRequest(const String&);
    107     bool isLikelySafeResource(const String& url);
    108 
    109     KURL m_documentURL;
    110     bool m_isEnabled;
    111 
    112     ReflectedXSSDisposition m_xssProtection;
    113     bool m_didSendValidCSPHeader;
    114     bool m_didSendValidXSSProtectionHeader;
    115 
    116     String m_decodedURL;
    117     String m_decodedHTTPBody;
    118     OwnPtr<SuffixTree<ASCIICodebook> > m_decodedHTTPBodySuffixTree;
    119 
    120     State m_state;
    121     bool m_scriptTagFoundInRequest;
    122     unsigned m_scriptTagNestingLevel;
    123     WTF::TextEncoding m_encoding;
    124 };
    125 
    126 }
    127 
    128 #endif
    129