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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     void setEncoding(const WTF::TextEncoding&);
     68 
     69 private:
     70     static const size_t kMaximumFragmentLengthTarget = 100;
     71 
     72     enum State {
     73         Uninitialized,
     74         FilteringTokens,
     75         PermittingAdjacentCharacterTokens,
     76         SuppressingAdjacentCharacterTokens
     77     };
     78 
     79     enum TruncationKind {
     80         NoTruncation,
     81         NormalAttributeTruncation,
     82         SrcLikeAttributeTruncation,
     83         ScriptLikeAttributeTruncation
     84     };
     85 
     86     bool filterStartToken(const FilterTokenRequest&);
     87     void filterEndToken(const FilterTokenRequest&);
     88     bool filterCharacterToken(const FilterTokenRequest&);
     89     bool filterScriptToken(const FilterTokenRequest&);
     90     bool filterObjectToken(const FilterTokenRequest&);
     91     bool filterParamToken(const FilterTokenRequest&);
     92     bool filterEmbedToken(const FilterTokenRequest&);
     93     bool filterAppletToken(const FilterTokenRequest&);
     94     bool filterFrameToken(const FilterTokenRequest&);
     95     bool filterMetaToken(const FilterTokenRequest&);
     96     bool filterBaseToken(const FilterTokenRequest&);
     97     bool filterFormToken(const FilterTokenRequest&);
     98     bool filterInputToken(const FilterTokenRequest&);
     99     bool filterButtonToken(const FilterTokenRequest&);
    100 
    101     bool eraseDangerousAttributesIfInjected(const FilterTokenRequest&);
    102     bool eraseAttributeIfInjected(const FilterTokenRequest&, const QualifiedName&, const String& replacementValue = String(), TruncationKind treatment = NormalAttributeTruncation);
    103 
    104     String canonicalizedSnippetForTagName(const FilterTokenRequest&);
    105     String canonicalizedSnippetForJavaScript(const FilterTokenRequest&);
    106     String nameFromAttribute(const FilterTokenRequest&, const HTMLToken::Attribute&);
    107     String snippetFromAttribute(const FilterTokenRequest&, const HTMLToken::Attribute&);
    108     String canonicalize(String, TruncationKind);
    109 
    110     bool isContainedInRequest(const String&);
    111     bool isLikelySafeResource(const String& url);
    112 
    113     KURL m_documentURL;
    114     bool m_isEnabled;
    115 
    116     ReflectedXSSDisposition m_xssProtection;
    117     bool m_didSendValidCSPHeader;
    118     bool m_didSendValidXSSProtectionHeader;
    119 
    120     String m_decodedURL;
    121     String m_decodedHTTPBody;
    122     String m_httpBodyAsString;
    123     OwnPtr<SuffixTree<ASCIICodebook> > m_decodedHTTPBodySuffixTree;
    124 
    125     State m_state;
    126     bool m_scriptTagFoundInRequest;
    127     unsigned m_scriptTagNestingLevel;
    128     WTF::TextEncoding m_encoding;
    129 };
    130 
    131 }
    132 
    133 #endif
    134