tor-browser

The Tor Browser
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PolicyTokenizer.h (2095B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #ifndef PolicyTokenizer_h___
      8 #define PolicyTokenizer_h___
      9 
     10 #include "nsContentUtils.h"
     11 #include "nsString.h"
     12 
     13 /**
     14 * How does the parsing work?
     15 *
     16 * We generate tokens by splitting the policy-string by whitespace and
     17 * semicolon. Interally the tokens are represented as an array of string-arrays:
     18 *
     19 *  [
     20 *    [ name, src, src, src, ... ],
     21 *    [ name, src, src, src, ... ],
     22 *    [ name, src, src, src, ... ]
     23 *  ]
     24 *
     25 * for example:
     26 *  [
     27 *    [ img-src, http://www.example.com, http:www.test.com ],
     28 *    [ default-src, 'self'],
     29 *    [ script-src, 'unsafe-eval', 'unsafe-inline' ],
     30 *  ]
     31 */
     32 
     33 using policyTokens = nsTArray<CopyableTArray<nsString>>;
     34 
     35 class PolicyTokenizer {
     36 public:
     37  static void tokenizePolicy(const nsAString& aPolicyString,
     38                             policyTokens& outTokens);
     39 
     40 private:
     41  PolicyTokenizer(const char16_t* aStart, const char16_t* aEnd);
     42  ~PolicyTokenizer();
     43 
     44  inline bool atEnd() { return mCurChar >= mEndChar; }
     45 
     46  inline void skipWhiteSpace() {
     47    while (mCurChar < mEndChar && nsContentUtils::IsHTMLWhitespace(*mCurChar)) {
     48      mCurChar++;
     49    }
     50    mCurToken.Truncate();
     51  }
     52 
     53  inline void skipWhiteSpaceAndSemicolon() {
     54    while (mCurChar < mEndChar &&
     55           (*mCurChar == ';' || nsContentUtils::IsHTMLWhitespace(*mCurChar))) {
     56      mCurChar++;
     57    }
     58    mCurToken.Truncate();
     59  }
     60 
     61  inline bool accept(char16_t aChar) {
     62    NS_ASSERTION(mCurChar < mEndChar, "Trying to dereference mEndChar");
     63    if (*mCurChar == aChar) {
     64      mCurToken.Append(*mCurChar++);
     65      return true;
     66    }
     67    return false;
     68  }
     69 
     70  void generateNextToken();
     71  void generateTokens(policyTokens& outTokens);
     72 
     73  const char16_t* mCurChar;
     74  const char16_t* mEndChar;
     75  nsString mCurToken;
     76 };
     77 
     78 #endif /* PolicyTokenizer_h___ */