Relax Content-Type parameter parsing

Source/core/platform/network/ParsedContentType.cpp

  /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 31 matching lines @@
     void setContentType(const SubstringRange&) const { }
     void setContentTypeParameter(const SubstringRange&, const SubstringRange&) const { }
 };
 
 static void skipSpaces(const String& input, unsigned& startIndex)
 {
     while (startIndex < input.length() && input[startIndex] == ' ')
         ++startIndex;
 }
 
-static bool isTokenCharacter(char c)
-{
-    return isASCII(c) && c > ' ' && c != '"' && c != '(' && c != ')' && c != ',' && c != '/' && (c < ':' || c > '@') && (c < '[' || c > ']');
-}
-
-static SubstringRange parseToken(const String& input, unsigned& startIndex)
+static SubstringRange parseParameterPart(const String& input, unsigned& startIndex)
 {
     unsigned inputLength = input.length();
     unsigned tokenStart = startIndex;
     unsigned& tokenEnd = startIndex;
 
     if (tokenEnd >= inputLength)
         return SubstringRange();
 
+    bool quoted = input[tokenStart] == '\"';
+
     while (tokenEnd < inputLength) {
-        if (!isTokenCharacter(input[tokenEnd]))

[abarth-chromium, 2013/09/12 18:16:11]

I see.  The key is that you're trying to lift this requirement.

+        if (quoted && tokenStart != tokenEnd && input[tokenEnd] == '\"' && input[tokenEnd - 1] != '\\')

[abarth-chromium, 2013/09/12 18:16:11]

I don't think this is correct.  Consider the following case:

foo="\\"

This code thinks that the second \ escapes the ", which isn't correct.  The
second \ is escaped by the first \.  To do this correctly, you need to do what
the parseQuotedString code did and scan the string from left to right and keep
track of whether lastCharacterWasBackslash. 

+            return SubstringRange(tokenStart + 1, tokenEnd++ - tokenStart - 1);
+        if (!quoted && (input[tokenEnd] == ';' || input[tokenEnd] == '='))
             return SubstringRange(tokenStart, tokenEnd - tokenStart);
         ++tokenEnd;
     }
 
     return SubstringRange(tokenStart, tokenEnd - tokenStart);
 }
 
-static SubstringRange parseQuotedString(const String& input, unsigned& startIndex)
-{
-    unsigned inputLength = input.length();
-    unsigned quotedStringStart = startIndex + 1;
-    unsigned& quotedStringEnd = startIndex;
-
-    if (quotedStringEnd >= inputLength)
-        return SubstringRange();
-
-    if (input[quotedStringEnd++] != '"' || quotedStringEnd >= inputLength)
-        return SubstringRange();
-
-    bool lastCharacterWasBackslash = false;
-    char currentCharacter;
-    while ((currentCharacter = input[quotedStringEnd++]) != '"' || lastCharacterWasBackslash) {
-        if (quotedStringEnd >= inputLength)
-            return SubstringRange();
-        if (currentCharacter == '\\' && !lastCharacterWasBackslash) {
-            lastCharacterWasBackslash = true;
-            continue;
-        }
-        if (lastCharacterWasBackslash)
-            lastCharacterWasBackslash = false;
-    }
-    return SubstringRange(quotedStringStart, quotedStringEnd - quotedStringStart - 1);
-}
-
 static String substringForRange(const String& string, const SubstringRange& range)
 {
     return string.substring(range.first, range.second);
 }
 
 // From http://tools.ietf.org/html/rfc2045#section-5.1:
 //
 // content := "Content-Type" ":" type "/" subtype
 //            *(";" parameter)
 //            ; Matching of media type and subtype
@@ skipping 53 matching lines @@
     size_t semiColonIndex = contentType.find(';', index);
     if (semiColonIndex == notFound) {
         receiver.setContentType(SubstringRange(index, contentTypeLength - index));
         return true;
     }
 
     receiver.setContentType(SubstringRange(index, semiColonIndex - index));
     index = semiColonIndex + 1;
     while (true) {
         skipSpaces(contentType, index);
-        SubstringRange keyRange = parseToken(contentType, index);
+        SubstringRange keyRange = parseParameterPart(contentType, index);
         if (!keyRange.second || index >= contentTypeLength) {
-            LOG_ERROR("Invalid Content-Type parameter name.");
+            LOG_ERROR("Invalid Content-Type parameter name. (at %i)", index);
             return false;
         }
 
         // Should we tolerate spaces here?
         if (contentType[index++] != '=' || index >= contentTypeLength) {
-            LOG_ERROR("Invalid Content-Type malformed parameter.");
+            LOG_ERROR("Invalid Content-Type malformed parameter (at %i).", index);
             return false;
         }
 
         // Should we tolerate spaces here?
-        String value;
-        SubstringRange valueRange;
-        if (contentType[index] == '"')
-            valueRange = parseQuotedString(contentType, index);
-        else
-            valueRange = parseToken(contentType, index);
+        SubstringRange valueRange = parseParameterPart(contentType, index);
 
         if (!valueRange.second) {
-            LOG_ERROR("Invalid Content-Type, invalid parameter value.");
+            LOG_ERROR("Invalid Content-Type, invalid parameter value (at %i, for '%s').", index, substringForRange(contentType, keyRange).stripWhiteSpace().ascii().data());
             return false;
         }
 
         // Should we tolerate spaces here?
         if (index < contentTypeLength && contentType[index++] != ';') {
-            LOG_ERROR("Invalid Content-Type, invalid character at the end of key/value parameter.");
+            LOG_ERROR("Invalid Content-Type, invalid character at the end of key/value parameter (at %i).", index);
             return false;
         }
 
         receiver.setContentTypeParameter(keyRange, valueRange);
 
         if (index >= contentTypeLength)
             return true;
     }
 
     return true;
@@ skipping 33 matching lines @@
 {
     m_mimeType = substringForRange(m_contentType, contentRange).stripWhiteSpace();
 }
 
 void ParsedContentType::setContentTypeParameter(const SubstringRange& key, const SubstringRange& value)
 {
     m_parameters.set(substringForRange(m_contentType, key), substringForRange(m_contentType, value));
 }
 
 }