org.owasp.encoder.XMLCommentEncoder Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of encoder Show documentation

The OWASP Encoders package is a collection of high-performance low-overhead contextual encoders, that when utilized correctly, is an effective tool in preventing Web Application security vulnerabilities such as Cross-Site Scripting.

There is a newer version: 1.3.1

Show newest version

// Copyright (c) 2012 Jeff Ichnowski
// 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.
//
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials
//       provided with the distribution.
//
//     * Neither the name of the OWASP nor the names of its
//       contributors may be used to endorse or promote products
//       derived from this software without specific prior written
//       permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
// OF THE POSSIBILITY OF SUCH DAMAGE.
package org.owasp.encoder;

import java.nio.CharBuffer;
import java.nio.charset.CoderResult;

/**
 * XMLCommentEncoder -- Encodes for the XML/HTML comment context. The sequence "--" is not allowed in comments, and must be
 * removed/replaced. We also must be careful of trailing hyphens at end of input, as they could combine with the external comment
 * ending sequence "-->" to become "--->", which is also invalid. As with all XML-based context, invalid XML characters are not
 * allowed.
 *
 * @author Jeff Ichnowski
 */
class XMLCommentEncoder extends Encoder {

    /**
     * This is the character used to replace a hyphen when a sequence of hypens is encountered.
     */
    static final char HYPHEN_REPLACEMENT = '~';

    // Input:
    // 
    // Possible Options:
    // 
    // 
    // 
    // 
    //  (Unicode Hyphen)
    //  (Unicode en-dash)
    // Note: HTML comments differ, in that they cannot start with: ">", "->".
    // On IE, "