io.micronaut.http.util.HtmlEntityEncodingHtmlSanitizer Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of micronaut-http Show documentation

Natively Cloud Native

The newest version!

/*
 * Copyright 2017-2024 original authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.micronaut.http.util;

import io.micronaut.context.annotation.Requires;
import io.micronaut.core.annotation.NonNull;
import jakarta.annotation.Nullable;
import jakarta.inject.Singleton;

import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Given an HTML string, it encodes the following characters: {@code &} to {@code &}, {@code <} to {@code <}, {@code >} to {@code >}, {@code "} to {@code "}, and {@code '} to {@code '}.
 * @see Cross site Scripting Prevention Cheat Sheet
 */
@Singleton
@Requires(missingBeans = HtmlSanitizer.class)
public class HtmlEntityEncodingHtmlSanitizer implements HtmlSanitizer {
    private final Map encodedMap;

    public HtmlEntityEncodingHtmlSanitizer() {
        encodedMap = new LinkedHashMap<>();
        encodedMap.put("&", "&");
        encodedMap.put("<", "<");
        encodedMap.put(">", ">");
        encodedMap.put("\"", """);
        encodedMap.put("'", "'");
    }

    @Override
    @NonNull
    public String sanitize(@Nullable String html) {
        if (html == null) {
            return "";
        }
        String sanitized = html;
        for (Map.Entry entry : encodedMap.entrySet()) {
            sanitized = sanitized.replaceAll(entry.getKey(), entry.getValue());
        }
        return sanitized;
    }
}