org.graylog2.system.urlwhitelist.RegexHelper Maven / Gradle / Ivy
/*
* Copyright (C) 2020 Graylog, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* .
*/
package org.graylog2.system.urlwhitelist;
import org.apache.commons.lang3.StringUtils;
import java.util.Arrays;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
/**
* Utility class to help creating an appropriate regex to be used in a whitelist entry.
*/
public class RegexHelper {
/**
*
* Replaces all placeholders in a "url template" with {@code .*?}, quotes everything else and adds {@code ^} and
* {@code $} to it.
*
*
* An example:
*
*
*
https://example.com/api/lookup?key=${key}
* will become
* ^\Qhttps://example.com/api/lookup?key=\E.*?$
*
*/
public String createRegexForUrlTemplate(String url, String placeholder) {
String transformedUrl = Arrays.stream(StringUtils.splitByWholeSeparator(url, placeholder))
.map(part -> StringUtils.isBlank(part) ? part : Pattern.quote(part))
.collect(Collectors.joining(".*?"));
return "^" + transformedUrl + "$";
}
/**
* Quotes the url and adds a {@code ^} and {@code $}.
*/
public String createRegexForUrl(String url) {
return "^" + Pattern.quote(url) + "$";
}
}