urlcanon

A URL canonicalization (normalization) library for Python and Java.

It currently provides:

• A URL parser which preserves the input bytes exactly
• A precanned canonicalization ruleset that tries to match the normalization implicit in the parsing rules used by browsers
• An alternative URL serialization suitable for sorting and prefix-matching: SSURT.

Status: Stable and in production use for some time. But no API or output stability guarantees yet. There are differences in features between Java and Python versions.

Examples

Python

>>> import urlcanon
>>> input_url = "http://///EXAMPLE.com:80/foo/../bar"
>>> parsed_url = urlcanon.parse_url(input_url)
>>> print(parsed_url)
http://///EXAMPLE.com:80/foo/../bar
>>> urlcanon.whatwg(parsed_url)
<urlcanon.parse.ParsedUrl object at 0x10eb13a58>
>>> print(parsed_url)
http://example.com/bar
>>> print(parsed_url.ssurt())
b'com,example,//:http/bar'
>>>
>>> rule = urlcanon.MatchRule(ssurt=b'com,example,//:http/bar')
>>> urlcanon.whatwg.rule_applies(rule, b'https://example..com/bar/baz')
False
>>> urlcanon.whatwg.rule_applies(rule, b'HTtp:////eXAMple.Com/bar//baz//..///quu')
True

Python releases are available in PyPI:

pip install urlcanon

Java

String inputUrl = "http://///EXAMPLE.com:80/foo/../bar";
ParsedUrl parsedUrl = ParsedUrl.parseUrl(inputUrl);

System.out.println(parsedUrl);
// http://///EXAMPLE.com:80/foo/../bar

Canonicalizer.WHATWG.canonicalize(parsedUrl);

System.out.println(parsedUrl);
// http://example.com/bar

System.out.println(parsedUrl.ssurt());
// "com,example,//:http/bar"

Java releases are available in the Maven Central repository:

<dependency>
    <groupId>org.netpreserve</groupId>
    <artifactId>urlcanon</artifactId>
    <version>0.4.0</version>
</dependency>

Internationalized domain names

The Java version of urlcanon will use ICU4J for punycode encoding if available. Otherwise it will fall back to java.net.IDN which does not support the newer IDNA2008 rules. So if you need correct IDN handling make sure to add ICU4J to your project:

<dependency>
    <groupId>com.ibm.icu</groupId>
    <artifactId>icu4j</artifactId>
    <version>53.1</version>
</dependency>

License

• Copyright (C) 2016-2018 Internet Archive
• Copyright (C) 2016-2020 National Library of Australia

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this software except in compliance with the License. You may obtain a copy of the License at

http://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.