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libpsl - C library to handle the Public Suffix List
===================================================
A "public suffix" is a domain name under which Internet users can directly register own names.
Browsers and other web clients can use it to
- avoid privacy-leaking "supercookies"
- avoid privacy-leaking "super domain" certificates ([see post from Jeffry Walton](https://lists.gnu.org/archive/html/bug-wget/2014-03/msg00093.html))
- domain highlighting parts of the domain in a user interface
- sorting domain lists by site
Libpsl...
- has built-in PSL data for fast access (DAWG/DAFSA reduces size from 180kB to ~32kB)
- allows to load PSL data from files
- checks if a given domain is a "public suffix"
- provides immediate cookie domain verification
- finds the longest public part of a given domain
- finds the shortest private part of a given domain
- works with international domains (UTF-8 and IDNA2008 Punycode)
- is thread-safe
- handles IDNA2008 UTS#46 (if libicu is available)
Find more information about the Public Suffix List [here](https://publicsuffix.org/).
Download the Public Suffix List [here](https://hg.mozilla.org/mozilla-central/raw-file/tip/netwerk/dns/effective_tld_names.dat).
The DAFSA code has been taken from [Chromium Project](https://code.google.com/p/chromium/).
API Documentation
-----------------
You find the current API documentation [here](https://rockdaboot.github.io/libpsl).
Quick API example
-----------------
#include <stdio.h>
#include <libpsl.h>
int main(int argc, char **argv)
{
const char *domain = "www.example.com";
const char *cookie_domain = ".com";
const psl_ctx_t *psl = psl_builtin();
int is_public, is_acceptable;
is_public = psl_is_public_suffix(psl, domain);
printf("%s %s a public suffix.\n", domain, is_public ? "is" : "is not");
is_acceptable = psl_is_cookie_domain_acceptable(psl, domain, cookie_domain);
printf("cookie domain '%s' %s acceptable for domain '%s'.\n",
cookie_domain, is_acceptable ? "is" : "is not", domain);
return 0;
}
Command Line Tool
-----------------
Libpsl comes with a tool 'psl' that gives you access to most of the
library API via command line.
$ psl --help
prints the usage.
Convert PSL into DAFSA
----------------------
The [DAFSA](https://en.wikipedia.org/wiki/Deterministic_acyclic_finite_state_automaton) format is a compressed
representation of strings. Here we use it to reduce the whole PSL to about 32k in size.
Generate `psl.dafsa` from `list/public_suffix_list.dat`
$ src/psl-make-dafsa --output-format=binary list/public_suffix_list.dat psl.dafsa
Test the result (example)
$ tools/psl --load-psl-file psl.dafsa aeroclub.aero
License
-------
Libpsl is made available under the terms of the MIT license.<br>
See the LICENSE file that accompanies this distribution for the full text of the license.
src/psl-make-dafsa and src/lookup_string_in_fixed_set.c are licensed under the term written in
src/LICENSE.chromium.
Building from git
-----------------
You should have python2.7+ installed.
Download project and prepare sources with
git clone https://github.com/rockdaboot/libpsl
./autogen.sh
./configure
make
make check
Mailing List
------------
[Mailing List Archive](http://news.gmane.org/gmane.network.dns.libpsl.bugs)
[Mailing List](https://groups.google.com/forum/#!forum/libpsl-bugs)
To join the mailing list send an email to
libpsl-bugs+subscribe@googlegroups.com
and follow the instructions provided by the answer mail.
Or click [join](https://groups.google.com/forum/#!forum/libpsl-bugs/join).