What authentication libraries for PHP are not attached to a framework and meet these requirements?

Question

Whenever I Google things like "php authentication library" I continue to come up with a ton of results of authentication libraries designed for Code Igniter.

What I am looking for is things like the following,

1. A robust library that handles login, logout, registration, login retrieval etc...
2. Very secure authentication possibly using sha-256+?
3. Library that can be integrated into any code, framework or not
4. Active project and community so that I can rely on it in the future.
5. Compatible with MySQL
6. Maybe some things I do not know about?

Answer 1

I am hoping my answer fits your needs , its in two parts :

1- Zend Acl + Zend + Auth :

1. very robust code and 100% unit tested
2. it could support any encryption method or create your own method
3. it can support any backend you like [mysql , msssql , or even a session based auth]
4. custom acl to fits your application needs
5. you may choose php5.2 version = ZF 1.11 or the php5.3 = ZF2 beta released the last week
6. in ZF2 beta you could use the pyrus to package the required classes only , not the whole library http://zend-framework-community.634137.n4.nabble.com/Packaging-and-distribution-of-ZF2-td3597632.html
7. its very active project

2-symfony2 security component :

1. in sf2 you combine the [ACL , AUTH] in very powerful library called security
2. symfony2 has the support of bundles , and the FOS UserBundle its the ideal match for my usage

3. you can use it in your own project as its

   Symfony's security component is available as a standalone PHP library for use inside any PHP project. http://symfony.com/doc/2.0/book/security.html

4. it support many backend solutions , they called providers you my see even create your own custom provider

5. you can even create many protected areas , in case you need it via firewalls , its basically as DMZs

6. support any encryption method you might need , or create your own

7. its very active project too