# `paste.auth.form` – HTML form/cookie authentication

Authentication via HTML Form

This is a very simple HTML form login screen that asks for the username and password. This middleware component requires that an authorization function taking the name and passsword and that it be placed in your application stack. This class does not include any session management code or way to save the user’s authorization; however, it is easy enough to put `paste.auth.cookie` in your application stack.

    >>> from paste.wsgilib import dump_environ
    >>> from paste.httpserver import serve
    >>> from paste.auth.cookie import AuthCookieHandler
    >>> from paste.auth.form import AuthFormHandler
    >>> def authfunc(environ, username, password):
    ...    return username == password
    >>> serve(AuthCookieHandler(
    ...           AuthFormHandler(dump_environ, authfunc)))
    serving on...

## Module Contents

class `paste.auth.form.``AuthFormHandler`(application, authfunc, template=None)

  HTML-based login middleware

  This causes a HTML form to be returned if `REMOTE_USER` is not found in the `environ`. If the form is returned, the `username` and `password` combination are given to a user-supplied authentication function, `authfunc`. If this is successful, then application processing continues.

  Parameters:

  > `application`

  > > The application object is called only upon successful authentication, and can assume `environ['REMOTE_USER']` is set. If the `REMOTE_USER` is already set, this middleware is simply pass-through.

  > `authfunc`

  > > This is a mandatory user-defined function which takes a `environ`, `username` and `password` for its first three arguments. It should return `True` if the user is authenticated.

  > `template`

  > > This is an optional (a default is provided) HTML fragment that takes exactly one `%s` substution argument; which must be used for the form’s `action` to ensure that this middleware component does not alter the current path. The HTML form must use `POST` and have two input names: `username` and `password`.

  Since the authentication form is submitted (via `POST`) neither the `PATH_INFO` nor the `QUERY_STRING` are accessed, and hence the current path remains _unaltered_ through the entire authentication process. If authentication succeeds, the `REQUEST_METHOD` is converted from a `POST` to a `GET`, so that a redirect is unnecessary (unlike most form auth implementations)

`paste.auth.form.``make_form`(app, global_conf, realm, authfunc, **kw)

  Grant access via form authentication

  Config looks like this:

      [filter:grant]
      use = egg:Paste#auth_form
      realm=myrealm
      authfunc=somepackage.somemodule:somefunction