Imported from SVN by Bitbucket

Paste-1.7.5.1-py2.6.egg/paste/auth/basic.py

@@ -0,0 +1,122 @@
+# (c) 2005 Clark C. Evans
+# This module is part of the Python Paste Project and is released under
+# the MIT License: http://www.opensource.org/licenses/mit-license.php
+# This code was written with funding by http://prometheusresearch.com
+"""
+Basic HTTP/1.0 Authentication
+
+This module implements ``Basic`` authentication as described in
+HTTP/1.0 specification [1]_ .  Do not use this module unless you
+are using SSL or need to work with very out-dated clients, instead
+use ``digest`` authentication.
+
+>>> from paste.wsgilib import dump_environ
+>>> from paste.httpserver import serve
+>>> # from paste.auth.basic import AuthBasicHandler
+>>> realm = 'Test Realm'
+>>> def authfunc(environ, username, password):
+...     return username == password
+>>> serve(AuthBasicHandler(dump_environ, realm, authfunc))
+serving on...
+
+.. [1] http://www.w3.org/Protocols/HTTP/1.0/draft-ietf-http-spec.html#BasicAA
+"""
+from paste.httpexceptions import HTTPUnauthorized
+from paste.httpheaders import *
+
+class AuthBasicAuthenticator(object):
+    """
+    implements ``Basic`` authentication details
+    """
+    type = 'basic'
+    def __init__(self, realm, authfunc):
+        self.realm = realm
+        self.authfunc = authfunc
+
+    def build_authentication(self):
+        head = WWW_AUTHENTICATE.tuples('Basic realm="%s"' % self.realm)
+        return HTTPUnauthorized(headers=head)
+
+    def authenticate(self, environ):
+        authorization = AUTHORIZATION(environ)
+        if not authorization:
+            return self.build_authentication()
+        (authmeth, auth) = authorization.split(' ', 1)
+        if 'basic' != authmeth.lower():
+            return self.build_authentication()
+        auth = auth.strip().decode('base64')
+        username, password = auth.split(':', 1)
+        if self.authfunc(environ, username, password):
+            return username
+        return self.build_authentication()
+
+    __call__ = authenticate
+
+class AuthBasicHandler(object):
+    """
+    HTTP/1.0 ``Basic`` authentication middleware
+
+    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.
+
+        ``realm``
+
+            This is a identifier for the authority that is requesting
+            authorization.  It is shown to the user and should be unique
+            within the domain it is being used.
+
+        ``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.
+
+    """
+    def __init__(self, application, realm, authfunc):
+        self.application = application
+        self.authenticate = AuthBasicAuthenticator(realm, authfunc)
+
+    def __call__(self, environ, start_response):
+        username = REMOTE_USER(environ)
+        if not username:
+            result = self.authenticate(environ)
+            if isinstance(result, str):
+                AUTH_TYPE.update(environ, 'basic')
+                REMOTE_USER.update(environ, result)
+            else:
+                return result.wsgi_application(environ, start_response)
+        return self.application(environ, start_response)
+
+middleware = AuthBasicHandler
+
+__all__ = ['AuthBasicHandler']
+
+def make_basic(app, global_conf, realm, authfunc, **kw):
+    """
+    Grant access via basic authentication
+
+    Config looks like this::
+
+      [filter:grant]
+      use = egg:Paste#auth_basic
+      realm=myrealm
+      authfunc=somepackage.somemodule:somefunction
+      
+    """
+    from paste.util.import_string import eval_import
+    import types
+    authfunc = eval_import(authfunc)
+    assert isinstance(authfunc, types.FunctionType), "authfunc must resolve to a function"
+    return AuthBasicHandler(app, realm, authfunc)
+    
+
+if "__main__" == __name__:
+    import doctest
+    doctest.testmod(optionflags=doctest.ELLIPSIS)