# HG changeset patch
# User paulb
# Date 1085939057 0
# Node ID 29f53ea6be11e3459856e7c23b45e747a96927f5
# Parent f2878dc56e5dd0919a9d9788a1fb6948eab92465
[project @ 2004-05-30 17:44:17 by paulb]
Updated documentation in LoginRedirect.
Moved Login from the examples to WebStack.Resources.
diff -r f2878dc56e5d -r 29f53ea6be11 WebStack/Resources/Login.py
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/WebStack/Resources/Login.py Sun May 30 17:44:17 2004 +0000
@@ -0,0 +1,171 @@
+#!/usr/bin/env python
+
+"Login resources which redirect clients back to an application after a successful login."
+
+import WebStack.Generic
+from WebStack.Helpers.Auth import get_token
+
+class LoginResource:
+
+ "A resource providing a login screen."
+
+ def __init__(self, authenticator, use_redirect=1):
+
+ """
+ Initialise the resource with an 'authenticator'.
+
+ If the optional 'use_redirect' flag is set to 0, a confirmation screen is given
+ instead of redirecting the user back to the original application.
+ """
+
+ self.authenticator = authenticator
+ self.use_redirect = use_redirect
+
+ def respond(self, trans):
+
+ "Respond using the transaction 'trans'."
+
+ fields_path = trans.get_fields_from_path()
+ fields_body = trans.get_fields_from_body()
+
+ # NOTE: Handle missing redirects better.
+
+ if fields_body.has_key("redirect"):
+ redirects = fields_body["redirect"]
+ redirect = redirects[0]
+ elif fields_path.has_key("redirect"):
+ redirects = fields_path["redirect"]
+ redirect = redirects[0]
+ else:
+ redirect = ""
+
+ # Check for a submitted login form.
+
+ if fields_body.has_key("login"):
+ if self.authenticator.authenticate(trans):
+ self._redirect(trans, redirect)
+ return
+
+ # Otherwise, show the login form.
+
+ self._show_login(trans, redirect)
+
+ def _redirect(self, trans, redirect):
+
+ "Redirect the client using 'trans' and the given 'redirect' URL."
+
+ if self.use_redirect:
+ trans.set_header_value("Location", redirect)
+ trans.set_response_code(307)
+
+ # Show the success page anyway.
+
+ self._show_success(trans, redirect)
+
+ def _show_login(self, trans, redirect):
+
+ """
+ Writes a login screen using the transaction 'trans', including details of the
+ 'redirect' URL which the client was attempting to access.
+ """
+
+ trans.set_content_type(WebStack.Generic.ContentType("text/html"))
+ out = trans.get_response_stream()
+ out.write("""
+
+
+ Login Example
+
+
+ Login
+
+
+
+""" % redirect)
+
+ def _show_success(self, trans, redirect):
+
+ # When authentication fails or is yet to take place, show the login
+ # screen.
+
+ trans.set_content_type(WebStack.Generic.ContentType("text/html"))
+ out = trans.get_response_stream()
+ out.write("""
+
+
+ Login Example
+
+
+ Login Successful
+ Please proceed to the application.
+
+
+""" % redirect)
+
+ def _decode(self, url):
+
+ "Decode the given 'url' for redirection purposes."
+
+ return url.replace("%3f", "?").replace("%26", "&")
+
+class LoginAuthenticator:
+
+ def __init__(self, secret_key, credentials, cookie_name=None):
+
+ """
+ Initialise the authenticator with a 'secret_key', the authenticator's registry of
+ 'credentials' and an optional 'cookie_name'.
+
+ The 'credentials' must be an object which supports tests of the form
+ '(username, password) in credentials'.
+ """
+
+ self.secret_key = secret_key
+ self.credentials = credentials
+ self.cookie_name = cookie_name or "LoginAuthenticator"
+
+ def authenticate(self, trans):
+
+ """
+ Authenticate the sender of the transaction 'trans', returning 1 (true) if they are
+ recognised, 0 (false) otherwise.
+ """
+
+ # Process any supplied parameters.
+
+ fields = trans.get_fields_from_body()
+
+ if fields.has_key("username") and fields.has_key("password"):
+ usernames, passwords = fields["username"], fields["password"]
+
+ # Insist on only one username and password.
+
+ if len(usernames) == 1 and len(passwords) == 1:
+ username, password = usernames[0], passwords[0]
+
+ # Check against the class's credentials.
+
+ if (username, password) in self.credentials:
+
+ # Make a special cookie token.
+
+ self.set_token(trans, username)
+ return 1
+
+ return 0
+
+ def set_token(self, trans, username):
+
+ "Set an authentication token in 'trans' with the given 'username'."
+
+ trans.set_cookie_value(
+ self.cookie_name,
+ get_token(username, self.secret_key)
+ )
+
+# vim: tabstop=4 expandtab shiftwidth=4
diff -r f2878dc56e5d -r 29f53ea6be11 WebStack/Resources/LoginRedirect.py
--- a/WebStack/Resources/LoginRedirect.py Sun May 30 17:21:51 2004 +0000
+++ b/WebStack/Resources/LoginRedirect.py Sun May 30 17:44:17 2004 +0000
@@ -1,6 +1,6 @@
#!/usr/bin/env python
-"Login redirection."
+"Login redirection resources, sending unauthenticated users to a login screen URL."
from WebStack.Helpers.Auth import get_token
import WebStack.Generic
@@ -134,7 +134,10 @@
def authenticate(self, trans):
- "Authenticate the originator of 'trans', updating the object if successful."
+ """
+ Authenticate the originator of 'trans', updating the object if successful and
+ returning 1 (true) if successful, 0 (false) otherwise.
+ """
cookie = trans.get_cookie(self.cookie_name)
if cookie is None or cookie.value is None: