Files
edx-platform/djangoapps/ssl_auth/ssl_auth.py
2012-05-17 10:12:00 -04:00

282 lines
11 KiB
Python
Executable File

"""
User authentication backend for ssl (no pw required)
"""
from django.conf import settings
from django.contrib import auth
from django.contrib.auth.models import User, check_password
from django.contrib.auth.backends import ModelBackend
from django.contrib.auth.middleware import RemoteUserMiddleware
from django.core.exceptions import ImproperlyConfigured
import os, string, re
from random import choice
from student.models import UserProfile
#-----------------------------------------------------------------------------
def ssl_dn_extract_info(dn):
'''
Extract username, email address (may be anyuser@anydomain.com) and full name
from the SSL DN string. Return (user,email,fullname) if successful, and None
otherwise.
'''
ss = re.search('/emailAddress=(.*)@([^/]+)',dn)
if ss:
user = ss.group(1)
email = "%s@%s" % (user,ss.group(2))
else:
return None
ss = re.search('/CN=([^/]+)/',dn)
if ss:
fullname = ss.group(1)
else:
return None
return (user,email,fullname)
def check_nginx_proxy(request):
'''
Check for keys in the HTTP header (META) to se if we are behind an ngix reverse proxy.
If so, get user info from the SSL DN string and return that, as (user,email,fullname)
'''
m = request.META
if m.has_key('HTTP_X_REAL_IP'): # we're behind a nginx reverse proxy, which has already done ssl auth
if not m.has_key('HTTP_SSL_CLIENT_S_DN'):
return None
dn = m['HTTP_SSL_CLIENT_S_DN']
return ssl_dn_extract_info(dn)
return None
#-----------------------------------------------------------------------------
def get_ssl_username(request):
x = check_nginx_proxy(request)
if x:
return x[0]
env = request._req.subprocess_env
if env.has_key('SSL_CLIENT_S_DN_Email'):
email = env['SSL_CLIENT_S_DN_Email']
user = email[:email.index('@')]
return user
return None
#-----------------------------------------------------------------------------
class NginxProxyHeaderMiddleware(RemoteUserMiddleware):
'''
Django "middleware" function for extracting user information from HTTP request.
'''
# this field is generated by nginx's reverse proxy
header = 'HTTP_SSL_CLIENT_S_DN' # specify the request.META field to use
def process_request(self, request):
# AuthenticationMiddleware is required so that request.user exists.
if not hasattr(request, 'user'):
raise ImproperlyConfigured(
"The Django remote user auth middleware requires the"
" authentication middleware to be installed. Edit your"
" MIDDLEWARE_CLASSES setting to insert"
" 'django.contrib.auth.middleware.AuthenticationMiddleware'"
" before the RemoteUserMiddleware class.")
#raise ImproperlyConfigured('[ProxyHeaderMiddleware] request.META=%s' % repr(request.META))
try:
username = request.META[self.header] # try the nginx META key first
except KeyError:
try:
env = request._req.subprocess_env # else try the direct apache2 SSL key
if env.has_key('SSL_CLIENT_S_DN'):
username = env['SSL_CLIENT_S_DN']
else:
raise ImproperlyConfigured('no ssl key, env=%s' % repr(env))
username = ''
except:
# If specified header doesn't exist then return (leaving
# request.user set to AnonymousUser by the
# AuthenticationMiddleware).
return
# If the user is already authenticated and that user is the user we are
# getting passed in the headers, then the correct user is already
# persisted in the session and we don't need to continue.
#raise ImproperlyConfigured('[ProxyHeaderMiddleware] username=%s' % username)
if request.user.is_authenticated():
if request.user.username == self.clean_username(username, request):
#raise ImproperlyConfigured('%s already authenticated (%s)' % (username,request.user.username))
return
# We are seeing this user for the first time in this session, attempt
# to authenticate the user.
#raise ImproperlyConfigured('calling auth.authenticate, remote_user=%s' % username)
user = auth.authenticate(remote_user=username)
if user:
# User is valid. Set request.user and persist user in the session
# by logging the user in.
request.user = user
if settings.DEBUG: print "[ssl_auth.ssl_auth.NginxProxyHeaderMiddleware] logging in user=%s" % user
auth.login(request, user)
def clean_username(self,username,request):
'''
username is the SSL DN string - extract the actual username from it and return
'''
info = ssl_dn_extract_info(username)
if not info:
return None
(username,email,fullname) = info
return username
#-----------------------------------------------------------------------------
class SSLLoginBackend(ModelBackend):
'''
Django authentication back-end which auto-logs-in a user based on having
already authenticated with an MIT certificate (SSL).
'''
def authenticate(self, username=None, password=None, remote_user=None):
# remote_user is from the SSL_DN string. It will be non-empty only when
# the user has already passed the server authentication, which means
# matching with the certificate authority.
if not remote_user:
# no remote_user, so check username (but don't auto-create user)
if not username:
return None
return None # pass on to another authenticator backend
#raise ImproperlyConfigured("in SSLLoginBackend, username=%s, remote_user=%s" % (username,remote_user))
try:
user = User.objects.get(username=username) # if user already exists don't create it
return user
except User.DoesNotExist:
return None
return None
#raise ImproperlyConfigured("in SSLLoginBackend, username=%s, remote_user=%s" % (username,remote_user))
#if not os.environ.has_key('HTTPS'):
# return None
#if not os.environ.get('HTTPS')=='on': # only use this back-end if HTTPS on
# return None
def GenPasswd(length=8, chars=string.letters + string.digits):
return ''.join([choice(chars) for i in range(length)])
# convert remote_user to user, email, fullname
info = ssl_dn_extract_info(remote_user)
#raise ImproperlyConfigured("[SSLLoginBackend] looking up %s" % repr(info))
if not info:
#raise ImproperlyConfigured("[SSLLoginBackend] remote_user=%s, info=%s" % (remote_user,info))
return None
(username,email,fullname) = info
try:
user = User.objects.get(username=username) # if user already exists don't create it
except User.DoesNotExist:
raise "User does not exist. Not creating user; potential schema consistency issues"
#raise ImproperlyConfigured("[SSLLoginBackend] creating %s" % repr(info))
user = User(username=username, password=GenPasswd()) # create new User
user.is_staff = False
user.is_superuser = False
# get first, last name from fullname
name = fullname
if not name.count(' '):
user.first_name = " "
user.last_name = name
mn = ''
else:
user.first_name = name[:name.find(' ')]
ml = name[name.find(' '):].strip()
if ml.count(' '):
user.last_name = ml[ml.rfind(' '):]
mn = ml[:ml.rfind(' ')]
else:
user.last_name = ml
mn = ''
# set email
user.email = email
# cleanup last name
user.last_name = user.last_name.strip()
# save
user.save()
# auto-create user profile
up = UserProfile(user=user)
up.name = fullname
up.save()
#tui = user.get_profile()
#tui.middle_name = mn
#tui.role = 'Misc'
#tui.section = None # no section assigned at first
#tui.save()
# return None
return user
def get_user(self, user_id):
#if not os.environ.has_key('HTTPS'):
# return None
#if not os.environ.get('HTTPS')=='on': # only use this back-end if HTTPS on
# return None
try:
return User.objects.get(pk=user_id)
except User.DoesNotExist:
return None
#-----------------------------------------------------------------------------
# OLD!
class AutoLoginBackend:
def authenticate(self, username=None, password=None):
raise ImproperlyConfigured("in AutoLoginBackend, username=%s" % username)
if not os.environ.has_key('HTTPS'):
return None
if not os.environ.get('HTTPS')=='on':# only use this back-end if HTTPS on
return None
def GenPasswd(length=8, chars=string.letters + string.digits):
return ''.join([choice(chars) for i in range(length)])
try:
user = User.objects.get(username=username)
except User.DoesNotExist:
user = User(username=username, password=GenPasswd())
user.is_staff = False
user.is_superuser = False
# get first, last name
name = os.environ.get('SSL_CLIENT_S_DN_CN').strip()
if not name.count(' '):
user.first_name = " "
user.last_name = name
mn = ''
else:
user.first_name = name[:name.find(' ')]
ml = name[name.find(' '):].strip()
if ml.count(' '):
user.last_name = ml[ml.rfind(' '):]
mn = ml[:ml.rfind(' ')]
else:
user.last_name = ml
mn = ''
# get email
user.email = os.environ.get('SSL_CLIENT_S_DN_Email')
# save
user.save()
tui = user.get_profile()
tui.middle_name = mn
tui.role = 'Misc'
tui.section = None# no section assigned at first
tui.save()
# return None
return user
def get_user(self, user_id):
if not os.environ.has_key('HTTPS'):
return None
if not os.environ.get('HTTPS')=='on':# only use this back-end if HTTPS on
return None
try:
return User.objects.get(pk=user_id)
except User.DoesNotExist:
return None