Files
edx-platform/common/djangoapps/external_auth/views.py
2012-08-29 15:28:44 -04:00

511 lines
18 KiB
Python

import functools
import json
import logging
import random
import re
import string
from external_auth.models import ExternalAuthMap
from django.conf import settings
from django.contrib.auth import REDIRECT_FIELD_NAME, authenticate, login
from django.contrib.auth.models import User
from student.models import UserProfile
from django.http import HttpResponse, HttpResponseRedirect
from django.utils.http import urlquote
from django.shortcuts import redirect
from mitxmako.shortcuts import render_to_response, render_to_string
try:
from django.views.decorators.csrf import csrf_exempt
except ImportError:
from django.contrib.csrf.middleware import csrf_exempt
from django_future.csrf import ensure_csrf_cookie
from util.cache import cache_if_anonymous
import django_openid_auth.views as openid_views
from django_openid_auth import auth as openid_auth
from openid.consumer.consumer import SUCCESS
from openid.server.server import Server
from openid.server.trustroot import TrustRoot
from openid.store.filestore import FileOpenIDStore
from openid.extensions import ax, sreg
import student.views as student_views
log = logging.getLogger("mitx.external_auth")
@csrf_exempt
def default_render_failure(request,
message,
status=403,
template_name='extauth_failure.html',
exception=None):
"""Render an Openid error page to the user."""
message = "In openid_failure " + message
log.debug(message)
data = render_to_string(template_name,
dict(message=message, exception=exception))
return HttpResponse(data, status=status)
#-----------------------------------------------------------------------------
# Openid
def edXauth_generate_password(length=12, chars=string.letters + string.digits):
"""Generate internal password for externally authenticated user"""
return ''.join([random.choice(chars) for i in range(length)])
@csrf_exempt
def edXauth_openid_login_complete(request,
redirect_field_name=REDIRECT_FIELD_NAME,
render_failure=None):
"""Complete the openid login process"""
redirect_to = request.REQUEST.get(redirect_field_name, '') # TODO: [rocha] redirect_to never used?
render_failure = (render_failure or
getattr(settings, 'OPENID_RENDER_FAILURE', None) or
default_render_failure)
openid_response = openid_views.parse_openid_response(request)
if not openid_response:
return render_failure(request,
'This is an OpenID relying party endpoint.')
if openid_response.status == SUCCESS:
external_id = openid_response.identity_url
oid_backend = openid_auth.OpenIDBackend()
details = oid_backend._extract_user_details(openid_response)
log.debug('openid success, details=%s' % details)
external_domain = "openid:%s" % settings.OPENID_SSO_SERVER_URL
fullname = '%s %s' % (details.get('first_name', ''),
details.get('last_name', ''))
return edXauth_external_login_or_signup(request,
external_id,
external_domain,
details,
details.get('email', ''),
fullname,
)
return render_failure(request, 'Openid failure')
#-----------------------------------------------------------------------------
# generic external auth login or signup
def edXauth_external_login_or_signup(request,
external_id,
external_domain,
credentials,
email,
fullname,
retfun=None):
# see if we have a map from this external_id to an edX username
try:
eamap = ExternalAuthMap.objects.get(external_id=external_id,
external_domain=external_domain,
)
log.debug('Found eamap=%s' % eamap)
except ExternalAuthMap.DoesNotExist:
# go render form for creating edX user
eamap = ExternalAuthMap(external_id=external_id,
external_domain=external_domain,
external_credentials=json.dumps(credentials),
)
eamap.external_email = email
eamap.external_name = fullname
eamap.internal_password = edXauth_generate_password()
log.debug('created eamap=%s' % eamap)
eamap.save()
internal_user = eamap.user
if internal_user is None:
log.debug('ExtAuth: no user for %s yet, doing signup' %
eamap.external_email)
return edXauth_signup(request, eamap)
uname = internal_user.username
user = authenticate(username=uname, password=eamap.internal_password)
if user is None:
log.warning("External Auth Login failed for %s / %s" %
(uname, eamap.internal_password))
return edXauth_signup(request, eamap)
if not user.is_active:
log.warning("External Auth: user %s is not active" % (uname))
# TODO: improve error page
msg = 'Account not yet activated: please look for link in your email'
return render_failure(request, msg) # TODO: [rocha] render_failure not defined?
login(request, user)
request.session.set_expiry(0)
student_views.try_change_enrollment(request)
log.info("Login success - {0} ({1})".format(user.username, user.email))
if retfun is None:
return redirect('/')
return retfun()
#-----------------------------------------------------------------------------
# generic external auth signup
@ensure_csrf_cookie
@cache_if_anonymous
def edXauth_signup(request, eamap=None):
"""
Present form to complete for signup via external authentication.
Even though the user has external credentials, he/she still needs
to create an account on the edX system, and fill in the user
registration form.
eamap is an ExteralAuthMap object, specifying the external user
for which to complete the signup.
"""
if eamap is None:
pass
# save this for use by student.views.create_account
request.session['ExternalAuthMap'] = eamap
# default conjoin name, no spaces
username = eamap.external_name.replace(' ', '')
context = {'has_extauth_info': True,
'show_signup_immediately': True,
'extauth_email': eamap.external_email,
'extauth_username': username,
'extauth_name': eamap.external_name,
}
log.debug('ExtAuth: doing signup for %s' % eamap.external_email)
return student_views.index(request, extra_context=context)
#-----------------------------------------------------------------------------
# MIT SSL
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)
@csrf_exempt
def edXauth_ssl_login(request):
"""
This is called by student.views.index when
MITX_FEATURES['AUTH_USE_MIT_CERTIFICATES'] = True
Used for MIT user authentication. This presumes the web server
(nginx) has been configured to require specific client
certificates.
If the incoming protocol is HTTPS (SSL) then authenticate via
client certificate. The certificate provides user email and
fullname; this populates the ExternalAuthMap. The user is
nevertheless still asked to complete the edX signup.
Else continues on with student.views.index, and no authentication.
"""
certkey = "SSL_CLIENT_S_DN" # specify the request.META field to use
cert = request.META.get(certkey, '')
if not cert:
cert = request.META.get('HTTP_' + certkey, '')
if not cert:
try:
# try the direct apache2 SSL key
cert = request._req.subprocess_env.get(certkey, '')
except Exception:
pass
if not cert:
# no certificate information - go onward to main index
return student_views.index(request)
(user, email, fullname) = ssl_dn_extract_info(cert)
retfun = functools.partial(student_views.index, request)
return edXauth_external_login_or_signup(request,
external_id=email,
external_domain="ssl:MIT",
credentials=cert,
email=email,
fullname=fullname,
retfun=retfun)
def get_dict_for_openid(data):
"""
Return a dictionary suitable for the OpenID library
"""
return dict((k, v) for k, v in data.iteritems())
def get_xrds_url(resource, request):
"""
Return the XRDS url for a resource
"""
location = request.META['HTTP_HOST'] + '/openid/provider/' + resource + '/'
if request.is_secure():
url = 'https://' + location
else:
url = 'http://' + location
return url
def provider_respond(server, request, response, data):
"""
Respond to an OpenID request
"""
# get simple registration request
sreg_data = {}
sreg_request = sreg.SRegRequest.fromOpenIDRequest(request)
sreg_fields = sreg_request.allRequestedFields()
# if consumer requested simple registration fields, add them
if sreg_fields:
for field in sreg_fields:
if field == 'email' and 'email' in data:
sreg_data['email'] = data['email']
elif field == 'fullname' and 'fullname' in data:
sreg_data['fullname'] = data['fullname']
# construct sreg response
sreg_response = sreg.SRegResponse.extractResponse(sreg_request,
sreg_data)
sreg_response.toMessage(response.fields)
# get attribute exchange request
try:
ax_request = ax.FetchRequest.fromOpenIDRequest(request)
except ax.AXError:
pass
else:
ax_response = ax.FetchResponse()
# if consumer requested attribute exchange fields, add them
if ax_request and ax_request.requested_attributes:
for type_uri in ax_request.requested_attributes.iterkeys():
if type_uri == 'http://axschema.org/contact/email' and 'email' in data:
ax_response.addValue('http://axschema.org/contact/email', data['email'])
elif type_uri == 'http://axschema.org/namePerson' and 'fullname' in data:
ax_response.addValue('http://axschema.org/namePerson', data['fullname'])
# construct ax response
ax_response.toMessage(response.fields)
# create http response from OpenID response
webresponse = server.encodeResponse(response)
http_response = HttpResponse(webresponse.body)
http_response.status_code = webresponse.code
# add OpenID headers to response
for k, v in webresponse.headers.iteritems():
http_response[k] = v
return http_response
def validate_trust_root(openid_request):
"""
Only allow OpenID requests from valid trust roots
"""
# don't allow empty trust roots
if openid_request.trust_root is None:
return False
# ensure trust root parses cleanly (one wildcard, of form *.foo.com, etc.)
trust_root = TrustRoot.parse(openid_request.trust_root)
if trust_root is None:
return False
# don't allow empty return tos
if openid_request.return_to is None:
return False
# ensure return to is within trust root
if not trust_root.validateURL(openid_request.return_to):
return False
# only allow *.cs50.net for now
return trust_root.host.endswith('cs50.net')
@csrf_exempt
def provider_login(request):
"""
OpenID login endpoint
"""
# initialize store and server
endpoint = get_xrds_url('login', request)
store = FileOpenIDStore('/tmp/openid_provider')
server = Server(store, endpoint)
# handle OpenID request
query = get_dict_for_openid(request.REQUEST)
error = False
if 'openid.mode' in request.GET or 'openid.mode' in request.POST:
# decode request
openid_request = server.decodeRequest(query)
# don't allow invalid and non-*.cs50.net trust roots
if not validate_trust_root(openid_request):
return default_render_failure(request, "Invalid OpenID trust root")
# checkid_immediate not supported, require user interaction
if openid_request.mode == 'checkid_immediate':
return provider_respond(server, openid_request,
openid_request.answer(False), {})
# checkid_setup, so display login page
elif openid_request.mode == 'checkid_setup':
if openid_request.idSelect():
# remember request and original path
request.session['openid_request'] = {
'request': openid_request,
'url': request.get_full_path()
}
# user failed login on previous attempt
if 'openid_error' in request.session:
error = True
del request.session['openid_error']
# OpenID response
else:
return provider_respond(server, openid_request,
server.handleRequest(openid_request), {})
# handle login
if request.method == 'POST' and 'openid_request' in request.session:
# get OpenID request from session
openid_request = request.session['openid_request']
del request.session['openid_request']
# don't allow invalid and non-*.cs50.net trust roots
if not validate_trust_root(openid_request):
return default_render_failure(request, "Invalid OpenID trust root")
# check if user with given email exists
email = request.POST['email']
password = request.POST['password']
try:
user = User.objects.get(email=email)
except User.DoesNotExist:
request.session['openid_error'] = True
msg = "OpenID login failed - Unknown user email: {0}".format(email)
log.warning(msg)
return HttpResponseRedirect(openid_request['url'])
# attempt to authenticate user
username = user.username
user = authenticate(username=username, password=password)
if user is None:
request.session['openid_error'] = True
msg = "OpenID login failed - password for {0} is invalid".format(email)
log.warning(msg)
return HttpResponseRedirect(openid_request['url'])
# authentication succeeded, so log user in
if user is not None and user.is_active:
# remove error from session since login succeeded
if 'openid_error' in request.session:
del request.session['openid_error']
# fullname field comes from user profile
profile = UserProfile.objects.get(user=user)
log.info("OpenID login success - {0} ({1})".format(user.username,
user.email))
# redirect user to return_to location
response = openid_request['request'].answer(True, None, endpoint + urlquote(user.username))
return provider_respond(server,
openid_request['request'],
response,
{
'fullname': profile.name,
'email': user.email
})
request.session['openid_error'] = True
log.warning("Login failed - Account not active for user {0}".format(username))
return HttpResponseRedirect(openid_request['url'])
# determine consumer domain if applicable
return_to = ''
if 'openid.return_to' in request.REQUEST:
matches = re.match(r'\w+:\/\/([\w\.-]+)', request.REQUEST['openid.return_to'])
return_to = matches.group(1)
# display login page
response = render_to_response('provider_login.html', {
'error': error,
'return_to': return_to
})
# custom XRDS header necessary for discovery process
response['X-XRDS-Location'] = get_xrds_url('xrds', request)
return response
def provider_identity(request):
"""
XRDS for identity discovery
"""
response = render_to_response('identity.xml', {
'url': get_xrds_url('login', request)
}, mimetype='text/xml')
# custom XRDS header necessary for discovery process
response['X-XRDS-Location'] = get_xrds_url('identity', request)
return response
def provider_xrds(request):
"""
XRDS for endpoint discovery
"""
response = render_to_response('xrds.xml', {
'url': get_xrds_url('login', request)
}, mimetype='text/xml')
# custom XRDS header necessary for discovery process
response['X-XRDS-Location'] = get_xrds_url('xrds', request)
return response