Support for Django 3.2

[django-cas-provider.git] / cas_provider / views.py

diff --git a/cas_provider/views.py b/cas_provider/views.py
index 452c071..6b39131 100644 (file)
--- a/cas_provider/views.py
+++ b/cas_provider/views.py
@@ -1,95 +1,397 @@
-from django.conf import settings
-from django.contrib.auth import login as auth_login, \
-    logout as auth_logout
+import logging
+logger = logging.getLogger('cas_provider.views')
+
+from urllib.error import HTTPError, URLError
+from urllib.parse import parse_qsl, urlencode, urlparse, urlsplit, urlunsplit
+from urllib.request import urlopen
+from functools import wraps
+
+from django.views.decorators.debug import sensitive_post_parameters
+from django.views.decorators.cache import cache_control
+from django.utils.cache import patch_cache_control
+from django.views.decorators.csrf import csrf_protect
+

 from django.http import HttpResponse, HttpResponseRedirect
 from django.http import HttpResponse, HttpResponseRedirect

-from django.shortcuts import render_to_response
+from django.conf import settings
+from django.contrib.auth import login as auth_login, logout as auth_logout
+
+from django.shortcuts import render
+from django.utils.translation import ugettext as _

 from django.template import RequestContext
 from django.template import RequestContext

-from forms import LoginForm
-from models import ServiceTicket, LoginTicket
+from django.contrib.auth import authenticate
+from django.utils.translation import ugettext as _

 
 

+from lxml import etree
+from cas_provider.attribute_formatters import NSMAP, CAS
+from cas_provider.models import ProxyGrantingTicket, ProxyTicket
+from cas_provider.models import ServiceTicket
+
+from cas_provider.forms import LoginForm, MergeLoginForm
+
+from . import signals
+
+from django.urls import get_callable, reverse

 
 __all__ = ['login', 'validate', 'logout', 'service_validate']
 
 
 __all__ = ['login', 'validate', 'logout', 'service_validate']
 

+INVALID_TICKET = 'INVALID_TICKET'
+INVALID_SERVICE = 'INVALID_SERVICE'
+INVALID_REQUEST = 'INVALID_REQUEST'
+INTERNAL_ERROR = 'INTERNAL_ERROR'
+
+ERROR_MESSAGES = (
+    (INVALID_TICKET, 'The provided ticket is invalid.'),
+    (INVALID_SERVICE, 'Service is invalid'),
+    (INVALID_REQUEST, 'Not all required parameters were sent.'),
+    (INTERNAL_ERROR, 'An internal error occurred during ticket validation'),
+    )
+
+
+logger = logging.getLogger(__name__)
+
+
+_never_cache = cache_control(no_cache=True, must_revalidate=True)
+
+
+def never_cache(view_func):
+    """
+    Decorator that adds headers to a response so that it will
+    never be cached.
+    """
+    @wraps(view_func)
+    def _wrapped_view_func(request, *args, **kwargs):
+        response = view_func(request, *args, **kwargs)
+        patch_cache_control(response, no_cache=True,
+                            must_revalidate=True, proxy_revalidate=True)
+        response['Pragma'] = 'no-cache'
+        return response
+    return _wrapped_view_func
+
+
+@sensitive_post_parameters()
+@csrf_protect
+@never_cache
+def login(request, template_name='cas/login.html',
+          success_redirect=settings.LOGIN_REDIRECT_URL,
+          warn_template_name='cas/warn.html', **kwargs):
+    merge = kwargs.get('merge', False)
+    logging.debug('CAS Provider Login view. Method is %s, merge is %s, template is %s.',
+                  request.method, merge, template_name)

 
 

-def login(request, template_name='cas/login.html', \
-                success_redirect=settings.LOGIN_REDIRECT_URL):

     service = request.GET.get('service', None)
     service = request.GET.get('service', None)

-    if request.user.is_authenticated():
-        if service is not None:
-            ticket = ServiceTicket.objects.create(service=service, user=request.user)
-            return HttpResponseRedirect(ticket.get_redirect_url())
-        else:
-            return HttpResponseRedirect(success_redirect)
+    if service is not None:
+        # Save the service on the session, for later use if we end up
+        # in one of the more complicated workflows.
+        request.session['service'] = service
+
+    user = request.user
+
+    errors = []
+

     if request.method == 'POST':
     if request.method == 'POST':

-        form = LoginForm(request.POST)
+        if merge:
+            form = MergeLoginForm(request.POST, request=request)
+        else:
+            form = LoginForm(request.POST, request=request)
+

         if form.is_valid():
         if form.is_valid():

-            user = form.get_user()
-            auth_login(request, user)
-            service = form.cleaned_data.get('service')
-            if service is not None:
+            service = form.cleaned_data.get('service', None)
+            try:
+                auth_args = dict(username=form.cleaned_data['username'],
+                                 password=form.cleaned_data['password'])
+                if merge:
+                    # We only want to send the merge argument if it's
+                    # True. If it it's False, we want it to propagate
+                    # through the auth backends properly.
+                    auth_args['merge'] = merge
+                user = authenticate(**auth_args)
+            except:
+                # Need to merge the accounts?
+                if merge:
+                    # We shouldn't get here...
+                    raise
+                else:
+                    base_url = reverse('cas_provider_merge')
+                    args = dict(
+                        success_redirect=success_redirect,
+                        username=form.cleaned_data['username'],
+                        )
+                    if service is not None:
+                        args['service'] = service
+                    args = urlencode(args)
+
+                    url = '%s?%s' % (base_url, args)
+                    logging.debug('Redirecting to %s', url)
+                    return HttpResponseRedirect(url)
+
+            if user is None:
+                errors.append(_('Incorrect username and/or password.'))
+            else:
+                if user.is_active:
+                    auth_login(request, user)
+
+    else:  # Not a POST...
+        if merge:
+            form = MergeLoginForm(initial={'service': service, 'username': request.GET.get('username')})
+        else:
+            form = LoginForm(initial={'service': service})
+
+    if user is not None and user.is_authenticated:
+        # We have an authenticated user.
+        if not user.is_active:
+            errors.append(_('This account is disabled. Please contact us if you feel it should be enabled again.'))
+        else:
+            # Send the on_cas_login signal. If we get an HttpResponse, return that.
+            for receiver, response in signals.on_cas_login.send(sender=login, request=request, **kwargs):
+                if isinstance(response, HttpResponse):
+                    return response
+
+            if service is None:
+                # Try and pull the service off the session
+                service = request.session.pop('service', service)
+
+            signals.on_cas_login_success.send(sender=login, request=request,
+                                              service=service, **kwargs)
+
+            if service is None:
+                # Normal internal success redirection.
+                logging.debug('Redirecting to %s', success_redirect)
+                return HttpResponseRedirect(success_redirect)
+            else:
+                if request.GET.get('warn', False):
+                    return render(request, warn_template_name, {
+                        'service': service,
+                        'warn': False
+                    })
+
+                # Create a service ticket and redirect to the service.

                 ticket = ServiceTicket.objects.create(service=service, user=user)
                 ticket = ServiceTicket.objects.create(service=service, user=user)

-                success_redirect = ticket.get_redirect_url()
-            return HttpResponseRedirect(success_redirect)
-    else:
-        form = LoginForm(initial={
-            'service': service,
-            'lt': LoginTicket.objects.create()
-        })
-    return render_to_response(template_name, {
-        'form': form,
-        'errors': form.get_errors()
-    }, context_instance=RequestContext(request))
+                if 'service' in request.session:
+                    # Don't need this any more.
+                    del request.session['service']

 
 

+                url = ticket.get_redirect_url()
+                logging.debug('Redirecting to %s', url)
+                return HttpResponseRedirect(url)

 
 

+    logging.debug('Rendering response on %s, merge is %s', template_name, merge)
+    return render(request, template_name, {'form': form, 'errors': errors})
+
+
+@never_cache

 def validate(request):
 def validate(request):

-    """Validate ticket via CAS v.1 protocol"""
+    """Validate ticket via CAS v.1 protocol
+    """

     service = request.GET.get('service', None)
     ticket_string = request.GET.get('ticket', None)
     service = request.GET.get('service', None)
     ticket_string = request.GET.get('ticket', None)

+    logger.info('Validating ticket %s for %s', ticket_string, service)

     if service is not None and ticket_string is not None:
     if service is not None and ticket_string is not None:

+        #renew = request.GET.get('renew', True)
+        #if not renew:
+        # TODO: check user SSO session

         try:
             ticket = ServiceTicket.objects.get(ticket=ticket_string)
         try:
             ticket = ServiceTicket.objects.get(ticket=ticket_string)

+            assert ticket.service == service
+        except ServiceTicket.DoesNotExist:
+            logger.exception("Tried to validate with an invalid ticket %s for %s", ticket_string, service)
+        except Exception as e:
+            logger.exception('Got an exception: %s', e)
+        else:

             username = ticket.user.username
             ticket.delete()
             username = ticket.user.username
             ticket.delete()

-            return HttpResponse("yes\r\n%s\r\n" % username)
-        except:
-            pass
-    return HttpResponse("no\r\n\r\n")

 
 

+            results = signals.on_cas_collect_histories.send(sender=validate, for_user=ticket.user)
+            histories = '\n'.join('\n'.join(rs) for rc, rs in results)
+            logger.info('Validated %s %s', username, "(also %s)" % histories if histories else '')
+            return HttpResponse("yes\n%s\n%s" % (username, histories))

 
 

-def logout(request, template_name='cas/logout.html'):
+    logger.info('Validation failed.')
+    return HttpResponse("no\n\n")
+
+
+@never_cache
+def logout(request, template_name='cas/logout.html',
+           auto_redirect=settings.CAS_AUTO_REDIRECT_AFTER_LOGOUT):

     url = request.GET.get('url', None)
     url = request.GET.get('url', None)

-    auth_logout(request)
-    return render_to_response(template_name, {'url': url}, context_instance=RequestContext(request))
+    if request.user.is_authenticated:
+        for ticket in ServiceTicket.objects.filter(user=request.user):
+            ticket.delete()
+        auth_logout(request)
+        if url and auto_redirect:
+            return HttpResponseRedirect(url)
+    return render(request, template_name, {'url': url})
+
+
+@never_cache
+def proxy(request):
+    targetService = request.GET['targetService']
+    pgt_id = request.GET['pgt']
+
+    try:
+        proxyGrantingTicket = ProxyGrantingTicket.objects.get(ticket=pgt_id)
+    except ProxyGrantingTicket.DoesNotExist:
+        return _cas2_error_response(INVALID_TICKET)
+
+    pt = ProxyTicket.objects.create(proxyGrantingTicket=proxyGrantingTicket,
+        user=proxyGrantingTicket.user,
+        service=targetService)
+    return _cas2_proxy_success(pt.ticket)

 
 
 
 

+def ticket_validate(service, ticket_string, pgtUrl):
+    if service is None or ticket_string is None:
+        return _cas2_error_response(INVALID_REQUEST)
+
+    try:
+        if ticket_string.startswith('ST'):
+            ticket = ServiceTicket.objects.get(ticket=ticket_string)
+        elif ticket_string.startswith('PT'):
+            ticket = ProxyTicket.objects.get(ticket=ticket_string)
+        else:
+            return _cas2_error_response(INVALID_TICKET,
+                '%(ticket)s is neither Service (ST-...) nor Proxy Ticket (PT-...)' % {
+                    'ticket': ticket_string})
+    except ServiceTicket.DoesNotExist:
+        return _cas2_error_response(INVALID_TICKET)
+
+    ticketUrl = urlparse(ticket.service)
+    serviceUrl = urlparse(service)
+
+    if not(ticketUrl.hostname == serviceUrl.hostname and ticketUrl.path == serviceUrl.path and ticketUrl.port == serviceUrl.port):
+        return _cas2_error_response(INVALID_SERVICE)
+
+    pgtIouId = None
+    proxies = ()
+    if pgtUrl is not None:
+        pgt = generate_proxy_granting_ticket(pgtUrl, ticket)
+        if pgt:
+            pgtIouId = pgt.pgtiou
+
+    try:
+        proxyTicket = ticket.proxyticket
+    except ProxyTicket.DoesNotExist:
+        pass
+    else:
+        pgt = proxyTicket.proxyGrantingTicket
+        # I am issued by this proxy granting ticket
+        while pgt.pgt is not None:
+            proxies += (pgt.service,)
+            pgt = pgt.pgt
+
+    user = ticket.user
+    ticket.delete()
+    return _cas2_sucess_response(user, pgtIouId, proxies)
+
+
+@never_cache

 def service_validate(request):
     """Validate ticket via CAS v.2 protocol"""
     service = request.GET.get('service', None)
     ticket_string = request.GET.get('ticket', None)
 def service_validate(request):
     """Validate ticket via CAS v.2 protocol"""
     service = request.GET.get('service', None)
     ticket_string = request.GET.get('ticket', None)

-    if service is None or ticket_string is None:
-        return _cas2_error_response(u'INVALID_REQUEST', u'Not all required parameters were sent.')
+    pgtUrl = request.GET.get('pgtUrl', None)
+    if ticket_string.startswith('PT-'):
+        return _cas2_error_response(INVALID_TICKET, "serviceValidate cannot verify proxy tickets")
+    else:
+        return ticket_validate(service, ticket_string, pgtUrl)
+
+
+@never_cache
+def proxy_validate(request):
+    """Validate ticket via CAS v.2 protocol"""
+    service = request.GET.get('service', None)
+    ticket_string = request.GET.get('ticket', None)
+    pgtUrl = request.GET.get('pgtUrl', None)
+    return ticket_validate(service, ticket_string, pgtUrl)
+
+
+def generate_proxy_granting_ticket(pgt_url, ticket):
+    proxy_callback_good_status = (200, 202, 301, 302, 304)
+    uri = list(urlsplit(pgt_url))
+
+    pgt = ProxyGrantingTicket()
+    pgt.user = ticket.user
+    pgt.service = ticket.service
+    # Remember if it's a chained PGT.
+    pgt.pgt = getattr(ticket, 'proxyGrantingTicket', None)
+
+    params = {'pgtId': pgt.ticket, 'pgtIou': pgt.pgtiou}
+
+    query = dict(parse_qsl(uri[4]))
+    query.update(params)
+
+    uri[3] = urlencode(query)

 
     try:
 
     try:

-        ticket = ServiceTicket.objects.get(ticket=ticket_string)
-    except ServiceTicket.DoesNotExist:
-        return _cas2_error_response(u'INVALID_TICKET', u'The provided ticket is invalid.')
+        urlopen(urlunsplit(uri))
+    except HTTPError as e:
+        if not e.code in proxy_callback_good_status:
+            logger.debug('Checking Proxy Callback URL {0} returned {1}. Not issuing PGT.'.format(uri, e.code))
+            return
+    except URLError as e:
+        logger.debug('Checking Proxy Callback URL {0} raised URLError. Not issuing PGT.'.format(uri))
+        return

 
 

-    if settings.CAS_CHECK_SERVICE and ticket.service != service:
-        ticket.delete()
-        return _cas2_error_response('INVALID_SERVICE', u'Service is invalid')
+    pgt.save()
+    return pgt

 
 

-    username = ticket.user.username
-    ticket.delete()
-    return HttpResponse(u'''<cas:serviceResponse xmlns:cas="http://www.yale.edu/tp/cas">
-        <cas:authenticationSuccess>
-            <cas:user>%(username)s</cas:user>
-        </cas:authenticationSuccess>
-    </cas:serviceResponse>''' % {'username': username}, mimetype='text/xml')
+
+def _cas2_proxy_success(pt):
+    return HttpResponse(proxy_success(pt))
+
+
+def _cas2_sucess_response(user, pgt=None, proxies=None):
+    return HttpResponse(auth_success_response(user, pgt, proxies), content_type='text/xml')

 
 
 
 

-def _cas2_error_response(code, message):
-    return HttpResponse(u''''<cas:serviceResponse xmlns:cas="http://www.yale.edu/tp/cas">
-            <cas:authenticationFailure code="%s">
-                %s
+def _cas2_error_response(code, message=None):
+    return HttpResponse('''<cas:serviceResponse xmlns:cas="http://www.yale.edu/tp/cas">
+            <cas:authenticationFailure code="%(code)s">
+                %(message)s

             </cas:authenticationFailure>
             </cas:authenticationFailure>

-        </cas:serviceResponse>''', mimetype='text/xml')
+        </cas:serviceResponse>''' % {
+        'code': code,
+        'message': message if message else dict(ERROR_MESSAGES).get(code)
+    }, content_type='text/xml')
+
+
+def proxy_success(pt):
+    response = etree.Element(CAS + 'serviceResponse', nsmap=NSMAP)
+    proxySuccess = etree.SubElement(response, CAS + 'proxySuccess')
+    proxyTicket = etree.SubElement(proxySuccess, CAS + 'proxyTicket')
+    proxyTicket.text = pt
+    return etree.tostring(response, encoding='unicode')
+
+
+def auth_success_response(user, pgt, proxies):
+    response = etree.Element(CAS + 'serviceResponse', nsmap=NSMAP)
+    auth_success = etree.SubElement(response, CAS + 'authenticationSuccess')
+    username = etree.SubElement(auth_success, CAS + 'user')
+    username.text = user.username
+
+    attrs = {}
+    for receiver, custom in signals.cas_collect_custom_attributes.send(sender=auth_success_response, user=user):
+        if custom:
+            attrs.update(custom)
+
+    identifiers = [i for sr, rr in signals.on_cas_collect_histories.send(sender=validate, for_user=user)
+                   for i in rr]
+
+    if identifiers:
+        # Singular `identifier`, as that is the name of the element tag(s).
+        attrs['identifier'] = identifiers
+
+    if attrs:
+        formatter = get_callable(settings.CAS_CUSTOM_ATTRIBUTES_FORMATER)
+        formatter(auth_success, attrs)
+
+    if pgt:
+        pgtElement = etree.SubElement(auth_success, CAS + 'proxyGrantingTicket')
+        pgtElement.text = pgt
+
+    if proxies:
+        proxiesElement = etree.SubElement(auth_success, CAS + "proxies")
+        for proxy in proxies:
+            proxyElement = etree.SubElement(proxiesElement, CAS + "proxy")
+            proxyElement.text = proxy
+
+    return etree.tostring(response, encoding='unicode')