cas_provider/views.py

   1 import logging
   2 logger = logging.getLogger('cas_provider.views')
   3 import urllib
   4
   5 import logging
   6 from urllib import urlencode
   7 import urllib2
   8 import urlparse
   9
  10 from django.http import HttpResponse, HttpResponseRedirect
  11 from django.conf import settings
  12 from django.contrib.auth import login as auth_login, logout as auth_logout
  13 from django.core.urlresolvers import get_callable
  14 from django.shortcuts import render_to_response
  15 from django.template import RequestContext
  16 from django.contrib.auth import authenticate
  17 from django.core.urlresolvers import reverse
  18
  19 from lxml import etree
  20 from cas_provider.attribute_formatters import NSMAP, CAS
  21 from cas_provider.models import ProxyGrantingTicket, ProxyTicket
  22 from cas_provider.models import ServiceTicket
  23
  24 from cas_provider.exceptions import SameEmailMismatchedPasswords
  25 from cas_provider.forms import LoginForm, MergeLoginForm
  26
  27 from . import signals
  28
  29 __all__ = ['login', 'validate', 'logout', 'service_validate']
  30
  31 INVALID_TICKET = 'INVALID_TICKET'
  32 INVALID_SERVICE = 'INVALID_SERVICE'
  33 INVALID_REQUEST = 'INVALID_REQUEST'
  34 INTERNAL_ERROR = 'INTERNAL_ERROR'
  35
  36 ERROR_MESSAGES = (
  37     (INVALID_TICKET, u'The provided ticket is invalid.'),
  38     (INVALID_SERVICE, u'Service is invalid'),
  39     (INVALID_REQUEST, u'Not all required parameters were sent.'),
  40     (INTERNAL_ERROR, u'An internal error occurred during ticket validation'),
  41     )
  42
  43
  44 logger = logging.getLogger(__name__)
  45
  46
  47 def login(request, template_name='cas/login.html',
  48           success_redirect=settings.LOGIN_REDIRECT_URL,
  49           warn_template_name='cas/warn.html', **kwargs):
  50     merge = kwargs.get('merge', False)
  51     logging.debug('CAS Provider Login view. Method is %s, merge is %s, template is %s.',
  52                   request.method, merge, template_name)
  53
  54     service = request.GET.get('service', None)
  55     if service is not None:
  56         # Save the service on the session, for later use if we end up
  57         # in one of the more complicated workflows.
  58         request.session['service'] = service
  59
  60     user = request.user
  61
  62     errors = []
  63
  64     if request.method == 'POST':
  65         if merge:
  66             form = MergeLoginForm(request.POST, request=request)
  67         else:
  68             form = LoginForm(request.POST, request=request)
  69
  70         if form.is_valid():
  71             service = form.cleaned_data.get('service', None)
  72             try:
  73                 auth_args = dict(username=form.cleaned_data['email'],
  74                                  password=form.cleaned_data['password'])
  75                 if merge:
  76                     # We only want to send the merge argument if it's
  77                     # True. If it it's False, we want it to propagate
  78                     # through the auth backends properly.
  79                     auth_args['merge'] = merge
  80                 user = authenticate(**auth_args)
  81             except SameEmailMismatchedPasswords:
  82                 # Need to merge the accounts?
  83                 if merge:
  84                     # We shouldn't get here...
  85                     raise
  86                 else:
  87                     base_url = reverse('cas_provider_merge')
  88                     args = dict(
  89                         success_redirect=success_redirect,
  90                         email=form.cleaned_data['email'],
  91                         )
  92                     if service is not None:
  93                         args['service'] = service
  94                     args = urllib.urlencode(args)
  95
  96                     url = '%s?%s' % (base_url, args)
  97                     logging.debug('Redirecting to %s', url)
  98                     return HttpResponseRedirect(url)
  99
 100             if user is None:
 101                 errors.append('Incorrect username and/or password.')
 102             else:
 103                 if user.is_active:
 104                     auth_login(request, user)
 105
 106     else:  # Not a POST...
 107         if merge:
 108             form = MergeLoginForm(initial={'service': service, 'email': request.GET.get('email')})
 109         else:
 110             form = LoginForm(initial={'service': service})
 111
 112     if user is not None and user.is_authenticated():
 113         # We have an authenticated user.
 114         if not user.is_active:
 115             errors.append('This account is disabled.')
 116         else:
 117             # Send the on_cas_login signal. If we get an HttpResponse, return that.
 118             for receiver, response in signals.on_cas_login.send(sender=login, request=request, **kwargs):
 119                 if isinstance(response, HttpResponse):
 120                     return response
 121
 122             if service is None:
 123                 # Try and pull the service off the session
 124                 service = request.session.pop('service', service)
 125
 126             if service is None:
 127                 # Normal internal success redirection.
 128                 logging.debug('Redirecting to %s', success_redirect)
 129                 return HttpResponseRedirect(success_redirect)
 130             else:
 131                 if request.GET.get('warn', False):
 132                     return render_to_response(warn_template_name, {
 133                         'service': service,
 134                         'warn': False
 135                     }, context_instance=RequestContext(request))
 136
 137                 # Create a service ticket and redirect to the service.
 138                 ticket = ServiceTicket.objects.create(service=service, user=user)
 139                 if 'service' in request.session:
 140                     # Don't need this any more.
 141                     del request.session['service']
 142
 143                 url = ticket.get_redirect_url()
 144                 logging.debug('Redirecting to %s', url)
 145                 return HttpResponseRedirect(url)
 146
 147     logging.debug('Rendering response on %s, merge is %s', template_name, merge)
 148     return render_to_response(template_name, {'form': form, 'errors': errors}, context_instance=RequestContext(request))
 149
 150
 151 def validate(request):
 152     """Validate ticket via CAS v.1 protocol
 153     """
 154     service = request.GET.get('service', None)
 155     ticket_string = request.GET.get('ticket', None)
 156     logger.info('Validating ticket %s for %s', ticket_string, service)
 157     if service is not None and ticket_string is not None:
 158         #renew = request.GET.get('renew', True)
 159         #if not renew:
 160         # TODO: check user SSO session
 161         try:
 162             ticket = ServiceTicket.objects.get(ticket=ticket_string)
 163             assert ticket.service == service
 164         except ServiceTicket.DoesNotExist:
 165             logger.exception("Tried to validate with an invalid ticket %s for %s", ticket_string, service)
 166         except Exception as e:
 167             logger.exception('Got an exception: %s', e)
 168         else:
 169             username = ticket.user.username
 170             ticket.delete()
 171
 172             results = signals.on_cas_collect_histories.send(sender=validate, for_user=ticket.user)
 173             histories = '\n'.join('\n'.join(rs) for rc, rs in results)
 174             logger.info('Validated %s %s', username, "(also %s)" % histories if histories else '')
 175             return HttpResponse("yes\n%s\n%s" % (username, histories))
 176
 177     logger.info('Validation failed.')
 178     return HttpResponse("no\n\n")
 179
 180
 181 def logout(request, template_name='cas/logout.html',
 182            auto_redirect=settings.CAS_AUTO_REDIRECT_AFTER_LOGOUT):
 183     url = request.GET.get('url', None)
 184     if request.user.is_authenticated():
 185         for ticket in ServiceTicket.objects.filter(user=request.user):
 186             ticket.delete()
 187         auth_logout(request)
 188         if url and auto_redirect:
 189             return HttpResponseRedirect(url)
 190     return render_to_response(template_name, {'url': url},
 191         context_instance=RequestContext(request))
 192
 193
 194 def proxy(request):
 195     targetService = request.GET['targetService']
 196     pgt_id = request.GET['pgt']
 197
 198     try:
 199         proxyGrantingTicket = ProxyGrantingTicket.objects.get(ticket=pgt_id)
 200     except ProxyGrantingTicket.DoesNotExist:
 201         return _cas2_error_response(INVALID_TICKET)
 202
 203     pt = ProxyTicket.objects.create(proxyGrantingTicket=proxyGrantingTicket,
 204         user=proxyGrantingTicket.serviceTicket.user,
 205         service=targetService)
 206     return _cas2_proxy_success(pt.ticket)
 207
 208
 209 def ticket_validate(service, ticket_string, pgtUrl):
 210     if service is None or ticket_string is None:
 211         return _cas2_error_response(INVALID_REQUEST)
 212
 213     try:
 214         if ticket_string.startswith('ST'):
 215             ticket = ServiceTicket.objects.get(ticket=ticket_string)
 216         elif ticket_string.startswith('PT'):
 217             ticket = ProxyTicket.objects.get(ticket=ticket_string)
 218         else:
 219             return _cas2_error_response(INVALID_TICKET,
 220                 '%(ticket)s is neither Service (ST-...) nor Proxy Ticket (PT-...)' % {
 221                     'ticket': ticket_string})
 222     except ServiceTicket.DoesNotExist:
 223         return _cas2_error_response(INVALID_TICKET)
 224
 225     ticketUrl = urlparse.urlparse(ticket.service)
 226     serviceUrl = urlparse.urlparse(service)
 227
 228     if not(ticketUrl.hostname == serviceUrl.hostname and ticketUrl.path == serviceUrl.path and ticketUrl.port == serviceUrl.port):
 229         return _cas2_error_response(INVALID_SERVICE)
 230
 231     pgtIouId = None
 232     proxies = ()
 233     if pgtUrl is not None:
 234         pgt = generate_proxy_granting_ticket(pgtUrl, ticket)
 235         if pgt:
 236             pgtIouId = pgt.pgtiou
 237
 238     if hasattr(ticket, 'proxyticket'):
 239         pgt = ticket.proxyticket.proxyGrantingTicket
 240         # I am issued by this proxy granting ticket
 241         if hasattr(pgt.serviceTicket, 'proxyticket'):
 242             while pgt:
 243                 if hasattr(pgt.serviceTicket, 'proxyticket'):
 244                     proxies += (pgt.serviceTicket.service,)
 245                     pgt = pgt.serviceTicket.proxyticket.proxyGrantingTicket
 246                 else:
 247                     pgt = None
 248
 249     user = ticket.user
 250     ticket.delete()
 251     return _cas2_sucess_response(user, pgtIouId, proxies)
 252
 253
 254 def service_validate(request):
 255     """Validate ticket via CAS v.2 protocol"""
 256     service = request.GET.get('service', None)
 257     ticket_string = request.GET.get('ticket', None)
 258     pgtUrl = request.GET.get('pgtUrl', None)
 259     if ticket_string.startswith('PT-'):
 260         return _cas2_error_response(INVALID_TICKET, "serviceValidate cannot verify proxy tickets")
 261     else:
 262         return ticket_validate(service, ticket_string, pgtUrl)
 263
 264
 265 def proxy_validate(request):
 266     """Validate ticket via CAS v.2 protocol"""
 267     service = request.GET.get('service', None)
 268     ticket_string = request.GET.get('ticket', None)
 269     pgtUrl = request.GET.get('pgtUrl', None)
 270     return ticket_validate(service, ticket_string, pgtUrl)
 271
 272
 273 def generate_proxy_granting_ticket(pgt_url, ticket):
 274     proxy_callback_good_status = (200, 202, 301, 302, 304)
 275     uri = list(urlparse.urlsplit(pgt_url))
 276
 277     pgt = ProxyGrantingTicket()
 278     pgt.serviceTicket = ticket
 279     pgt.targetService = pgt_url
 280
 281     if hasattr(ticket, 'proxyGrantingTicket'):
 282         # here we got a proxy ticket! tata!
 283         pgt.pgt = ticket.proxyGrantingTicket
 284
 285     params = {'pgtId': pgt.ticket, 'pgtIou': pgt.pgtiou}
 286
 287     query = dict(urlparse.parse_qsl(uri[4]))
 288     query.update(params)
 289
 290     uri[3] = urlencode(query)
 291
 292     try:
 293         response = urllib2.urlopen(urlparse.urlunsplit(uri))
 294     except urllib2.HTTPError as e:
 295         if not e.code in proxy_callback_good_status:
 296             logger.debug('Checking Proxy Callback URL {} returned {}. Not issuing PGT.'.format(uri, e.code))
 297             return
 298     except urllib2.URLError as e:
 299         logger.debug('Checking Proxy Callback URL {} raised URLError. Not issuing PGT.'.format(uri))
 300         return
 301
 302     pgt.save()
 303     return pgt
 304
 305
 306 def _cas2_proxy_success(pt):
 307     return HttpResponse(proxy_success(pt))
 308
 309
 310 def _cas2_sucess_response(user, pgt=None, proxies=None):
 311     return HttpResponse(auth_success_response(user, pgt, proxies), mimetype='text/xml')
 312
 313
 314 def _cas2_error_response(code, message=None):
 315     return HttpResponse(u'''<cas:serviceResponse xmlns:cas="http://www.yale.edu/tp/cas">
 316             <cas:authenticationFailure code="%(code)s">
 317                 %(message)s
 318             </cas:authenticationFailure>
 319         </cas:serviceResponse>''' % {
 320         'code': code,
 321         'message': message if message else dict(ERROR_MESSAGES).get(code)
 322     }, mimetype='text/xml')
 323
 324
 325 def proxy_success(pt):
 326     response = etree.Element(CAS + 'serviceResponse', nsmap=NSMAP)
 327     proxySuccess = etree.SubElement(response, CAS + 'proxySuccess')
 328     proxyTicket = etree.SubElement(proxySuccess, CAS + 'proxyTicket')
 329     proxyTicket.text = pt
 330     return unicode(etree.tostring(response, encoding='utf-8'), 'utf-8')
 331
 332
 333 def auth_success_response(user, pgt, proxies):
 334     response = etree.Element(CAS + 'serviceResponse', nsmap=NSMAP)
 335     auth_success = etree.SubElement(response, CAS + 'authenticationSuccess')
 336     username = etree.SubElement(auth_success, CAS + 'user')
 337     username.text = user.username
 338
 339     attrs = {}
 340     for receiver, custom in signals.cas_collect_custom_attributes.send(sender=auth_success_response, user=user):
 341         if custom:
 342             attrs.update(custom)
 343
 344     attrs['identifiers'] = [i for r, i in signals.on_cas_collect_histories.send(sender=validate, for_user=user)]
 345
 346     if attrs:
 347         formatter = get_callable(settings.CAS_CUSTOM_ATTRIBUTES_FORMATER)
 348         formatter(auth_success, attrs)
 349
 350     if pgt:
 351         pgtElement = etree.SubElement(auth_success, CAS + 'proxyGrantingTicket')
 352         pgtElement.text = pgt
 353
 354     if proxies:
 355         proxiesElement = etree.SubElement(auth_success, CAS + "proxies")
 356         for proxy in proxies:
 357             proxyElement = etree.SubElement(proxiesElement, CAS + "proxy")
 358             proxyElement.text = proxy
 359
 360     return unicode(etree.tostring(response, encoding='utf-8'), 'utf-8')