Edited README.rst via GitHub
[django-cas-provider.git] / cas_provider / views.py
1 from lxml import etree
2 from urllib import urlencode
3 import urllib2
4 import urlparse
5 from django.conf import settings
6 from django.contrib.auth import login as auth_login, logout as auth_logout
7 from django.core.urlresolvers import get_callable
8 from django.http import HttpResponse, HttpResponseRedirect
9 from django.shortcuts import render_to_response
10 from django.template import RequestContext
11 from cas_provider.attribute_formatters import NSMAP, CAS
12 from cas_provider.models import ProxyGrantingTicket, ProxyTicket
13 from forms import LoginForm
14 from models import ServiceTicket, LoginTicket
15
16
17 __all__ = ['login', 'validate', 'logout', 'service_validate']
18
19 INVALID_TICKET = 'INVALID_TICKET'
20 INVALID_SERVICE = 'INVALID_SERVICE'
21 INVALID_REQUEST = 'INVALID_REQUEST'
22 INTERNAL_ERROR = 'INTERNAL_ERROR'
23
24 ERROR_MESSAGES = (
25     (INVALID_TICKET, u'The provided ticket is invalid.'),
26     (INVALID_SERVICE, u'Service is invalid'),
27     (INVALID_REQUEST, u'Not all required parameters were sent.'),
28     (INTERNAL_ERROR, u'An internal error occurred during ticket validation'),
29     )
30
31
32 def login(request, template_name='cas/login.html',\
33           success_redirect=settings.LOGIN_REDIRECT_URL,
34           warn_template_name='cas/warn.html',
35           form_class=LoginForm):
36     service = request.GET.get('service', None)
37     if request.user.is_authenticated():
38         if service is not None:
39             if request.GET.get('warn', False):
40                 return render_to_response(warn_template_name, {
41                     'service': service,
42                     'warn': False
43                 }, context_instance=RequestContext(request))
44             ticket = ServiceTicket.objects.create(service=service, user=request.user)
45             return HttpResponseRedirect(ticket.get_redirect_url())
46         else:
47             return HttpResponseRedirect(success_redirect)
48     if request.method == 'POST':
49         form = form_class(data=request.POST, request=request)
50         if form.is_valid():
51             user = form.get_user()
52             auth_login(request, user)
53             service = form.cleaned_data.get('service')
54             if service is not None:
55                 ticket = ServiceTicket.objects.create(service=service, user=user)
56                 success_redirect = ticket.get_redirect_url()
57             return HttpResponseRedirect(success_redirect)
58     else:
59         form = form_class(request=request, initial={
60             'service': service,
61             'lt': LoginTicket.objects.create()
62         })
63     if hasattr(request, 'session') and hasattr(request.session, 'set_test_cookie'):
64         request.session.set_test_cookie()
65     return render_to_response(template_name, {
66         'form': form,
67         'errors': form.get_errors() if hasattr(form, 'get_errors') else None,
68         }, context_instance=RequestContext(request))
69
70
71 def validate(request):
72     """Validate ticket via CAS v.1 protocol"""
73     service = request.GET.get('service', None)
74     ticket_string = request.GET.get('ticket', None)
75     if service is not None and ticket_string is not None:
76         #renew = request.GET.get('renew', True)
77         #if not renew:
78         # TODO: check user SSO session
79         try:
80             ticket = ServiceTicket.objects.get(ticket=ticket_string)
81             assert ticket.service == service
82             username = ticket.user.username
83             return HttpResponse("yes\n%s\n" % username)
84         except:
85             pass
86     return HttpResponse("no\n\n")
87
88
89 def logout(request, template_name='cas/logout.html',
90            auto_redirect=settings.CAS_AUTO_REDIRECT_AFTER_LOGOUT):
91     url = request.GET.get('url', None)
92     if request.user.is_authenticated():
93         for ticket in ServiceTicket.objects.filter(user = request.user):
94             ticket.delete()
95         auth_logout(request)
96         if url and auto_redirect:
97             return HttpResponseRedirect(url)
98     return render_to_response(template_name, {'url': url},\
99                               context_instance=RequestContext(request))
100
101 def proxy(request):
102     targetService =  request.GET['targetService']
103     pgtiou = request.GET['pgt']
104
105     try:
106         proxyGrantingTicket = ProxyGrantingTicket.objects.get(pgtiou=pgtiou)
107     except ProxyGrantingTicket.DoesNotExist:
108         return _cas2_error_response(INVALID_TICKET)
109
110     pt = ProxyTicket.objects.create(proxyGrantingTicket = proxyGrantingTicket,
111         user=proxyGrantingTicket.serviceTicket.user,
112         service=targetService)
113     return _cas2_proxy_success(pt.ticket)
114
115
116 def ticket_validate(service, ticket_string, pgtUrl):
117     if service is None or ticket_string is None:
118         return _cas2_error_response(INVALID_REQUEST)
119
120     try:
121         ticket = ServiceTicket.objects.get(ticket=ticket_string)
122     except ServiceTicket.DoesNotExist:
123         return _cas2_error_response(INVALID_TICKET)
124
125     if ticket.service != service:
126         return _cas2_error_response(INVALID_SERVICE)
127
128
129     pgtIouId = None
130     proxies = ()
131     if pgtUrl is not None:
132         pgt = generate_proxy_granting_ticket(pgtUrl, ticket)
133         if pgt:
134             pgtIouId = pgt.pgtiou
135
136             while pgt:
137                 proxies += (pgt.serviceTicket.service,)
138                 pgt = pgt.serviceTicket.proxyGrantingTicket if hasattr(pgt.serviceTicket, 'proxyGrantingTicket') else None
139
140
141     user = ticket.user
142     return _cas2_sucess_response(user, pgtIouId, proxies)
143
144
145 def service_validate(request):
146     """Validate ticket via CAS v.2 protocol"""
147     service = request.GET.get('service', None)
148     ticket_string = request.GET.get('ticket', None)
149     pgtUrl = request.GET.get('pgtUrl', None)
150     if ticket_string.startswith('PT-'):
151         return _cas2_error_response(INVALID_TICKET, "serviceValidate cannot verify proxy tickets")
152     else:
153         return ticket_validate(service, ticket_string, pgtUrl)
154
155
156 def proxy_validate(request):
157     """Validate ticket via CAS v.2 protocol"""
158     service = request.GET.get('service', None)
159     ticket_string = request.GET.get('ticket', None)
160     pgtUrl = request.GET.get('pgtUrl', None)
161     return ticket_validate(service, ticket_string, pgtUrl)
162
163 def generate_proxy_granting_ticket(pgt_url, ticket):
164     proxy_callback_good_status = (200, 202, 301, 302, 304)
165     uri = list(urlparse.urlsplit(pgt_url))
166
167     pgt = ProxyGrantingTicket()
168     pgt.serviceTicket = ticket
169
170     if hasattr(ticket, 'proxyGrantingTicket'):
171         # here we got a proxy ticket! tata!
172         pgt.pgt = ticket.proxyGrantingTicket
173
174     params = {'pgtId': pgt.ticket, 'pgtIou': pgt.pgtiou}
175
176     query = dict(urlparse.parse_qsl(uri[4]))
177     query.update(params)
178
179     uri[4] = urlencode(query)
180
181
182     try:
183         response = urllib2.urlopen(urlparse.urlunsplit(uri))
184     except urllib2.HTTPError, e:
185         if not e.code in proxy_callback_good_status:
186             return
187     except urllib2.URLError, e:
188         return
189
190     pgt.save()
191     return pgt
192
193
194 def _cas2_proxy_success(pt):
195     return HttpResponse(proxy_success(pt))
196
197 def _cas2_sucess_response(user, pgt = None, proxies = None):
198     return HttpResponse(auth_success_response(user, pgt, proxies), mimetype='text/xml')
199
200 def _cas2_error_response(code, message = None):
201     return HttpResponse(u''''<cas:serviceResponse xmlns:cas="http://www.yale.edu/tp/cas">
202             <cas:authenticationFailure code="%(code)s">
203                 %(message)s
204             </cas:authenticationFailure>
205         </cas:serviceResponse>''' % {
206             'code': code,
207             'message': message if message else dict(ERROR_MESSAGES).get(code)
208     }, mimetype='text/xml')
209
210 def proxy_success(pt):
211     response = etree.Element(CAS + 'serviceResponse', nsmap=NSMAP)
212     proxySuccess = etree.SubElement(response, CAS + 'proxySuccess')
213     proxyTicket = etree.SubElement(proxySuccess, CAS + 'proxyTicket')
214     proxyTicket.text = pt
215     return unicode(etree.tostring(response, encoding='utf-8'), 'utf-8')
216
217 def auth_success_response(user, pgt, proxies):
218
219
220     response = etree.Element(CAS + 'serviceResponse', nsmap=NSMAP)
221     auth_success = etree.SubElement(response, CAS + 'authenticationSuccess')
222     username = etree.SubElement(auth_success, CAS + 'user')
223     username.text = user.username
224
225     if settings.CAS_CUSTOM_ATTRIBUTES_CALLBACK:
226         callback = get_callable(settings.CAS_CUSTOM_ATTRIBUTES_CALLBACK)
227         attrs = callback(user)
228         if len(attrs) > 0:
229             formater = get_callable(settings.CAS_CUSTOM_ATTRIBUTES_FORMATER)
230             formater(auth_success, attrs)
231
232
233     if pgt:
234         pgtElement = etree.SubElement(auth_success, CAS + 'proxyGrantingTicket')
235         pgtElement.text = pgt
236
237     if proxies:
238         proxiesElement = etree.SubElement(auth_success , CAS + "proxies")
239         for proxy in proxies:
240             proxyElement = etree.SubElement(proxiesElement, CAS + "proxy")
241             proxyElement.text = proxy
242
243
244
245     return unicode(etree.tostring(response, encoding='utf-8'), 'utf-8')