some code refactoring and better error handling on ticket validation

cas_server/utils.py

@@ -9,8 +9,14 @@
 #
 # (c) 2015 Valentin Samir
 """Some util function for the app"""
+from . import default_settings
+
+from django.conf import settings
+
 import urlparse
 import urllib
+import random
+import string
 
 def update_url(url, params):
     """update params in the `url` query string"""
@@ -19,3 +25,46 @@ def update_url(url, params):
     query.update(params)
     url_parts[4] = urllib.urlencode(query)
     return urlparse.urlunparse(url_parts)
+
+def unpack_nested_exception(error):
+    """If exception are stacked, return the first one"""
+    i = 0
+    while True:
+        if error.args[i:]:
+            if isinstance(error.args[i], Exception):
+                error = error.args[i]
+                i = 0
+            else:
+                i += 1
+        else:
+            break
+    return error
+
+
+def _gen_ticket(prefix):
+    """Generate a ticket with prefix `prefix`"""
+    return '%s-%s' % (
+        prefix,
+        ''.join(
+            random.choice(
+                string.ascii_letters + string.digits
+            ) for _ in range(settings.CAS_ST_LEN)
+        )
+    )
+
+def gen_st():
+    """Generate a Service Ticket"""
+    return _gen_ticket('ST')
+
+def gen_pt():
+    """Generate a Proxy Ticket"""
+    return _gen_ticket('PT')
+
+def gen_pgt():
+    """Generate a Proxy Granting Ticket"""
+    return _gen_ticket('PGT')
+
+def gen_pgtiou():
+    """Generate a Proxy Granting Ticket IOU"""
+    return _gen_ticket('PGTIOU')
+