ProtoGeni slices may have special characters that need to be filtered out

[sfa.git] / sfa / util / namespace.py

diff --git a/sfa/util/namespace.py b/sfa/util/namespace.py
index e898f3c..512f398 100644 (file)
--- a/sfa/util/namespace.py
+++ b/sfa/util/namespace.py
@@ -1,6 +1,6 @@
 ### $Id$
 ### $URL$
-
+import re
 from sfa.util.faults import *
 URN_PREFIX = "urn:publicid:IDN"
 
@@ -57,6 +57,9 @@ def urn_to_hrn(urn):
     """
     convert a urn to hrn
     return a tuple (hrn, type)
+    Warning: urn_to_hrn() replces some special characters that 
+    are not replaced in hrn_to_urn(). Due to this, 
+    urn_to_hrn() -> hrn_to_urn() may not return the original urn
     """
 
     # if this is already a hrn dont do anything
@@ -65,19 +68,22 @@ def urn_to_hrn(urn):
 
     name = urn[len(URN_PREFIX):]
     hrn_parts = name.split("+")
+    type = hrn_parts.pop(2)
     
-    # type is always the second to last element in the list
-    type = hrn_parts.pop(-2)
+         
+    # Remove the authority name (e.g. '.sa')
+    if type == 'authority':
+        hrn_parts = hrn_parts[:-1]
 
     # convert hrn_parts (list) into hrn (str) by doing the following    
+    # dont allow special characters (except ':') in the site login base
     # remove blank elements
     # replace ':' with '.'
     # join list elements using '.'
-    hrn = '.'.join([part.replace(':', '.') for part in hrn_parts if part]) 
+    only_alphanum = re.compile('[^a-zA-Z0-9:]+')
+    valid_chars = lambda x: only_alphanum.sub('', x).replace(':', '.')
+    hrn = '.'.join([valid_chars(part) for part in hrn_parts if part]) 
     
-    if type == 'authority':
-        hrn = hrn.replace ('.sa', '')
-   
     return str(hrn), str(type)