improve logic for preventing downloads of hidden files

The use of file_listed is inefficient and will make s3 support more
difficult. We also need to remove the use of local file references in
views.py. This uses the artifact object to make the decision.

Change-Id: I2c1759e176ef249d858c9286be285a4bcbe81db1

2 files changed, 11 insertions, 28 deletions

diff --git a/license_protected_downloads/common.py b/license_protected_downloads/common.py
index 98d93b3..a0560fc 100644
--- a/license_protected_downloads/common.py
+++ b/license_protected_downloads/common.py
@@ -183,15 +183,6 @@ def find_artifact(request, path):
     raise Http404
 
 
-def _hidden_file(file_name):
-    hidden_files = ["BUILD-INFO.txt", "EULA.txt", "HEADER.html",
-                    "HOWTO_", "textile", ".htaccess", "licenses"]
-    for pattern in hidden_files:
-        if re.search(pattern, file_name):
-            return True
-    return False
-
-
 def _sort_artifacts(a, b):
     '''Ensures directory listings follow our ordering rules for artifacts.
 
@@ -241,6 +232,14 @@ class Artifact(object):
     def isdir(self):
         raise RuntimeError()
 
+    def hidden(self):
+        hidden_files = ["BUILD-INFO.txt", "EULA.txt", "HEADER.html",
+                        "HOWTO_", "textile", ".htaccess", "licenses"]
+        for pattern in hidden_files:
+            if re.search(pattern, self.file_name):
+                return True
+        return False
+
     def url(self):
         url = self.urlbase
         if url:
@@ -323,6 +322,6 @@ def dir_list(url, path, human_readable=True):
 
     listing = []
     for artifact in artifacts:
-        if not _hidden_file(artifact.file_name):
+        if not artifact.hidden():
             listing.append(artifact.get_listing())
     return listing
diff --git a/license_protected_downloads/views.py b/license_protected_downloads/views.py
index 17ae1da..71d1b71 100644
--- a/license_protected_downloads/views.py
+++ b/license_protected_downloads/views.py
@@ -160,20 +160,6 @@ def redirect_to_root(request):
     return redirect('/')
 
 
-def file_listed(path, url):
-    """Boolean response to "does this files show up in a directory listing."""
-    file_name = os.path.basename(path)
-    dir_name = os.path.dirname(path)
-
-    found = False
-    file_list = dir_list(url, dir_name)
-    for file in file_list:
-        if file["name"] == file_name:
-            found = True
-
-    return found
-
-
 def is_whitelisted(url):
     """ Check if requested file is under whitelisted path.
     """
@@ -339,10 +325,8 @@ def file_server_get(request, path):
     if artifact.isdir():
         return _handle_dir_list(request, url, path)
 
-    # If the file listing doesn't contain the file requested for download,
-    # return a 404. This prevents the download of BUILD-INFO.txt and other
-    # hidden files.
-    if not file_listed(path, url):
+    # prevent download of files like BUILD-INFO.txt
+    if artifact.hidden():
         raise Http404
 
     resp = _check_file_permission(request, artifact, internal)