Use python-magic to get file types

boards/models/attachment/__init__.py

@@ -1,43 +1,46 b''
+import magic
+
 from django.db import models
 
 from boards import utils
 from boards.models.attachment.viewers import get_viewers, AbstractViewer
 from boards.utils import get_upload_filename
 
 FILES_DIRECTORY = 'files/'
 FILE_EXTENSION_DELIMITER = '.'
 
 
 class AttachmentManager(models.Manager):
     def create_with_hash(self, file):
         file_hash = utils.get_file_hash(file)
         existing = self.filter(hash=file_hash)
         if len(existing) > 0:
             attachment = existing[0]
         else:
-            file_type = file.name.split(FILE_EXTENSION_DELIMITER)[-1].lower()
+            file_type = magic.from_buffer(file.chunks().__next__(), mime=True)\
+                .decode().split('/')[-1]
             attachment = Attachment.objects.create(
                 file=file, mimetype=file_type, hash=file_hash)
 
         return attachment
 
 
 class Attachment(models.Model):
     objects = AttachmentManager()
 
     file = models.FileField(upload_to=get_upload_filename)
     mimetype = models.CharField(max_length=50)
     hash = models.CharField(max_length=36)
 
     def get_view(self):
         file_viewer = None
         for viewer in get_viewers():
             if viewer.supports(self.mimetype):
                 file_viewer = viewer
                 break
         if file_viewer is None:
             file_viewer = AbstractViewer
 
         return file_viewer(self.file, self.mimetype).get_view()
 
 

boards/utils.py

@@ -1,138 +1,142 b''
 """
 This module contains helper functions and helper classes.
 """
 import hashlib
 from random import random
 import time
 import hmac
 
 from django.core.cache import cache
 from django.db.models import Model
 from django import forms
 from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
 from portage import os
 
 import boards
 from boards.settings import get_bool
 from neboard import settings
 
 CACHE_KEY_DELIMITER = '_'
 PERMISSION_MODERATE = 'moderation'
 
 HTTP_FORWARDED = 'HTTP_X_FORWARDED_FOR'
 META_REMOTE_ADDR = 'REMOTE_ADDR'
 
 SETTING_MESSAGES = 'Messages'
 SETTING_ANON_MODE = 'AnonymousMode'
 
 ANON_IP = '127.0.0.1'
 
 UPLOAD_DIRS ={
     'PostImage': 'images/',
     'Attachment': 'files/',
 }
 FILE_EXTENSION_DELIMITER = '.'
 
 
 def is_anonymous_mode():
     return get_bool(SETTING_MESSAGES, SETTING_ANON_MODE)
 
 
 def get_client_ip(request):
     if is_anonymous_mode():
         ip = ANON_IP
     else:
         x_forwarded_for = request.META.get(HTTP_FORWARDED)
         if x_forwarded_for:
             ip = x_forwarded_for.split(',')[-1].strip()
         else:
             ip = request.META.get(META_REMOTE_ADDR)
     return ip
 
 
 # TODO The output format is not epoch because it includes microseconds
 def datetime_to_epoch(datetime):
     return int(time.mktime(timezone.localtime(
         datetime,timezone.get_current_timezone()).timetuple())
                * 1000000 + datetime.microsecond)
 
 
 def get_websocket_token(user_id='', timestamp=''):
     """
     Create token to validate information provided by new connection.
     """
 
     sign = hmac.new(settings.CENTRIFUGE_PROJECT_SECRET.encode())
     sign.update(settings.CENTRIFUGE_PROJECT_ID.encode())
     sign.update(user_id.encode())
     sign.update(timestamp.encode())
     token = sign.hexdigest()
 
     return token
 
 
 def cached_result(key_method=None):
     """
     Caches method result in the Django's cache system, persisted by object name,
     object name and model id if object is a Django model.
     """
     def _cached_result(function):
         def inner_func(obj, *args, **kwargs):
             # TODO Include method arguments to the cache key
             cache_key_params = [obj.__class__.__name__, function.__name__]
             if isinstance(obj, Model):
                 cache_key_params.append(str(obj.id))
 
             if key_method is not None:
                 cache_key_params += [str(arg) for arg in key_method(obj)]
 
             cache_key = CACHE_KEY_DELIMITER.join(cache_key_params)
 
             persisted_result = cache.get(cache_key)
             if persisted_result is not None:
                 result = persisted_result
             else:
                 result = function(obj, *args, **kwargs)
                 cache.set(cache_key, result)
 
             return result
 
         return inner_func
     return _cached_result
 
 
 def is_moderator(request):
     try:
         moderate = request.user.has_perm(PERMISSION_MODERATE)
     except AttributeError:
         moderate = False
 
     return moderate
 
 
 def get_file_hash(file) -> str:
     md5 = hashlib.md5()
     for chunk in file.chunks():
         md5.update(chunk)
     return md5.hexdigest()
 
 
 def validate_file_size(size: int):
     max_size = boards.settings.get_int('Forms', 'MaxFileSize')
     if size > max_size:
         raise forms.ValidationError(
             _('File must be less than %s bytes')
             % str(max_size))
 
 
 def get_upload_filename(model_instance, old_filename):
     # TODO Use something other than random number in file name
+    if hasattr(model_instance, 'file_type'):
+        extension = model_instance.file_type
+    else:
+        extension = old_filename.split(FILE_EXTENSION_DELIMITER)[-1:][0]
     new_name = '{}{}.{}'.format(
         str(int(time.mktime(time.gmtime()))),
         str(int(random() * 1000)),
-        old_filename.split(FILE_EXTENSION_DELIMITER)[-1:][0])
+        extension)
 
     directory = UPLOAD_DIRS[type(model_instance).__name__]
 
     return os.path.join(directory, new_name)

requirements.txt

@@ -1,9 +1,10 b''
+magic
 pytube
 requests
 adjacent
 django-haystack
 pillow
 django>=1.8
 bbcode
 django-debug-toolbar
 pytz