From 23caadad93a5378fd0664e8898b7a0f2c7de8973 Mon Sep 17 00:00:00 2001
From: LongHairedHacker <sebastian@sebastians-site.de>
Date: Thu, 26 Dec 2013 13:52:56 +0100
Subject: [PATCH] Added (in) sanity checks for stl files

---
 pastebin/forms.py  | 74 ++++++++++++++++++++++++++++++++++++++++++++--
 pastebin/models.py |  2 --
 2 files changed, 72 insertions(+), 4 deletions(-)

diff --git a/pastebin/forms.py b/pastebin/forms.py
index b984c0a..917fd9d 100644
--- a/pastebin/forms.py
+++ b/pastebin/forms.py
@@ -1,16 +1,86 @@
+import re
+import os
+import struct
+
 from django.forms import ModelForm
 from django import forms
 
 from models import Geometry
 
+facet_pattern = re.compile(r'facet normal\s+[0-9.e+-]+\s+[0-9.e+-]+\s+[0-9.e+-]+')
+loop_pattern = re.compile(r'outer\s+loop')
+vertex_pattern = re.compile(r'vertex\s+[0-9.e+-]+\s+[0-9.e+-]+\s+[0-9.e+-]+')
+endloop_pattern = re.compile(r'endloop')
+endfacet_pattern = re.compile(r'endfacet')
+endsolid_pattern = re.compile(r'endsolid .*')
 
-class GeometryForm(ModelForm):
+class STLUploadForm(ModelForm):
+	def clean_file(self):
+
+		stlfile = self.cleaned_data.get("file")
+		stlfile.open()
+
+		print dir(stlfile)
+
+		if 	stlfile.read(5) != "solid":
+			print "binary"
+			#Skip header
+			stlfile.seek(80)
+			count = struct.unpack("i",stlfile.read(4))[0]
+			if stlfile.size - 84 != count * 50:
+				raise forms.ValidationError("Not a valid binary STL file.")
+
+		else:
+			print "ascii"	
+			next_patterns = [facet_pattern]
+			stlfile.readline()
+			line = stlfile.readline().strip()
+		
+			matched_pattern = None
+			vertex_count = 0
+
+			while line != "":
+
+				corret = False
+				for pattern in next_patterns:
+					if pattern.match(line) != None:
+						corret = True
+						matched_pattern = pattern
+				if not corret:
+					raise forms.ValidationError("Not a valid ascii STL file.")
+
+				if matched_pattern == facet_pattern:
+					next_patterns = [loop_pattern]
+				if matched_pattern == loop_pattern:
+					vertex_count = 0
+					next_patterns = [vertex_pattern]
+				if matched_pattern == vertex_pattern:
+					vertex_count += 1 
+					if vertex_count < 3:
+						next_patterns = [vertex_pattern, endloop_pattern]
+					else :
+						next_patterns = [endloop_pattern]
+				if matched_pattern == endloop_pattern:
+					next_patterns = [endfacet_pattern]
+				if matched_pattern == endfacet_pattern:
+					next_patterns = [facet_pattern, endsolid_pattern]
+
+				line = stlfile.readline().strip()
+
+			if matched_pattern != endsolid_pattern:
+				raise forms.ValidationError("Not a valid ascii STL file.")
+
+		stlfile.close()
+		return stlfile
+
+
+class GeometryForm(STLUploadForm):
 	class Meta:
 		model = Geometry
 		fields = ['name', 'description', 'public', 'expiration',  'file', 'sourcefile']
 
 
-class AnonymousGeometryForm(ModelForm):
+class AnonymousGeometryForm(STLUploadForm):
 	expiration =  forms.ChoiceField(choices=Geometry.EXPIRATION_CHOICES[:-1])
 	class Meta:
 		model = Geometry
diff --git a/pastebin/models.py b/pastebin/models.py
index e079b2b..ddeca43 100644
--- a/pastebin/models.py
+++ b/pastebin/models.py
@@ -9,8 +9,6 @@ from django.core.urlresolvers import reverse
 from django.contrib.auth.models import User
 from django.db import models
 
-
-
 vertex_pattern = re.compile(r'vertex\s+([0-9.e+-]+)\s+([0-9.e+-]+)\s+([0-9.e+-]+)')
 
 def safe_upload_path(base_dir):