Cleaned up smart.Signature code, fixed Python3 ctypes bugs.

src/binwalk/core/filter.py

 import re
 import binwalk.core.common as common
-from binwalk.core.smart import SmartSignature
+from binwalk.core.smart import Signature
 from binwalk.core.compat import *
 
 class Filter:
@@ -32,7 +32,7 @@ class Filter:
 		self.grep_filters = []
 		self.show_invalid_results = show_invalid_results
 		self.exclusive_filter = False
-		self.smart = SmartSignature(self)
+		self.smart = Signature(self)
 
 	def include(self, match, exclusive=True):
 		'''
@@ -134,7 +134,7 @@ class Filter:
 
 		# Don't include quoted strings or keyword arguments in this search, as 
 		# strings from the target file may legitimately contain the INVALID_RESULT text.
-		if self.INVALID_RESULT in common.strip_quoted_strings(self.smart._strip_tags(data)):
+		if self.INVALID_RESULT in common.strip_quoted_strings(self.smart.strip_tags(data)):
 			return False
 
 		# There should be no non-printable characters in any of the data

src/binwalk/modules/compression.py

@@ -3,6 +3,7 @@
 import os
 import ctypes
 import ctypes.util
+from binwalk.core.compat import str2bytes
 from binwalk.core.module import Option, Kwarg, Module
 
 class Deflate(object):
@@ -46,7 +47,7 @@ class Deflate(object):
 	def decompress(self, data):
 		description = None
 
-		decomp_size = self.tinfl.is_deflated(data, len(data), 0)
+		decomp_size = self.tinfl.is_deflated(str2bytes(data), len(data), 0)
 		if decomp_size >= self.MIN_DECOMP_SIZE:
 			description = self.DESCRIPTION + ', uncompressed size >= %d' % decomp_size
 

src/binwalk/modules/signature.py

@@ -48,8 +48,8 @@ class Signature(Module):
 	VERBOSE_HEADER_FORMAT = "%s    %d"
 
 	def init(self):
-		# Create SmartSignature and MagicParser class instances. These are mostly for internal use.
-		self.smart = binwalk.core.smart.SmartSignature(self.config.filter, ignore_smart_signatures=self.dumb_scan)
+		# Create Signature and MagicParser class instances. These are mostly for internal use.
+		self.smart = binwalk.core.smart.Signature(self.config.filter, ignore_smart_signatures=self.dumb_scan)
 		self.parser = binwalk.core.parser.MagicParser(self.config.filter, self.smart)
 
 		# If a raw byte sequence was specified, build a magic file from that instead of using the default magic files

src/binwalk/plugins/zlibvalid.py

 import ctypes
 import ctypes.util
+from binwalk.core.compat import str2bytes
 from binwalk.core.common import BlockFile
 
 class Plugin(object):
@@ -23,9 +24,9 @@ class Plugin(object):
 		# If this result is a zlib signature match, try to decompress the data
 		if self.tinfl and result.file and result.description.lower().startswith('zlib'):
 			# Seek to and read the suspected zlib data
-			fd = self.module.config.open_file(result.file.name, offset=result.offset)
-			#BlockFile(result.file.name, offset=result.offset, swap=self.module.config.swap_size)
-			data = fd.read(self.MAX_DATA_SIZE)
+			fd = self.module.config.open_file(result.file.name, offset=result.offset, length=self.MAX_DATA_SIZE)
+			# Python3 ctypes needs a bytes object, not a str
+			data = str2bytes(fd.read(self.MAX_DATA_SIZE))
 			fd.close()
 
 			# Check if this is valid zlib data