X-Git-Url: https://www.irasnyder.com/gitweb/?p=rarslave2.git;a=blobdiff_plain;f=Par2Parser.py;h=c57d1e6d5b5f552ca566457dc82c64228d7c88e2;hp=804848f5604ddd426096cc8e35358fc360687cde;hb=177e50d8e9bd3f89a5ef83418f2e21f30f909b5d;hpb=2a46cbb79142c6a829bbbc6b97cdb319c88607ec

diff --git a/Par2Parser.py b/Par2Parser.py
index 804848f..c57d1e6 100644
--- a/Par2Parser.py
+++ b/Par2Parser.py
@@ -7,10 +7,7 @@
 # This was stolen from cfv (see http://cfv.sourceforge.net/ for a copy)
 ################################################################################
 
-import struct, errno, os
-
-def get_full_filename (dir, file):
-	return os.path.abspath (os.path.expanduser (os.path.join (dir, file)))
+import struct, errno, os, md5
 
 def chompnulls(line):
 	p = line.find('\0')
@@ -21,13 +18,19 @@ def get_protected_files (dir, filename):
 	"""Get all of the filenames that are protected by the par2
 	file given as the filename"""
 
-	full_filename = get_full_filename (dir, filename)
+	assert os.path.isdir (dir) # MUST be a valid directory
+	assert os.path.isfile (os.path.join (dir, filename))
+
+	full_filename = os.path.join (dir, filename)
 
 	try:
 		file = open(full_filename, 'rb')
 	except:
 		print 'Could not open %s' % (full_filename, )
-		raise EnvironmentError, (errno.EINVAL, 'can not open par2 file')
+		return []
+
+	# We always want to do crc checks
+	docrcchecks = True
 
 	pkt_header_fmt = '< 8s Q 16s 16s 16s'
 	pkt_header_size = struct.calcsize(pkt_header_fmt)
@@ -41,16 +44,26 @@ def get_protected_files (dir, filename):
 	filenames = []
 
 	while 1:
-		try:
-			d = file.read(pkt_header_size)
-		except OverflowError:
-			raise EnvironmentError, (errno.EINVAL, 'bad par2 file')
+		d = file.read(pkt_header_size)
 		if not d:
 			break
 
 		magic, pkt_len, pkt_md5, set_id, pkt_type = struct.unpack(pkt_header_fmt, d)
 
+		if docrcchecks:
+			control_md5 = md5.new()
+			control_md5.update(d[0x20:])
+			d = file.read(pkt_len - pkt_header_size)
+			control_md5.update(d)
+
+			if control_md5.digest() != pkt_md5:
+				raise EnvironmentError, (errno.EINVAL, \
+					"corrupt par2 file - bad packet hash")
+
 		if pkt_type == 'PAR 2.0\0FileDesc':
+			if not docrcchecks:
+				d = file.read(pkt_len - pkt_header_size)
+
 			file_id, file_md5, file_md5_16k, file_size = \
 				struct.unpack(file_pkt_fmt, d[:file_pkt_size])
 
@@ -60,10 +73,8 @@ def get_protected_files (dir, filename):
 				filenames.append(filename)
 
 		elif pkt_type == "PAR 2.0\0Main\0\0\0\0":
-			try:
+			if not docrcchecks:
 				d = file.read(pkt_len - pkt_header_size)
-			except OverflowError:
-				raise EnvironmentError, (errno.EINVAL, 'corrupt par2 file')
 
 			if expected_file_ids is None:
 				expected_file_ids = []
@@ -74,10 +85,8 @@ def get_protected_files (dir, filename):
 					expected_file_ids.append(d[i:i+16])
 
 		else:
-			try:
+			if not docrcchecks:
 				file.seek(pkt_len - pkt_header_size, 1)
-			except OverflowError, IOError:
-				raise EnvironmentError, (errno.EINVAL, 'corrupt par2 file')
 
 	if expected_file_ids is None:
 		raise EnvironmentError, (errno.EINVAL, \