From 60ec1f43987c95acde8bb00ab5fc13796cb63a05 Mon Sep 17 00:00:00 2001
From: devttys0 <heffnercj@gmail.com>
Date: Sat, 8 Nov 2014 06:53:17 -0800
Subject: [PATCH] Fixed offset parsing bugs in magic.py
---
src/binwalk/core/magic.py | 30 +++++++++++++++++++++++++++---
1 file changed, 27 insertions(+), 3 deletions(-)
diff --git a/src/binwalk/core/magic.py b/src/binwalk/core/magic.py
index b6ab712..c275d12 100644
--- a/src/binwalk/core/magic.py
+++ b/src/binwalk/core/magic.py
@@ -91,6 +91,17 @@ class SignatureLine(object):
# characters to an integer offset. This will fail if the offset is a complex
# value (e.g., '(4.l+16)').
self.offset = parts[0].replace('>', '')
+
+ # Check to see if the up-level character ('&') has been specified
+ if self.offset.startswith('&'):
+ self.uplevel = True
+ self.offset = self.offset[1:]
+ else:
+ self.uplevel = False
+
+ # Check if the offset is an indirect offset
+ self.is_indirect_offset = self.offset.startswith('(')
+
try:
self.offset = int(self.offset, 0)
except ValueError as e:
@@ -439,7 +450,9 @@ class Magic(object):
v = expression
# Evaluate the final expression
- return binwalk.core.common.MathExpression(v).value
+ value = binwalk.core.common.MathExpression(v).value
+
+ return value
def _analyze(self, signature, offset):
'''
@@ -453,6 +466,7 @@ class Magic(object):
description = []
tag_strlen = None
max_line_level = 0
+ last_indirect_offset = 0
tags = {'id' : signature.id, 'offset' : offset, 'invalid' : False}
# Apply each line of the signature to self.data, starting at the specified offset
@@ -466,6 +480,11 @@ class Magic(object):
else:
line_offset = self._do_math(offset, line.offset)
+ # If the uplevel delimiter was set in the signature line, add the last indirect
+ # offset to the line's specified offset.
+ if line.uplevel:
+ line_offset += last_indirect_offset
+
# The start of the data needed by this line is at offset + line_offset.
# The end of the data will be line.size bytes later.
start = offset + line_offset
@@ -581,6 +600,10 @@ class Magic(object):
if not self.show_invalid and tags['invalid']:
break
+ # Track the last indirect offset value
+ if line.is_indirect_offset:
+ last_indirect_offset = line_offset
+
# If this line satisfied its comparison, +1 the max indentation level
max_line_level = line.level + 1
else:
@@ -680,8 +703,9 @@ class Magic(object):
for line in lines:
# Split at the first comment delimiter (if any) and strip the result
line = line.split('#')[0].strip()
- # Ignore blank lines and lines that are nothing but comments
- if line:
+ # Ignore blank lines and lines that are nothing but comments.
+ # We also don't support the !mime style line entries.
+ if line and line[0] != '!':
# Parse this signature line
sigline = SignatureLine(line)
# Level 0 means the first line of a signature entry
--
libgit2 0.26.0