sefcontext_parser (sefparse)

sefcontext_parser is a module and utility (sefparse) that can be used to parse/decode compiled SEAndroid "file_context.bin" files.

About

Google switched from using a cleartext "file_context" format to a binary format in Android API 24 ("Nougat"). This format was changed and expanded in API 25 and API 26 ("Oreo"). The format is documented by Google here. I was inspired to write this library based on the sefcontext_decompile developed by GitHub user wuxianlin. The functionality is roughly the same, but is implemented in python instead of C.

Setup

The following commands can be used to install sefcontext_parser:

git clone https://github.com/jakev/sefcontext-parser
cd sefcontext-parser
sudo python setup.py install

Usage

There are two ways to use this project: by importing it into your current project, or by running the sefparse utility from the command-line. Using sefparse is straightforward and can be used as follows:

adb pull /file_contexts.bin
sefparse file_contexts.bin

To integrate the module into an existing python project, you can use the library as follows:

from sefcontext_parser import sefcontext_parser as sefparse

parser = sefparse.SefContextParser("file_context.bin")
for entry in parser.process_file():
    print "Regex=%s, Context=%s" % (entry.regex, entry.context)

Results returned by process_file will be sorted by regex pattern.

License

sefcontext_parser is licened under the Apache License, Version 2.0. This means it is freely available for use and modification in a personal and professional capacity.