File Type - VCDIFF binary extract

Question

I have a file I am trying to extract to view and I'm stuck... If I use binwalk I am able to get the gunzip file but unable to extract it... If I attempt to extract with gunzip I return the errors and if I use binwalk, when I get a file 0.gz. It will remain in a 'loop' meaning I can continue to extract it over and over again with binwalk ending up in with a 'directory loop'. Does anyone know a solution to this? am I doing it all wrong?

root@svr3:/home/monday_home_test# file testfile
testfile: VCDIFF binary diff
root@svr3:/home/monday_home_test# binwalk --extract testfile 

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
465           0x1D1           gzip compressed data, from Unix, last modified: Sun Sep 28 08:49:05 2014

root@svr3:/home/monday_home_test# 
root@svr3:/home/monday_home_test/_testfile.extracted# ls
1D1.gz
root@svr3:/home/monday_home_test/_testfile.extracted# binwalk --extract 1D1.gz 

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
0             0x0             gzip compressed data, from Unix, last modified: Sun Sep 28 08:49:05 2014

root@svr3:/home/monday_home_test/_testfile.extracted# ls
1D1.gz  _1D1.gz.extracted
root@svr3:/home/monday_home_test/_testfile.extracted# cd _1D1.gz.extracted/
root@svr3:/home/monday_home_test/_testfile.extracted/_1D1.gz.extracted# ls
0.gz

root@svr3:/home/monday_home_test/_testfile.extracted/_1D1.gz.extracted/_0.gz.extracted/_0.gz.extracted# ls
0.gz
root@svr3:/home/monday_home_test/_testfile.extracted/_1D1.gz.extracted/_0.gz.extracted/_0.gz.extracted#  binwalk --extract 0.gz 

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
0             0x0             gzip compressed data, from Unix, last modified: Sun Sep 28 08:49:05 2014

root@svr3:/home/monday_home_test/_testfile.extracted/_1D1.gz.extracted/_0.gz.extracted/_0.gz.extracted# ls
0.gz  _0.gz.extracted
root@svr3:/home/monday_home_test/_testfile.extracted/_1D1.gz.extracted/_0.gz.extracted/_0.gz.extracted#     

Gunzip Errors

root@svr3:/home/monday_home_test/_testfile.extracted# gunzip --decompress 1D1.gz         
gzip: 1D1.gz: invalid compressed data--format violated
root@svr3:/home/monday_home_test/_testfile.extracted/_1D1.gz.extracted# gunzip --decompress 0.gz 
gzip: 0.gz: invalid compressed data--format violated

Answer 1

It looks like VCDIFF is not a standalone container, but a binary patch file, intended to be applied on top of some already existing data. The results from binwalk are likely false positives.

If you don't have the original data, you're unlikely to extract anything meaningful from it. That said, you can check the RFC3284 describing the file format, or some of the tools listed in the Wikipedia article.