EBK backup extraction scripts

Readme.md

How to use

Assumed you have files with extension .ebk stored by Kies.

Prerequisites

Install Ruby 2.3 or later

Example for running in Bash terminal. Linux is not mandatory for running Ruby program.

1. Decrypt .ebk container into .bin file

# define environment variables for proper work - can be taken from https://goo.gl/gViBqb lines 31, 32
export KIES_KEY='HERE YOU PUT ENCRYPTION KEY'
export KIES_IV='HERE YOU PUT ENCRYPTION IV'

ruby ebk_decrypter.rb myfile.ebk

Header of .bin container represents XML file. If XML tag "zipType" has value "ZLib" (by Kies 4) then you can extract ZIP from .bin file with this command:

ruby extract_zip.rb myfile.ebk.bin

ebk_decrypter.rb

# Note: KIES_KEY and KIES_IV must be passed as environment variables for work.

require 'openssl'

CRYPT_BLOCK_LEN = 0x110
CRYPT_BLOCK_PAD = 0x100

cipher = OpenSSL::Cipher::AES256.new(:CBC)
cipher.decrypt
cipher.key = ENV['KIES_KEY']
cipher.iv  = ENV['KIES_IV']

plain = ""
File.open(ARGV[0], 'rb') do |f|
  begin
    s = f.read(CRYPT_BLOCK_LEN)
    plain << cipher.update(s)[0, CRYPT_BLOCK_PAD]
    cipher.reset
  end until f.eof
end

File.open(ARGV[0] + '.bin', 'wb') do |f2|
  f2.write(plain)
end

# Uncomment this for debugging output
# print plain

extract_zip.rb

# Read decrypted EBK file and write ZIP file

s = IO.binread ARGV[0]
i = s.bytes.rindex { |x| x != 16 }
IO.binwrite ARGV[0] + '.zip', s[512..i]