######################################################################
# A simple script written to find keywords and digits inside         #
# blobs of hex data, used for some quick and dirty basic protocol    #
# reverse-engineering.                                               #
#                                                                    #
# You can find a given string or digit inside a hex                  #
# in a blob of text.                                                 #
# Usage: ruby brute.rb <keys_to_find> <paste your hex>               #
#                                                                    #
# Multiple keys:                                                     #
# if you want to find multiple keys just use space seperated values  #
# Usage: ruby brute.rb <key1> <key2> <keyn> <hex>                    #
#                                                                    #
# Manual input:                                                      #
# If you want to type the keys but would like us to prompt you for   #
# the hex data, simply write 'i' or 'input' as the last parameter.   #
# Usage: ruby brute.rb <key1> <keyn> input                           #
#                                                                    #
#                                                                    #
# By: Andrés Colón (github.com/mindware)                             #
# Released under MIT License                                         #
######################################################################

require 'shellwords'
require 'colorize'

class String
  def convert_base(from, to)
    self.to_i(from).to_s(to)
  end
end


if(ARGV.length < 2)
	puts "Usage: ruby brute.rb <key1..keyn> < ('i'| 'input')> | \"<blob of text>\""
	exit
end

text = ARGV.pop
keys = ARGV

# detect if user requested to input the data manually
if(text == "input" or text == "i")
	text = ""
	while(text.length == 0)
		print "Enter your blob of text: "
		text = STDIN.gets.chomp
	end
end

index = {}
keys.each do |key|
	index[key] = []
	puts "Searching for #{key}"
	(2..32).each do |i|
		break if i > text.length
		found = false
		slice = text.chars.each_slice(i).map(&:join)
		puts "Breaking by #{i} chars, result is #{slice.length} slices."
		slice.each do |chunk|
			# explicit check
			word = chunk
			if(word.include? key)
				word = Shellwords.escape(word)
                                puts "--"
                                puts "Found (base): '#{key}'"
                                puts "'#{word}' in '#{chunk}'"
                                puts "Index starts at: #{text.index(chunk)}"
                                puts "--"
                                index[key] << [text.index(chunk), (text.index(chunk) + word.length - 1), word]
                                found = true
			end
			# convert chunk of hex to ascii
			#word = chunk.gsub(/../) { |pair| pair.hex.chr }
			word = chunk.convert_base(16, 10)
			if(word.include? key)
				word = Shellwords.escape(word)
	                        puts "--"
				puts "Found (base): '#{key}'"
				puts "'#{word}' in '#{chunk}'"
				puts "Index starts at: #{text.index(chunk)}"
				puts "--"
				index[key] << [text.index(chunk), (text.index(chunk) + word.length - 1), word]
				found = true
			end

			# unpack hex
			word = [chunk].pack("H*")
			if(word.include? key)
                                word = Shellwords.escape(word)
	                        puts "--"
				puts "Found (unpack): '#{key}'"
				puts "'#{word}' in '#{chunk}'"
				puts "Index starts at: #{text.index(chunk)}"
				puts "--"
                                index[key] << [text.index(chunk), (text.index(chunk) + word.length - 1), word]
				found = true
				break
			end
		end
		break if found
	end
end

if index.keys.length > 0
	index.each do |key, values|
		next if(index[key].length == 0)
		puts "Result: "
		puts "The string: #{key.red}"
		values.each do |value|
			puts "--".yellow
			first = value[0]
			last  = value[1]
			word = value[2]
			puts "Converted: #{word.green}"
			puts "Start: #{value[0]}  End: #{value[1]}"
			puts "#{text.gsub( text[(first)..(last)], text[(first)..(last)].red)}"
			puts "--".yellow
		end
	end
end