crack_otrp.rb

#!/usr/bin/env ruby

cipher_texts = [
  '315c4eeaa8b5f8aaf9174145bf43e1784b8fa00dc71d885a804e5ee9fa40b16349c146fb778cdf2d3aff021dfff5b403b510d0d0455468aeb98622b137dae857553ccd8883a7bc37520e06e515d22c954eba5025b8cc57ee59418ce7dc6bc41556bdb36bbca3e8774301fbcaa3b83b220809560987815f65286764703de0f3d524400a19b159610b11ef3e',
  '234c02ecbbfbafa3ed18510abd11fa724fcda2018a1a8342cf064bbde548b12b07df44ba7191d9606ef4081ffde5ad46a5069d9f7f543bedb9c861bf29c7e205132eda9382b0bc2c5c4b45f919cf3a9f1cb74151f6d551f4480c82b2cb24cc5b028aa76eb7b4ab24171ab3cdadb8356f',
  '32510ba9a7b2bba9b8005d43a304b5714cc0bb0c8a34884dd91304b8ad40b62b07df44ba6e9d8a2368e51d04e0e7b207b70b9b8261112bacb6c866a232dfe257527dc29398f5f3251a0d47e503c66e935de81230b59b7afb5f41afa8d661cb',
  '32510ba9aab2a8a4fd06414fb517b5605cc0aa0dc91a8908c2064ba8ad5ea06a029056f47a8ad3306ef5021eafe1ac01a81197847a5c68a1b78769a37bc8f4575432c198ccb4ef63590256e305cd3a9544ee4160ead45aef520489e7da7d835402bca670bda8eb775200b8dabbba246b130f040d8ec6447e2c767f3d30ed81ea2e4c1404e1315a1010e7229be6636aaa',
  '3f561ba9adb4b6ebec54424ba317b564418fac0dd35f8c08d31a1fe9e24fe56808c213f17c81d9607cee021dafe1e001b21ade877a5e68bea88d61b93ac5ee0d562e8e9582f5ef375f0a4ae20ed86e935de81230b59b73fb4302cd95d770c65b40aaa065f2a5e33a5a0bb5dcaba43722130f042f8ec85b7c2070',
  '32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd2061bbde24eb76a19d84aba34d8de287be84d07e7e9a30ee714979c7e1123a8bd9822a33ecaf512472e8e8f8db3f9635c1949e640c621854eba0d79eccf52ff111284b4cc61d11902aebc66f2b2e436434eacc0aba938220b084800c2ca4e693522643573b2c4ce35050b0cf774201f0fe52ac9f26d71b6cf61a711cc229f77ace7aa88a2f19983122b11be87a59c355d25f8e4',
  '32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd90f1fa6ea5ba47b01c909ba7696cf606ef40c04afe1ac0aa8148dd066592ded9f8774b529c7ea125d298e8883f5e9305f4b44f915cb2bd05af51373fd9b4af511039fa2d96f83414aaaf261bda2e97b170fb5cce2a53e675c154c0d9681596934777e2275b381ce2e40582afe67650b13e72287ff2270abcf73bb028932836fbdecfecee0a3b894473c1bbeb6b4913a536ce4f9b13f1efff71ea313c8661dd9a4ce',
  '315c4eeaa8b5f8bffd11155ea506b56041c6a00c8a08854dd21a4bbde54ce56801d943ba708b8a3574f40c00fff9e00fa1439fd0654327a3bfc860b92f89ee04132ecb9298f5fd2d5e4b45e40ecc3b9d59e9417df7c95bba410e9aa2ca24c5474da2f276baa3ac325918b2daada43d6712150441c2e04f6565517f317da9d3',
  '271946f9bbb2aeadec111841a81abc300ecaa01bd8069d5cc91005e9fe4aad6e04d513e96d99de2569bc5e50eeeca709b50a8a987f4264edb6896fb537d0a716132ddc938fb0f836480e06ed0fcd6e9759f40462f9cf57f4564186a2c1778f1543efa270bda5e933421cbe88a4a52222190f471e9bd15f652b653b7071aec59a2705081ffe72651d08f822c9ed6d76e48b63ab15d0208573a7eef027',
  '466d06ece998b7a2fb1d464fed2ced7641ddaa3cc31c9941cf110abbf409ed39598005b3399ccfafb61d0315fca0a314be138a9f32503bedac8067f03adbf3575c3b8edc9ba7f537530541ab0f9f3cd04ff50d66f1d559ba520e89a2cb2a83'
]

target_cypertext = '32510ba9babebbbefd001547a810e67149caee11d945cd7fc81a05e9f85aac650e9052ba6a8cd8257bf14d13e6f0a803b54fde9e77472dbff89d71b57bddef121336cb85ccb8f3315f4b52e301d16e9f52f904'

$target_plaintext = []

xor_messages = []

$the_space = 'the '.split(//).map { |x| "%02x" % x.ord }
$space_the_space = ' the '.split(//).map { |x| "%02x" % x.ord }
$space = ' '.ord

def convert_to_hex_array(str)
  str.scan(/../).map(&:hex)
end

def xor_hex_arrs(arr1, arr2)
  if arr1.size < arr2.size
    arr1.each_with_index.map do |a, index|
      "%02x" % (a ^ arr2[index])
    end.join
  else
    arr2.each_with_index.map do |a, index|
      "%02x" % (a ^ arr1[index])
    end.join
  end
end

$stuff = []

def xor_with_target(str, target)
  puts str
  convert_to_hex_array(str).each_with_index.map do |elem, index|
    res = target.map do |chr|
      val = chr.hex ^ elem

      if (val >= 'A'.ord && val <= 'Z'.ord) || (val >= 'a'.ord && val <= 'z'.ord)
        val.chr
      else
        ' '
      end
    end

    puts ' ' * index +  res.join
  end
end


def xor_with_chr(str, chr)
  convert_to_hex_array(str).each_with_index.map do |elem, index|
    val = elem ^ chr
    if (val >= 'A'.ord && val <= 'Z'.ord) || (val >= 'a'.ord && val <= 'z'.ord)
      $stuff[index] ||= []
      $stuff[index] << val.chr

      #$target_plaintext[index] = $stuff[val.chr].size > 4 ? val.chr : chr.chr

      #" #{val.chr}:#{val}:#{elem}:#{chr} "
      " #{val.chr} "
    else
      "%02x" % val
    end
  end.join
end

cipher_texts.each_with_index do |ct, index|
  xor_messages << xor_hex_arrs(convert_to_hex_array(ct), convert_to_hex_array(target_cypertext))
end

puts xor_messages.first

#xor_messages.each { |msg| xor_with_target(msg, $the_space) }
xor_messages.each { |msg| puts xor_with_chr(msg, ' '.ord) }
#xor_messages.each { |msg| xor_with_chr(msg, 'e'.ord) }
#xor_messages.each { |msg| xor_with_chr(msg, 't'.ord) }
#xor_messages.each { |msg| xor_with_chr(msg, 'a'.ord) }

# convert_to_hex_array(target_cypertext).map do |elem|
#   if $stuff[elem.chr]
#     print " #{elem.chr} "
#   else
#     print elem
#   end
# end

# $stuff.each do |k, v|
#   puts "#{k} -> #{v.join(' ')}"
# end

to_encode = "The secret message is: When using a stream cipher, never use the key more than once"
encoded_answer = to_encode.scan(/./).map do |chr|
  "%02x" % chr.ord
end.join

# puts "ENCODED: #{encoded_answer}"

puts "\n\nCiphertexts\n\n"
cipher_texts.each { |x| puts x }

puts "\n\n"

$stuff.each_with_index do |elem, index|
  puts "#{elem.sort.join(' ')}"
  #puts "#{index} #{elem.max_by { |i| elem.count(i) }}"
end

# xor_messages.each do |msg|
#   x = msg[21].hex
#   chr = x ^ 'e'.ord
#   puts chr.chr
# end

# puts "RESULT: #{$target_plaintext.join}"