Quote from: yourstruly on March 03, 2013, 05:21:37 AM

I lost my password to a wallet that had 20 bitcoins in it, its now worth my effort to retrieve it. I tried using Revalins script found here https://bitcointalk.org/index.php?topic=85495.msg942171#msg942171 without any luck.

So I have modified it to brute force based off a base password that I know is correct, so I'm only have to brute force between 6-8 characters which is feasible.

Code:

#!/usr/bin/ruby -w
class Cracker
  def initialize(char_array, password_range)
   @char_array = char_array
   @password_range = password_range
  end

  def password_correct?(phrase)
   print "basepassword" + phrase, "\t"
   system("./bitcoind walletpassphrase basepassword#{phrase} 20")
   case $?.exitstatus
   when 0
   puts "Found it! basepassword#{phrase}"
   exit 0
   end
   return false
  end

  def generate_password( perm_number, password_length )
   password=""
   (1..password_length).each do |char_number| # loop through characters
   char_reference = (perm_number / @char_array.length**(char_number-1)).floor % @char_array.length
   character = @char_array[char_reference]
   password << character
   end
   password
  end

  def do_combination( num_combinations, password_length )
   (0..num_combinations-1).each do |perm_number| # loop through combinations for a given length
   password = generate_password( perm_number, password_length )
   return password, perm_number if password_correct?(password)
   end
  end

  def crack()
   (@password_range).each do |password_length| # loop to gradually increase password length
   num_combinations=@char_array.length**password_length
   password, perm_number = do_combination(num_combinations, password_length)
   if password
   puts "#{password} | Access Granted | #{perm_number} / #{num_combinations}"
   return password
   end
   end
  end
end

# I removed characters I was sure I didn't use
characters = "!$@01235@ABCDEFGIKLMNOSTWYZabcdefgiklmnopqrstuwyz".split(//)

cracker = Cracker.new( characters, (6..8) )
password = cracker.crack()

puts "No luck."
exit 1

This is going terribly slow though, but that is because I'm using CPU to try to crack this and I should take a lesson from the mining community and try to use my GPU through CUDA or OpenCL. I was wondering if anyone could help me adapt this script to python or a ruby OpenCL/CUDA library so that I can harness my GPU power to try to crack my password to recover it.

If not perhaps this will help someone else who ends up losing their wallet password and needs to brute force it. At 3-5 characters this would work find with a Quadcore.

Dear Sir,
I have many time tried to find tested password as "abc11" but it is not find. Could you please give me a guideline to operate the script. I have run your script before i have run the C:\Program Files (x86)\Bitcoin\daemon\bitcoind.exe please ask me anything wrong......