GPU brute forcing an encrypted wallet

[silverfuture]

btchris I sent you a PM.

[1715083904]

1715083904

[1715083904]

1715083904

[1715083904]

1715083904

[1715083904]

1715083904

[1715083904]

1715083904

[1715083904]

1715083904

[btchris]

btchris I sent you a PM.

Been away for a while and I'm slowly catching up. I did get it, will hopefully reply soon...

[silverfuture]

Just wanted to let folks know that btchris cracked a password for me and I would consider him a trustworthy individual.  He could have stolen the btc but did not.

[Simon8x]

silverfuture and btchris, would you mind telling me (or through PM) about how complicated the password is (length? consists of upper-case/lower-case/special/numeric characters?) and how long the brute-forcing process takes?

[btchris]

silverfuture and btchris, would you mind telling me (or through PM) about how complicated the password is (length? consists of upper-case/lower-case/special/numeric characters?) and how long the brute-forcing process takes?

I hope you'll understand that I will not... that's up to silverfuture to decide.

Although if you have a set of password criteria in mind, I might be able to estimate such a thing for your circumstances, but you'd need to be fairly specific (about the password, about your wallet software, and possibly about your PC as well).

[ashraful1980]

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......

[sapce]

I only remember part of the wallet password. What command can I use in btcrecover to find it?