gistfile1.rb

require 'digest/sha1'

class Miner
  attr_reader :tree, :parent, :timestamp
  def initialize
    @tree=`git write-tree`.chomp
    @parent=`git rev-parse HEAD`.chomp
    @timestamp=12345
    prepare_index
  end

def prepare_index
  user_name = "user-7vxutq41"
  `perl -i -pe 's/(#{user_name}: )(\d+)/$1 . ($2+1)/e' LEDGER.txt`
  `grep -q "#{user_name}" LEDGER.txt || echo "#{user_name}: 1" >> LEDGER.txt`
  `git add LEDGER.txt`
  `git update-index --add 100644`
end

def gitify_body_with_header(content)
"commit #{content.length}\0#{content}"
end

def commit_body_with_git(content)
  `git hash-object -t commit -w --stdin <<< "#{content.chomp}"`
end

def git_sha(content)
  Digest::SHA1.hexdigest(gitify_body_with_header(content))
end

def difficulty
 "0001"
end

def commit_body(counter)
body="tree #{tree}
parent #{parent}
author CTF user <me@example.com> #{timestamp} +0000
committer CTF user <me@example.com> #{timestamp} +0000

Give me a Gitcoin

#{counter}
"
end

def generate_sha(counter)
  git_sha(commit_body(counter))
end

  def run
    threads = []
    10.times do |i|
      threads << Thread.new do
        start_time = Time.now
        counter = i * 1000000
        while true
          sha = generate_sha(counter)
          counter += 1
          if sha < difficulty
            #puts "THREAD #{i} got a hit!"
            #puts "total time: #{Time.now.to_f - start_time.to_f}"
            puts "sha: #{sha}"
            #puts "counter: #{counter}"
            #puts "difficulty: #{difficulty}"
            puts "committing #{commit_body_with_git(commit_body(counter))}"
            puts commit_body(counter)
          end
          if counter > (i+1) * 10000000
            break
          end
        end
      end
    end
    threads.map(&:join)
    puts "done"
  end
end

Miner.new.run

class Miner
  attr_reader :tree, :parent, :timestamp
  def initialize
    @tree=`git write-tree`.chomp
    @parent=`git rev-parse HEAD`.chomp
    @timestamp=12345
  end

  def gitify_body_with_header(content)
    "commit #{content.length}\0#{content}"
  end

  def git_sha(content)
    Digest::SHA1.hexdigest(gitify_body_with_header(content))
  end

  def difficulty
   "f"
  end

  def generate_body(counter)
    body="tree #{tree}
parent #{parent}
author CTF user <me@example.com> #{timestamp} +0000
committer CTF user <me@example.com> #{timestamp} +0000

Give me a Gitcoin

#{counter}
"
  end

  def run
    threads = []
    1.times do |i|
      threads << Thread.new do
        start_time = Time.now
        counter = i * 10000000
        while true
          #puts "Thread #{i} trying with counter #{counter}"
          body = generate_body(counter)
          sha = git_sha(body)
          counter += 1
          if sha < difficulty
            puts "THREAD #{i} got a hit!"
            puts "total time: #{Time.now.to_f - start_time.to_f}"
            puts "sha: #{sha}"
            puts "counter: #{counter}"
            puts "difficulty: #{difficulty}"
            puts ""
            puts "#{body}"
          end
          if counter > (i+1) * 100000000
            break
          end
        end
      end
    end
    threads.map(&:join)
    puts "done"
  end
end

Miner.new.run