Class: Bcome::Encryptor

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/objects/encryptor.rb

Constant Summary collapse

UNENC_SIGNIFIER = 
''
ENC_SIGNIFIER = 
'enc'
AFFIRMATIVE = 
'yes'

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/objects/encryptor.rb', line 13

def key
  @key
end

Instance Method Details

#all_encrypted_filenames ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 176

def all_encrypted_filenames
  Dir["#{metadata_path}/*.enc"]
end

#all_unencrypted_filenames ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 172

def all_unencrypted_filenames
  Dir["#{metadata_path}/*"].reject { |f| f =~ /\.enc/ }
end

#decrypt_file_data(filename) ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 67

def decrypt_file_data(filename)
  raw_contents = File.read(filename)
  raw_contents.send(:decrypt, @key)
end

#diff ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 106

def diff
  prompt_for_key
  puts "\n"
  all_encrypted_filenames.each do |filename|
    opposing_file = opposing_file_for_filename(filename)
    if File.exist?(opposing_file)
      if diffs = enc_file_diff(filename)
        puts "\n[+/-]\s".warning + filename + "\sis different to your local unpacked version\n\n"
        puts diffs + "\n\n"
      else
        puts filename.to_s.informational + "\s- no differences".bc_green
      end
    else
      puts filename.to_s.informational + "\s- new file".warning
    end
  end
  puts "\n"
end

#enc_file_diff(filename) ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 72

def enc_file_diff(filename)
  # Get decrypted file data
  decrypted_data_for_filename = decrypt_file_data(filename)

  # Get unpacked file data
  opposing_filename = opposing_file_for_filename(filename)
  return nil unless File.exist?(opposing_filename)

  unpacked_file_data = File.read(opposing_filename)

  # there are no differences
  return nil if decrypted_data_for_filename.eql?(unpacked_file_data)

  get_diffs(unpacked_file_data, decrypted_data_for_filename)
end

#get_diffs(file_one, file_two) ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 93

def get_diffs(file_one, file_two)
  diffy = ::Diffy::SplitDiff.new(file_one, file_two)
  left_diffs = diffy.left.split("\n").each_with_index.collect { |l, index| "#{index + 1}:\s#{l}" }
  right_diffs = diffy.right.split("\n").each_with_index.collect { |l, index| "#{index + 1}:\s#{l}" }

  diffed_lines = (left_diffs + right_diffs).select { |line| line =~ /^[0-9]+:\s[+-](.+)$/ }
  return nil if diffed_lines.empty?

  diffed_lines.collect do |line|
    line =~ /^[0-9]+:\s\+(.+)$/ ? line.bc_green : line.bc_red
  end.join("\n")
end

#has_encrypted_files? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/objects/encryptor.rb', line 45

def has_encrypted_files?
  all_encrypted_filenames.any?
end

#has_files_to_encrypt? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/objects/encryptor.rb', line 49

def has_files_to_encrypt?
  all_unencrypted_filenames.any?
end

#metadata_path ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 180

def metadata_path
  'bcome/metadata'
end

#opposing_file_for_filename(filename) ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 88

def opposing_file_for_filename(filename)
  filename =~ %r{#{path_to_metadata}/(.+)\.enc}
  "#{path_to_metadata}/#{Regexp.last_match(1)}"
end

#pack ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 15

def pack
  # Bcome currently works with a single encryption key - the same one - for all files
  # When we attempt an encrypt we'll check first to see if any encrypted files already exists, and
  # we'll try our key on it. If the fails to unpack the file, we abort the encryption attempt.
  prompt_for_key
  if has_files_to_encrypt?
    verify_presented_key if has_encrypted_files?
    toggle_packed_files(all_unencrypted_filenames, :encrypt)
  else
    puts "\nNo unencrypted files to encrypt.\n".warning
  end
  nil
end

#path_to_metadata ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 163

def path_to_metadata
  'bcome/metadata'
end

#prompt_for_key ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 29

def prompt_for_key
  puts "\n"
  print 'Please enter an encryption key (and if your data is already encrypted, you must provide the same key): '.informational
  @key = STDIN.noecho(&:gets).chomp
  # puts "\n"
end

#prompt_to_overwrite ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 36

def prompt_to_overwrite
  valid_answers = [AFFIRMATIVE, 'no']
  puts "\n"
  print "Do you want to continue with unpacking this file? Your local changes would be overwritten [#{valid_answers.join(',')}]\s"
  answer = STDIN.gets.chomp
  prompt_to_overwrite unless valid_answers.include?(answer)
  answer
end

#toggle_packed_files(filenames, packer_method) ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 125

def toggle_packed_files(filenames, packer_method)
  raise 'Missing encryption key. Please set an encryption key' unless @key

  filenames.each do |filename|
    # Get raw
    raw_contents = File.read(filename)

    if packer_method == :decrypt
      filename =~ %r{#{path_to_metadata}/(.+)\.enc}
      opposing_filename = Regexp.last_match(1)
      action = 'Unpacking'

      # Skip unpacking a file if there are local modifications that the user does not want to lose.
      if diffs = enc_file_diff(filename)
        puts "\n[+/-]\s".warning + filename + "\sis different to your local unpacked version\n\n"
        puts diffs

        if prompt_to_overwrite != AFFIRMATIVE
          puts "\n\nskipping\s".warning + filename + "\n"
          next
        end
        puts "\n"
      end
    else
      filename =~ %r{#{path_to_metadata}/(.*)}
      opposing_filename = "#{Regexp.last_match(1)}.enc"
      action = 'Packing'
    end

    # Write encrypted/decryption action
    enc_decrypt_result = raw_contents.send(packer_method, @key)
    print "\n\n"
    puts "#{action}\s".informational + filename + "\sto\s".informational + "#{path_to_metadata}/" + opposing_filename
    write_file(opposing_filename, enc_decrypt_result)
  end
  puts "\ndone".informational
end

#unpack ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 61

def unpack
  prompt_for_key
  toggle_packed_files(all_encrypted_filenames, :decrypt)
  nil
end

#verify_presented_key ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 53

def verify_presented_key
  # We attempt a decrypt of any encrypted file in order to verify that a newly presented key
  # matches the key used to previously encrypt. Bcome operates on a one-key-per-implementation basis.
  test_file = all_encrypted_filenames.first
  file_contents = File.read(test_file)
  file_contents.decrypt(@key)
end

#write_file(filename, contents) ⇒ Object 



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# File 'lib/objects/encryptor.rb', line 167

def write_file(filename, contents)
  filepath = "#{path_to_metadata}/#{filename}"
  File.open(filepath.to_s, 'w') { |f| f.write(contents) }
end