module C7Decrypt::Type5

Public Class Methods

bit_specified_base64encode(input) click to toggle source

A helper method for bit specified base64 output (the format Type-5 hashes are in) @param [String] input @return [String] encoded_input

# File lib/c7decrypt/type5/type5.rb, line 55
def self.bit_specified_base64encode(input)
  b64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
  input = input.bytes.to_a
  output = ""
  Constants::BYTE_INDEXES.each do |i3, i2, i1|
    b1, b2, b3 = i1 && input[i1] || 0, i2 && input[i2] || 0, i3 && input[i3] || 0
    output <<
      b64[  b1 & 0b00111111]         <<
      b64[((b1 & 0b11000000) >> 6) |
          ((b2 & 0b00001111) << 2)]  <<
      b64[((b2 & 0b11110000) >> 4) |
          ((b3 & 0b00000011) << 4)]  <<
      b64[ (b3 & 0b11111100) >> 2]
  end

  remainder = 3 - (16 % 3)
  remainder = 0 if remainder == 3

  return output[0..-1-remainder]
end
cisco_md5_format(salt, hash) click to toggle source

A helper method for formating Cisco Type-5 hashes

# File lib/c7decrypt/type5/type5.rb, line 48
def self.cisco_md5_format(salt, hash)
  return "$1$" + salt + "$" + hash
end
encrypt(password, salt = generate_salt) click to toggle source

The Encryption Method for Cisco Type-5 Encrypted Strings @param [String] password @param [String] salt @return [String] formatted Type-5 hash

# File lib/c7decrypt/type5/type5.rb, line 21
def self.encrypt(password, salt = generate_salt)
  password = password.encode("UTF-8")
  password.force_encoding("ASCII-8BIT")

  b = Digest::MD5.digest("#{password}#{salt}#{password}")
  a_string = "#{password}$1$#{salt}#{b * (password.length/16)}#{b[0...password.length % 16]}"

  password_length = password.length
  while password_length > 0
    a_string += (password_length & 1 != 0) ? "\x0" : password[0].chr
    password_length >>= 1
  end

  input = Digest::MD5.digest(a_string)

  1000.times do |index|
    c_string = ((index & 1 != 0) ? password : input)
    c_string += salt unless index % 3 == 0
    c_string += password unless index % 7 == 0
    c_string += ((index & 1 != 0) ? input : password)
    input = Digest::MD5.digest(c_string)
  end

  return cisco_md5_format(salt, bit_specified_base64encode(input))
end
generate_salt(size = 4) click to toggle source

Generates a random salt using the same character set as the base64 encoding used by the hash encoder. @return [String] salt

# File lib/c7decrypt/type5/type5.rb, line 79
def self.generate_salt(size = 4)
  SecureRandom.base64((size * 6 / 8.0).ceil).tr("+", ".")[0...size]
end