Class: IPCrypt::Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/ipcrypt/engine.rb

Constant Summary collapse

IPv4 = 
/^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*ips) ⇒ Engine

Returns a new instance of Engine.



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# File 'lib/ipcrypt/engine.rb', line 8

def initialize(*ips)
  @default_key = SecureRandom.random_bytes(16)
  @ips = ips.flatten.map do |ip|
    raise InvalidIPv4Error.new(ip) unless IPv4.match? ip
    ip
  end
end

Instance Attribute Details

#default_key ⇒ Object (readonly)

Returns the value of attribute default_key.



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# File 'lib/ipcrypt/engine.rb', line 5

def default_key
  @default_key
end

#ips ⇒ Object

Returns the value of attribute ips.



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# File 'lib/ipcrypt/engine.rb', line 5

def ips
  @ips
end

Instance Method Details

#decrypt(key) ⇒ Object

Raises:



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# File 'lib/ipcrypt/engine.rb', line 45

def decrypt(key)
  raise InvalidKeyTypeError.new(key, key.class) unless key.is_a? String

  bytes = key.bytesize
  raise InvalidKeyBytesError.new(key, bytes) unless bytes == 16

  decrypted = @ips.map do |ip|
    k     = key.chars.map {|c| c.unpack('<C').first }
    state = ip.split(?.).map &:to_i

    state = xor4 state, k[12...16]
    state = permute_bwd state
    state = xor4 state, k[8...12]
    state = permute_bwd state
    state = xor4 state, k[4...8]
    state = permute_bwd state
    state = xor4 state, k[0...4]

    state * ?.
  end

  decrypted.size == 1 ? decrypted.first : decrypted
end

#encrypt(key = @default_key) ⇒ Object

Raises:



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# File 'lib/ipcrypt/engine.rb', line 21

def encrypt(key = @default_key)
  raise InvalidKeyTypeError.new(key, key.class) unless key.is_a? String

  bytes = key.bytesize
  raise InvalidKeyBytesError.new(key, bytes) unless bytes == 16

  encrypted = @ips.map do |ip|
    k     = key.chars.map {|c| c.unpack('<C').first }
    state = ip.split(?.).map &:to_i

    state = xor4 state, k[0...4]
    state = permute_fwd state
    state = xor4 state, k[4...8]
    state = permute_fwd state
    state = xor4 state, k[8...12]
    state = permute_fwd state
    state = xor4 state, k[12...16]

    state * ?.
  end

  encrypted.size == 1 ? encrypted.first : encrypted
end