Class: IPCrypt::Deterministic

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

Overview

Implementation of ipcrypt-deterministic using AES-128

Class Method Summary collapse

Class Method Details

.bytes_to_ip(bytes16) ⇒ Object

Convert a 16-byte representation back to an IP address

Raises:



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# File 'lib/ipcrypt/deterministic.rb', line 22

def self.bytes_to_ip(bytes16)
  raise InvalidDataError, 'Input must be 16 bytes' unless bytes16.length == 16

  # Check for IPv4-mapped IPv6 format
  zero_bytes = [0] * 10
  ff_bytes = [255, 255]

  if bytes16[0, 10].bytes == zero_bytes && bytes16[10, 2].bytes == ff_bytes
    IPAddr.new_ntoh(bytes16[12, 4])
  else
    IPAddr.new_ntoh(bytes16)
  end
end

.decrypt(ip, key) ⇒ Object

Decrypt an IP address using AES-128

Raises:



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# File 'lib/ipcrypt/deterministic.rb', line 51

def self.decrypt(ip, key)
  raise InvalidKeyError, 'Key must be 16 bytes' unless key.length == 16

  ciphertext = ip_to_bytes(ip)
  cipher = OpenSSL::Cipher.new('AES-128-ECB')
  cipher.decrypt
  cipher.padding = 0 # Disable padding for exact 16-byte blocks
  cipher.key = key
  plaintext = cipher.update(ciphertext) + cipher.final

  bytes_to_ip(plaintext)
end

.encrypt(ip, key) ⇒ Object

Encrypt an IP address using AES-128

Raises:



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# File 'lib/ipcrypt/deterministic.rb', line 37

def self.encrypt(ip, key)
  raise InvalidKeyError, 'Key must be 16 bytes' unless key.length == 16

  plaintext = ip_to_bytes(ip)
  cipher = OpenSSL::Cipher.new('AES-128-ECB')
  cipher.encrypt
  cipher.padding = 0 # Disable padding for exact 16-byte blocks
  cipher.key = key
  ciphertext = cipher.update(plaintext) + cipher.final

  bytes_to_ip(ciphertext)
end

.ip_to_bytes(ip) ⇒ Object

Convert an IP address to its 16-byte representation



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# File 'lib/ipcrypt/deterministic.rb', line 10

def self.ip_to_bytes(ip)
  ip_addr = ip.is_a?(String) ? IPAddr.new(ip) : ip
  if ip_addr.ipv4?
    # Convert IPv4 to IPv4-mapped IPv6 format (::ffff:0:0/96)
    bytes = [0] * 10 + [0xff, 0xff] + ip_addr.hton.bytes
    bytes.pack('C*').force_encoding('BINARY')
  else
    ip_addr.hton.force_encoding('BINARY')
  end
end