Class: Pandoru::Transport::BlowfishCryptor

Inherits:
Object
  • Object
show all
Defined in:
lib/pandoru/transport.rb

Overview

Blowfish cryptography for Pandora API encryption/decryption

Constant Summary collapse

BLOCK_SIZE = 
8

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key) ⇒ BlowfishCryptor

Returns a new instance of BlowfishCryptor.



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# File 'lib/pandoru/transport.rb', line 60

def initialize(key)
  @cipher = Crypt::Blowfish.new(key)
end

Class Method Details

.strip_padding(data) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/pandoru/transport.rb', line 93

def self.strip_padding(data)
  pad_size = data[-1].ord
  computed_padding = pad_size.chr * pad_size
  
  raise ArgumentError, "Invalid padding" unless data[-pad_size..-1] == computed_padding
  
  data[0...-pad_size]
end

Instance Method Details

#decrypt(data, strip_padding: true) ⇒ Object 



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# File 'lib/pandoru/transport.rb', line 74

def decrypt(data, strip_padding: true)
  return '' if data.empty?
  decoded_data = decode_hex(data)

  # Decrypt block by block (decrypt_string only does one block!)
  blocks = decoded_data.scan(/.{#{BLOCK_SIZE}}/m)
  decrypted = blocks.map { |block| @cipher.decrypt_block(block) }.join

  strip_padding ? self.class.strip_padding(decrypted) : decrypted
end

#encrypt(data) ⇒ Object 



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# File 'lib/pandoru/transport.rb', line 64

def encrypt(data)
  padded_data = add_padding(data)

  # Encrypt block by block for consistency with decrypt
  blocks = padded_data.scan(/.{#{BLOCK_SIZE}}/m)
  encrypted = blocks.map { |block| @cipher.encrypt_block(block) }.join

  encode_hex(encrypted)
end