Class: Ubiq::Algo

Inherits:
Object
  • Object
show all
Defined in:
lib/ubiq/algo.rb

Overview

Class to provide some basic information mapping between an encryption algorithm name and the cooresponding key size, initialization vector length, and tag

Constant Summary collapse

UBIQ_HEADER_V0_FLAG_AAD = 
0b00000001

Instance Method Summary collapse

Instance Method Details

#decryptor(obj, key, iv) ⇒ Object

Raises:

  • (RuntimeError) 


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# File 'lib/ubiq/algo.rb', line 66

def decryptor(obj, key, iv)
  raise RuntimeError, 'Invalid key length' if key.length != obj[:key_length]

  raise RuntimeError, 'Invalid initialization vector length' if !iv.nil? && iv.length != obj[:iv_length]

  cipher = obj[:mode]
  cipher.decrypt
  cipher.key = key
  cipher.iv = iv
  return cipher
end

#encryptor(obj, key, iv = nil) ⇒ Object

Raises:

  • (RuntimeError) 


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# File 'lib/ubiq/algo.rb', line 49

def encryptor(obj, key, iv = nil)
  # key : A byte string containing the key to be used with this encryption
  # If the caller specifies the initialization vector, it must be
  # the correct length and, if so, will be used. If it is not
  # specified, the function will generate a new one

  raise RuntimeError, 'Invalid key length' if key.length != obj[:key_length]

  raise RuntimeError, 'Invalid initialization vector length' if !iv.nil? && iv.length != obj[:iv_length]

  cipher = obj[:mode]
  cipher.encrypt
  cipher.key = key
  iv = cipher.random_iv
  return cipher, iv
end

#find_alg(id) ⇒ Object 



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# File 'lib/ubiq/algo.rb', line 36

def find_alg(id)
  set_algo.each do |k,v|
    if v[:id] == id
       return k
     end
  end
  "unknown"
end

#get_algo(name) ⇒ Object 



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# File 'lib/ubiq/algo.rb', line 45

def get_algo(name)
  set_algo[name]
end

#set_algo ⇒ Object 



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# File 'lib/ubiq/algo.rb', line 15

def set_algo
  @algorithm = {
    'aes-256-gcm' => {
      id: 0,
      algorithm: OpenSSL::Cipher::AES256,
      mode: OpenSSL::Cipher::AES256.new(:GCM),
      key_length: 32,
      iv_length: 12,
      tag_length: 16
    },
    'aes-128-gcm' => {
      id: 1,
      algorithm: OpenSSL::Cipher::AES128,
      mode: OpenSSL::Cipher::AES128.new(:GCM),
      key_length: 16,
      iv_length: 12,
      tag_length: 16
    }
  }
end