Method: Ably::Models::CipherParams#initialize

Defined in:

lib/ably/models/cipher_params.rb

#initialize(params = {}) ⇒ CipherParams

Returns a new instance of CipherParams.

Options Hash (params):

• :key (String, Binary) —

  Required private key must be either a binary (e.g. a ASCII_8BIT encoded string), or a base64-encoded string. If the key is a base64-encoded string, the it will be automatically converted into a binary

• :algorithm (String) —

  optional (default AES), specify the encryption algorithm supported by OpenSSL::Cipher

• :mode (String) —

  optional (default CBC), specify the cipher mode supported by OpenSSL::Cipher

• :key_length (Integer) —

  optional (default 128), specify the key length of the cipher supported by OpenSSL::Cipher

• :combined (String) —

  optional (default AES-128-CBC), specify in one option the algorithm, key length and cipher of the cipher supported by OpenSSL::Cipher

Raises:

Parameters:

• (defaults to: {})

# File 'lib/ably/models/cipher_params.rb', line 31

def initialize(params = {})
  @attributes = IdiomaticRubyWrapper(params.clone)

  raise Ably::Exceptions::CipherError, ':key param is required' unless attributes[:key]
  raise Ably::Exceptions::CipherError, ':key param must be a base64-encoded string or byte array (ASCII_8BIT enocdede string)' unless key.kind_of?(String)
  attributes[:key] = decode_key(key) if key.kind_of?(String) && key.encoding != Encoding::ASCII_8BIT

  if attributes[:combined]
    match = /(?<algorithm>\w+)-(?<key_length>\d+)-(?<mode>\w+)/.match(attributes[:combined])
    raise Ably::Exceptions::CipherError, "Invalid :combined param, expecting format such as AES-256-CBC" unless match
    attributes[:algorithm] = match[:algorithm]
    attributes[:key_length] = match[:key_length].to_i
    attributes[:mode] = match[:mode]
  end

  if attributes[:key_length] && (key_length != attributes[:key_length])
    raise Ably::Exceptions::CipherError, "Incompatible :key length of #{key_length} and provided :key_length of #{attributes[:key_length]}"
  end

  if algorithm == 'aes' && mode == 'cbc'
    unless [128, 256].include?(key_length)
      raise Ably::Exceptions::CipherError, "Unsupported key length #{key_length} for aes-cbc encryption. Encryption key must be 128 or 256 bits (16 or 32 ASCII characters)"
    end
  end

  attributes.freeze
end