Class: IOP::CipherEncryptor

Inherits:
Object
  • Object
show all
Includes:
Feed, Sink
Defined in:
lib/iop/openssl.rb

Overview

Filter class to perform encryption with a symmetric key algorithm (ciphering) of the data passed through.

The class is an adapter for OpenSSL::Cipher & compatible classes.

### Use case: generate 1024 bytes of random data encrypt is with default cipher algorithm and generated key & initial vector.

require 'iop/openssl'
require 'iop/securerandom'
( IOP::SecureRandomGenerator.new(1024) | (c = IOP::CipherEncryptor.new) ).process!
puts c.key

Since:

  • 0.1

Instance Attribute Summary collapse

Attributes included from Sink

#upstream

Attributes included from Feed

#downstream

Instance Method Summary collapse

Methods included from Sink

#process!

Methods included from Feed

#process!, #|

Constructor Details

#initialize(cipher = DEFAULT_OPENSSL_CIPHER, key: nil, iv: nil) ⇒ CipherEncryptor

Creates class instance.

cipher can be either a String or OpenSSL::Cipher instance. If it is a string, a corresponding OpenSSL::Cipher instance will be created.

If key is nil, a new key will be generated in secure manner which can be accessed later with #key method.

If iv is nil, a new initial vector will be generated in secure manner which can be accessed later with #iv method. If iv is nil the generated initial vector will be injected into the downstream data preceding the encrypted data itself.

Note that key and initial vector are both cipher-dependent. Refer to OpenSSL::Cipher documentation for more information.

Parameters:

  • cipher (String, OpenSSL::Cipher) (defaults to: DEFAULT_OPENSSL_CIPHER) —

    cipher used for encryption

  • key (String) (defaults to: nil) —

    string representing an encryption key or nil

  • iv (String) (defaults to: nil) —

    string representing an initial vector or nil

Since:

  • 0.1



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# File 'lib/iop/openssl.rb', line 54

def initialize(cipher = DEFAULT_OPENSSL_CIPHER, key: nil, iv: nil)
  @cipher = cipher.is_a?(String) ? OpenSSL::Cipher.new(cipher) : cipher
  @cipher.encrypt
  @key = key.nil? ? @cipher.random_key : @cipher.key = key
  @iv = if iv.nil?
          @embed_iv = true
          @cipher.random_iv
        else
          @cipher.iv = iv
        end
end

Instance Attribute Details

#iv ⇒ Object (readonly)

Returns initial vector (IV) for encryption session.

Since:

  • 0.1



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# File 'lib/iop/openssl.rb', line 32

def iv
  @iv
end

#key ⇒ Object (readonly)

Returns encryption key.

Since:

  • 0.1



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# File 'lib/iop/openssl.rb', line 35

def key
  @key
end

Instance Method Details

#process(data = nil) ⇒ Object

Since:

  • 0.1



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# File 'lib/iop/openssl.rb', line 66

def process(data = nil)
  unless @continue
    @continue = true
    super(iv) if @embed_iv
    @buffer = IOP.allocate_string(data.size)
  end
  if data.nil?
    super(@cipher.final)
    super
  else
    super(@cipher.update(data, @buffer)) unless data.size.zero?
  end
end