Class: Xml::Kit::Crypto::SymmetricCipher

Inherits:
Object
  • Object
show all
Defined in:
lib/xml/kit/crypto/symmetric_cipher.rb

Constant Summary collapse

DEFAULT_ALGORITHM = 
"#{::Xml::Kit::Namespaces::XMLENC}aes256-cbc".freeze
ALGORITHMS = 
{
  "#{::Xml::Kit::Namespaces::XMLENC}tripledes-cbc" => 'DES-EDE3-CBC',
  "#{::Xml::Kit::Namespaces::XMLENC}aes128-cbc" => 'AES-128-CBC',
  "#{::Xml::Kit::Namespaces::XMLENC}aes192-cbc" => 'AES-192-CBC',
  "#{::Xml::Kit::Namespaces::XMLENC}aes256-cbc" => 'AES-256-CBC',
}.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(algorithm, key = nil, padding = nil) ⇒ SymmetricCipher

Returns a new instance of SymmetricCipher.



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# File 'lib/xml/kit/crypto/symmetric_cipher.rb', line 17

def initialize(algorithm, key = nil, padding = nil)
  @algorithm = algorithm
  @key = key || cipher.random_key
  @padding = padding
end

Instance Attribute Details

#algorithm ⇒ Object (readonly)

Returns the value of attribute algorithm.



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# File 'lib/xml/kit/crypto/symmetric_cipher.rb', line 15

def algorithm
  @algorithm
end

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/xml/kit/crypto/symmetric_cipher.rb', line 15

def key
  @key
end

#padding ⇒ Object (readonly)

Returns the value of attribute padding.



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# File 'lib/xml/kit/crypto/symmetric_cipher.rb', line 15

def padding
  @padding
end

Class Method Details

.matches?(algorithm) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xml/kit/crypto/symmetric_cipher.rb', line 23

def self.matches?(algorithm)
  ALGORITHMS[algorithm]
end

Instance Method Details

#decrypt(cipher_text) ⇒ Object 



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# File 'lib/xml/kit/crypto/symmetric_cipher.rb', line 33

def decrypt(cipher_text)
  result = default_decrypt(
    cipher_text[0...cipher.iv_len],
    cipher_text[cipher.iv_len..-1]
  )
  return result if padding.nil?

  padding_size = result.bytes.last
  result[0...-padding_size]
end

#encrypt(plain_text) ⇒ Object 



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# File 'lib/xml/kit/crypto/symmetric_cipher.rb', line 27

def encrypt(plain_text)
  cipher.encrypt
  cipher.key = @key
  cipher.random_iv + cipher.update(plain_text) + cipher.final
end