Class: TagAuth::EncryptionHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/tag_auth/encryption_helper.rb

Instance Method Summary collapse

Constructor Details

#initialize(algorithm, key) ⇒ EncryptionHelper

Returns a new instance of EncryptionHelper.

Raises:

  • (ArgumentError) 


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# File 'lib/tag_auth/encryption_helper.rb', line 6

def initialize(algorithm, key)
  raise ArgumentError, 'Invalid algorithm' unless valid_algorithm?(algorithm.downcase)
  raise ArgumentError, 'Invalid key length' unless valid_key?(key, algorithm)

  @algorithm = algorithm.downcase
  @key = key
end

Instance Method Details

#decrypt(encrypted_string) ⇒ Object 



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# File 'lib/tag_auth/encryption_helper.rb', line 25

def decrypt(encrypted_string)
  decipher = OpenSSL::Cipher.new(@algorithm)
  decipher.decrypt
  decipher.key = @key

  decoded_data = Base64.decode64(encrypted_string)

  iv_len = decipher.iv_len
  data_len = decoded_data.length - iv_len

  encrypted_data = decoded_data[0, data_len]
  iv = decoded_data[data_len, iv_len]

  decipher.iv = iv
  decipher.update(encrypted_data) + decipher.final
end

#encrypt(data) ⇒ Object 



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# File 'lib/tag_auth/encryption_helper.rb', line 14

def encrypt(data)
  cipher = OpenSSL::Cipher.new(@algorithm)
  cipher.encrypt
  cipher.key = @key
  iv = cipher.random_iv

  encrypted_data = cipher.update(data) + cipher.final

  Base64.encode64(encrypted_data + iv)
end