Update devise-two-factor to version 5.0.0 (#28325)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

app/models/concerns/legacy_otp_secret.rb

@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+# TODO: This file is here for legacy support during devise-two-factor upgrade.
+# It should be removed after all records have been migrated.
+
+module LegacyOtpSecret
+  extend ActiveSupport::Concern
+
+  private
+
+  # Decrypt and return the `encrypted_otp_secret` attribute which was used in
+  # prior versions of devise-two-factor
+  # @return [String] The decrypted OTP secret
+  def legacy_otp_secret
+    return nil unless self[:encrypted_otp_secret]
+    return nil unless self.class.otp_secret_encryption_key
+
+    hmac_iterations = 2000 # a default set by the Encryptor gem
+    key = self.class.otp_secret_encryption_key
+    salt = Base64.decode64(encrypted_otp_secret_salt)
+    iv = Base64.decode64(encrypted_otp_secret_iv)
+
+    raw_cipher_text = Base64.decode64(encrypted_otp_secret)
+    # The last 16 bytes of the ciphertext are the authentication tag - we use
+    # Galois Counter Mode which is an authenticated encryption mode
+    cipher_text = raw_cipher_text[0..-17]
+    auth_tag =  raw_cipher_text[-16..-1] # rubocop:disable Style/SlicingWithRange
+
+    # this alrorithm lifted from
+    # https://github.com/attr-encrypted/encryptor/blob/master/lib/encryptor.rb#L54
+
+    # create an OpenSSL object which will decrypt the AES cipher with 256 bit
+    # keys in Galois Counter Mode (GCM). See
+    # https://ruby.github.io/openssl/OpenSSL/Cipher.html
+    cipher = OpenSSL::Cipher.new('aes-256-gcm')
+
+    # tell the cipher we want to decrypt. Symmetric algorithms use a very
+    # similar process for encryption and decryption, hence the same object can
+    # do both.
+    cipher.decrypt
+
+    # Use a Password-Based Key Derivation Function to generate the key actually
+    # used for encryptoin from the key we got as input.
+    cipher.key = OpenSSL::PKCS5.pbkdf2_hmac_sha1(key, salt, hmac_iterations, cipher.key_len)
+
+    # set the Initialization Vector (IV)
+    cipher.iv = iv
+
+    # The tag must be set after calling Cipher#decrypt, Cipher#key= and
+    # Cipher#iv=, but before calling Cipher#final. After all decryption is
+    # performed, the tag is verified automatically in the call to Cipher#final.
+    #
+    # If the auth_tag does not verify, then #final will raise OpenSSL::Cipher::CipherError
+    cipher.auth_tag = auth_tag
+
+    # auth_data must be set after auth_tag has been set when decrypting See
+    # http://ruby-doc.org/stdlib-2.0.0/libdoc/openssl/rdoc/OpenSSL/Cipher.html#method-i-auth_data-3D
+    # we are not adding any authenticated data but OpenSSL docs say this should
+    # still be called.
+    cipher.auth_data = ''
+
+    # #update is (somewhat confusingly named) the method which actually
+    # performs the decryption on the given chunk of data. Our OTP secret is
+    # short so we only need to call it once.
+    #
+    # It is very important that we call #final because:
+    #
+    # 1. The authentication tag is checked during the call to #final
+    # 2. Block based cipher modes (e.g. CBC) work on fixed size chunks. We need
+    #    to call #final to get it to process the last chunk properly. The output
+    #    of #final should be appended to the decrypted value. This isn't
+    #    required for streaming cipher modes but including it is a best practice
+    #    so that your code will continue to function correctly even if you later
+    #    change to a block cipher mode.
+    cipher.update(cipher_text) + cipher.final
+  end
+end

app/models/user.rb

@@ -39,6 +39,7 @@
 #  role_id                   :bigint(8)
 #  settings                  :text
 #  time_zone                 :string
+#  otp_secret                :string
 #
 
 class User < ApplicationRecord
@@ -72,6 +73,8 @@ class User < ApplicationRecord
   devise :two_factor_authenticatable,
          otp_secret_encryption_key: Rails.configuration.x.otp_secret
 
+  include LegacyOtpSecret # Must be after the above `devise` line in order to override the legacy method
+
   devise :two_factor_backupable,
          otp_number_of_backup_codes: 10
 
@@ -131,11 +134,6 @@ class User < ApplicationRecord
   normalizes :time_zone, with: ->(time_zone) { ActiveSupport::TimeZone[time_zone].nil? ? nil : time_zone }
   normalizes :chosen_languages, with: ->(chosen_languages) { chosen_languages.compact_blank.presence }
 
-  # This avoids a deprecation warning from Rails 5.1
-  # It seems possible that a future release of devise-two-factor will
-  # handle this itself, and this can be removed from our User class.
-  attribute :otp_secret
-
   has_many :session_activations, dependent: :destroy
 
   delegate :can?, to: :role