1 files changed, 118 insertions, 0 deletions
diff --git a/activesupport/test/message_encryptor_test.rb b/activesupport/test/message_encryptor_test.rb
index 1fbe655642..17baf3550b 100644
--- a/activesupport/test/message_encryptor_test.rb
+++ b/activesupport/test/message_encryptor_test.rb
@@ -115,6 +115,124 @@ class MessageEncryptorTest < ActiveSupport::TestCase
     assert_equal "Ruby on Rails", encryptor.decrypt_and_verify(encrypted_message)
   end
 
+  def test_with_rotated_raw_key
+    old_raw_key = SecureRandom.random_bytes(32)
+    old_encryptor = ActiveSupport::MessageEncryptor.new(old_raw_key, cipher: "aes-256-gcm")
+    old_message = old_encryptor.encrypt_and_sign("message encrypted with old raw key")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret, cipher: "aes-256-gcm")
+    encryptor.rotate raw_key: old_raw_key, cipher: "aes-256-gcm"
+
+    assert_equal "message encrypted with old raw key", encryptor.decrypt_and_verify(old_message)
+  end
+
+  def test_with_rotated_secret_and_salt
+    old_secret, old_salt = SecureRandom.random_bytes(32), "old salt"
+    old_raw_key = ActiveSupport::KeyGenerator.new(old_secret, iterations: 1000).generate_key(old_salt, 32)
+
+    old_encryptor = ActiveSupport::MessageEncryptor.new(old_raw_key, cipher: "aes-256-gcm")
+    old_message = old_encryptor.encrypt_and_sign("message encrypted with old secret and salt")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret, cipher: "aes-256-gcm")
+    encryptor.rotate secret: old_secret, salt: old_salt, cipher: "aes-256-gcm"
+
+    assert_equal "message encrypted with old secret and salt", encryptor.decrypt_and_verify(old_message)
+  end
+
+  def test_with_rotated_key_generator
+    old_key_gen, old_salt = ActiveSupport::KeyGenerator.new(SecureRandom.random_bytes(32), iterations: 256), "old salt"
+
+    old_raw_key = old_key_gen.generate_key(old_salt, 32)
+    old_encryptor = ActiveSupport::MessageEncryptor.new(old_raw_key, cipher: "aes-256-gcm")
+    old_message = old_encryptor.encrypt_and_sign("message encrypted with old key generator and salt")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret, cipher: "aes-256-gcm")
+    encryptor.rotate key_generator: old_key_gen, salt: old_salt, cipher: "aes-256-gcm"
+
+    assert_equal "message encrypted with old key generator and salt", encryptor.decrypt_and_verify(old_message)
+  end
+
+  def test_with_rotated_aes_cbc_encryptor_with_raw_keys
+    old_raw_key, old_raw_signed_key = SecureRandom.random_bytes(32), SecureRandom.random_bytes(16)
+
+    old_encryptor = ActiveSupport::MessageEncryptor.new(old_raw_key, old_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1")
+    old_message = old_encryptor.encrypt_and_sign("message encrypted with old raw keys")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret)
+    encryptor.rotate raw_key: old_raw_key, raw_signed_key: old_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1"
+
+    assert_equal "message encrypted with old raw keys", encryptor.decrypt_and_verify(old_message)
+  end
+
+  def test_with_rotated_aes_cbc_encryptor_with_secret_and_salts
+    old_secret, old_salt, old_signed_salt = SecureRandom.random_bytes(32), "old salt", "old signed salt"
+
+    old_key_gen = ActiveSupport::KeyGenerator.new(old_secret, iterations: 1000)
+    old_raw_key = old_key_gen.generate_key(old_salt, 32)
+    old_raw_signed_key = old_key_gen.generate_key(old_signed_salt)
+
+    old_encryptor = ActiveSupport::MessageEncryptor.new(old_raw_key, old_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1")
+    old_message = old_encryptor.encrypt_and_sign("message encrypted with old secret and salts")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret)
+    encryptor.rotate secret: old_secret, salt: old_salt, signed_salt: old_signed_salt, cipher: "aes-256-cbc", digest: "SHA1"
+
+    assert_equal "message encrypted with old secret and salts", encryptor.decrypt_and_verify(old_message)
+  end
+
+  def test_with_rotating_multiple_encryptors
+    older_raw_key, older_raw_signed_key = SecureRandom.random_bytes(32), SecureRandom.random_bytes(16)
+    old_raw_key, old_raw_signed_key = SecureRandom.random_bytes(32), SecureRandom.random_bytes(16)
+
+    older_encryptor = ActiveSupport::MessageEncryptor.new(older_raw_key, older_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1")
+    older_message = older_encryptor.encrypt_and_sign("message encrypted with older raw key")
+
+    old_encryptor = ActiveSupport::MessageEncryptor.new(old_raw_key, old_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1")
+    old_message = old_encryptor.encrypt_and_sign("message encrypted with old raw key")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret)
+    encryptor.rotate raw_key: old_raw_key, raw_signed_key: old_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1"
+    encryptor.rotate raw_key: older_raw_key, raw_signed_key: older_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1"
+
+    assert_equal "encrypted message", encryptor.decrypt_and_verify(encryptor.encrypt_and_sign("encrypted message"))
+    assert_equal "message encrypted with old raw key", encryptor.decrypt_and_verify(old_message)
+    assert_equal "message encrypted with older raw key", encryptor.decrypt_and_verify(older_message)
+  end
+
+  def test_on_rotation_instance_callback_is_called_and_returns_modified_messages
+    callback_ran, message = nil, nil
+
+    older_raw_key, older_raw_signed_key = SecureRandom.random_bytes(32), SecureRandom.random_bytes(16)
+    old_raw_key, old_raw_signed_key = SecureRandom.random_bytes(32), SecureRandom.random_bytes(16)
+
+    older_encryptor = ActiveSupport::MessageEncryptor.new(older_raw_key, older_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1")
+    older_message = older_encryptor.encrypt_and_sign(encoded: "message")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret)
+    encryptor.rotate raw_key: old_raw_key, raw_signed_key: old_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1"
+    encryptor.rotate raw_key: older_raw_key, raw_signed_key: older_raw_signed_key, cipher: "aes-256-cbc", digest: "SHA1"
+
+    message = encryptor.decrypt_and_verify(older_message, on_rotation: proc { callback_ran = true })
+
+    assert callback_ran, "callback was ran"
+    assert_equal({ encoded: "message" }, message)
+  end
+
+  def test_with_rotated_metadata
+    old_secret, old_salt = SecureRandom.random_bytes(32), "old salt"
+    old_raw_key = ActiveSupport::KeyGenerator.new(old_secret, iterations: 1000).generate_key(old_salt, 32)
+
+    old_encryptor = ActiveSupport::MessageEncryptor.new(old_raw_key, cipher: "aes-256-gcm")
+    old_message = old_encryptor.encrypt_and_sign(
+      "message encrypted with old secret, salt, and metadata", purpose: "rotation")
+
+    encryptor = ActiveSupport::MessageEncryptor.new(@secret, cipher: "aes-256-gcm")
+    encryptor.rotate secret: old_secret, salt: old_salt, cipher: "aes-256-gcm"
+
+    assert_equal "message encrypted with old secret, salt, and metadata",
+      encryptor.decrypt_and_verify(old_message, purpose: "rotation")
+  end
+
   private
     def assert_aead_not_decrypted(encryptor, value)
       assert_raise(ActiveSupport::MessageEncryptor::InvalidMessage) do