1 files changed, 32 insertions, 0 deletions
diff --git a/app/helpers/ci/user_sessions_helper.rb b/app/helpers/ci/user_sessions_helper.rb
new file mode 100644
index 00000000000..0296a74395c
--- /dev/null
+++ b/app/helpers/ci/user_sessions_helper.rb
@@ -0,0 +1,32 @@
+module Ci
+  module UserSessionsHelper
+    def generate_oauth_salt
+      SecureRandom.hex(16)
+    end
+
+    def generate_oauth_hmac(salt, return_to)
+      return unless return_to
+      digest = OpenSSL::Digest.new('sha256')
+      key = Gitlab::Application.secrets.db_key_base + salt
+      OpenSSL::HMAC.hexdigest(digest, key, return_to)
+    end
+
+    def generate_oauth_state(return_to)
+      return unless return_to
+      salt = generate_oauth_salt
+      hmac = generate_oauth_hmac(salt, return_to)
+      "#{salt}:#{hmac}:#{return_to}"
+    end
+
+    def get_ouath_state_return_to(state)
+      state.split(':', 3)[2] if state
+    end
+
+    def is_oauth_state_valid?(state)
+      return true unless state
+      salt, hmac, return_to = state.split(':', 3)
+      return false unless return_to
+      hmac == generate_oauth_hmac(salt, return_to)
+    end
+  end
+end