Start to create 2FA exemption after successful 2FA login

src/constants.rs

@@ -19,6 +19,10 @@ pub const MAX_INACTIVITY_DURATION: u64 = 60 * 30;
 /// Maximum session duration (6 hours)
 pub const MAX_SESSION_DURATION: u64 = 3600 * 6;
 
+/// When the user successfully authenticate using 2FA, period of time during which the user is
+/// exempted from this IP address to use 2FA
+pub const SECOND_FACTOR_EXEMPTION_AFTER_SUCCESSFUL_LOGIN: u64 = 7 * 24 * 3600;
+
 /// Minimum password length
 pub const MIN_PASS_LEN: usize = 4;