1
0
Fork 0

Recoded TOTP time drift validation

Dieser Commit ist enthalten in:
BlackDex 2019-10-12 15:28:28 +02:00
Ursprung d989a19f76
Commit 9466f02696

Datei anzeigen

@ -118,43 +118,32 @@ pub fn validate_totp_code(user_uuid: &str, totp_code: u64, secret: &str, conn: &
let current_time: u64 = SystemTime::now().duration_since(UNIX_EPOCH)
.expect("Earlier than 1970-01-01 00:00:00 UTC").as_secs();
// First check the current time for a valid token.
let time_step_now = (current_time / 30) as i32;
let generated_now = totp_raw_custom_time(&decoded_secret, 6, 0, 30, current_time, &HashType::SHA1);
if generated_now == totp_code && time_step_now > twofactor.last_used {
twofactor.last_used = time_step_now;
twofactor.save(&conn)?;
return Ok(());
} else if generated_now == totp_code && time_step_now <= twofactor.last_used {
warn!("This or a future TOTP code has already been used!");
err!("Invalid TOTP code!");
// The amount of steps back and forward in time
let steps = 1;
for step in -steps..=steps {
let time_step = (current_time / 30) as i32 + step;
// We need to calculate the time offsite and cast it as an i128.
// Else we can't do math with it on a default u64 variable.
let time_offset: i128 = (step * 30).into();
let generated = totp_raw_custom_time(&decoded_secret, 6, 0, 30, (current_time as i128 + time_offset) as u64, &HashType::SHA1);
// Check the the given code equals the generated and if the time_step is larger then the one last used.
if generated == totp_code && time_step > twofactor.last_used {
// If the step does not equals 0 the time is drifted either server or client side.
if step != 0 {
info!("TOTP Time drift detected. The step offset is {}", step);
}
// Check for time drifted codes
// First check the previous TOTP code
let time_step_prev = ((current_time - 30) / 30) as i32;
let generated_prev = totp_raw_custom_time(&decoded_secret, 6, 0, 30, current_time - 30, &HashType::SHA1);
if generated_prev == totp_code && time_step_prev > twofactor.last_used {
info!("TOTP Time drift detected. Token is valide for one step on the past.");
twofactor.last_used = time_step_prev;
// Save the last used time step so only totp time steps higher then this one are allowed.
twofactor.last_used = time_step;
twofactor.save(&conn)?;
return Ok(());
} else if generated_prev == totp_code && time_step_prev <= twofactor.last_used {
warn!("This or a future TOTP code has already been used!");
err!("Invalid TOTP code!");
} else if generated == totp_code && time_step <= twofactor.last_used {
warn!("This or a TOTP code within {} steps back and forward has already been used!", steps);
err!("Invalid TOTP Code!");
}
// Second check the next TOTP code
let time_step_next = ((current_time + 30) / 30) as i32;
let generated_next = totp_raw_custom_time(&decoded_secret, 6, 0, 30, current_time + 30, &HashType::SHA1);
if generated_next == totp_code && time_step_next > twofactor.last_used {
info!("TOTP Time drift detected. Token is valide for one step on the future.");
twofactor.last_used = time_step_next;
twofactor.save(&conn)?;
return Ok(());
} else if generated_next == totp_code && time_step_next <= twofactor.last_used {
warn!("This or a previous TOTP code has already been used!");
err!("Invalid TOTP code!");
}
// Else no valide code received, deny access