XTLS/Xray-core · error

padding turns %d and %d have the same direction

Error message

padding turns %d and %d have the same direction

What it means

Error "padding turns %d and %d have the same direction" thrown in XTLS/Xray-core.

Source

Thrown at transport/internet/finalmask/xmc/padding.go:125

			if len(turn.variants) > 0 {
				return fmt.Errorf("padding turn %d combines variants with a send range", i)
			}
			if turn.sendMinLength < minLength || turn.sendMaxLength < turn.sendMinLength || turn.sendMaxLength > maxLength {
				return fmt.Errorf("padding turn %d has an invalid send range: %d-%d", i, turn.sendMinLength, turn.sendMaxLength)
			}
		}
		if i == 0 && minLength-firstTurnPrefixLength < 1 {
			return fmt.Errorf("padding turn 0 is too short for %d prefix bytes", firstTurnPrefixLength)
		}
		if i == 0 && len(turn.variants) > 0 {
			for j, variant := range turn.variants {
				if _, _, err = trimPaddingPrefix(variant, firstTurnPrefixLength); err != nil {
					return fmt.Errorf("padding turn 0 variant %d: %w", j, err)
				}
			}
		}
		if i > 0 && turn.direction == schedule[i-1].direction {
			return fmt.Errorf("padding turns %d and %d have the same direction", i-1, i)
		}
	}
	return nil
}

func writePaddingTurn(w io.Writer, turn paddingTurn, prefixLength int) error {
	return writePaddingTurnWithSleep(w, turn, prefixLength, time.Sleep)
}

func writePaddingTurnWithSleep(w io.Writer, turn paddingTurn, prefixLength int, sleep func(time.Duration)) error {
	return writePaddingTurnWithBuffer(w, turn, prefixLength, sleep, nil)
}

func writePaddingTurnWithBuffer(w io.Writer, turn paddingTurn, prefixLength int, sleep func(time.Duration), reusableBuffer *[]byte) error {
	startDelay, err := randomPaddingDelay(turn.startDelay)
	if err != nil {
		return fmt.Errorf("select padding start delay: %w", err)
	}

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at transport/internet/finalmask/xmc/padding.go:125 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/a526e099c41b7d56. Report an issue: GitHub.