XTLS/Xray-core · error

empty password

Error message

empty password

What it means

XMC.Build requires a non-empty password because the RSA key pair used by the Minecraft masking layer is deterministically derived from it (xmc.DeriveRSAKey). An empty password would yield a known, public key pair and is rejected outright.

Source

Thrown at infra/conf/transport_finalmask.go:767

	if c.TexturesValue == "" || c.TexturesSignature == "" {
		return nil, fmt.Errorf("incomplete minecraft profile textures")
	}

	return &xmc.Profile{
		Username:          c.Username,
		Uuid:              append([]byte(nil), profileUUID[:]...),
		TexturesValue:     c.TexturesValue,
		TexturesSignature: c.TexturesSignature,
	}, nil
}

func (c *XMC) Build() (proto.Message, error) {
	if len(c.Profiles) == 0 {
		return nil, fmt.Errorf("minecraft profiles are required")
	}

	if c.Password == "" {
		return nil, fmt.Errorf("empty password")
	}

	rsaPrivateKey, err := xmc.DeriveRSAKey(c.Password)
	if err != nil {
		return nil, fmt.Errorf("derive minecraft rsa key: %w", err)
	}

	rsaPublicKey, err := x509.MarshalPKIXPublicKey(&rsaPrivateKey.PublicKey)
	if err != nil {
		return nil, fmt.Errorf("marshal minecraft rsa public key: %w", err)
	}

	profiles := make([]*xmc.Profile, 0, len(c.Profiles))
	for i := range c.Profiles {
		profile, err := c.Profiles[i].Build()
		if err != nil {
			return nil, fmt.Errorf("build minecraft profile %d: %w", i, err)
		}

View on GitHub (pinned to 7d214f8b09)

Solutions

1. Set a strong non-empty password shared by both client and server xmc configs
2. Verify the exact JSON key "password" is used
3. Keep the password identical on both ends — the derived RSA keys must match

Example fix

// before
"xmc": { "password": "", "profiles": [ ... ] }

// after
"xmc": { "password": "a-long-shared-secret", "profiles": [ ... ] }

func validXmcPassword(pw string) bool { return pw != "" }

When it happens

Trigger: Omitting "password" in the xmc settings block or setting it to "".

Common situations: Placeholder configs with an empty password meant to be filled later; password key typo (pass/pwd) leaving the field zero-valued.

Related errors

• invalid minecraft profile username: %q
• minecraft profiles are required
• build minecraft profile %d: %w
• not a Service.
• Dispatcher: Invalid destination.

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/1bb6eec15f3c6259. Report an issue: GitHub.