Xray-core: Forbid unencrypted outbounds on public Internet for VLESS and Trojan; Remove "none/zero/plain" for VMess and Shadowsocks (#6303)

https://github.com/XTLS/Xray-core/pull/5640#issuecomment-4611416512
https://github.com/XTLS/Xray-core/pull/6303#issuecomment-4668055274

---------

Co-authored-by: Meow <197331664+Meo597@users.noreply.github.com>

infra/conf/shadowsocks.go

@@ -24,8 +24,6 @@ func cipherFromString(c string) shadowsocks.CipherType {
 		return shadowsocks.CipherType_CHACHA20_POLY1305
 	case "xchacha20-poly1305", "aead_xchacha20_poly1305", "xchacha20-ietf-poly1305":
 		return shadowsocks.CipherType_XCHACHA20_POLY1305
-	case "none", "plain":
-		return shadowsocks.CipherType_NONE
 	default:
 		return shadowsocks.CipherType_UNKNOWN
 	}

infra/conf/vmess.go

@@ -31,10 +31,6 @@ func (a *VMessAccount) Build() *vmess.Account {
 		st = protocol.SecurityType_CHACHA20_POLY1305
 	case "auto":
 		st = protocol.SecurityType_AUTO
-	case "none":
-		st = protocol.SecurityType_NONE
-	case "zero":
-		st = protocol.SecurityType_ZERO
 	default:
 		st = protocol.SecurityType_AUTO
 	}

infra/conf/xray.go

@@ -230,6 +230,40 @@ func (c *OutboundDetourConfig) checkChainProxyConfig() error {
 	return nil
 }
 
+func requiresTransportSecurity(address *Address) bool {
+	if address == nil || address.Address == nil {
+		return false
+	}
+	if address.Family().IsIP() {
+		return !geodata.GetPrivateIPMatcher().Match(address.IP())
+	}
+	domain := strings.TrimSuffix(strings.ToLower(address.Domain()), ".")
+	return !geodata.GetPrivateDomainMatcher().MatchAny(domain)
+}
+
+func validateOutboundTransportSecurity(rawConfig interface{}, senderSettings *proxyman.SenderConfig) error {
+	if senderSettings.StreamSettings != nil && senderSettings.StreamSettings.GetSecurityType() != "" {
+		return nil
+	}
+
+	if vlessCfg, ok := rawConfig.(*VLessOutboundConfig); ok {
+		if vlessCfg.Encryption != "" && vlessCfg.Encryption != "none" {
+			return nil
+		}
+		if requiresTransportSecurity(vlessCfg.Address) {
+			return errors.New("vless without TLS or other encryption is prohibited unless the server address is a private IP or domain")
+		}
+	}
+
+	if tjCfg, ok := rawConfig.(*TrojanClientConfig); ok {
+		if requiresTransportSecurity(tjCfg.Address) {
+			return errors.New("trojan without TLS is prohibited unless the server address is a private IP or domain")
+		}
+	}
+
+	return nil
+}
+
 // Build implements Buildable.
 func (c *OutboundDetourConfig) Build() (*core.OutboundHandlerConfig, error) {
 	senderSettings := &proxyman.SenderConfig{}
@@ -323,6 +357,9 @@ func (c *OutboundDetourConfig) Build() (*core.OutboundHandlerConfig, error) {
 	if err != nil {
 		return nil, errors.New("failed to load outbound detour config for protocol ", c.Protocol).Base(err)
 	}
+	if err := validateOutboundTransportSecurity(rawConfig, senderSettings); err != nil {
+		return nil, err
+	}
 	ts, err := rawConfig.(Buildable).Build()
 	if err != nil {
 		return nil, errors.New("failed to build outbound handler for protocol ", c.Protocol).Base(err)