fix: require Feishu webhook authentication (#1638)

* fix: require Feishu webhook authentication

* fix: handle Feishu v2 webhook token auth

* fix: skip empty verification token write, consistent with app_id/app_secret

Address zmanian review nit #4: only write verification_token to workspace
when present, matching the if-let pattern used for app_id and app_secret.
Functionally identical (the auth check filters empty strings), but
consistent.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>

src/channels/wasm/loader.rs

@@ -317,6 +317,14 @@ impl LoadedChannel {
             .map(|f| f.webhook_secret_name())
             .unwrap_or_else(|| format!("{}_webhook_secret", self.channel.channel_name()))
     }
+
+    /// Whether the host should enforce generic webhook-secret validation.
+    pub fn webhook_secret_managed_by_host(&self) -> bool {
+        self.capabilities_file
+            .as_ref()
+            .map(|f| f.webhook_secret_managed_by_host())
+            .unwrap_or(true)
+    }
 }
 
 /// Results from loading multiple channels.

src/channels/wasm/schema.rs

@@ -185,6 +185,19 @@ impl ChannelCapabilitiesFile {
             .and_then(|w| w.secret_name.clone())
             .unwrap_or_else(|| format!("{}_webhook_secret", self.name))
     }
+
+    /// Whether the host should enforce generic webhook-secret validation.
+    ///
+    /// Defaults to true. Channels can opt out when they validate the shared
+    /// secret themselves using provider-specific request body fields.
+    pub fn webhook_secret_managed_by_host(&self) -> bool {
+        self.capabilities
+            .channel
+            .as_ref()
+            .and_then(|c| c.webhook.as_ref())
+            .and_then(|w| w.managed_by_host)
+            .unwrap_or(true)
+    }
 }
 
 /// Schema for channel capabilities.
@@ -302,6 +315,14 @@ pub struct WebhookSchema {
     /// Secret name in secrets store for HMAC-SHA256 signing (Slack-style).
     #[serde(default)]
     pub hmac_secret_name: Option<String>,
+
+    /// Whether the host/router should enforce generic webhook-secret
+    /// validation before the channel sees the request.
+    ///
+    /// Default: true. Set to false when the provider sends the shared secret
+    /// in a provider-specific request field rather than the configured header.
+    #[serde(default)]
+    pub managed_by_host: Option<bool>,
 }
 
 /// Setup configuration schema.
@@ -611,6 +632,25 @@ mod tests {
             Some("X-Telegram-Bot-Api-Secret-Token")
         );
         assert_eq!(file.webhook_secret_name(), "telegram_webhook_secret");
+        assert!(file.webhook_secret_managed_by_host());
+    }
+
+    #[test]
+    fn test_webhook_schema_can_disable_host_managed_secret_validation() {
+        let json = r#"{
+            "name": "feishu",
+            "capabilities": {
+                "channel": {
+                    "webhook": {
+                        "secret_name": "feishu_verification_token",
+                        "managed_by_host": false
+                    }
+                }
+            }
+        }"#;
+
+        let file = ChannelCapabilitiesFile::from_json(json).unwrap();
+        assert!(!file.webhook_secret_managed_by_host());
     }
 
     #[test]

src/channels/wasm/setup.rs

@@ -139,13 +139,18 @@ async fn register_channel(
     };
 
     let secret_header = loaded.webhook_secret_header().map(|s| s.to_string());
+    let host_webhook_secret = if loaded.webhook_secret_managed_by_host() {
+        webhook_secret.clone()
+    } else {
+        None
+    };
 
     let webhook_path = format!("/webhook/{}", channel_name);
     let endpoints = vec![RegisteredEndpoint {
         channel_name: channel_name.clone(),
         path: webhook_path,
         methods: vec!["POST".to_string()],
-        require_secret: webhook_secret.is_some(),
+        require_secret: host_webhook_secret.is_some(),
     }];
 
     let channel_arc = Arc::new(loaded.channel.with_owner_actor_id(owner_actor_id.clone()));
@@ -205,7 +210,7 @@ async fn register_channel(
 
     tracing::info!(
         channel = %channel_name,
-        has_webhook_secret = webhook_secret.is_some(),
+        has_webhook_secret = host_webhook_secret.is_some(),
         secret_header = ?secret_header,
         "Registering channel with router"
     );
@@ -214,7 +219,7 @@ async fn register_channel(
         .register(
             Arc::clone(&channel_arc),
             endpoints,
-            webhook_secret.clone(),
+            host_webhook_secret.clone(),
             secret_header,
         )
         .await;
@@ -392,8 +397,9 @@ pub async fn inject_channel_credentials(
 /// placeholders in URLs and headers, so this function fills config fields
 /// that map to secret names.
 ///
-/// Mapping: for a channel named "feishu", secrets `feishu_app_id` and
-/// `feishu_app_secret` are injected as config keys `app_id` and `app_secret`.
+/// Mapping: for a channel named "feishu", secrets `feishu_app_id`,
+/// `feishu_app_secret`, and `feishu_verification_token` are injected as config
+/// keys `app_id`, `app_secret`, and `verification_token`.
 async fn inject_channel_secrets_into_config(
     channel_name: &str,
     secrets_store: &Option<Arc<dyn SecretsStore + Send + Sync>>,
@@ -404,6 +410,7 @@ async fn inject_channel_secrets_into_config(
         "feishu" => &[
             ("app_id", "feishu_app_id"),
             ("app_secret", "feishu_app_secret"),
+            ("verification_token", "feishu_verification_token"),
         ],
         _ => return,
     };