feat(security): harden gateway boundaries and usage policies

Consolidate subscription usage policy enforcement, privacy-safe persistence, and gateway security hardening into one reviewable change.

Includes bounded HTTP and execution envelopes, header and protocol guards, DNS and relay validation, authentication and secret projection hardening, secure backup/install paths, and regression coverage.

apps/aether-gateway/src/backup/config.rs

@@ -5,7 +5,7 @@ use serde_json::{Map, Value};
 use super::schedule::{BackupSchedule, BackupScheduleUnit};
 use super::scopes::BackupScope;
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq)]
 pub(crate) struct S3BackupConfig {
     pub(crate) enabled: bool,
     pub(crate) scope: BackupScope,
@@ -22,6 +22,28 @@ pub(crate) struct S3BackupConfig {
     pub(crate) retention_count: u32,
 }
 
+impl fmt::Debug for S3BackupConfig {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let endpoint_origin = sanitized_endpoint_origin(&self.endpoint);
+        formatter
+            .debug_struct("S3BackupConfig")
+            .field("enabled", &self.enabled)
+            .field("scope", &self.scope)
+            .field("endpoint_origin", &endpoint_origin)
+            .field("region", &self.region)
+            .field("user_agent", &self.user_agent)
+            .field("bucket", &self.bucket)
+            .field("prefix", &self.prefix)
+            .field("has_access_key_id", &!self.access_key_id.is_empty())
+            .field("has_secret_access_key", &!self.secret_access_key.is_empty())
+            .field("path_style", &self.path_style)
+            .field("compression", &self.compression)
+            .field("schedule", &self.schedule)
+            .field("retention_count", &self.retention_count)
+            .finish()
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub(crate) struct BackupConfigError {
     message: String,
@@ -84,6 +106,9 @@ impl S3BackupConfig {
             "Endpoint（S3 地址）",
             enabled,
         )?;
+        if enabled {
+            validate_s3_endpoint(&endpoint)?;
+        }
         let bucket =
             required_or_disabled_string(entries, "backup_s3_bucket", "Bucket（存储桶）", enabled)?;
         let access_key_id = required_or_disabled_string(
@@ -99,6 +124,11 @@ impl S3BackupConfig {
             enabled,
         )?;
 
+        let prefix = normalize_s3_prefix(
+            &optional_string(entries, "backup_s3_prefix")?
+                .unwrap_or_else(|| "aether/backups/".to_string()),
+        )?;
+
         Ok(Self {
             enabled,
             scope,
@@ -108,8 +138,7 @@ impl S3BackupConfig {
             user_agent: optional_string(entries, "backup_s3_user_agent")?
                 .unwrap_or_else(|| "rclone/v1.68.0".to_string()),
             bucket,
-            prefix: optional_string(entries, "backup_s3_prefix")?
-                .unwrap_or_else(|| "aether/backups/".to_string()),
+            prefix,
             access_key_id,
             secret_access_key,
             path_style: optional_bool(entries, "backup_s3_path_style")?.unwrap_or(true),
@@ -121,6 +150,48 @@ impl S3BackupConfig {
     }
 }
 
+fn normalize_s3_prefix(prefix: &str) -> Result<String, BackupConfigError> {
+    let prefix = prefix.trim().trim_matches('/');
+    if prefix.is_empty() {
+        return Ok(String::new());
+    }
+    if prefix
+        .split('/')
+        .any(|segment| segment.is_empty() || segment == "." || segment == "..")
+        || prefix.contains('\\')
+    {
+        return Err(BackupConfigError::new(
+            "Prefix（备份前缀）不能包含空路径段、相对路径段或反斜杠",
+        ));
+    }
+
+    Ok(format!("{prefix}/"))
+}
+
+fn validate_s3_endpoint(endpoint: &str) -> Result<(), BackupConfigError> {
+    let parsed = url::Url::parse(endpoint)
+        .map_err(|_| BackupConfigError::new("Endpoint（S3 地址）必须是有效的 HTTPS URL"))?;
+    if parsed.scheme() != "https"
+        || parsed.host_str().is_none()
+        || !parsed.username().is_empty()
+        || parsed.password().is_some()
+        || parsed.query().is_some()
+        || parsed.fragment().is_some()
+    {
+        return Err(BackupConfigError::new(
+            "Endpoint（S3 地址）必须使用 HTTPS，且不能包含用户凭据、查询参数或片段",
+        ));
+    }
+    Ok(())
+}
+
+fn sanitized_endpoint_origin(endpoint: &str) -> String {
+    url::Url::parse(endpoint)
+        .ok()
+        .map(|parsed| parsed.origin().ascii_serialization())
+        .unwrap_or_else(|| "<invalid>".to_string())
+}
+
 fn validate_range(label: &str, value: u32, min: u32, max: u32) -> Result<(), BackupConfigError> {
     if (min..=max).contains(&value) {
         Ok(())
@@ -374,6 +445,69 @@ mod tests {
         assert!(err.to_string().contains("Endpoint"));
     }
 
+    #[test]
+    fn rejects_insecure_or_credential_bearing_endpoints() {
+        for endpoint in [
+            "http://s3.example.com",
+            "https://user:[email protected]",
+            "https://s3.example.com?token=secret",
+            "https://s3.example.com/#fragment",
+        ] {
+            let entries = serde_json::json!({
+                "backup_s3_enabled": true,
+                "backup_s3_endpoint": endpoint,
+                "backup_s3_bucket": "aether-backups",
+                "backup_s3_access_key_id": "access",
+                "backup_s3_secret_access_key": "secret"
+            });
+
+            let error = S3BackupConfig::from_json_map(entries.as_object().unwrap())
+                .expect_err("unsafe endpoint should fail closed");
+            assert!(error.to_string().contains("Endpoint"));
+        }
+    }
+
+    #[test]
+    fn debug_output_does_not_expose_s3_credentials() {
+        let entries = serde_json::json!({
+            "backup_s3_enabled": true,
+            "backup_s3_endpoint": "https://s3.example.com/path",
+            "backup_s3_bucket": "aether-backups",
+            "backup_s3_access_key_id": "access-key-value",
+            "backup_s3_secret_access_key": "secret-key-value"
+        });
+        let config = S3BackupConfig::from_json_map(entries.as_object().unwrap())
+            .expect("config should parse");
+
+        let debug = format!("{config:?}");
+        assert!(debug.contains("https://s3.example.com"));
+        assert!(!debug.contains("/path"));
+        assert!(!debug.contains("access-key-value"));
+        assert!(!debug.contains("secret-key-value"));
+    }
+
+    #[test]
+    fn canonicalizes_s3_backup_prefix_once() {
+        let entries = serde_json::json!({
+            "backup_s3_enabled": true,
+            "backup_s3_endpoint": "https://s3.example.com",
+            "backup_s3_bucket": "aether-backups",
+            "backup_s3_prefix": "/prod/backups//",
+            "backup_s3_access_key_id": "access",
+            "backup_s3_secret_access_key": "secret"
+        });
+        let config = S3BackupConfig::from_json_map(entries.as_object().unwrap())
+            .expect("prefix should be canonicalized");
+
+        assert_eq!(config.prefix, "prod/backups/");
+
+        for invalid_prefix in ["prod//backups", "prod/../backups", "prod\\backups"] {
+            let mut entries = entries.clone();
+            entries["backup_s3_prefix"] = serde_json::json!(invalid_prefix);
+            assert!(S3BackupConfig::from_json_map(entries.as_object().unwrap()).is_err());
+        }
+    }
+
     #[test]
     fn applies_default_values_from_system_config_contract() {
         let entries = serde_json::json!({