Do not leak decoding_key in JwtAuth's Debug representation

zenith_utils/src/auth.rs

@@ -85,7 +85,6 @@ pub fn check_permission(claims: &Claims, tenantid: Option<ZTenantId>) -> Result<
     }
 }
 
-#[derive(Debug)]
 pub struct JwtAuth {
     decoding_key: DecodingKey<'static>,
     validation: Validation,
@@ -113,6 +112,14 @@ impl JwtAuth {
     }
 }
 
+impl std::fmt::Debug for JwtAuth {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("JwtAuth")
+            .field("validation", &self.validation)
+            .finish()
+    }
+}
+
 // this function is used only for testing purposes in CLI e g generate tokens during init
 pub fn encode_from_key_file(claims: &Claims, key_data: &[u8]) -> Result<String> {
     let key = EncodingKey::from_rsa_pem(key_data)?;