fix pagination cursors (#1776)

crates/service/web/storyteller_web/src/http_server/endpoints/tts/list_user_tts_inference_results.rs

@@ -84,11 +84,7 @@ pub async fn list_user_tts_inference_results_handler(
   let cursor_is_reversed = query.cursor_is_reversed.unwrap_or(false);
 
   let cursor = if let Some(cursor) = query.cursor.as_deref() {
-    let cursor = server_state.sort_key_crypto.decrypt_id(cursor)
-        .map_err(|e| {
-          warn!("crypto error: {:?}", e);
-          CommonWebError::from_anyhow_error(e)
-        })?;
+    let cursor = server_state.sort_key_crypto.decrypt_id(cursor)?;
     Some(cursor)
   } else {
     None
@@ -117,22 +113,14 @@ pub async fn list_user_tts_inference_results_handler(
   };
 
   let cursor_next = if let Some(id) = results_page.last_id {
-    let cursor = server_state.sort_key_crypto.encrypt_id(id as u64)
-        .map_err(|e| {
-          warn!("crypto error: {:?}", e);
-          CommonWebError::from_anyhow_error(e)
-        })?;
+    let cursor = server_state.sort_key_crypto.encrypt_id(id as u64)?;
     Some(cursor)
   } else {
     None
   };
 
   let cursor_previous = if let Some(id) = results_page.first_id {
-    let cursor = server_state.sort_key_crypto.encrypt_id(id as u64)
-        .map_err(|e| {
-          warn!("crypto error: {:?}", e);
-          CommonWebError::from_anyhow_error(e)
-        })?;
+    let cursor = server_state.sort_key_crypto.encrypt_id(id as u64)?;
     Some(cursor)
   } else {
     None

crates/service/web/storyteller_web/src/http_server/endpoints/weights/list/list_available_weights_handler.rs

@@ -107,6 +107,7 @@ pub struct ModelWeightForList {
 
 #[derive(Debug,ToSchema)]
 pub enum ListWeightError {
+    BadInput,
     NotAuthorized,
     ServerError,
 }
@@ -120,6 +121,7 @@ impl std::fmt::Display for ListWeightError {
 impl ResponseError for ListWeightError {
     fn status_code(&self) -> StatusCode {
         match *self {
+            ListWeightError::BadInput => StatusCode::BAD_REQUEST,
             ListWeightError::NotAuthorized => StatusCode::UNAUTHORIZED,
             ListWeightError::ServerError => StatusCode::INTERNAL_SERVER_ERROR,
         }
@@ -165,11 +167,10 @@ pub async fn list_available_weights_handler(
     let cursor_is_reversed = query.cursor_is_reversed.unwrap_or(false);
 
     let cursor = if let Some(cursor) = query.cursor.as_deref() {
+        // Cursors arrive from clients verbatim; garbage is bad input, not a
+        // server fault.
         let cursor = server_state.sort_key_crypto.decrypt_id(cursor)
-            .map_err(|e| {
-                warn!("crypto error: {:?}", e);
-                ListWeightError::ServerError
-            })?;
+            .map_err(|_| ListWeightError::BadInput)?;
         Some(cursor)
     } else {
         None

crates/service/web/storyteller_web/src/http_server/web_utils/mod.rs

@@ -13,3 +13,4 @@ pub mod response_success_helpers;
 pub mod scoped_temp_dir_creator;
 pub mod serialize_as_json_error;
 pub mod try_delete_session_cache;
+pub mod web_sort_key_crypto;

crates/service/web/storyteller_web/src/http_server/web_utils/web_sort_key_crypto.rs

@@ -0,0 +1,43 @@
+use log::warn;
+
+use crate::http_server::common_responses::common_web_error::CommonWebError;
+use crate::util::encrypted_sort_id::SortKeyCrypto;
+
+/// [`SortKeyCrypto`] with a web-facing interface: results map to
+/// [`CommonWebError`] so handlers can use `?` directly, with the right HTTP
+/// status for each direction. This is the flavor injected into Actix via
+/// `ServerState`.
+#[derive(Clone)]
+pub struct WebSortKeyCrypto {
+  crypto: SortKeyCrypto,
+}
+
+impl WebSortKeyCrypto {
+  pub fn new(secret: &str) -> Self {
+    Self {
+      crypto: SortKeyCrypto::new(secret),
+    }
+  }
+
+  /// Encrypt a row id into an opaque pagination cursor.
+  /// Failure is a genuine server fault (500).
+  pub fn encrypt_id(&self, id: u64) -> Result<String, CommonWebError> {
+    self.crypto.encrypt_id(id)
+        .map_err(|err| {
+          warn!("Failed to encrypt pagination cursor: {:?}", err);
+          CommonWebError::from_anyhow_error(err)
+        })
+  }
+
+  /// Decrypt a client-supplied pagination cursor.
+  /// Cursors arrive from clients verbatim, so garbage is bad input (400),
+  /// not a server fault — a 500 here would trip the error-alerting
+  /// middleware on any bot or stale client.
+  pub fn decrypt_id(&self, cursor: &str) -> Result<u64, CommonWebError> {
+    self.crypto.decrypt_id(cursor)
+        .map_err(|err| {
+          warn!("Invalid pagination cursor: {:?}", err);
+          CommonWebError::BadInputWithSimpleMessage("Invalid pagination cursor.".to_string())
+        })
+  }
+}

crates/service/web/storyteller_web/src/startup/build_dependencies.rs

@@ -46,7 +46,7 @@ use crate::state::server_state::{
   ServerState, TrollBans,
 };
 use crate::threads::db_health_checker_thread::db_health_check_status::HealthCheckStatus;
-use crate::util::encrypted_sort_id::SortKeyCrypto;
+use crate::http_server::web_utils::web_sort_key_crypto::WebSortKeyCrypto;
 
 // Bucket config
 const ENV_ACCESS_KEY: &str = "ACCESS_KEY";
@@ -156,7 +156,7 @@ pub async fn setup_dependencies(server_hostname: &str) -> AnyhowResult<SetupResu
   );
 
   let sort_key_crypto_secret = easyenv::get_env_string_or_default("SORT_KEY_SECRET", "webscale");
-  let sort_key_crypto = SortKeyCrypto::new(&sort_key_crypto_secret);
+  let sort_key_crypto = WebSortKeyCrypto::new(&sort_key_crypto_secret);
   let opaque_cursor_encoder = OpaqueCursorEncoderV2::new(&sort_key_crypto_secret);
 
   let health_check_interval = easyenv::get_env_duration_seconds_or_default(

crates/service/web/storyteller_web/src/state/server_state.rs

@@ -11,7 +11,7 @@ use crate::state::certs::google_sign_in_cert::GoogleSignInCert;
 use crate::state::flags::paging_flags::PagingFlags;
 use crate::state::memory_cache::model_token_to_info_cache::ModelTokenToInfoCache;
 use crate::threads::db_health_checker_thread::db_health_check_status::HealthCheckStatus;
-use crate::util::encrypted_sort_id::SortKeyCrypto;
+use crate::http_server::web_utils::web_sort_key_crypto::WebSortKeyCrypto;
 use crate::util::troll_user_bans::troll_user_ban_list::TrollUserBanList;
 
 use actix_artcraft::sessions::anonymous_visitor_tracking::avt_cookie_manager::AvtCookieManager;
@@ -98,7 +98,7 @@ pub struct ServerState {
   /// Where to store audio uploads for w2l
   pub audio_uploads_bucket_root: String,
 
-  pub sort_key_crypto: SortKeyCrypto,
+  pub sort_key_crypto: WebSortKeyCrypto,
   pub opaque_cursors: OpaqueCursorEncoderV2,
 
   pub ip_ban_list: IpBanList,