fix: обработка выхода за пределы индекса сортировки в архиве и улучшение декодирования LZSS с поддержкой XOR

crates/nres/src/lib.rs

@@ -111,7 +111,9 @@ impl Archive {
             let mut high = self.entries.len();
             while low < high {
                 let mid = low + (high - low) / 2;
-                let target_idx = self.entries[mid].meta.sort_index as usize;
+                let Ok(target_idx) = usize::try_from(self.entries[mid].meta.sort_index) else {
+                    break;
+                };
                 if target_idx >= self.entries.len() {
                     break;
                 }
@@ -396,7 +398,10 @@ fn parse_archive(bytes: &[u8], raw_mode: bool) -> Result<(Vec<EntryRecord>, u64)
                 name
             },
         };
-        return Ok((vec![entry], bytes.len() as u64));
+        return Ok((
+            vec![entry],
+            u64::try_from(bytes.len()).map_err(|_| Error::IntegerOverflow)?,
+        ));
     }
 
     if bytes.len() < 16 {

crates/nres/src/tests.rs

@@ -609,6 +609,52 @@ fn nres_synthetic_read_find_and_edit() {
     let _ = fs::remove_file(&path);
 }
 
+#[test]
+fn nres_find_falls_back_when_sort_index_is_out_of_range() {
+    let mut bytes = build_nres_bytes(&[
+        SyntheticEntry {
+            kind: 1,
+            attr1: 0,
+            attr2: 0,
+            attr3: 0,
+            name: "Alpha",
+            data: b"a",
+        },
+        SyntheticEntry {
+            kind: 2,
+            attr1: 0,
+            attr2: 0,
+            attr3: 0,
+            name: "Beta",
+            data: b"b",
+        },
+        SyntheticEntry {
+            kind: 3,
+            attr1: 0,
+            attr2: 0,
+            attr3: 0,
+            name: "Gamma",
+            data: b"c",
+        },
+    ]);
+
+    let entry_count = 3usize;
+    let directory_offset = bytes
+        .len()
+        .checked_sub(entry_count * 64)
+        .expect("directory offset underflow");
+    let mid_entry_sort_index = directory_offset + 64 + 60;
+    bytes[mid_entry_sort_index..mid_entry_sort_index + 4].copy_from_slice(&u32::MAX.to_le_bytes());
+
+    let archive = Archive::open_bytes(Arc::from(bytes.into_boxed_slice()), OpenOptions::default())
+        .expect("open archive with corrupted sort index failed");
+
+    assert_eq!(archive.find("alpha"), Some(EntryId(0)));
+    assert_eq!(archive.find("BETA"), Some(EntryId(1)));
+    assert_eq!(archive.find("gamma"), Some(EntryId(2)));
+    assert_eq!(archive.find("missing"), None);
+}
+
 #[test]
 fn nres_validation_error_cases() {
     let valid = build_nres_bytes(&[SyntheticEntry {