From 464f32cc3e1bbbad77f4bdd7a75967c0609a8efb Mon Sep 17 00:00:00 2001
From: Computer Network Investigation
 <121175071+JSCU-CNI@users.noreply.github.com>
Date: Mon, 19 Feb 2024 20:19:32 +0100
Subject: [PATCH] Improve exception when reading out of bounds EWF segment
 (#21)

---
 dissect/evidence/ewf.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/dissect/evidence/ewf.py b/dissect/evidence/ewf.py
index b7cf23e..7017d2e 100644
--- a/dissect/evidence/ewf.py
+++ b/dissect/evidence/ewf.py
@@ -228,7 +228,11 @@ def _read(self, offset: int, length: int) -> bytes:
         sector_count = (length + self.sector_size - 1) // self.sector_size
 
         segment_idx = bisect_right(self.ewf._segment_offsets, sector_offset)
+
         while sector_count > 0:
+            if segment_idx > len(self.ewf._segment_offsets):
+                raise EWFError(f"Missing EWF file for segment index: {segment_idx}")
+
             segment = self.ewf.open_segment(segment_idx)
 
             segment_remaining_sectors = segment.sector_count - (sector_offset - segment.sector_offset)