From 81c888f2f5cbf36356c7cf94073cfa050bb10eba Mon Sep 17 00:00:00 2001
From: Sebastian Krause <sebastian@realpath.org>
Date: Fri, 17 Feb 2017 11:26:45 +0100
Subject: [PATCH 1/2] Improved performance and security for
 ContentStream_readInlineImage.

---
 PyPDF2/pdf.py | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/PyPDF2/pdf.py b/PyPDF2/pdf.py
index 7b7f08bf3..53ebf4acd 100644
--- a/PyPDF2/pdf.py
+++ b/PyPDF2/pdf.py
@@ -2840,11 +2840,27 @@ def _readInlineImage(self, stream):
         # left at beginning of ID
         tmp = stream.read(3)
         assert tmp[:2] == b_("ID")
-        data = b_("")
+        data = BytesIO()
+        # Read the inline image, while checking for EI (End Image) operator.
         while True:
-            # Read the inline image, while checking for EI (End Image) operator.
-            tok = stream.read(1)
-            if tok == b_("E"):
+            # Read 8 kB at a time and check if the chunk contains the E operator.
+            buf = stream.read(8192)
+            
+            # We have reached the end of the stream, but haven't found the EI operator.
+            if not buf:
+                raise utils.PdfReadError("Unexpected end of stream")
+            
+            loc = buf.find(b_("E"))
+
+            if loc == -1:
+                data.write(buf)
+            else:
+                # Write out everything before the E.
+                data.write(buf[0:loc])
+
+                # Seek back in the stream to read the E next.
+                stream.seek(loc - len(buf), 1)
+                tok = stream.read(1)
                 # Check for End Image
                 tok2 = stream.read(1)
                 if tok2 == b_("I"):
@@ -2861,14 +2877,12 @@ def _readInlineImage(self, stream):
                         stream.seek(-1, 1)
                         break
                     else:
-                        stream.seek(-1,1)
-                        data += info
+                        stream.seek(-1, 1)
+                        data.write(info)
                 else:
                     stream.seek(-1, 1)
-                    data += tok
-            else:
-                data += tok
-        return {"settings": settings, "data": data}
+                    data.write(tok)
+        return {"settings": settings, "data": data.getvalue()}
 
     def _getData(self):
         newdata = BytesIO()

From 894c61807a66d185f6a73ef5ffbbd0ba56cf66a4 Mon Sep 17 00:00:00 2001
From: Martin Thoma <info@martin-thoma.de>
Date: Fri, 15 Apr 2022 13:17:14 +0200
Subject: [PATCH 2/2] Minor style change

---
 PyPDF2/pdf.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/PyPDF2/pdf.py b/PyPDF2/pdf.py
index c3845d392..6d1824384 100644
--- a/PyPDF2/pdf.py
+++ b/PyPDF2/pdf.py
@@ -2822,11 +2822,9 @@ def _readInlineImage(self, stream):
         while True:
             # Read 8 kB at a time and check if the chunk contains the E operator.
             buf = stream.read(8192)
-            
             # We have reached the end of the stream, but haven't found the EI operator.
             if not buf:
                 raise utils.PdfReadError("Unexpected end of stream")
-            
             loc = buf.find(b_("E"))
 
             if loc == -1: