From 7d224779170cf6e3a6cb1d844c1e878f5ad3a5e8 Mon Sep 17 00:00:00 2001
From: Michael R Sweet <msweet@msweet.org>
Date: Wed, 21 Aug 2024 11:28:39 -0400
Subject: [PATCH] Fix opening of certain encrypted PDF files (Issue #62)

---
 CHANGES.md     |  1 +
 pdfio-file.c   | 12 +++++++++++-
 pdfio-stream.c | 10 ++++------
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index d82e8e1..42baa8b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,7 @@ v1.3.2 - YYYY-MM-DD
 -------------------
 
 - Added some more sanity checks to the TrueType font reader.
+- Fixed an issue when opening certain encrypted PDF files (Issue #62)
 
 
 v1.3.1 - 2024-08-05
diff --git a/pdfio-file.c b/pdfio-file.c
index abc2f65..ee972a8 100644
--- a/pdfio-file.c
+++ b/pdfio-file.c
@@ -648,11 +648,12 @@ pdfioFileFindObj(
   if ((current = number - 1) >= pdf->num_objs)
     current = pdf->num_objs / 2;
 
-  PDFIO_DEBUG("pdfioFileFindObj: objs[current=%lu]=%p\n", (unsigned long)current, (void *)pdf->objs[current]);
+  PDFIO_DEBUG("pdfioFileFindObj: objs[current=%lu]=%p(%lu)\n", (unsigned long)current, (void *)pdf->objs[current], (unsigned long)(pdf->objs[current] ? pdf->objs[current]->number : 0));
 
   if (number == pdf->objs[current]->number)
   {
     // Fast match...
+    PDFIO_DEBUG("pdfioFileFindObj: Returning %lu (%p)\n", (unsigned long)current, pdf->objs[current]);
     return (pdf->objs[current]);
   }
   else if (number < pdf->objs[current]->number)
@@ -679,11 +680,20 @@ pdfioFileFindObj(
   }
 
   if (number == pdf->objs[left]->number)
+  {
+    PDFIO_DEBUG("pdfioFileFindObj: Returning %lu (%p)\n", (unsigned long)left, pdf->objs[left]);
     return (pdf->objs[left]);
+  }
   else if (number == pdf->objs[right]->number)
+  {
+    PDFIO_DEBUG("pdfioFileFindObj: Returning %lu (%p)\n", (unsigned long)right, pdf->objs[right]);
     return (pdf->objs[right]);
+  }
   else
+  {
+    PDFIO_DEBUG("pdfioFileFindObj: Returning NULL\n");
     return (NULL);
+  }
 }
 
 
diff --git a/pdfio-stream.c b/pdfio-stream.c
index 3a7f419..d7ebcb3 100644
--- a/pdfio-stream.c
+++ b/pdfio-stream.c
@@ -408,6 +408,7 @@ _pdfioStreamOpen(pdfio_obj_t *obj,	// I - Object
   pdfio_stream_t	*st;		// Stream
   pdfio_dict_t		*dict = pdfioObjGetDict(obj);
 					// Object dictionary
+  const char		*type;		// Object type
 
 
   PDFIO_DEBUG("_pdfioStreamOpen(obj=%p(%u), decode=%s)\n", obj, (unsigned)obj->number, decode ? "true" : "false");
@@ -434,7 +435,9 @@ _pdfioStreamOpen(pdfio_obj_t *obj,	// I - Object
     return (NULL);
   }
 
-  if (obj->pdf->encryption)
+  type = pdfioObjGetType(obj);
+
+  if (obj->pdf->encryption && (!type || strcmp(type, "XRef")))
   {
     uint8_t	iv[64];			// Initialization vector
     size_t	ivlen;			// Length of initialization vector, if any
@@ -1069,11 +1072,6 @@ stream_read(pdfio_stream_t *st,		// I - Stream
 	_pdfioFileError(st->pdf, "Unable to decompress stream data for object %ld: %s", (long)st->obj->number, zstrerror(status));
 	return (-1);
       }
-      else if (avail_in == st->flate.avail_in && avail_out == st->flate.avail_out)
-      {
-	_pdfioFileError(st->pdf, "Corrupt stream data.");
-	return (-1);
-      }
 
       return (st->flate.next_out - (Bytef *)buffer);
     }