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don't lose object stream offsets when brute-forcing offsets

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This commit is contained in:
Eliot Jones
2021-03-01 14:18:19 -04:00
parent 3437b48925
commit 12ad8278e3
1 changed files with 3 additions and 40 deletions
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43
src/UglyToad.PdfPig/Parser/FileStructure/CrossReferenceObjectOffsetValidator.cs
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@@ -29,52 +29,15 @@
var bruteForceOffsets = BruteForceSearcher.GetObjectLocations(bytes); var bruteForceOffsets = BruteForceSearcher.GetObjectLocations(bytes);
if (bruteForceOffsets.Count > 0) if (bruteForceOffsets.Count > 0)
{ {
var objStreams = new List<IndirectReference>();
// find all object streams // find all object streams
foreach (var entry in crossReferenceTable.ObjectOffsets) foreach (var entry in crossReferenceTable.ObjectOffsets)
{ {
var offset = entry.Value; var offset = entry.Value;
if (offset < 0) if (offset < 0)
{ {
var objStream = new IndirectReference(-offset, 0); // Trust stream offsets for now.
if (!objStreams.Contains(objStream)) // TODO: more validation of streams.
{ builderOffsets[entry.Key] = entry.Value;
objStreams.Add(new IndirectReference(-offset, 0));
}
}
// remove all found object streams
if (objStreams.Count > 0)
{
foreach (var key in objStreams)
{
if (bruteForceOffsets.ContainsKey(key))
{
// remove all parsed objects which are part of an object stream
//ISet<long> objects = xrefTrailerResolver
// .getContainedObjectNumbers((int)(key.Number));
//foreach (long objNr in objects)
//{
// CosObjectKey streamObjectKey = new CosObjectKey(objNr, 0);
// if (bfCOSObjectKeyOffsets.TryGetValue(streamObjectKey, out long streamObjectOffset) && streamObjectOffset > 0)
// {
// bfCOSObjectKeyOffsets.Remove(streamObjectKey);
// }
//}
}
else
{
// remove all objects which are part of an object stream which wasn't found
//ISet<long> objects = xrefTrailerResolver
// .getContainedObjectNumbers((int)(key.Number));
//foreach (long objNr in objects)
//{
// xrefOffset.Remove(new CosObjectKey(objNr, 0));
//}
}
}
} }
foreach (var item in bruteForceOffsets) foreach (var item in bruteForceOffsets)