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Properly update examined when parsing chunked requests (part 2) #8360

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Merged
merged 1 commit into from
Mar 9, 2019
Merged

Properly update examined when parsing chunked requests (part 2) #8360

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18 changes: 11 additions & 7 deletions src/Servers/Kestrel/Core/src/Internal/Http/Http1ChunkedEncodingMessageBody.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -323,7 +323,7 @@ private void ParseChunkedPrefix(ReadOnlySequence<byte> buffer, out SequencePosit
return;
}

// Assigned this before calculating the chunk size since that can throw
// Advance examined before possibly throwing, so we don't risk examining less than the previous call to ParseChunkedPrefix.
examined = reader.Position;

var chunkSize = CalculateChunkSize(ch1, 0);
Expand All @@ -348,10 +348,12 @@ private void ParseChunkedPrefix(ReadOnlySequence<byte> buffer, out SequencePosit
return;
}

// Advance examined before possibly throwing, so we don't risk examining less than the previous call to ParseChunkedPrefix.
examined = reader.Position;

if (ch1 == '\r' && ch2 == '\n')
{
consumed = reader.Position;
examined = reader.Position;

AddAndCheckConsumedBytes(reader.Consumed);
_inputLength = chunkSize;
Expand All @@ -363,9 +365,6 @@ private void ParseChunkedPrefix(ReadOnlySequence<byte> buffer, out SequencePosit
ch1 = ch2;
}

// Set examined so that we capture the progress that way made
examined = reader.Position;

// At this point, 10 bytes have been consumed which is enough to parse the max value "7FFFFFFF\r\n".
BadHttpRequestException.Throw(RequestRejectionReason.BadChunkSizeData);
}
Expand Down Expand Up @@ -453,10 +452,13 @@ private void ParseChunkedSuffix(ReadOnlySequence<byte> buffer, out SequencePosit

var suffixBuffer = buffer.Slice(0, 2);
var suffixSpan = suffixBuffer.ToSpan();

// Advance examined before possibly throwing, so we don't risk examining less than the previous call to ParseChunkedSuffix.
examined = suffixBuffer.End;

if (suffixSpan[0] == '\r' && suffixSpan[1] == '\n')
{
consumed = suffixBuffer.End;
examined = suffixBuffer.End;
AddAndCheckConsumedBytes(2);
_mode = Mode.Prefix;
}
Expand All @@ -480,10 +482,12 @@ private void ParseChunkedTrailer(ReadOnlySequence<byte> buffer, out SequencePosi
var trailerBuffer = buffer.Slice(0, 2);
var trailerSpan = trailerBuffer.ToSpan();

// Advance examined before possibly throwing, so we don't risk examining less than the previous call to ParseChunkedTrailer.
examined = trailerBuffer.End;

if (trailerSpan[0] == '\r' && trailerSpan[1] == '\n')
{
consumed = trailerBuffer.End;
examined = trailerBuffer.End;
AddAndCheckConsumedBytes(2);
_mode = Mode.Complete;
}
Expand Down