VAR/VAR.PdfTools
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ParseObject: Fix stream parsing, detecting "endstream" when it is unavailable on the dictionary (forward references or missing)

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This commit is contained in:
Valeriano A.R.
2016-06-18 02:42:15 +02:00
parent c9370080b1
commit a5b5b97e7b
1 changed files with 48 additions and 8 deletions
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56
VAR.PdfTools/PdfParser.cs
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@@ -56,6 +56,33 @@ namespace VAR.PdfTools
return memStream.ToArray();
}
private bool TestMarker(long position, char[] marker)
{
for(int i = 0; i < marker.Length; i++)
{
if ((position + i) >= _stream.Length) { return false; }
if(_stream[position+i] != marker[i]) { return false; }
}
return true;
}
private long MeasureToMarkers(char[][] markers)
{
long position = _streamPosition;
do
{
foreach(char[] marker in markers)
{
if (TestMarker(position, marker))
{
return (position - _streamPosition);
}
}
position++;
} while (position < _stream.Length);
return 0;
}
private byte PeekChar()
{
if (_streamPosition >= _stream.Length)
@@ -107,9 +134,11 @@ namespace VAR.PdfTools
private bool IsEndOfLine(byte character)
{
byte lineFeed = 0x0A;
byte carriageReturn = 0x0D;
if (
character == 0x0A || // Line Feed (LF)
character == 0x0D || // Carriage Return (CR)
character == lineFeed ||
character == carriageReturn ||
false)
{
return true;
@@ -174,7 +203,7 @@ namespace VAR.PdfTools
}
return;
}
if (PeekChar() != lineFeed)
if (PeekChar() == lineFeed)
{
NextChar();
return;
@@ -687,12 +716,23 @@ namespace VAR.PdfTools
{
throw new Exception(string.Format("Stream after a not dictionary element at: {0}", _streamPosition));
}
if (streamDict.Values.ContainsKey("Length") == false)
{
throw new Exception(string.Format("Dictionary of stream does not specify Lenght at: {0}", _streamPosition));
}
long length = ((PdfInteger)streamDict.Values["Length"]).Value;
SkipEndOfLine();
long length;
if (streamDict.Values.ContainsKey("Length") && streamDict.Values["Length"] is PdfInteger)
{
length = ((PdfInteger)streamDict.Values["Length"]).Value;
}
else
{
byte lineFeed = 0x0A;
byte carriageReturn = 0x0D;
length = MeasureToMarkers(new char[][] {
new char[] {(char)carriageReturn, (char)lineFeed, 'e', 'n', 'd', 's', 't', 'r', 'e', 'a', 'm'},
new char[] {(char)lineFeed, 'e', 'n', 'd', 's', 't', 'r', 'e', 'a', 'm'},
new char[] {'e', 'n', 'd', 's', 't', 'r', 'e', 'a', 'm', (char)lineFeed},
new char[] {'e', 'n', 'd', 's', 't', 'r', 'e', 'a', 'm', (char)carriageReturn, (char)lineFeed},
});
}
byte[] streamBody = GetRawData(length);
SkipEndOfLine();
endToken = ParseToken();