Author: lehmi
Date: Sun Dec 8 12:58:49 2013
New Revision: 1549025
URL: http://svn.apache.org/r1549025
Log:
PDFBOX-1769: identify corrupt stream length and use workaround if necessary
Modified:
pdfbox/trunk/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/NonSequentialPDFParser.java
Modified:
pdfbox/trunk/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/NonSequentialPDFParser.java
URL:
http://svn.apache.org/viewvc/pdfbox/trunk/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/NonSequentialPDFParser.java?rev=1549025&r1=1549024&r2=1549025&view=diff
==============================================================================
---
pdfbox/trunk/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/NonSequentialPDFParser.java
(original)
+++
pdfbox/trunk/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/NonSequentialPDFParser.java
Sun Dec 8 12:58:49 2013
@@ -110,6 +110,7 @@ public class NonSequentialPDFParser exte
protected static final char[] OBJ_MARKER = new char[] { 'o', 'b', 'j' };
private final File pdfFile;
+ private long fileLen;
private final RandomAccessBufferedFileInputStream raStream;
/**
@@ -558,7 +559,7 @@ public class NonSequentialPDFParser exte
long skipBytes;
// ---- read trailing bytes into buffer
- final long fileLen = pdfFile.length();
+ fileLen = pdfFile.length();
FileInputStream fIn = null;
try
@@ -1518,31 +1519,34 @@ public class NonSequentialPDFParser exte
throw new IOException("Missing length for stream.");
}
+ boolean useReadUntilEnd = false;
// ---- get output stream to copy data to
out = stream.createFilteredStream(streamLengthObj);
-
- long remainBytes = streamLengthObj.longValue();
- int bytesRead = 0;
- boolean unexpectedEndOfStream = false;
- while (remainBytes > 0)
- {
- final int readBytes = pdfSource.read(streamCopyBuf, 0,
- (remainBytes > streamCopyBufLen) ? streamCopyBufLen :
(int) remainBytes);
- if (readBytes <= 0)
- {
- // throw new IOException(
- // "No more bytes from stream but expected: " + remainBytes
- // );
- unexpectedEndOfStream = true;
- break;
- }
- out.write(streamCopyBuf, 0, readBytes);
- remainBytes -= readBytes;
- bytesRead += readBytes;
+ if (validateStreamLength(streamLengthObj.longValue()))
+ {
+ long remainBytes = streamLengthObj.longValue();
+ int bytesRead = 0;
+ while (remainBytes > 0)
+ {
+ final int readBytes = pdfSource.read(streamCopyBuf, 0,
+ (remainBytes > streamCopyBufLen) ?
streamCopyBufLen : (int) remainBytes);
+ if (readBytes <= 0)
+ {
+ useReadUntilEnd = true;
+ pdfSource.unread(bytesRead);
+ break;
+ }
+ out.write(streamCopyBuf, 0, readBytes);
+ remainBytes -= readBytes;
+ bytesRead += readBytes;
+ }
+ }
+ else
+ {
+ useReadUntilEnd = true;
}
- if (unexpectedEndOfStream)
+ if (useReadUntilEnd)
{
- pdfSource.unread(bytesRead);
out = stream.createFilteredStream(streamLengthObj);
readUntilEndStream(out);
}
@@ -1563,6 +1567,28 @@ public class NonSequentialPDFParser exte
return stream;
}
+ private boolean validateStreamLength(long streamLength) throws IOException
+ {
+ boolean streamLengthIsValid = true;
+ long originOffset = pdfSource.getOffset();
+ long expectedEndOfStream = originOffset + streamLength;
+ if (expectedEndOfStream > fileLen)
+ {
+ streamLengthIsValid = false;
+ LOG.error("The end of the stream is out of range, using
workaround to read the stream");
+ }
+ else
+ {
+ pdfSource.seek(expectedEndOfStream);
+ if (!checkBytesAtOffset("endstream".getBytes("ISO-8859-1")))
+ {
+ streamLengthIsValid = false;
+ LOG.error("The end of the stream doesn't point to the
correct offset, using workaround to read the stream");
+ }
+ pdfSource.seek(originOffset);
+ }
+ return streamLengthIsValid;
+ }
private void readUntilEndStream(final OutputStream out) throws IOException
{
@@ -1742,6 +1768,11 @@ public class NonSequentialPDFParser exte
*/
private long calculateFixingOffset(long objectOffset, byte[] string)
throws IOException
{
+ if (objectOffset < 0)
+ {
+ LOG.error("Invalid object offset " + objectOffset + " for
object " + new String(string));
+ return 0;
+ }
long originOffset = pdfSource.getOffset();
pdfSource.seek(objectOffset);
// most likely the object can be found at the given offset
