[
https://issues.apache.org/jira/browse/PDFBOX-3933?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16172187#comment-16172187
]
ASF subversion and git services commented on PDFBOX-3933:
---------------------------------------------------------
Commit 1808931 from [~tilman] in branch 'pdfbox/branches/1.8'
[ https://svn.apache.org/r1808931 ]
PDFBOX-3933: don't swallow CR at end of stream if there is one at the
beginning; add testcase from issue 2079
> PDFParser swallows a CR at the end of a stream
> ----------------------------------------------
>
> Key: PDFBOX-3933
> URL: https://issues.apache.org/jira/browse/PDFBOX-3933
> Project: PDFBox
> Issue Type: Bug
> Affects Versions: 1.8.14
> Reporter: Petr Slaby
> Attachments: Beispiel2.pdf, EndlinePrediction2.patch,
> EndlinePrediction.patch
>
>
> I have a PDF which I cannot share at the moment, maybe later if I get a
> permission from the customer.
> The PDF is protected by an empty password, all streams are encrypted using
> AES. The PDF consistently uses the LF character for line endings. One of the
> streams looks like this:
> {code}
> 10 0 obj
> <</Length 9 0 R/Filter/FlateDecode/N 3/Range[0 1 0 1 0 1 ]>>
> stream
> ....<0x0D><0x0A>
> endstream
> {code}
> i.e. Length field is a reference to an object, in the content, the length
> object is stored immediately after the stream as
> {code}
> 9 0 obj
> 2624
> endobj
> {code}
> The byte <0x0D> belongs to the stream and is not to be treated as line
> separator in this case. The parser is not able to read the length field so it
> manually searches for the stream end in the class EndstreamOutputStream. This
> class searches both for the pair <0x0D><0x0A> and the single <0x0A>, so it
> strips off the <0x0D> from this particular stream content. Since the stream
> is encrypted, PDFBox runs into a BadPaddingException later on when trying to
> decrypt the stream.
> The problem is reproducible using org.apache.pdfbox.PDFToImage in current
> 1.8.14-SNAPSHOT. The same works fine in current PDFBox 2.0.x, presumably
> because it uses the non-sequential parser by default.
> The proposed fix is to analyze the PDF content while reading it and search
> for the CR character only if it was ever encountered as a line separator
> prior to the stream being parsed.
> Note: I do not exactly know or understand the usage of the other classes
> inherited from BaseParser, like PDFObjectStreamParser. Maybe the line ending
> heuristic should be kept "as before" in these classes, by setting the new
> field BaseParser.hasCR to true already in the constructor.
> A patch is attached.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@pdfbox.apache.org
For additional commands, e-mail: dev-h...@pdfbox.apache.org
