Re: PDFBOX-2469 still have problem while decrypting a pdf file

[Andreas Lehmkuehler <an...@lehmi.de>]

Hi,

Am 30.12.2014 um 18:29 schrieb Thomas Chojecki:
> Am Tue, 30 Dec 2014 10:08:14 +0100
> schrieb Tilman Hausherr <TH...@t-online.de>:
>
>> Hi,
> Hi Tilman,
>
>> ...
>>
>> And then there's the second one in PDFBOX-2469, that doesn't work
>> either. The text at the end of PDFBOX-2469 is somewhat unclear, but
>> it seems we didn't solve them all.
>
> I discussed the problem with Adreas already. See the comment
> https://issues.apache.org/jira/browse/PDFBOX-2469#comment-14216197
>
> In some documents the decryption is broken or something else does not
> seems working. So while decrypting and finalizing the stream, an
> exception will stop the decryption process.
>
> Ignoring the exception will help but let the document maybe in an
> incosistent form. Maybe we can use the "force" flag for the parser to
> skip this decryption errors. So people who work with the "force" flag
> will know what they do and can risk inconsistance.
The "old" parser is behaving wrong, see my comment in PDFBOX-2469 [1]. The 
exception is just a subsequent issue.

> +1 from my side :P because I need it only for signature parsing and
> verifying, which aren't encrypted at all.
>
> Best regards
> Thomas
>

BR
Andreas Lehmkühler

[1] 
https://issues.apache.org/jira/browse/PDFBOX-2469?focusedCommentId=14216027&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14216027

>>
>> Tilman
>>
>>
>>
>> Am 30.12.2014 um 03:15 schrieb Barry Zhao [Zhao]:
>>> Hi team,
>>>
>>> I see that the PDFBox has staged out new release 1.8.8, so I just
>>> try to use the new version.
>>> When I decrypt a PDF file which is decrypted, I got the exception
>>> bellow:
>>>
>>> org.apache.pdfbox.exceptions.WrappedIOException
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.encryptData(SecurityHandler.java:375)
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.decryptString(SecurityHandler.java:577)
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.decrypt(SecurityHandler.java:429)
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.decryptDictionary(SecurityHandler.java:530)
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.decrypt(SecurityHandler.java:437)
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.decryptObject(SecurityHandler.java:403)
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.proceedDecryption(SecurityHandler.java:221)
>>> at
>>> org.apache.pdfbox.pdmodel.encryption.StandardSecurityHandler.decryptDocument(StandardSecurityHandler.java:158)
>>> at
>>> org.apache.pdfbox.pdmodel.PDDocument.openProtection(PDDocument.java:1601)
>>> at Testpdf10.main(Testpdf10.java:44)
>>> Caused by: javax.crypto.BadPaddingException: Given final block not
>>> properly padded
>>> at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:811)
>>> at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:676)
>>> at
>>> com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:313)
>>> at javax.crypto.Cipher.doFinal(Cipher.java:1969) at
>>> org.apache.pdfbox.pdmodel.encryption.SecurityHandler.encryptData(SecurityHandler.java:351)
>>> ... 9 more
>>>
>>> And my code is :
>>> PDDocument doc = PDDocument.load(originFile);
>>> if (doc.isEncrypted())
>>> {
>>> try
>>> {
>>> DecryptionMaterial dm = new StandardDecryptionMaterial("");
>>> doc.openProtection(dm);
>>> doc.setAllSecurityToBeRemoved(true);
>>> }
>>> catch (Exception cre) {
>>> cre.printStackTrace();
>>> }
>>> }
>>>
>>> I use the attachment file to do the operation.
>>>
>>>
>>> I found this
>>> http://stackoverflow.com/questions/26963718/badpaddingexception-when-decrypting-with-pdfbox
>>> in stackoverflow.
>>> I tried by the advices and it still not work.
>>> So I post this email to you. Hope to get your answer.
>>>
>>> Best wishes,
>>> Barry
>>
>