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From Andreas Beeker <andreas.bee...@gmx.de>
Subject Re: Problem POI 3.9 with extracting hashValue and saltValue from excel 2013 protected worksheet
Date Sat, 01 Feb 2014 21:02:41 GMT
Hi Mikheil,

you can find the documentation for Agile-Encryption (and others) at the
"[MS-OFFCRYPTO]: Office Document Cryptography Structure Specification" [1]

The difference between POI 3.9 and the current POI (after #55818) is that now also
other ciphers and hash algorithms apart of AES/SHA1 are supported.

- The are still a few security related features which POI doesn't support right now:
   - CryptoAPI *)
   - I haven't tested RC4 (stream cipher) at all - only the block ciphers -
     I'm quite sure that implementation, which is focused on block ciphers, doesn't
     work well with RC4
   - XOR Obfuscation *)
   - (Binary) Document Write Protection

- So the current POI version can decrypt your Excel 2013 samples, right?
- Does your program support agile and standard encryption?

 > ... some explanation on how to read sheet protection information from excel 2013 ...
Just to clarify, the encryption is not specific to Excel files, but covers/wraps the whole
file -
I don't know if there's a sheet protection feature via encryption.

Please narrow your question a bit to where you want to have an explanation.

Best wishes,

[1] http://msdn.microsoft.com/en-us/library/cc313071(v=office.12).aspx
*) I haven't checked the BiffEncryption classes, so I might be wrong ...

On 01.02.2014 10:43, Mikheil wrote:
> I have problem from extracting hashValue and saltValue from Excel 2013
> Protected worksheet using POI 3.9.
> People can't use my little opensource program if they had Excel 2013.
> There is no problem read and check password validation in Excel 2010, Excle
> 2007 and Excel 2003;
> I found your issue related to this problem  55544
> <http://poi.apache.org/changes.html>  . But 3.10.final is not yet avalaible
> to download.
> I have downloaded and built "3.11.beta1" version poi sourceCode (Until
> 3.10.final will be published).
> I will be so glead if you give me some explanation on how to read sheet
> protection information from excel 2013 workbook (hashValue, saltValue,
> algoritmName), because there is no documentation about this.
> Thank you.

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