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Hi
I have to add some extra information to this files (it's going to be digital signature of the document), but I don't know how to start (I heard that this files are connected with OLE but I don't know anything about OLE). After adding the signature to the file of course I must be able to read only the document part of the file. I have also encountered another problem, Excel files is changing in one place after being opened (at the end of the file, in the record beginning with "Root Entry"). Is this will be ok to omit this few changing bytes in order to signature doc and verify the signature (I don't know what this few bytes stands for)? I don't expect to have one solution for Excel and Word (but it would be nice of course), but is there a chance that one solution(one code) will work in Office 97 and 2000 (it would be great)? Thanks in advance for any help.
greetings
Mariusz Popiolek
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You're dreaming of an imaginary world where you can take whatever file format you want, and modify it on will. Let's get back to earth mate!
sometimes it helps to look at the IL generated code
a MS guy on develop.com "answering" .NET issues
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You exxagerate a bit. This is possible (I have seen application which is doing exactly what I want to do in MsOffice). Office docs are stored in a kind of a filesystem (this is connected somehow with OLE) and all I have to do is to read and write properly in this filesystem (probably using OLE in some way).
Greetings
Mariusz Popiolek
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Again, if you add anything to the core file format, then it must mean something to the associated application : what do you think Excel will say if you add your binary stuff in it ? GPF!
Ok, just to give a hint : Office documents are compound documents (ole storage). They use IStorage/IStream. Because IStorage acts like a folder, and IStream like a file, you could add internal folders inside a given compound document (then use DocFile viewer, one of the tools of VisualC++6.0 to see them). That's the only common thing between all office file formats. And of course, don't even dare to open such a modified document in Office.
sometimes it helps to look at the IL generated code
a MS guy on develop.com "answering" .NET issues
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That's what is on my mind! I just didn't know how to make it(I will try using IStorage/IStream). I don't think that any Office application will be confused when I add another folder to the file (for example Word should read it's own folder without looking for nothing else!), but this is only my presumption  . DocFile viewer seems to be very useful at the moment, if you have any other hints (especially about using IStorage/IStream, but of course I should dig in MSDN for myself and I will do it surely)I would be very grateful. Thanks for help
Greeting
Mariusz Popiolek
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Mariusz Popiolek wrote:
I don't think that any Office application will be confused when I add another folder to the file
I wouldn't bet socks on that.
Mariusz Popiolek wrote:
if you have any other hints
Internals are documented in MSDN release 98 (yes, everything has been removed since then).
sometimes it helps to look at the IL generated code
a MS guy on develop.com "answering" .NET issues
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>I wouldn't bet socks on that.
But you should, try this site:
http://www.softpile.com/Utilities/Encryption/Review_05296_index.html
I mentioned about this software before and I found out that this program works just like I expected (it adds file with digital signature into document and Office has nothing to do with this because it just omit it).
>Internals are documented in MSDN release 98 (yes, everything has been >removed since then).
I heard about it before but I haven't checked it yet, so far I found some info on the web (I hope that MSDN is more comprehensible).
Greeting
Mariusz Popiolek
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Ok, I've tested this shareware and indeed it creates a separate IStorage in the Excel files I have tested.
But this program is useless :
- when it comes to signing a document, this separate storage makes it prone to erasure, or intentional cloneage. In other words, if someone wants to bypass or spoof the signatures, he just needs a 10-line tool that either destroys or clones this IStorage.
- when it comes to encrypting a document, it creates a totally separate document, which does not load anymore in Excel. This feature is thus nothing more relevant than a password-protected zip file.
sometimes it helps to look at the IL generated code
a MS guy on develop.com "answering" .NET issues
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Hi
I gave you this link just to give an example that putting something inside Office files is reasonable, I don't mean that this program is good (actually it sucks, not only because of silly encrypting, I can give you more reasons why ), but I don't agree with you in one issue (about signing the doc in such way). Firstly show me the way of signing the doc that will be resistant to destroying the signature (teoretically it is possible but in this case it's not, if you don't agree I can elaborate my opinion). Secondly I don't see any sense in cloning the signatures. What would you do with such signature? Put in another document? I don't see your point (can you give some details?).
Greetings
Mariusz Popiolek
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Mariusz Popiolek wrote:
Firstly show me the way of signing the doc that will be resistant to destroying the signature
Watermarking. (for instance in pictures).
Mariusz Popiolek wrote:
Secondly I don't see any sense in cloning the signatures
That's aimed at spoofing documents, just like if you would mimic the signature of your mum for any signed paper you had to return to people at school. Seriously, spoofing is a great business. I am looking forward such tools would be licensed by national public administrations or the like, I would make a lot of $$$.
sometimes it helps to look at the IL generated code
a MS guy on develop.com "answering" .NET issues
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Hi
>Watermarking. (for instance in pictures).
Ok, but what if I will destroy picture? Seriously I mean that there is always possibility that someone will destroy the signature. The one thing we can is that we can find out that someone has destroyed or messed in the signature (for example digital signature with message recovery)
>just like if you would mimic the signature of your mum for any signed paper >you had to return to people at school.
Can you forge digital signature? I bet you won't (and probably nobody at the moment). Of course I mean "modern" digital signature. For example we take some document, put it through some hash function (for example SHA1), encode result of hash function using RSA (with private key of the signer) and put together encoded hash and document. Now everybody can verify the signature, just by making hash from document, decoding encoded hash (with public key of the signer) and comparing this two hashes. If they are different signature is forged. It was simple example, real algorithms are more complex.
Greetings
Mariusz Popiolek
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I need to implement a COM object (using ATL) which will have a property that is a collection. Anybody got a tutorial of how to do that?
Michel
It is a lovely language, but it takes a very long time to say anything in it, because we do not say anything in it, unless it is worth taking a very long time to say, and to listen to.
- TreeBeard
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http://www.codeproject.com/com/
Search for Dunn and u have bunch of good tutorials!
About ur property u can do it then quite easily
Papa
while (TRUE)
Papa.WillLove ( Bebe ) ;
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Other than vaguely remembering this article[^], i have no clue.
Shog9
------
If you really what to get shitfacde tell a crowded bar that is is yourt borthday and hife your wallet. you ka will many more friends.
- David Wulff, Brithday selebrations, 9/19/02
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Your property should return a SAFEARRAY containing the collection of data. Check out KB article Q207931[^] which has some sample code. (It's written for VB folks, but should be applicable to you as well.)
--Mike--
Just released - 1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm
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I know that the size of enum in VC++ is by default "integral". So the following structure is 4 bytes (or sizeof(int)). I also know that the size will scale based upon the value of said enumeration. However, I need my enum to be 'short' in order to read some binary data into a much larger structure that contains many of these enums? How can I cahnge the size?
typedef enum _ALARM_TYPE
{
LATCHING = 0,
SELF_CLEARING
} ALARM_TYPE;
Ryan Baillargeon
Software Specialist
Fuel Cell Technologies Inc.
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Got It, Nevermind....
#pragma enum(2)
Ryan Baillargeon
Software Specialist
Fuel Cell Technologies Inc.
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nope, I was wrong.. still looking
that was under AIX
Ryan Baillargeon
Software Specialist
Fuel Cell Technologies Inc.
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for everyones benefit I am going to post that I have found you cannot change the size of enum under VC++. In some other environments you can.
Ryan Baillargeon
Software Specialist
Fuel Cell Technologies Inc.
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Can you do the conversion yourself? By that I mean, if you want the enum to fit into a short then convert it to a short and read/write that. You may need to do some funky casting and/or memcpy'ing, but the effects will be the same and will work on other compilers too
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not mfc 
thanks
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SendMessage(
(HWND) hWnd,
BM_SETCHECK,
(WPARAM) wParam;
(LPARAM) lParam;
); For wParam use BST_CHECKED, BST_UNCHECKED or
BST_INDETERMINATE.
/ravi
Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com
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SendMessage is Great but there is a macro which do the same
BOOL CheckDlgButton(
HWND hDlg, // handle to dialog box
int nIDButton, // button identifier
UINT uCheck // check state
);
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You're right, CheckDlgButton() is easier to use.
/ravi
Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com
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I am looking at MS HTML Help and cant quite figure out what I need to do and how to do it. Going around in circles.... plus it looks like I need to know HTML - I dont. Any suggestions on the easiest way to write help docs? I do want the tabbed sort of help file window to pop up with Index, Contents etc (like you get with the MSDN). Help! 
Appreciate your help,
ns
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