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Osborn wrote:
Can you tell me where is a safe place for that?
In reality, there is none.
Osborn wrote:
File and Registry changes are easily to observe or spy. So I think this is not a good idea!
If you are not willing to use the registry, or some form of a file, you've just limited your options to near zero.
Having said that, a file or the registry is perfectly suited to what you want, as long as you account for the human factor. Let me explain.
More often than not when folks are putting (sensitive) data into a file, it's as obvious as the nose on your face. It practically has "invite" written all over it. Take into account that if you use words/tokens that people are familiar with, curiosity will get the best of them and the data could become compromised. If your program is called "eric", can you tell me what would be wrong with naming your data file eric.dat, with a line such as NumberOfTimesFileHasBeenDecrypted= in it?
I snoop around on my computer quite a bit to see what files are contained where. If a file has an interesting name, rest assured that I'm gonna try and open it. If the file looks like an ordinary file that could be found anyplace else, I'm probably not going to be interested. Ok, let's say that I've opened the file. If I see things in it such as Password=, it's a safe bet that I'm gonna try and do something with that. However, if it had stuff in it such as ColorDelta=, or DeviceDependency=, that probably is of no interest to me. You could take that one step further by renaming the entries in the file, either each time your program is ran, or on certain days of the week. Get the idea?
You could do the same thing with the registry. Just because the registry is more hierarchical than a file, don't think it's any more secure. I watch my registry on a regular basis, too! Programs "hide" stuff in the oddest places.
One other option that is available to you is to put the decryption count in the program itself. See UpdateResource() for this.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Most Sharewares use a combination of self-modifying code, the registry, and hidden files they stick in your system directory.
To know for sure what software is doing to your file system you need to be running a utility that monitors and reports on all disk activity.
You might think about using steganography throughout the encrypted file itself to store data about how many times that file has been attacked. Using this method will prevent the file from being copied and/or renamed and starting all over.
Maybe define a table at the beginning of each encrypted file that contains byte offsets for which data bits of which bytes contain not encrypted data but rather the number of attempts used to open that file:
struct steg_table
{
int nByteOffsets[NUM_STEG_BYTES];
int nStegBitNumbers[NUM_STEG_BYTES];
int nActualBitData[NUM_STEG_BYTES];
};
So maybe the nByteOffsets array might look like 68, 155, 366, 1204, 1344, 2265, 4976, 6512
and the nStegBitNumbers might be 1, 1, 2, 4, 6, 2, 3, 3
and the nActualBitData might be 0, 0, 1, 0, 1, 1, 0, 1
Meaning that the 1st bit of the 68th byte would actually act as the first bit of the count for how many times that file has been attacked.
The actual value for that bit would be stored as the first element of the nActualBitData array.
But this only works if the person doing the attacking is using your program!
There is no way to prevent a brute force attack on your data files themselves.
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Like you mentioned it, with disk tracker utilities it's quite easy to find out what has changed since the last decryption.
And if I modify the encrypted file, they can overwrite the encrypted file with the original version, they copied before.
So I think I've no chance to prevent this. So maybe I can make a triple protection, I save the value into 1 file and 2 registry entry or vice versa...
So it's much better than without a protection.
If you're interested in the encryption program take a look at www.osborn-software.com!
Greetings from rainy cold Germany
Thx
Eric
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You can put files in your own directory but disguise their intent. That way they appear necessary, and are not installed in some strange place. For example a sample file.
J.
----------------------------
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I'm trying to create a dialog with the web browser control embedded inside. I would like to load an html web form and get both the static text from the html page and the data entered in the edit boxes to display on another webpage. Any ideas?
Thanks
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Hi,
I have an app that uses MoveFileEx with MOVEFILE_DELAY_UNTIL_REBOOT. The app basically extracts some temporary files from a .zip file to a cache directory. After each file is extracted, a delete on reboot key is added to the registry if the system is WinNT/2000/XP, otherwise WinInit.ini is used. If the program ends normally, the registry keys are deleted (or WinInit.ini is restored to its former state). The idea is simply that the cached files are cleaned up no matter how the program ends.
However, there seems to be some bug whereby the files aren't always deleted on boot up. Strangely, sometimes they are, sometimes they aren't. I can't find any logic behind it, despite having tested it over and over again. In every case my code seems to be working fine, as I check the registry before rebooting and the PendingFileRenameOperations key contains all of the info that should be there (all the paths to the files I want to delete with \\?\ before them or whatever). When I reboot, the PendingFileRenameOperations key is gone - as though it has been executed - but the files are not always deleted. Very strange. This is the basics of the code I am using to do this:
<br />
<br />
for (int currfile = 0; currfile < fileno; currfile++)<br />
{<br />
<br />
zip.ExtractFile(currfile,OutputPath_str);
<br />
<br />
<br />
if(MoveFileEx(szCurrFile,NULL,MOVEFILE_DELAY_UNTIL_REBOOT)==0)<br />
{<br />
}<br />
<br />
SetFileAttributes(szCurrFile,FILE_ATTRIBUTE_HIDDEN);<br />
<br />
if(PeekMessage(&msg,NULL,0,0,PM_REMOVE))<br />
{<br />
if(msg.message == WM_QUIT) {<br />
GRS_quit = 1;
break;<br />
}<br />
TranslateMessage(&msg);<br />
DispatchMessage(&msg);<br />
}<br />
}<br />
Like I say, if I reboot during this loop or immediately after it, although the correct info is in the registry, the files are not always deleted in restarting.
If anyone has any idea as to why I might be getting this peculiar problem, I would be really grateful.
Many thanks,
KB
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Does MoveFileEx() or SetFileAttributes() (is this required) ever fail? If so, what is the error from GetLastError()?
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Hi, thanks for the reply. This is the weird (and really annoying) thing - neither fail. I have checked their return values, and all is okay. And I have even checked the registry itself, and found that all the values are perfectly correct inside PendingFileRenameOperations, and everything seems fine. And yet still, sometimes when I reset the computer, nothing is deleted.
At first I thought that it must somehow be falling through to the code at the end of my program which removes the entries from the registry if the files have been deleted normally after the program has closed, but I tried commenting this code out and it made no difference.
This is really strange. Does anyone know of any reason why PendingFileRenameOperations in the registry might be ignored or just deleted at boot up without actually running?
Many thanks,
KB
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Could it be a permissions issue? Are the files on an NTFS volume?
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Hi
My Programm needs VC++ installed to run. When i compile it i got this warning:
Linking...
LINK : warning LNK4089: all references to "SHELL32.dll" discarded by /OPT:REF
Why i get this error and how can i make my programm running without VC++ installed?
Settings: Release + Static Library
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But other programms that i have written whith VC++ are working without such a "Run-Time Paket". Why?
Do this happen because i use ActiveX copmonents in this programm?
->Microsoft Communication Control 6.0 for RS232 acces.
DarkMarine
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It all depends on what you are trying to do.
Sometimes mfc42.dll is enough. If you are using an ActiveX component, you might need some additional OCX files.
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Thanks for your quick answere!
I used the Dependency Walker to determine which dll are needed for my programm and one dll is red marked: MPR.DLL
And i get this error message:
Warning: At least one module has an unresolved import due to a missing export function in a delay-load dependent module.
And how do i find out which Files i need?
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Did you copy and register you MSCOMM32.OCX file on your target PC?
What does msdn.microsoft.com have to say about MPR.DLL?
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Thanks for your help!
After i registerd the OCX File the Programm works no.
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That is an error generated by the linker:
Linker Tools Warning LNK4089
all references to "dynamic-link library" discarded by /OPT:REF
The linker discarded all packaged functions that referenced exports in dynamic-link library. As a result, dynamic-link library and its import library are unneeded.
This is just a warning that says basically that you've told the linker to include the MFC library as static but since you aren't using it it will not be included in your executable.
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Run "depends.exe" on your exe to see what depencies you have.
I would guess that you need the MFC dll:s atleast.
Note that the depends that comes with VC is a bit old and there is a newer version (that is much better) on the net.
The warning you get is because the linker realized that you weren't using that dll.
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Hi all,
I need some help figuring out what to use for my app. I need to have a list of items displayed in a dialog window. I am stuck here because I am not sure I am doing the right thing.
The list of item has to be displayed one after another, but one particular type of item has to be in columns. Lets say i want to list sporting equipment and only display the quantity and price for baseball equpi. So an example would be:
<code> Quantity Price ($) Total Price
Baseball hat 4 $25 $100
Baseball ball 11 $5 $55
Basketball shoes $100
Basketball shorts $35
Basketball $40
Soccer ball $30
Baseball bat 2 $65 $130</code>
Right now I am using a listbox because i don't think a list control will let me span across columns. Can this be done? Is there a way to format the string I add in the list box (using addstring()) to consistantly be in column alignment?
THANKS for the help everyone
Jimmy
Just cause I am 15, doesn't mean I'm dumb! (I'll really be 4 on Feb. 29...the year 2004)
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Use a list control, with a report style. Give it four columns: Item, Quantity, Price, and Total Price. Empty columns are certainly permissible.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Hi,
I wanted to clarify what i needed. I want to be able to add the other types of equpiment as the way i entered in the example as well as write a sentence that will go across the columns. I want to be able to write a description or a cause for the purchases that are made that are not baseball related.
So in other words, I want to put to be able to put the paragraph above under the basketball equpiment purchases and before having the last baseball item in the list in the columns again. Can this be done? I couldn't figure this out, so i went with the listbox. This is making it hard to get the baseball equpiment to be lined up though.
Any help would be appreciated.
Jimmy
Just cause I am 15, doesn't mean I'm dumb! (I'll really be 4 on Feb. 29...the year 2004)
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Sounds like you either need to employ a grid control, or use the LBS_USETABSTOPS style with your listbox.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Can a list control insert across columns? Something along the line of merging cells in MS excel?
Jimmy
Just cause I am 15, doesn't mean I'm dumb! (I'll really be 4 on Feb. 29...the year 2004)
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Not that I'm aware of, but, I've never tried.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Hi,
would you be offended if i asked this to other members of the forum? (post a new message about this?)
thanks again for your help
Jimmy
Just cause I am 15, doesn't mean I'm dumb! (I'll really be 4 on Feb. 29...the year 2004)
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