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VI's password

I forget the password of my Vi , anyone can help me how can I open the "block diagram"
many thanks!
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Message 1 of 82
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You cannot without the password.
Message 2 of 82
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Although, if you do remember what your passwords *sort of* looks like (specifically, which letters it has), you can do this by programmaticaly running a brute force attack using a limited dictionary and it should work quite fast. There are a few examples floating around the web. I think Michael Aivaliotis and Brian Renken may have had some on their sites. I suggest you try searching google for it.

If you don't rememeber the password, then you're more-or-less stuck and the only advice for you (for the future) is to not password protect VIs with a password you can't remember and if you do protect them, to write down the password somewhere.


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Message 3 of 82
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Further to tst's post, if the password is simple you might find the following link of interest.

I tested the software (some time ago Labview 6.X) and it seems to functions as described, it won't get into a seriously protected VI in any reasonable length of time (that is what I was testing... was my protection good enough {15 character mixed letter number sequence with special characters}, it was a pain to enter). But if it was a couple of numbers or you know the password structure; you could build a dictionary based variant.

I once lost a password as well, it was quicker to re-engineer the solution. It was better second time round as well.

When I use them now, I write them down and put the copy in a fire proof safe.

links used: -
http://www.aivaliotis.com/archives/lv/vi_password_cracking.shtml
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@Conseils wrote:
I tested the software (some time ago Labview 6.X) and it seems to functions as described, it won't get into a seriously protected VI in any reasonable length of time

Any newer version of LabVIEW has an intentional time delay if you try to set the lock state programmatically. This means any blind brute force attempt will take an infinite amount of time if the password is more than a few digits. 😉

Message 5 of 82
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Thanks that puts my mind at rest a little, I always thought it a bit strange that you could try as many as you wanted as quickly as you wanted too.

Do you happen to know the retry interval?
Is there a retry limit?

Just out of curiosity....
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Message 6 of 82
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I don't think there is a limit.
 
The timeout is not very long, but it is a enough to delay you significantly when you need to do something many times. I think it's on the order of a millisecond.
 
BTW, a brute force attack will work fairly efficiently if you have a limited dictionary, since most of the overhead (at least for short passwords) comes from the number of possiblities for the letters and not from the number of letters itself.

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Message 7 of 82
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Are you aware which version of the software this started from?
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Message 8 of 82
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I can't see any real difference between 6.1 and 7.0. Both take about the same time when running the method for 100,000 iterations (about 300-350 ms with a single character for a VI with an 8 character password). In some cases 7.0 was faster and in some cases 6.1.

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Message 9 of 82
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Well just so you know that I am persistent, I left the software running for 8 days continously before I got bored. I could have set it up to remember its position and now I have a server box for Skype, I could potentially set up something on there and leave it running for weeks (If I had a license for that box, of course).

Now if only I could be bothered.....Smiley Very Happy
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Message 10 of 82
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