How many months are you prepared to set aside for this?

the main question is file size

Would probably be easier to create a script to go through variations of your password. heh

Errius wrote:

How many months are you prepared to set aside for this?

That's why I want something that will try using the almost complete password, just changing one character each try, to *massively* cut down on the variations to be tested. I need the files by 4pm on Thursday.

mrau wrote:

the main question is file size

it's a 29 MB file (most of which is unimportant, as I didn't modify them from the work's machine, I only edited about six of them plus created two more).

DosFreak wrote:

Would probably be easier to create a script to go through variations of your password. heh

That's a good idea, but beyond me. It's not a major problem anyway, it will only take a few hours to redo the work, and it will teach me the valuable lesson to ALWAYS check backups (which I usually do, but not this time, ironically - I always e-mail the newly made RARs to myself as well as work, and keep a copy on USB stick, to be safe, but that's irrelevant now since it's a password related fault). I just thought that there might be a password cracking program that would take the intended password and test all possible mistypings of it in a RAR file. I can't be the only idiot who's ever ended up needing one.

I would imagine there are dictionary attack programs out there to crack rar files. The library files for unrar are available in c++ if not, so you can write it yourself or find someone willing.

You can then write a little script to dump a text file with your regular password and every variation of each character that could represent the typo to use as the dictionary. If it really is only a single character typo it'll be found in seconds. Beyond that the time to crack it would grow exponentially, but if you know the majority of the password its not unreasonable.

Edit: if its only a few hours of work I think you should just bite the bullet and redo it. I can probably bust it open but I wont really have free time until this weekend to fool with it.

Errius wrote:

How many months are you prepared to set aside for this?

I believe how many billion years is more accurate to brute force 15 characters assuming a digit at the end and a capital at the beginning if we had no other input about the password 🤣

BeginnerGuy wrote:

I would imagine there are dictionary attack programs out there to crack rar files. The library files for unrar are available in c++ if not, so you can write it yourself or find someone willing.

You can then write a little script to dump a text file with your regular password and every variation of each character that could represent the typo to use as the dictionary. If it really is only a single character typo it'll be found in seconds. Beyond that the time to crack it would grow exponentially, but if you know the majority of the password its not unreasonable.

Edit: if its only a few hours of work I think you should just bite the bullet and redo it. I can probably bust it open but I wont really have free time until this weekend to fool with it.

Thanks for the offer, mate, but I have to post the report by Thursday, so I'll just redo everything tomorrow (unless anyone can suggest anything quick to try, of course), and be glad that I've learnt this lesson over something so trivial. Not that I ever actually handle important data, of course, but if I did and I lost it I'd be rather upset about now.

You say that cracking my password could potentially take billions of years, I had no idea it could take that long (so it probably wouldn't be done by Thursday!). I didn't realise that free or reasonably priced software could make archives that secure, I thought only the military, governments, etc, had access to really powerful encryption systems? Not that I'd trust the government with anything technical, of course...

You can try this: https://www.lostmypass.com/file-types/rar/
Or, if the RAR is created in older versions of RAR/WinRAR, there are older tools: https://translate.google.com/translate?sl=ru& … 1698&edit-text=

Also to help look for tools the right terminology is "Brute-force with Mask"

How is it that you mistyped the password twice? If I remember corretcly WinRAR asks for password confirmation, so you have to type it twice.

http://crark.net/

The tested, tried and true utility for the job (and conveniently freeware also). Easy to use and can do exactly what you want it to do, that is, feed it your password and have it automatically try the extra character(s) that may have been mistyped in.

I'm not sure but how is the integrity of the RAR file? Is it still intact?

If the archive is corrupt somehow (like incomplete download, unsafe or too early unplugging of USB stick after copying), then it won't extract even if you entered the right password as it won't be able to decrypt contents that have a few bytes corrupted.

By the way, be careful with NTFS file compression. A few years ago (around Windows 7 and 8, I think) I discovered that my files on hard drives were plagued by that old and nasty bug, resulted in losses of access to quite a few of my old archives (encrypted or not). It seems disk defragmentation could be the culprit and since then I have ceased using the functionality that I've been using, when hard drive space were much scarce.

EDIT: You may need to test the tools or methods mentioned above, and if after all possible combinations have been tried (that is, after ruling out all the possible passwords you could have typed) but still couldn't open or extract the archive, it is very likely that the archive is corrupt.

LSS10999 wrote:

I'm not sure but how is the integrity of the RAR file? Is it still intact?

WinRAR will by default tell you right away (upon attempting to open the file) whether or not it's integrity has been compromised, so unless he forgot to mention that tiny detail, I'd be inclined to believe it's very likely to be intact.

LSS10999 wrote:

If the archive is corrupt somehow (like incomplete download, unsafe or too early unplugging of USB stick after copying), then it won't extract even if you entered the right password as it won't be able to decrypt contents that have a few bytes corrupted.

Unless "Add recovery record" has been checked prior to archiving; In this case the file can take quite a bit of damage but WinRAR will still be able to undo it with it's built-in "Repair" functionality.

eL_PuSHeR wrote:

How is it that you mistyped the password twice? If I remember corretcly WinRAR asks for password confirmation, so you have to type it twice.

No, it definitely didn't ask me for password verification. It was on my mate's laptop, which was why I used WinRAR instead of 7Zip (7Zip does require you to enter the password twice), and maybe it was an old version of WinRAR, I don't know (though if anyone is genuinely interested then I can find out what version of WinRAR it was).

LSS10999, I'm 99.9% sure 7Zip (which I used to try to extract the archive) does tell you if an archive is corrupt, I do recall several instances of that in the past.

Anyway, I gave up and just redid the work (it wasn't difficult, just tedious, and I'm not sure anyone ever reads them anyway, moan moan), so thanks for all of the suggestions everyone, this is a great forum.

Kerr Avon wrote:

No, it definitely didn't ask me for password verification. It was on my mate's laptop, which was why I used WinRAR instead of 7Z […]
Show full quote

eL_PuSHeR wrote:

How is it that you mistyped the password twice? If I remember corretcly WinRAR asks for password confirmation, so you have to type it twice.

No, it definitely didn't ask me for password verification. It was on my mate's laptop, which was why I used WinRAR instead of 7Zip (7Zip does require you to enter the password twice), and maybe it was an old version of WinRAR, I don't know (though if anyone is genuinely interested then I can find out what version of WinRAR it was).

LSS10999, I'm 99.9% sure 7Zip (which I used to try to extract the archive) does tell you if an archive is corrupt, I do recall several instances of that in the past.

Anyway, I gave up and just redid the work (it wasn't difficult, just tedious, and I'm not sure anyone ever reads them anyway, moan moan), so thanks for all of the suggestions everyone, this is a great forum.

DosDaddy wrote:

WinRAR will by default tell you right away (upon attempting to open the file) whether or not it's integrity has been compromised […]
Show full quote

LSS10999 wrote:

I'm not sure but how is the integrity of the RAR file? Is it still intact?

WinRAR will by default tell you right away (upon attempting to open the file) whether or not it's integrity has been compromised, so unless he forgot to mention that tiny detail, I'd be inclined to believe it's very likely to be intact.

LSS10999 wrote:

If the archive is corrupt somehow (like incomplete download, unsafe or too early unplugging of USB stick after copying), then it won't extract even if you entered the right password as it won't be able to decrypt contents that have a few bytes corrupted.

Unless "Add recovery record" has been checked prior to archiving; In this case the file can take quite a bit of damage but WinRAR will still be able to undo it with it's built-in "Repair" functionality.

I think depending on where the corruption happens and how many bytes corrupted, the archive manager may not always detect corruptions. If the header got corrupted, the file could not be opened; if the end got corrupted, some archive managers like WinRAR may detect and report; but corruptions within archived data may not be detected until actual extraction takes place. And given the nature of encryption, the archive manager could not tell if the resulted CRC mismatch is due to incorrect password or actual data corruption.

I recall when downloading some encrypted archives from some unreliable connection (that tend to end the download stream incorrectly leaving some bytes incomplete or corrupt), the archive manager (WinRAR) didn't immediately tell me something was wrong with the archives, just that I couldn't extract them even with right password. The errors were the same as having typed the wrong password, CRC mismatch (wrong password?), so at one time I suspected the password might be wrong. But after redownloading them from a more stable connection, I was able to successfully extract them with the same password, implying the previous downloads were indeed incomplete for some reasons.

Anyway, it's good to hear the issue wasn't so serious, just again, take great care when handling archives especially encrypted ones.

CRC is often what's used to detect corruption. Of course, this has no capability of repair so redundant data needs to then be added.

Beware of 'solid' archives BTW. They are more tightly compressed, but if there is data corruption you will lose more of the data than with a regular archive.

I always use external PAR files for redundancy (c. 15%) with WinRAR archives. I've never used the recovery volume option. I assume the two are equivalent?