How to apply password known constraints while using dictionnary and rules ?
#1
Question 
Hello,

At first thank you very much to those who are developing and maintaining hashcat!

I'm trying to find passwords matching md5crypt salted hashes using CUDA with a P2000, the only GPU I have.
I know that the passwords have at least 8 characters, at least one lower (a-z) case letter (?l), at least one upper (A-Z) case letter (?u), at least one number (0-9) (?d) and at least one special character (?s without the "space").
I would like to use a dictionary like rockyou.txt and rules like OneRuleToRuleThemAll.rule from NotSoSecure to expand it.
However by doing that a lot of passwords which do not meet the known requirements, below the minimum length or including chars out of the known charset, are hashed uselessly.
From what I read, due to the fact that password candidates are generated using the rules directly by the GPU, no hashcat option exists to enforce these requirements, is that right ?

I also read about the "-S" option with the following description : "Enable slower (but advanced) candidate generators"
I don't know exactly what does it mean but probably that in this case the password candidates are not generated directly by the GPU ; so by using this option, if it makes any sense regarding the performances, is there a way to enforce the password known constraints detailed previously ?

I also read about a solution which consists to generate the candidates to stdout and then pipe them to hashcat through stdin.
Once again, I don't know the impacts regarding the performances and if it does make any sense, however by doing that how should I enforce the password constraints ? Through a mask or specific rules ?
Using the stdout / pipe / stdin solution I'll also inevitably lose the estimated time... if I try at first with for example 1% of the dictionary content and then multiply the time it needed to finish by 100, does it make any sense ?

If you have any other suggestion to meet to goal which is to crack those md5crypt salted hashes, feel free to share.

Thank you very much,
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Messages In This Thread
How to apply password known constraints while using dictionnary and rules ? - by fzeijtrf - 12-21-2020, 12:09 PM