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I need to crack my own password. Advantage is that I know possible characters and maximum length.

What I need is to create dictionary for brute force attack. Dictionary should contain all the combos of characters that I choose (for example I don't need word list which contain character T, because I didn't used T in my password).

How can I do that?

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Just a note on terminology, this is a "Dictionary attack", not a "Brute force attack". The more information you know, the better your dictionary can be; likely lengths, patterns such as starts with capital, ends with number, two words joined plus a number, l33t speak, etc. Even if you're not sure about something it can be used to order the dictionary. But don't put the information here or anyone will be able to use it. –  Ladadadada Sep 10 '13 at 8:01
    
1. Can you program? 2. What is the password for, i.e. how will you know when you have found the correct one? –  Jan Doggen Sep 10 '13 at 8:20

4 Answers 4

So you could use python to generate all possible combinations using itertools.permutation

import itertools
res = itertools.permutations('abc',3) # 3 is the length of your result.
for i in res: 
   print ''.join(i)

where 'abc' is a string of possible characters. Note that a and A are not the same!

This will output:

abc
acb
bac
bca
cab
cba
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This won't give you all possible passwords with a given charset (aaa is missing for example). itertools.combinations_with_replacement() can be more useful. –  buherator Sep 10 '13 at 10:31
    
Sorry itertools.combinations_with_replacement() is neither the right choice, you should use itertools.product(). –  buherator Sep 10 '13 at 11:08

You need to use a wordlist to create dictionary attack. You can write your own wordlist generator or use an exisisting one.

Here are some existing wordlist generators:

You can find more. After generating a wordlist, you need to try every combination of those words until you find a matching one with your password.

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Password cracking tools, such as John the Ripper or hashcat, can be used this way. They have various "mangling" rules that will take a dictionary (in your case a one word dictionary) and then apply a number of transformations on it. You can then specify the rules based on the kinds of things you may have done with your password.

Learning how to specify these sorts of rules isn't trivial, and unfortunately you aren't in a position to ask for detailed help without revealing too much about the password.

Here are some sample, annotated, john CONFIGs, which might be of some help:

https://sites.google.com/site/reusablesec/Home/john-the-ripper-files/john-the-ripper-sample-configs-1

And here is a list of john tutorials, but I haven't actually looked at any myself, so again, I can only point you in the general direction:

http://openwall.info/wiki/john/tutorials

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You will also need a tool to run through the dictionary.

For a website try:

or generally:

If it is a desktop application using the password for behaviour instead of data confidentiality, you may be able to simply delete setting files or hack its memory while running.

I am assuming you are not a script kiddie ;-)

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