SHA1 hash with custom Characters in it.

[Testosteron22]

Hello,

I've got a problem and need your help
I've been given a task at school to find an SHA1 hash that got some given digits at the end of the hash for example 38672373312

I can't figure out how to compute my own SHA1 hash with custom characters in it. So i'm thinking only way to do that is take some Hash, edit last digits of it with my own ones and then try to crack the new hash i made. Is that the only way or is there another way to do that?

Also could anyone help me please put the right configuration on Hashcat app to crack this Hash as fast as possible, like what charset etc to use?

Hash i used was generated from word "Book", then i just changed last 11 characters with my own, so the new Hash is:
dc81b81285e57d0c84522ac97e89a39211052511

Could anyone help me with that please?

[mastercracker]

You are way off. The hash is specific for the word "Book". If you change any character from it, you won't be able to crack it. Your best luck is to find a real hash that already fit the pattern that you are looking for. The 3 sources I can suggest that you look into are Insidepro's forum, MD5dekryptor and Hashes.org. Look in cracked or uncracked SHA-1 (or length 40) lists and find one that fit your need.

[atom]

hey,

hashcat is the wrong approach for this. what you basically need is a program that takes some input data or increments some input data and tests the resulting hash digest for the number you're searching. a slow example would be this:

Code:

root@sf:~# perl -MDigest::SHA -e 'my $i = 1; while ($i++) { my $hash = Digest::SHA::sha1_hex ($i); next unless $hash =~ /12345$/; print "$hash:$i\n" }'
b7ad56c1f60c4a92da5baeb09f757d9548c12345:3062
79484ae7a3165b2dadc7d19e3d6f74084e212345:1334921
76b58496be5ef264940af787fbfd380083012345:1945762
4719d198feeeefa52980437f0ba175b32aa12345:2148068
5f9837ee319ca2d1c31ea8f147e54d7c94912345:2377383

It's a very slow solution, don't use it. But it might give you an idea how to do it.