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I am attempting to use hashcat to crack a hash that is 32 characters in length. I know the hash is sha256.

When i run the following command

hashcat -m 1400 binary-hashfound.txt /path/to/rockyou.txt  

I receive the following error:

This copy of hashcat will expire soon ... Skipping line (line length exception) No hashes loaded

My first guess is that because the hash I am using is 32 characters long, I gathered that it is a binary type sha256hash - I assumed that because of this thread with RickNZ's comment : https://stackoverflow.com/questions/2240973/when-using-a-sha256-hash-how-long-is-the-hash-ie-how-long-should-my-mysql-va

Is this a correct assumption? I don't see another relevant sha256 hash type selection option for "sha256 binary 32" or something.

Not sure where to turn

  • isn't a SHA256 hash 64 characters long? – schroeder Dec 22 '15 at 18:14
  • do you mind posting the hash? – schroeder Dec 22 '15 at 18:15
  • Sure, after I post it can you delete it however? – Oscalation Dec 22 '15 at 18:16
  • 2
    You should assume that posting it means it will never be secret again. So if you care about keeping it secret, you must keep it to yourself. – Neil Smithline Dec 22 '15 at 18:18
  • StackExchange never forgets .... – schroeder Dec 22 '15 at 18:19
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This question basically comes down to the encoding method that is being used to encode the SHA256 hash.

A SHA256 hash is 256 bits long.

So, a SHA256 hash could be represented by a string of 64 hexadecimal characters, because there are 16 different hexadecimal characters [0123456789ABCDEF], so each hexadecimal character represents 4 bits (2^4=16). 256 bits * (1 character / 4 bits) = 64 characters.

Or, a SHA256 hash could be represented by a string of 43 base64 characters, because there are 64 different base64 characters [a-z, A-Z, 0-9, +, /], so each base64 character represents 6 bits (2^6=64). 256 bits * (1 character / 6 bits) = 42.667 characters.

But, you are saying that the SHA256 hash that you are dealing with is 32 characters long. So, that would mean that each character would represent 8 bits. 256 bits * (1 character / 8 bits) = 32 characters. So in this case, each character could have 256 different values (2^8=256).

Do the characters in your hash look like they could be from a characters set which could potentially have 256 different characters?

If so, then you may need to convert the encoding to some other encoding that is more widely-used to represent SHA256 hashes, such as hexadecimal. If not, then it may not be a SHA256 hash after all.

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