I am trying to do a known plaintext attack on DES-OFB through crack.sh. I have been having trouble lately. I keep getting blank text file back with no keys returned. Does anybody know if DES-OFB is supported by Crack.sh? I tried contacting them but did not get a response. Here is what I have last submitted.

$ ./des_kpt.py parse -p 6c42e85de2e82693 -m fffffffffffffff -c 57ef7750e24ab08f

                 PT = 6c42e85de2e82693
                  M = ffffffffffffffff
                 CT = 57ef7750e24ab08f
                  E = 0
crack.sh Submission = $98$bELoXeLoJpP////////1fvd1DiSrCP

I am not sure what exactly the mask dose either. I set it to all F's. Here is the key if it helps. There is 3 due to what DES_KPT spits back out when I run a decrypt command, which also does not produce correct PT. 345E207C6D2FE679 34bc83e6c5f9bc 345e207c6c2ee678

Any help or other tools is appreciated!

  • 1
    $\begingroup$ Welcome to crypto-SE. Sorry, this is off-topic per our rules against questions consisting largely of ciphertext/values, and questions on using tools. The question will get closed unless it moves to the crypto methods to solve such problems, their hardness… $\endgroup$
    – fgrieu
    Dec 18, 2020 at 8:38
  • 1
    $\begingroup$ Does the command support one of: -h, --help, -help, or -? options? The command is a shell script, maybe you can analyse the script yourself to figure out what options are needed. $\endgroup$
    – DannyNiu
    Dec 18, 2020 at 13:18


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