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Sebastien6's avatar
Sebastien6
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Jul 27, 2019

ASM RestAPI MD5 Hash calculation

when I use the following API for eample /mgmt/tm/asm/attack-types/CdlqS-GlMoFdQYr5VfSJDg, CdlqS-GlMoFdQYr5VfSJDg based on the F5 documentation is a MD5 hash. Based on test I did on the F5 ASM, all those MD5 hash come from the hash of the name, of the policy, signature, signature-set, etc...

 

but when I enter a value and calculate it's MD5, the value returned is not at all the same. Like if I do MD5 of "Detection Evasion", instead of returning CdlqS-GlMoFdQYr5VfSJDg, the value I obtained is fe81df82c81afd02556f5b7fdd7cec0e.

 

Is there a special way to calculate those F5 MD5, or is there a RestApi call that can be made with a name of policy, signature or other ASM items to obtain its equivalent MD5 hash value?

 

thanks

4 Replies

  • Hello Sebastien.

     

    The MD5 calculation is not made from the name and I don't think that F5 is going to share the algorithm.

    That's the only way to get the code.

    REF - https://support.f5.com/csp/article/K18432457

     

    KR,

    Dario.

  • well it's probably highly related to the name. The hash of ASM object in the API URL, are identical between various F5 cluster even with different TMOS version as long as the name is the same, and change only and only if the name of the object change. I made lot of testing about it and in the F5 ASM API, name == hash.

     

    I can understand they don't give the code, but at least an API call where we provide the name and it return the corresponding hash can be really helpful.

    • Dario_Garrido's avatar
      Dario_Garrido
      Icon for MVP rankMVP

      I wouldn't say that the name couldn't be involved in the calculation, but I'm sure there is something else.

       

      In your case, I would open a support-case trying to find out more info.

       

      BTW, if my last answer has helped you, I would appreciate if you mark the question as 'the best' or give me some upvotes.

       

      KR,

      Dario.

      • Dario_Garrido's avatar
        Dario_Garrido
        Icon for MVP rankMVP

        Hello Sebastien.

         

        I know you are in the another thread, but I post this to document it for another people in the future.

         

        How to perform MD5 calculation:

        https://devcentral.f5.com/s/question/0D51T00006oGG1VSAW/asm-rest-api-sigset-id

         

        KR,

        Dario.