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How to check if a certificate .pfx file has code signing ability (EKU)?

brad_Hbrad_H Member Posts: 86

Is there anyway to tell if a .pfx file in windows has the code signing ability using command or writing a program?

Code signing ability is added to the certificate via an EKU, so how to check this?

More specifically, kernel mode code signing ability.


  • Peter_Viscarola_(OSR)Peter_Viscarola_(OSR) Administrator Posts: 8,667

    Isn’t this indicated by an OID in the X509v3 Extended Key Usage thingy?


    Peter Viscarola

  • brad_Hbrad_H Member Posts: 86

    @Peter_Viscarola_(OSR) said:
    Isn’t this indicated by an OID in the X509v3 Extended Key Usage thingy?


    I Think so, but is there any simple command that can show me important features regarding the pfx file, including whether it has code signing EKU or not?
    Maybe a cmd or powershell command, or a signtool command? or any open source tool that parses the pfx file format?

  • Tim_RobertsTim_Roberts Member - All Emails Posts: 14,094

    The openssl command can certainly do it. That's one of those commands with a billion subcommands; it can do anything, if you can figure out how to spell it. If you import it with certmgr, you can examine the details and find the usages.

    Tim Roberts, [email protected]
    Providenza & Boekelheide, Inc.

  • Jason_StephensonJason_Stephenson Member Posts: 113

    openssl pkcs12 -info -in my.pfx

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