How to tamper a X509 format certificate?

Question

I used openssl command line tool to generate a CA signed certificate. now I need to tamper it to generate the signature mismatch error.

Is there any tool available to tamper the X509 certificate.

jariq · Accepted Answer

Open certificate file in ASN.1 Editor, find commonName node, right-click it and choose "Edit...":

enter image description here

Change the text of commonName field:

enter image description here

Hit OK, save your changes and there you are:

enter image description here

Donate For Us