How to export the public key of a certificate in software – VÀLid Ciutadania

A digital certificate consists of two elements: the public key and the private key. The private key is the element that contains the specific information of the holder of each certificate, while the public key includes the generic information related to the characteristics of the certificate.

To use a certificate for authentication, signature, etc., it is necessary to have the complete certificate (public key+private key). However, on some occasions the public key may be needed, for example to check its validity .

Warning: Never share your certificate's private key . Yes, you can share the public key, for example to resolve an incident in the use of the certificate.

Below we explain how to obtain the public key of a software certificate, depending on the browser you have it installed on (in the screenshots, a idCAT Certificate is shown as an example of a software certificate):

Export the public key of a certificate installed in Google Chrome

Step 1: Go to the button from the upper right. Option " Settings ">Privacy and Security>Security- Manage certificates .

Step 2 : select the certificate and click the "Export" button.

Select the export button

Step 3 : Select the " Do not export private key " option

Step 4: Finally set the file location and name. You already have the public key of the certificate exported.

Defines the location and name of the file

Export the public key of a certificate installed in Keychains - Mac

step 1 Go to Key Access > Login > my certificates.

step 2 Select the certificate we want to export, we will see that it shows us that it has a private key.

step 3 Click the right mouse button on the private key of the certificate, a window will open with several options, we must select "Export".

step 4 A window will open where we must select the "certificate (.cer)" file format from the drop-down list, indicate the name of the public key and in which location we want to save it. Finally we will click on Save.

We will already have the public key (.cer) of the certificate in the defined location.

Export the public key of a certificate installed in Microsoft Edge

Step 1: With the Microsoft Edge browser go to the button from the top right>Settings>Privacy, search and services tab>Security. At this point click on the "Manage Certificates" button and then the " Personal " tab.

Step 2: select the certificate and click the "Export" button.

Select your certificate and press Export

Step 3 : Select the " Do not export private key " option

Step 4: Finally set the file location and name. You already have the public key of the certificate exported.

Select the location where you want to export it

Export the public key of a certificate installed in Firefox

Step 1 : Go to Tools >Settings>Privacy and Security > Show certificates

Select show certificates

Step 2 : select the certificate and click the "View" button.

Press the view button, once the certificate has been selected

Step 3 : in the "Others" section, press the "PEM(cert)" option

Under Others in the Download row press PEM (true)

This option will allow you to download the public key of your certificate in .pem format.

Step 4 : To change the format to .cer, you can rename the file (by right-clicking on the file and selecting the Rename option) and change the .pem extension to . sky

Select change Name with the right button

when you do "intro" the file will already be in the .cer format

modified file with .cer format

You already have the public key of the certificate exported.