Certificate - PEM to PKCS12

 

Convert Lets encrypt PEM to tomcat PKCS12 

openssl pkcs12 -export \ -in fullchain.pem \ -inkey privkey.pem \ -out server.p12 \ -name my-domain-alias 

Renew OpenVPN certificate

 mv /etc/openvpn/easy-rsa/pki/reqs/server_xyzblablabla.req server_xyzblablabla.req.backup

mv /etc/openvpn/easy-rsa/pki/private/server_xyzblablabla.key server_xyzblablabla.key.backup

mv /etc/openvpn/easy-rsa/pki/issued/server_xyzblablabla.crt server_xyzblablabla.crt.backup

mv /etc/openvpn/server_xyzblablabla.crt server_xyzblablabla.crt.backup

mv /etc/openvpn/server_xyzblablabla.key server_xyzblablabla.key.backup

cd /etc/openvpn/easy-rsa

./easyrsa build-server-full server_xyzblablabla nopass

cp /etc/openvpn/easy-rsa/pki/issued/server_xyzblablabla.crt /etc/openvpn

cp /etc/openvpn/easy-rsa/pki/private/server_xyzblablabla.key /etc/openvpn

Create pem certificate

 Creating a .pem with the Private Key and Entire Trust Chain

    Log into your DigiCert Management Console and download your Intermediate (DigiCertCA.crt) and Primary Certificates (your_domain_name.crt).

    Open a text editor (such as wordpad) and paste the entire body of each certificate into one text file in the following order:
        The Private Key - your_domain_name.key
        The Primary Certificate - your_domain_name.crt
        The Intermediate Certificate - DigiCertCA.crt
        The Root Certificate - TrustedRoot.crt

Verify certificates

 3. Verify that the Public Keys contained in the Private Key file and the Main/Server Certificate are the same:

openssl x509 -in certificate.pem -noout -pubkey
openssl rsa -in ssl.key -pubout

The output of these two commands should be the same.
 
4. Check that the Valid From and Valid To dates of the certificate are correct:

openssl x509 -noout -in certificate.pem -dates

Ensure that the current date is between the certificate's Not Before and Not After dates.
 
5. Check the validity of the Certificate Chain:

openssl verify -CAfile certificate-chain.pem certificate.pem

If the response is OK, the check is valid.

Certificate expire date:

openssl x509 -enddate -noout -in server.crt

https://acquia.my.site.com/s/article/360004119234-Verifying-the-validity-of-an-SSL-certificate

 

https://forums.openvpn.net/viewtopic.php?t=18671