Re-signing an expired certificate for publishing gems

INFO.md

$ gem build wisper.gemspec
Enter PEM pass phrase:
INFO:  Your certificate has expired, trying to re-sign it...
ERROR:  While executing gem ... (Gem::Security::Exception)
    certificate /CN=kris.leech\/DC=gmail\/DC=com not valid after 2020-10-15 18:13:45 UTC   

$ gem cert --re-sign -C gem-public_cert.pem -K ~/.ssh/gem-private_key.pem
$ gem cert --add gem-public_cert.pem
$ gem build wisper.gemspec
# try to install
$ gem install ./wisper-3.0.0.rc1.gem -P HighSecurity
$ gem push wisper-3.0.0.rc1.gem