Issue with slackpkg and gpg key

I found an issue while using slackpkg where the following error presented itself:

ERROR: Verification of the  gpg signature on CHECKSUMS.md5
               failed! This could mean that the file is out of date
               or has been tampered with. If you use mirrors.slackware.com
               as your mirror, this could also mean that the mirror to
               which you got redirected is not yet updated with the most
               recent changes in the Slackware tree.

An alternative way to use wget

Normally wget works as expected but every now and then, you page is forbidden or similar, so the below is an alternative approach;

Import certificate into Java keystore

The below example involves importing a Zscaler root CA certificate into the java keystore on my Slackware installation.

sudo keytool -import -trustcacerts -alias zscaler -file /etc/ssl/certs/Zscaler-Dalzell.crt -keystore /opt/jdk1.8.0_341/jre/lib/security/cacerts