X.509 certificates

For document signatures and such, run this (only when you fully understand the command): s="$(mktemp)" cat > "$s" << EOF -----BEGIN CERTIFICATE----- MIIBzjCCAXSgAwIBAgIUaHmeGPiA6P9Uma8qBTFZKDzeAMkwCgYIKoZIzj0EAwIw GzEZMBcGA1UEAwwQUnVueGkgWXUgUm9vdCBDQTAeFw0yNjA3MDMxNjE1MDRaFw0y ODEwMDUxNjE1MDRaMDIxETAPBgNVBAMMCFJ1bnhpIFl1MR0wGwYJKoZIhvcNAQkB…