Install Smallstep and the HSM image

sudo apt-get update
sudo apt-get install -y ca-certificates curl docker.io jq opensc openssl
sudo systemctl enable --now docker

sudo docker info >/dev/null

curl -fL \
  https://github.com/smallstep/cli/releases/download/v0.30.6/step_linux_amd64.tar.gz \
  -o /tmp/step-cli.tgz
rm -rf /tmp/step-cli
mkdir -p /tmp/step-cli
tar -xzf /tmp/step-cli.tgz -C /tmp/step-cli
sudo install -m 0755 \
  "$(find /tmp/step-cli -type f -name step | head -1)" \
  /usr/local/bin/step
step version

curl -fL \
  https://github.com/smallstep/step-kms-plugin/releases/download/v0.17.0/step-kms-plugin_0.17.0_linux_amd64.tar.gz \
  -o /tmp/step-kms-plugin.tgz
rm -rf /tmp/step-kms-plugin
mkdir -p /tmp/step-kms-plugin
tar -xzf /tmp/step-kms-plugin.tgz -C /tmp/step-kms-plugin
sudo install -m 0755 \
  "$(find /tmp/step-kms-plugin -type f -name step-kms-plugin | head -1)" \
  /usr/local/bin/step-kms-plugin
step-kms-plugin version

sudo docker pull smallstep/step-ca:0.30.2-hsm
sudo docker run --rm \
  --entrypoint /usr/local/bin/step-ca \
  smallstep/step-ca:0.30.2-hsm version

export STEPPATH=/var/lib/smallstep/.step
sudo install -d -m 0750 -o "$USER" -g "$(id -gn)" \
  /var/lib/smallstep "$STEPPATH" "$STEPPATH/plugins"
ln -sf /usr/local/bin/step-kms-plugin \
  "$STEPPATH/plugins/step-kms-plugin"

STEPPATH=/var/lib/smallstep/.step step kms help >/dev/null