feat(deploy/tls): self-signed CA + server cert generator

generate-certs.sh mints the bus CA and a NATS server certificate whose SANs cover the public IP (135.125.201.30), the WireGuard IP (10.42.0.1), the om hostname, and localhost/127.0.0.1 for on-host smoke tests (all overridable via env). Only the public ca.crt is committed; ca.key, server.key and server.crt are gitignored and distributed out of band. README documents generation, use and rotation. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-07 12:44:13 +02:00
parent 2786ae2dde
commit 1b56f14c20
4 changed files with 137 additions and 0 deletions
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+#!/usr/bin/env bash
+#
+# generate-certs.sh — mint the unibus bus's self-signed CA and the NATS server
+# certificate. Run once on a trusted machine; distribute ca.crt to clients and
+# server.crt/server.key to the bus host (server.key by a secure channel, never
+# git). Re-running regenerates the server cert; pass --force to also regenerate
+# the CA (which invalidates every client that pinned the old ca.crt).
+#
+# SANs cover the public IP, the WireGuard IP, the om hostname, plus localhost so
+# the operator can smoke-test the TLS handshake on the box. Override via env:
+#   UNIBUS_PUBLIC_IP (default 135.125.201.30)
+#   UNIBUS_WG_IP     (default 10.42.0.1)
+#   UNIBUS_HOSTNAME  (default om)
+#
+# Key material: EC P-256 (widely supported by Go's crypto/tls and nats-server).
+set -euo pipefail
+
+DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+cd "$DIR"
+
+PUBLIC_IP="${UNIBUS_PUBLIC_IP:-135.125.201.30}"
+WG_IP="${UNIBUS_WG_IP:-10.42.0.1}"
+HOSTNAME_OM="${UNIBUS_HOSTNAME:-om}"
+DAYS_CA=3650
+DAYS_SRV=825
+
+force=0
+[[ "${1:-}" == "--force" ]] && force=1
+
+# --- CA (long-lived; only the cert is public) ---
+if [[ ! -f ca.crt || ! -f ca.key || $force -eq 1 ]]; then
+  echo "==> generating CA"
+  openssl ecparam -name prime256v1 -genkey -noout -out ca.key
+  chmod 600 ca.key
+  openssl req -x509 -new -key ca.key -sha256 -days "$DAYS_CA" \
+    -subj "/CN=unibus-ca" -out ca.crt
+else
+  echo "==> reusing existing CA (pass --force to regenerate)"
+fi
+
+# --- server certificate, signed by the CA, with the bus SANs ---
+echo "==> generating server certificate (SAN: $PUBLIC_IP, $WG_IP, $HOSTNAME_OM, localhost, 127.0.0.1)"
+openssl ecparam -name prime256v1 -genkey -noout -out server.key
+chmod 600 server.key
+openssl req -new -key server.key -subj "/CN=unibus-bus" -out server.csr
+
+cat > server.ext <<EOF
+subjectAltName=IP:${PUBLIC_IP},IP:${WG_IP},DNS:${HOSTNAME_OM},DNS:localhost,IP:127.0.0.1
+extendedKeyUsage=serverAuth
+keyUsage=digitalSignature,keyEncipherment
+EOF
+
+openssl x509 -req -in server.csr -CA ca.crt -CAkey ca.key -CAcreateserial \
+  -sha256 -days "$DAYS_SRV" -extfile server.ext -out server.crt
+
+rm -f server.csr server.ext ca.srl
+
+echo "==> done:"
+echo "    ca.crt      -> embed/distribute to every client (public)"
+echo "    server.crt  -> deploy to the bus host"
+echo "    server.key  -> deploy to the bus host over a secure channel (NEVER git)"
+echo
+echo "verify SANs with:"
+echo "    openssl x509 -in server.crt -noout -text | grep -A1 'Subject Alternative Name'"