From 1a746d98b8d282435450446aae424df53616c39a Mon Sep 17 00:00:00 2001
From: NotAnotherHelloWorld <christoffer+github@augdahl.no>
Date: Tue, 14 Jul 2026 03:02:34 +0200
Subject: [PATCH] Deploy certificate to FortiGate firewall using API (#6236)

* Deploy certificate to FortiGate firewall using API

* Refactor FortiGate deployment functions

Prefix private functions and working variables and use a timestamped certificate name.

* Replace grep -o for POSIX compatibility
---
 deploy/fortigate.sh | 175 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 deploy/fortigate.sh

diff --git a/deploy/fortigate.sh b/deploy/fortigate.sh
new file mode 100644
index 00000000..f00ca1cb
--- /dev/null
+++ b/deploy/fortigate.sh
@@ -0,0 +1,175 @@
+#!/usr/bin/env sh
+# Script to deploy a certificate to FortiGate via API and set it as the current web GUI certificate.
+#
+# FortiGate's native ACME integration does not support wildcard certificates or domain validation,
+# and is not supported if you have a custom management web port (eg. DNAT web traffic).
+#
+# REQUIRED:
+#     export FGT_HOST="fortigate_hostname-or-ip"
+#     export FGT_TOKEN="fortigate_api_token"
+#
+# OPTIONAL:
+#     export FGT_PORT="10443"             # Custom HTTPS port (defaults to 443 if not set)
+#
+# Run `acme.sh --deploy -d example.com --deploy-hook fortigate --insecure` to use this script.
+# `--insecure` is required on first run if not already using a valid SSL certificate on firewall.
+
+# Function to parse a FortiGate API response
+_fortigate_parse_response() {
+  _fortigate_response="$1"
+  _fortigate_func="$2"
+  _fortigate_status=$(echo "$_fortigate_response" | _egrep_o '"status":[ ]*"[^"]*"' | cut -d '"' -f 4)
+
+  if [ "$_fortigate_status" != "success" ]; then
+    _err "[$_fortigate_func] Operation failed. Deploy with --insecure if current certificate is invalid. Try deploying with --debug to troubleshoot."
+    return 1
+  fi
+
+  _debug "[$_fortigate_func] Operation successful."
+  return 0
+}
+
+# Function to deploy a base64-encoded certificate to the firewall
+_fortigate_deployer() {
+  _fortigate_cert_base64=$(_base64 <"$_fortigate_cfullchain" | tr -d '\n')
+  _fortigate_key_base64=$(_base64 <"$_fortigate_ckey" | tr -d '\n')
+  _fortigate_payload=$(
+    cat <<EOF
+{
+  "type": "regular",
+  "scope": "global",
+  "certname": "$_fortigate_cert_name",
+  "key_file_content": "$_fortigate_key_base64",
+  "file_content": "$_fortigate_cert_base64"
+}
+EOF
+  )
+
+  _fortigate_url="https://${FGT_HOST}:${FGT_PORT}/api/v2/monitor/vpn-certificate/local/import"
+  _debug "Uploading certificate via URL: $_fortigate_url"
+
+  _H1="Authorization: Bearer $FGT_TOKEN"
+  _fortigate_response=$(_post "$_fortigate_payload" "$_fortigate_url" "" "POST" "application/json")
+  _debug "FortiGate API Response: $_fortigate_response"
+
+  _fortigate_parse_response "$_fortigate_response" "Deploying certificate" || return 1
+}
+
+# Function to upload a CA certificate to the firewall
+# FortiGate does not automatically extract the CA from the full chain.
+_fortigate_upload_ca_cert() {
+  _fortigate_ca_base64=$(_base64 <"$_fortigate_cca" | tr -d '\n')
+  _fortigate_payload=$(
+    cat <<EOF
+{
+  "import_method": "file",
+  "scope": "global",
+  "file_content": "$_fortigate_ca_base64"
+}
+EOF
+  )
+
+  _fortigate_url="https://${FGT_HOST}:${FGT_PORT}/api/v2/monitor/vpn-certificate/ca/import"
+  _debug "Uploading CA certificate via URL: $_fortigate_url"
+
+  _H1="Authorization: Bearer $FGT_TOKEN"
+  _fortigate_response=$(_post "$_fortigate_payload" "$_fortigate_url" "" "POST" "application/json")
+  _debug "FortiGate API CA Response: $_fortigate_response"
+
+  # FortiGate error -328 means that the CA certificate already exists.
+  if echo "$_fortigate_response" | grep -q '"error":[ ]*-328'; then
+    _debug "CA certificate already exists. Skipping CA upload."
+    return 0
+  fi
+
+  _fortigate_parse_response "$_fortigate_response" "Deploying CA certificate" || return 1
+}
+
+# Function to activate the new certificate
+_fortigate_set_active_web_cert() {
+  _fortigate_payload=$(
+    cat <<EOF
+{
+  "admin-server-cert": "$_fortigate_cert_name"
+}
+EOF
+  )
+
+  _fortigate_url="https://${FGT_HOST}:${FGT_PORT}/api/v2/cmdb/system/global"
+  _debug "Setting GUI certificate..."
+
+  _H1="Authorization: Bearer $FGT_TOKEN"
+  _fortigate_response=$(_post "$_fortigate_payload" "$_fortigate_url" "" "PUT" "application/json")
+
+  _fortigate_parse_response "$_fortigate_response" "Assigning active certificate" || return 1
+}
+
+# Function to clean up the previously deployed certificate
+_fortigate_cleanup_previous_certificate() {
+  _getdeployconf FGT_LAST_CERT
+
+  if [ -n "$FGT_LAST_CERT" ] && [ "$FGT_LAST_CERT" != "$_fortigate_cert_name" ]; then
+    _debug "Found previously deployed certificate: $FGT_LAST_CERT. Deleting it."
+
+    _fortigate_url="https://${FGT_HOST}:${FGT_PORT}/api/v2/cmdb/vpn.certificate/local/${FGT_LAST_CERT}"
+    _H1="Authorization: Bearer $FGT_TOKEN"
+    _fortigate_response=$(_post "" "$_fortigate_url" "" "DELETE" "application/json")
+    _debug "Delete certificate API response: $_fortigate_response"
+
+    _fortigate_parse_response "$_fortigate_response" "Delete previous certificate" || return 1
+  else
+    _debug "No previous certificate found."
+  fi
+}
+
+# Main deploy-hook function
+fortigate_deploy() {
+  # Include date and time to ensure unique names.
+  _fortigate_cert_name="$(echo "$1" | sed 's/*/WILDCARD_/g')_$(date -u +"%Y-%m-%d_%H-%M-%S")"
+  _fortigate_ckey="$2"
+  _fortigate_cca="$4"
+  _fortigate_cfullchain="$5"
+
+  if [ ! -f "$_fortigate_ckey" ] || [ ! -f "$_fortigate_cfullchain" ]; then
+    _err "Valid key and/or certificate not found."
+    return 1
+  fi
+
+  # Save required environment variables if set; otherwise load saved values.
+  for _fortigate_var in FGT_HOST FGT_TOKEN FGT_PORT; do
+    if [ -n "$(eval echo "\$$_fortigate_var")" ]; then
+      _debug "Detected ENV variable $_fortigate_var. Saving to file."
+      _savedeployconf "$_fortigate_var" "$(eval echo "\$$_fortigate_var")" 1
+    else
+      _debug "Attempting to load variable $_fortigate_var from file."
+      _getdeployconf "$_fortigate_var"
+    fi
+  done
+
+  if [ -z "$FGT_HOST" ] || [ -z "$FGT_TOKEN" ]; then
+    _err "FGT_HOST and FGT_TOKEN must be set."
+    return 1
+  fi
+
+  FGT_PORT="${FGT_PORT:-443}"
+  _debug "Using FortiGate port: $FGT_PORT"
+
+  # Upload the new certificate.
+  _fortigate_deployer || return 1
+
+  # Upload the CA certificate.
+  if [ -n "$_fortigate_cca" ] && [ -f "$_fortigate_cca" ]; then
+    _fortigate_upload_ca_cert || return 1
+  else
+    _debug "No CA certificate provided."
+  fi
+
+  # Activate the new certificate.
+  _fortigate_set_active_web_cert || return 1
+
+  # Delete the previously deployed certificate only after successful activation.
+  _fortigate_cleanup_previous_certificate || return 1
+
+  # Save the new certificate name for cleanup during the next deployment.
+  _savedeployconf "FGT_LAST_CERT" "$_fortigate_cert_name" 1
+}