Deploy certificate to FortiGate firewall using API

Author: NotAnotherHelloWorld

deploy/fortigate.sh

@@ -0,0 +1,164 @@
+#!/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 response
+parse_response() {
+  response="$1"
+  func="$2"
+  status=$(echo "$response" | grep -o '"status":[ ]*"[^"]*"' | sed 's/"status":[ ]*"\([^"]*\)"/\1/')
+  if [ "$status" != "success" ]; then
+    _err "[$func] Operation failed. Deploy with --insecure if current certificate is invalid. Try deploying with --debug to troubleshoot."
+    return 1
+  else
+    _debug "[$func] Operation successful."
+    return 0
+  fi
+}
+
+# Function to deploy base64-encoded certificate to firewall
+deployer() {
+  cert_base64=$(_base64 <"$_cfullchain" | tr -d '\n')
+  key_base64=$(_base64 <"$_ckey" | tr -d '\n')
+  payload=$(
+    cat <<EOF
+{
+  "type": "regular",
+  "scope": "global",
+  "certname": "$_cdomain",
+  "key_file_content": "$key_base64",
+  "file_content": "$cert_base64"
+}
+EOF
+  )
+  url="https://${FGT_HOST}:${FGT_PORT}/api/v2/monitor/vpn-certificate/local/import"
+  _debug "Uploading certificate via URL: $url"
+  _H1="Authorization: Bearer $FGT_TOKEN"
+  response=$(_post "$payload" "$url" "" "POST" "application/json")
+  _debug "FortiGate API Response: $response"
+  parse_response "$response" "Deploying certificate" || return 1
+}
+
+# Function to upload CA certificate to firewall (FortiGate doesn't automatically extract CA from fullchain)
+upload_ca_cert() {
+  ca_base64=$(_base64 <"$_cca" | tr -d '\n')
+  payload=$(
+    cat <<EOF
+{
+  "import_method": "file",
+  "scope": "global",
+  "file_content": "$ca_base64"
+}
+EOF
+  )
+  url="https://${FGT_HOST}:${FGT_PORT}/api/v2/monitor/vpn-certificate/ca/import"
+  _debug "Uploading CA certificate via URL: $url"
+  _H1="Authorization: Bearer $FGT_TOKEN"
+  response=$(_post "$payload" "$url" "" "POST" "application/json")
+  _debug "FortiGate API CA Response: $response"
+  # Handle response -328 (CA already exists)
+  if echo "$response" | grep -q '"error":[ ]*-328'; then
+    _debug "CA certificate already exists. Skipping CA upload."
+    return 0
+  fi
+  parse_response "$response" "Deploying CA certificate" || return 1
+}
+
+# Function to activate the new certificate
+set_active_web_cert() {
+  payload=$(
+    cat <<EOF
+{
+  "admin-server-cert": "$_cdomain"
+}
+EOF
+  )
+  url="https://${FGT_HOST}:${FGT_PORT}/api/v2/cmdb/system/global"
+  _debug "Setting GUI certificate..."
+  _H1="Authorization: Bearer $FGT_TOKEN"
+  response=$(_post "$payload" "$url" "" "PUT" "application/json")
+  parse_response "$response" "Assigning active certificate" || return 1
+}
+
+# Function to clean up previous certificate (if exists)
+cleanup_previous_certificate() {
+  _getdeployconf FGT_LAST_CERT
+
+  if [ -n "$FGT_LAST_CERT" ] && [ "$FGT_LAST_CERT" != "$_cdomain" ]; then
+    _debug "Found previously deployed certificate: $FGT_LAST_CERT. Deleting it."
+
+    url="https://${FGT_HOST}:${FGT_PORT}/api/v2/cmdb/vpn.certificate/local/${FGT_LAST_CERT}"
+
+    _H1="Authorization: Bearer $FGT_TOKEN"
+    response=$(_post "" "$url" "" "DELETE" "application/json")
+    _debug "Delete certificate API response: $response"
+
+    parse_response "$response" "Delete previous certificate" || return 1
+  else
+    _debug "No previous certificate found or new cert is the same as the previous one."
+  fi
+}
+
+# Main function
+fortigate_deploy() {
+  # Create new certificate name with date appended (cannot directly overwrite old certificate)
+  _cdomain="$(echo "$1" | sed 's/*/WILDCARD_/g')_$(date -u +"%Y-%m-%d")"
+  _ckey="$2"
+  _cca="$4"
+  _cfullchain="$5"
+
+  if [ ! -f "$_ckey" ] || [ ! -f "$_cfullchain" ]; then
+    _err "Valid key and/or certificate not found."
+    return 1
+  fi
+
+  # Save required environment variables if not already stored
+  for var in FGT_HOST FGT_TOKEN FGT_PORT; do
+    if [ "$(eval echo \$$var)" ]; then
+      _debug "Detected ENV variable $var. Saving to file."
+      _savedeployconf "$var" "$(eval echo \$$var)" 1
+    else
+      _debug "Attempting to load variable $var from file."
+      _getdeployconf "$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: $FGT_PORT"
+
+  # Upload new certificate
+  deployer || return 1
+
+  # Upload base64-encoded CA certificate
+  if [ -n "$_cca" ] && [ -f "$_cca" ]; then
+    upload_ca_cert || return 1
+  else
+    _debug "No CA certificate provided."
+  fi
+
+  # Activate new certificate
+  set_active_web_cert || return 1
+
+  # Delete previous certificate
+  cleanup_previous_certificate
+
+  # Store new certificate name for cleanup on next renewal
+  _savedeployconf "FGT_LAST_CERT" "$_cdomain" 1
+}