Add SYNO_USE_TEMP_ADMIN variable & Fix broken logic

1. Fix the broken logic in (Sorry for including fix commit in same PR, I'm feeling quite tired and would like to go to sleep right away...)
2. Provides new method to obtain credential info for authentication, it will create a temp admin user if SYNO_USE_TEMP_ADMIN is set, instead of requiring the user's own credentials which will be saved in disk.

I do really don't like to have plaintext credentials be saved in disk, and I noticed that you've spent a lot of time fighting with 2FA related stuffs, so why not just get rid of the whole old way. :)

deploy/synology_dsm.sh

@@ -9,6 +9,9 @@
 # Issues:  https://github.com/acmesh-official/acme.sh/issues/2727
 ################################################################################
 # Usage:
+# - Create temp admin user automatically:
+#   export SYNO_USE_TEMP_ADMIN=1
+# - Or provide your own admin user credential:
 #   1. export SYNO_Username="adminUser"
 #   2. export SYNO_Password="adminPassword"
 # Optional exports (shown values are the defaults):
@@ -22,6 +25,7 @@
 ################################################################################
 # Dependencies:
 # - jq & curl
+# - synouser & synogroup (When available and SYNO_USE_TEMP_ADMIN is set)
 ################################################################################
 # Return value:
 # 0 means success, otherwise error.
@@ -38,6 +42,7 @@ synology_dsm_deploy() {
   _debug _cdomain "$_cdomain"
 
   # Get username & password, but don't save until we authenticated successfully
+  _getdeployconf SYNO_USE_TEMP_ADMIN
   _getdeployconf SYNO_Username
   _getdeployconf SYNO_Password
   _getdeployconf SYNO_Create
@@ -45,12 +50,25 @@ synology_dsm_deploy() {
   _getdeployconf SYNO_TOTP_SECRET
   _getdeployconf SYNO_Device_Name
   _getdeployconf SYNO_Device_ID
-  if [ -z "${SYNO_Username:-}" ] || [ -z "${SYNO_Password:-}" ]; then
+
-    _err "SYNO_Username & SYNO_Password must be set"
+  # Prepare temp admin user info if SYNO_USE_TEMP_ADMIN is set
+  if [ -n "${SYNO_USE_TEMP_ADMIN:-}" ]; then
+    if ! _exists synouser; then
+      if ! _exists synogroup; then
+        _err "Tools are missing for creating temp admin user, please set SYNO_Username & SYNO_Password instead."
         return 1
       fi
-  if [ -n "${SYNO_Device_Name:-}" ] && [ -z "${SYNO_Device_ID:-}" ]; then
+    fi
-    _err "SYNO_Device_Name set, but SYNO_Device_ID is empty"
+    _debug "Setting temp admin user credential..."
+    SYNO_Username=sc-acmesh-tmp
+    SYNO_Password=`openssl rand -base64 16`
+    # Ignore 2FA-OTP settings which won't be needed.
+    SYNO_Device_Name=
+    SYNO_Device_ID=
+  fi
+  
+  if [ -z "${SYNO_Username:-}" ] || [ -z "${SYNO_Password:-}" ]; then
+    _err "You must set either SYNO_USE_TEMP_ADMIN, or set both SYNO_Username and SYNO_Password."
     return 1
   fi
   _debug2 SYNO_Username "$SYNO_Username"
@@ -69,6 +87,7 @@ synology_dsm_deploy() {
   [ -n "${SYNO_Scheme}" ] || SYNO_Scheme="http"
   [ -n "${SYNO_Hostname}" ] || SYNO_Hostname="localhost"
   [ -n "${SYNO_Port}" ] || SYNO_Port="5000"
+  _savedeployconf SYNO_USE_TEMP_ADMIN "$SYNO_USE_TEMP_ADMIN"
   _savedeployconf SYNO_Scheme "$SYNO_Scheme"
   _savedeployconf SYNO_Hostname "$SYNO_Hostname"
   _savedeployconf SYNO_Port "$SYNO_Port"
@@ -106,13 +125,11 @@ synology_dsm_deploy() {
     _info "WARNING: Usage of SYNO_TOTP_SECRET is deprecated!"
     _info "         See synology_dsm.sh script or ACME.sh Wiki page for details:"
     _info "         https://github.com/acmesh-official/acme.sh/wiki/Synology-NAS-Guide"
-    DEPRECATED_otp_code=""
+    if ! _exists oathtool; then
-    if _exists oathtool; then
-      DEPRECATED_otp_code="$(oathtool --base32 --totp "${SYNO_TOTP_SECRET}" 2>/dev/null)"
-    else
       _err "oathtool could not be found, install oathtool to use SYNO_TOTP_SECRET"
       return 1
     fi
+    DEPRECATED_otp_code="$(oathtool --base32 --totp "${SYNO_TOTP_SECRET}" 2>/dev/null)"
 
     if [ -n "$SYNO_DID" ]; then
       _H1="Cookie: did=$SYNO_DID"
@@ -123,21 +140,30 @@ synology_dsm_deploy() {
     response=$(_post "method=login&account=$encoded_username&passwd=$encoded_password&api=SYNO.API.Auth&version=$api_version&enable_syno_token=yes&otp_code=$DEPRECATED_otp_code&device_name=certrenewal&device_id=$SYNO_DID" "$_base_url/webapi/auth.cgi?enable_syno_token=yes")
     _debug3 response "$response"
   # END - DEPRECATED, only kept for legacy compatibility reasons
+  # If SYNO_DeviceDevice_ID & SYNO_Device_Name both empty, just log in normally
+  elif [ -z "${SYNO_Device_ID:-}" ] && [ -z "${SYNO_Device_Name:-}" ]; then
+    if [ -n "$SYNO_USE_TEMP_ADMIN" ]; then
+      _debug "Creating temp admin user in Synology DSM"
+      synouser --del "$SYNO_Username" >/dev/null 2>/dev/null
+      synouser --add "$SYNO_Username" "$SYNO_Password" "" 0 "" 0 >/dev/null
+      synogroup --memberadd administrators "$SYNO_Username" >/dev/null
+    fi
+    response=$(_get "$_base_url/webapi/entry.cgi?api=SYNO.API.Auth&version=$api_version&method=login&format=sid&account=$encoded_username&passwd=$encoded_password&enable_syno_token=yes")
+    _debug3 response "$response"
   # Get device ID if still empty first, otherwise log in right away
-  elif [ -z "${SYNO_Device_ID:-}" ]; then
+  elif [ -n "${SYNO_Device_Name:-}" ] && [ -z "${SYNO_Device_ID:-}" ]; then
     printf "Enter OTP code for user '%s': " "$SYNO_Username"
     read -r otp_code
-    if [ -z "${SYNO_Device_Name:-}" ]; then
-      printf "Enter device name or leave empty for default (CertRenewal): "
-      read -r SYNO_Device_Name
-      [ -n "${SYNO_Device_Name}" ] || SYNO_Device_Name="CertRenewal"
-    fi
-
     response=$(_get "$_base_url/webapi/entry.cgi?api=SYNO.API.Auth&version=$api_version&method=login&format=sid&account=$encoded_username&passwd=$encoded_password&otp_code=$otp_code&enable_syno_token=yes&enable_device_token=yes&device_name=$SYNO_Device_Name")
     _debug3 response "$response"
     SYNO_Device_ID=$(echo "$response" | grep "device_id" | sed -n 's/.*"device_id" *: *"\([^"]*\).*/\1/p')
     _secure_debug2 SYNO_Device_ID "$SYNO_Device_ID"
   else
+    if [ -z "${SYNO_Device_Name:-}" ]; then
+      printf "Enter device name or leave empty for default (CertRenewal): "
+      read -r SYNO_Device_Name
+      [ -n "${SYNO_Device_Name}" ] || SYNO_Device_Name="CertRenewal"
+    fi
     response=$(_get "$_base_url/webapi/entry.cgi?api=SYNO.API.Auth&version=$api_version&method=login&format=sid&account=$encoded_username&passwd=$encoded_password&enable_syno_token=yes&device_name=$SYNO_Device_Name&device_id=$SYNO_Device_ID")
     _debug3 response "$response"
   fi
@@ -146,9 +172,12 @@ synology_dsm_deploy() {
   token=$(echo "$response" | grep "synotoken" | sed -n 's/.*"synotoken" *: *"\([^"]*\).*/\1/p')
   _debug "Session ID" "$sid"
   _debug SynoToken "$token"
-  if [ -z "$SYNO_DID" ] && [ -z "$SYNO_Device_ID" ] || [ -z "$sid" ] || [ -z "$token" ]; then
+  if [ -z "$sid" ] || [ -z "$token" ]; then
     _err "Unable to authenticate to $_base_url - check your username & password."
-    _err "If two-factor authentication is enabled for the user, set SYNO_Device_ID."
+    _err "If two-factor authentication is enabled for the user:"
+    _err "- set SYNO_Device_Name then input *correct* OTP-code manually"
+    _err "- get & set SYNO_Device_ID via your browser cookies"
+    _remove_temp_admin "$SYNO_USE_TEMP_ADMIN" "$SYNO_Username"
     return 1
   fi
 
@@ -159,8 +188,10 @@ synology_dsm_deploy() {
   # Now that we know the username & password are good, save them
   _savedeployconf SYNO_Username "$SYNO_Username"
   _savedeployconf SYNO_Password "$SYNO_Password"
+  if [ -z "${SYNO_USE_TEMP_ADMIN:-}" ]; then
     _savedeployconf SYNO_Device_Name "$SYNO_Device_Name"
     _savedeployconf SYNO_Device_ID "$SYNO_Device_ID"
+  fi
 
   _info "Getting certificates in Synology DSM"
   response=$(_post "api=SYNO.Core.Certificate.CRT&method=list&version=1&_sid=$sid" "$_base_url/webapi/entry.cgi")
@@ -172,6 +203,7 @@ synology_dsm_deploy() {
 
   if [ -z "$id" ] && [ -z "${SYNO_Create:-}" ]; then
     _err "Unable to find certificate: $SYNO_Certificate & \$SYNO_Create is not set"
+    _remove_temp_admin "$SYNO_USE_TEMP_ADMIN" "$SYNO_Username"
     return 1
   fi
 
@@ -206,10 +238,11 @@ synology_dsm_deploy() {
     else
       _info "Restarting HTTP services failed"
     fi
-
+    _remove_temp_admin "$SYNO_USE_TEMP_ADMIN" "$SYNO_Username"
     _logout
     return 0
   else
+    _remove_temp_admin "$SYNO_USE_TEMP_ADMIN" "$SYNO_Username"
     _err "Unable to update certificate, error code $response"
     _logout
     return 1
@@ -222,3 +255,13 @@ _logout() {
   response=$(_get "$_base_url/webapi/entry.cgi?api=SYNO.API.Auth&version=$api_version&method=logout")
   _debug3 response "$response"
 }
+
+_remove_temp_admin() {
+  flag=$1
+  username=$2
+  
+  if [ -n "${flag}" ]; then
+    _debug "Removing temp admin user in Synology DSM"
+    synouser --del "$username" >/dev/null
+  fi
+}