SSO Connector Sync

Cross-site entity and configuration replication for SSO platforms. Running on any site, it pushes saved content entities and allow-listed Drupal configuration to peer sites and receives signed inbound payloads from them, over HMAC-signed webhooks. There is no scheduled pull client and no automatic conflict resolution — data replicates when a peer pushes it.

Features

• Signed outbound push of entity create / update / delete operations, queued on save.
• Inbound endpoint that receives and applies signed payloads from peers.
• Per-direction control: push only, receive only, or both.
• Inbound IP allow-list, fail-closed HMAC verification, a replay window and a nonce cache.
• Outbound SSRF guard: HTTPS-only, private/loopback/reserved IPs blocked, redirects not followed.
• User synchronisation off by default, with a protected-field blocklist (password, roles, status, mail, …).
• Opt-in configuration sync with a prefix allow-list, applied in an all-or-nothing transaction.
• Role/permission privilege-escalation guard on inbound user data.
• Queue-based delivery with bounded per-target retries.

Security model

Per-site HMAC keys live in State, never in exportable configuration. User and configuration sync are both off by default and must be explicitly enabled.

Requirements

• Drupal core ^11.2 || ^12
• PHP >= 8.1
• SSO Connector ^1.0

Installation

composer require drupal/sso_connector_sync
drush en sso_connector_sync

Part of the SSO Connector bundle

Requires SSO Connector (core). See the core project for the full suite.