dsh-client-connection-authz

DeepSeek Harness 0.1.0-rc.x ships a built-in connection module that manages HTTP, shared and dedicated RPC, WebSocket, and browser-client transports. In real deployments, if an external auth plugin is missing or misconfigured, that built-in connection can silently fall back to anonymous mode — a gap that is easy to miss in logs but dangerous in practice. dsh-client-connection-authz is a complete drop-in replacement for the built-in module that enforces an externally supplied ConnectionRequestAuthorizer before every remote entry point. If the authorizer plugin is absent or fails to configure, the connection refuses to start; there is no anonymous fallback path.

Under the hood, the package uses dual matching on both id and name to disable the upstream module (explicitly warning if the upstream renames itself), then injects the external authorization module with a forced connectionRequestAuthorizer. The per-connection execution order is fixed: Host / Origin / DNS-rebinding fence, loopback check, external authorizer, body read / protocol upgrade, business handler. A valid local bypass requires both a loopback Host header and a loopback TCP peer; a remote endpoint that merely spoofs Host: 127.0.0.1 is still routed to the authorizer. Shared RPC snapshots its handler and authority into the same target before authorization, closing timing-based interceptor-switching races. The authorizer receives rich context — transport, channel, endpoint, headers, TCP peer address, and the target authority (trusted-host or loopback) — enabling fine-grained permission tiering between ordinary API calls and privileged operations such as settings, credentials, and host-file access.

This package is intended for teams running Harness in trusted or semi-trusted network environments where connection-level authentication must be delegated to an external system, for example alongside dsh-auth-tailscale. It guarantees that every remote entry point is explicitly authorized before any business logic executes, rather than relying on a default-trust posture.