Files
larksuite-cli/main_noauthsidecar.go
sang-neo03 5943a20e2b Feat/auth sidecar proxy (#532)
* feat(sidecar): add sidecar proxy for sandbox credential isolation

Keep real secrets (app_secret, access_token) out of sandbox environments.
CLI instances inside sandboxes connect to a trusted sidecar process via
HTTP; the sidecar verifies HMAC-signed requests and injects real tokens
before forwarding to the Lark API.

Key components:

- `auth proxy` subcommand to start the sidecar server (build tag: authsidecar)
- Noop credential provider returns sentinel tokens in sidecar mode
- Transport interceptor rewrites requests to sidecar with HMAC signature
- Env provider yields to sidecar provider when AUTH_PROXY is set
- Supports both feishu and lark brand endpoints

* feat(sidecar): implement priority ordering for credential providers

* feat(sidecar): strip client-supplied auth headers and improve shutdown logging

* feat(sidecar): buffer request body to prevent HMAC mismatches on read errors

* feat(sidecar): fix CI

* refactor(sidecar): publish protocol package and move server to reference demo

  The sidecar server is no longer shipped as a `lark-cli auth proxy`
  subcommand. Instead, the CLI provides only the standard sidecar *client*
  (via `-tags authsidecar`), while the wire-protocol utilities are exposed
  as a public package for integrators to implement their own server.

  Changes:
  - Move `internal/sidecar/` → `sidecar/` so external integrators can
    import HMAC signing, headers, sentinels and address validators.
  - Remove `cmd/auth/proxy.go`, `proxy_stub.go`, `proxy_test.go` and the
    conditional registration in `cmd/auth/auth.go`.
  - Add `sidecar/server-demo/` — a reference server implementation behind
    the `authsidecar_demo` build tag. It reuses the lark-cli credential
    pipeline for local development; production integrators are expected
    to replace the credential layer with their own secrets source.
  - Update all internal imports from `internal/sidecar` to `sidecar`.

  Rationale:
  - Each integrator has different secrets management / HA / multi-tenant
    requirements, so a one-size-fits-all server doesn't belong in the
    shipped CLI.
  - Keeping the client in-tree guarantees all sandbox-side code stays
    protocol-compatible without a second repo to sync.
  - The public `sidecar/` package pins the wire protocol as a stable
    contract third-party servers must conform to.

  Build matrix after this change:
  - `go build`                         → standard CLI, no sidecar code
  - `go build -tags authsidecar`       → CLI + sidecar client
  - `go build -tags authsidecar_demo \
      ./sidecar/server-demo/`          → reference server binary

  No production users are affected today because the server was not yet
  released; existing sidecar-client users are unchanged.

* feat(sidecar): close 5 pre-release security gaps
  - Server: enforce https-only target (no path/query/userinfo), pin
    forwardURL to https:// — blocks cleartext token leak
  - Protocol v1: canonical now covers version/identity/auth-header,
    blocks identity-flip replay within drift window
  - Client: ValidateProxyAddr requires loopback or same-host alias,
    rejects userinfo and https (interceptor is http-only); cross-machine
    is out of scope
  - Build: non-authsidecar builds exit(2) when AUTH_PROXY is set,
    preventing silent fallback to env credentials
  - Demo: whitelist auth-header to Authorization / X-Lark-MCP-{UAT,TAT},
    blocks token injection into Cookie / UA / X-Forwarded-For exfil paths
2026-04-20 20:24:51 +08:00

55 lines
1.9 KiB
Go

// Copyright (c) 2026 Lark Technologies Pte. Ltd.
// SPDX-License-Identifier: MIT
//go:build !authsidecar
// This file is the fail-closed guard for builds that do NOT include the
// `authsidecar` tag. The sidecar credential-isolation feature is only
// compiled in under that tag; deploying the plain build into an environment
// that expects sidecar isolation would silently fall back to direct env
// credential use — exactly the failure mode the feature is meant to prevent.
//
// When LARKSUITE_CLI_AUTH_PROXY is set, we refuse to run rather than ignore
// the variable. The operator either rebuilt without realizing (wrong
// artifact) or the sandbox inherited the var by accident; both cases want
// a loud startup error, not a mysterious token leak on the first API call.
package main
import (
"fmt"
"io"
"os"
"github.com/larksuite/cli/internal/envvars"
)
func init() {
if code := checkNoAuthsidecarBuild(os.Getenv, os.Stderr); code != 0 {
os.Exit(code)
}
}
// checkNoAuthsidecarBuild returns a non-zero exit code (and writes a
// human-readable reason to stderr) when the environment asks for sidecar
// isolation that this binary cannot provide. Factored out from init() so
// tests can exercise the decision without actually calling os.Exit.
func checkNoAuthsidecarBuild(getenv func(string) string, stderr io.Writer) int {
v := getenv(envvars.CliAuthProxy)
if v == "" {
return 0
}
fmt.Fprintf(stderr,
"ERROR: %s is set, but this lark-cli binary was built WITHOUT the "+
"'authsidecar' build tag.\n"+
"The sidecar credential-isolation feature is compiled out — "+
"running would bypass isolation and\n"+
"send any real credentials present in the environment directly "+
"to the Lark API.\n\n"+
"To fix, either:\n"+
" - rebuild the CLI with: go build -tags authsidecar\n"+
" - or unset %s if sidecar isolation is not required\n",
envvars.CliAuthProxy, envvars.CliAuthProxy)
return 2
}