Commit Graph

2 Commits

Author SHA1 Message Date
Teknium
ed805f57ff fix(mcp-oauth): port mismatch, path traversal, and shared handler state (salvage #2521) (#2552)
* fix(mcp-oauth): port mismatch, path traversal, and shared state in OAuth flow

Three bugs in the new MCP OAuth 2.1 PKCE implementation:

1. CRITICAL: OAuth redirect port mismatch — build_oauth_auth() calls
   _find_free_port() to register the redirect_uri, but _wait_for_callback()
   calls _find_free_port() again getting a DIFFERENT port. Browser redirects
   to port A, server listens on port B — callback never arrives, 120s timeout.
   Fix: share the port via module-level _oauth_port variable.

2. MEDIUM: Path traversal via unsanitized server_name — HermesTokenStorage
   uses server_name directly in filenames. A name like "../../.ssh/config"
   writes token files outside ~/.hermes/mcp-tokens/.
   Fix: sanitize server_name with the same regex pattern used elsewhere.

3. MEDIUM: Class-level auth_code/state on _CallbackHandler causes data
   races if concurrent OAuth flows run. Second callback overwrites first.
   Fix: factory function _make_callback_handler() returns a handler class
   with a closure-scoped result dict, isolating each flow.

* test: add tests for MCP OAuth path traversal, handler isolation, and port sharing

7 new tests covering:
- Path traversal blocked (../../.ssh/config stays in mcp-tokens/)
- Dots/slashes sanitized and resolved within base dir
- Normal server names preserved
- Special characters sanitized (@, :, /)
- Concurrent handler result dicts are independent
- Handler writes to its own result dict, not class-level
- build_oauth_auth stores port in module-level _oauth_port

---------

Co-authored-by: 0xbyt4 <35742124+0xbyt4@users.noreply.github.com>
2026-03-22 15:02:26 -07:00
Teknium
b7091f93b1 feat(cli): MCP server management CLI + OAuth 2.1 PKCE auth
Add hermes mcp add/remove/list/test/configure CLI for managing MCP
server connections interactively. Discovery-first 'add' flow connects,
discovers tools, and lets users select which to enable via curses checklist.

Add OAuth 2.1 PKCE authentication for MCP HTTP servers (RFC 7636).
Supports browser-based and manual (headless) authorization, token
caching with 0600 permissions, automatic refresh. Zero external deps.

Add ${ENV_VAR} interpolation in MCP server config values, resolved
from os.environ + ~/.hermes/.env at load time.

Core OAuth module from PR #2021 by @imnotdev25. CLI and mcp_tool
wiring rewritten against current main. Closes #497, #690.
2026-03-22 04:52:52 -07:00