Files
hermes-agent/ansible/fleet_mtls.yml
Alexander Whitestone 4214082fb6
All checks were successful
Lint / lint (pull_request) Successful in 8s
feat: A2A auth — mutual TLS between fleet agents
Implements mTLS for securing agent-to-agent communication in the Hermes
fleet. Fixes #806.

Changes:
- scripts/gen_fleet_ca.sh: generate a self-signed Fleet CA (4096-bit RSA,
  10-year validity) that signs all agent certificates
- scripts/gen_agent_cert.sh: generate per-agent certs (Timmy, Allegro,
  Ezra) signed by the fleet CA with SAN entries and clientAuth/serverAuth
  extended key usage
- agent/mtls.py: new module providing:
  - build_server_ssl_context() — TLS_SERVER context with CERT_REQUIRED,
    enforces client cert against Fleet CA
  - build_client_ssl_context() — TLS_CLIENT context for outbound A2A calls
  - MTLSMiddleware — ASGI middleware that rejects unauthenticated requests
    to A2A routes (/.well-known/agent-card*, /api/agent-card, /a2a/) with
    HTTP 403 when mTLS is enabled
  - is_mtls_configured() — checks HERMES_MTLS_CERT/KEY/CA env vars
- hermes_cli/web_server.py: wire MTLSMiddleware into the FastAPI app;
  pass SSL context to uvicorn when HERMES_MTLS_* env vars are set so
  the server runs TLS with mandatory client cert verification
- ansible/roles/hermes_mtls/: Ansible role to distribute Fleet CA cert,
  agent cert, and agent key to fleet nodes; writes an env file with
  HERMES_MTLS_* vars and restarts the hermes-gateway service
- ansible/fleet_mtls.yml: fleet-wide playbook referencing the role for
  Timmy, Allegro, and Ezra nodes
- tests/test_mtls.py: 15 tests covering is_mtls_configured, SSL context
  creation with real cryptography-generated certs, and MTLSMiddleware
  (unauthorized agent rejected → 403, authorized agent accepted → 200)

mTLS is opt-in: set HERMES_MTLS_CERT, HERMES_MTLS_KEY, and HERMES_MTLS_CA
to enable. When unset, the server behaves exactly as before.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-21 18:04:00 -04:00

33 lines
1.0 KiB
YAML

---
# fleet_mtls.yml — Deploy mutual-TLS certificates to all fleet agents.
#
# Prerequisites:
# 1. Run scripts/gen_fleet_ca.sh to create the fleet CA.
# 2. For each agent, run:
# scripts/gen_agent_cert.sh --agent timmy
# scripts/gen_agent_cert.sh --agent allegro
# scripts/gen_agent_cert.sh --agent ezra
#
# Usage:
# ansible-playbook -i inventory/fleet.ini ansible/fleet_mtls.yml
#
# Inventory example (inventory/fleet.ini):
# [fleet]
# timmy.local agent_name=timmy
# allegro.local agent_name=allegro
# ezra.local agent_name=ezra
#
# Refs #806
- name: Distribute fleet mTLS certificates
hosts: fleet
become: true
vars:
_pki_base: "{{ lookup('env', 'HOME') }}/.hermes/pki"
roles:
- role: hermes_mtls
vars:
hermes_mtls_local_ca_cert: "{{ _pki_base }}/ca/fleet-ca.crt"
hermes_mtls_local_agent_cert: "{{ _pki_base }}/agents/{{ agent_name }}/{{ agent_name }}.crt"
hermes_mtls_local_agent_key: "{{ _pki_base }}/agents/{{ agent_name }}/{{ agent_name }}.key"