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From the Helix project
Product updates, engineering deep dives, and release notes.
mTLSMosquitto
Mosquitto CRL Revocation: Why crlfile Rejects Every Client
Adding crlfile to a working Mosquitto mTLS listener makes every device fail the handshake. The internet says remove it. Here are the four OpenSSL traps actually causing it, and a configuration that enforces revocation properly.
Aug 2, 2026·11 min read
MosquittomTLS
Mosquitto mTLS Tutorial: Per-Device Client Certificates with a Private CA
Take Mosquitto from a plain broker to one where every device authenticates with its own certificate from a private CA — TLS, require_certificate, CN-as-username, and per-device ACLs, step by step.
Aug 2, 2026·8 min read