# TLS-ALPN validation method

**URL:** <https://community.letsencrypt.org/t/tls-alpn-validation-method/63814>\
**Category:** API Announcements\
**Created:** [June 6, 2018, 8:31pm UTC](https://community.letsencrypt.org/t/tls-alpn-validation-method/63814 "2018-06-06T20:31:20Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![roland](https://sea3.discourse-cdn.com/letsencrypt/user_avatar/community.letsencrypt.org/roland/32/33298_2.png) [@roland](https://community.letsencrypt.org/u/roland)\
**Post date:** [June 6, 2018, 8:31pm UTC](https://community.letsencrypt.org/t/tls-alpn-validation-method/63814/1 "2018-06-06T20:31:20Z")

</div>

We’ve recently landed code in boulder to add support for the [draft TLS-ALPN validation method](https://tools.ietf.org/html/draft-ietf-acme-tls-alpn-01). This method provides a way to perform domain validation via the TLS layer without the issues discovered with the tls-sni-01/02 methods. This challenge type is available in both the **staging and production** environments as of July 12, 2018.

For those looking to test clients locally against a ACME server I’d recommend taking a look at the lightweight [pebble](https://github.com/letsencrypt/pebble) server which already has TLS-ALPN functionality.

We’d also be very interested in people taking a look at the draft specification and providing feedback based on implementation experience. Any feedback on the document itself should be sent to the [IETF ACME WG mailing list](https://www.ietf.org/mail-archive/web/acme/current/maillist.html).

---

<div class="post-metadata">

**Author:** ![roland](https://sea3.discourse-cdn.com/letsencrypt/user_avatar/community.letsencrypt.org/roland/32/33298_2.png) [@roland](https://community.letsencrypt.org/u/roland)\
**Post date:** [June 13, 2018, 6:24pm UTC](https://community.letsencrypt.org/t/tls-alpn-validation-method/63814/2 "2018-06-13T18:24:15Z")

</div>

TLS-ALPN challenges are now live in staging. Let us know if you encounter any issues.

---

<div class="post-metadata">

**Author:** ![roland](https://sea3.discourse-cdn.com/letsencrypt/user_avatar/community.letsencrypt.org/roland/32/33298_2.png) [@roland](https://community.letsencrypt.org/u/roland)\
**Post date:** [July 12, 2018, 9:57pm UTC](https://community.letsencrypt.org/t/tls-alpn-validation-method/63814/3 "2018-07-12T21:57:35Z")

</div>

TLS-ALPN challenges are now live in production. Let us know if you encounter any issues.