add EST provisioner

[jbpin]

Implementation of [RFC 7030] (https://datatracker.ietf.org/doc/html/rfc7030).
Support TLS client certificate authentication and basic auth.
Support webhook for authentication, notification and data.
Not covered :

• full CMC
• server-side key generation

Name of feature:

EST protocol support (RFC7030)

Pain or issue this feature alleviates:

add support for a protocol that was not yet implemented in certificates

Why is this important to the project (if not answered above):

EST is a protocol used by the industry

Is there documentation on how to use this feature? If so, where?

not yet :/

Supporting links/other PRs/issues:

#2366
#14
💔Thank you!

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Jean-Baptiste Pin seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Jean-Baptiste Pin seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[s5657]

Hi @jbpin
thanks for your great contribution for EST 👍
Looks like the PR #2507 will not be proceeded until the license-bot gets your GO:

license/cla
Waiting for status to be reported — Contributor License Agreement is not signed yet.

Just my 2 cents,
a step-ca user liking EST

[jbpin]

You can use replace github.com/smallstep/linkedca => github.com/jbpin/linkedca v0.0.0-20260108080200-10b2f2764841 at the end of the go.mod in the cli project to get a step ca command that support EST.