github.com/letsencrypt/boulder@v0.20251208.0/docs/acme-divergences.md (about) 1 # Boulder divergences from ACME 2 3 While Boulder attempts to implement the ACME specification ([RFC 8555]) as strictly as possible there are places at which we will diverge from the letter of the specification for various reasons. This document describes the difference between [RFC 8555] and Boulder's implementation of ACME, informally called ACMEv2 and available at https://acme-v02.api.letsencrypt.org/directory. A listing of RFC conformant design decisions that may differ from other ACME servers is listed in [implementation_details](https://github.com/letsencrypt/boulder/blob/main/docs/acme-implementation_details.md). 4 5 Presently, Boulder diverges from the [RFC 8555] ACME spec in the following ways: 6 7 ## [Section 6.3](https://tools.ietf.org/html/rfc8555#section-6.3) 8 9 Boulder supports POST-as-GET but does not mandate it for requests 10 that simply fetch a resource (certificate, order, authorization, or challenge). 11 12 ## [Section 7.1.2](https://tools.ietf.org/html/rfc8555#section-7.1.2) 13 14 Boulder does not supply the `orders` field on account objects. We intend to 15 support this non-essential feature in the future. Please follow Boulder Issue 16 [#3335](https://github.com/letsencrypt/boulder/issues/3335). 17 18 ## [Section 7.4](https://tools.ietf.org/html/rfc8555#section-7.4) 19 20 Boulder does not accept the optional `notBefore` and `notAfter` fields of a 21 `newOrder` request payload. 22 23 ## [Section 7.4.1](https://tools.ietf.org/html/rfc8555#section-7.4.1) 24 25 Pre-authorization is an optional feature and we have no plans to implement it. 26 V2 clients should use order based issuance without pre-authorization. 27 28 ## [Section 7.4.2](https://tools.ietf.org/html/rfc8555#section-7.4.2) 29 30 Boulder does not process `Accept` headers for `Content-Type` negotiation when retrieving certificates. 31 32 ## [Section 8.2](https://tools.ietf.org/html/rfc8555#section-8.2) 33 34 Boulder does not implement the ability to retry challenges or the `Retry-After` header. 35 36 [RFC 8555]: https://tools.ietf.org/html/rfc8555