package bhttp

Changelog

0.1.2 — 2026-10-04

Fixes for the CI of opam-repository; the libraries are those of 0.1.1.

• Mark the failure of ohttp-piaf on macOS with Homebrew as known to the CI of opam-repository: Piaf 0.2.0 includes OpenSSL's headers without asking pkg-config where they are, and Homebrew's are not on the compiler's path on Apple silicon. The guide to HTTP libraries shows how to build it there.
• Fix the tests of the adapters, which could start two servers on one port and then exit in the middle of a run: each server now listens on a socket that it holds from the start.

0.1.1 — 2026-10-04

Package metadata only; the code is that of 0.1.0.

• Mark ohttp-piaf unavailable on Windows, where Piaf 0.2.0 does not build: its C stubs call fcntl, which MinGW lacks.

0.1.0 — 2026-10-04

• Add bhttp, a codec for Binary HTTP (RFC 9292): known-length and indeterminate-length requests and responses, informational responses, trailers, padding, and truncation. Decoding accepts every integer size and every truncation that the RFC allows, and rejects invalid messages; encoding refuses to produce them.
• Add ohttp, an implementation of Oblivious HTTP (RFC 9458): key configurations in both of their encodings, and request and response encapsulation for clients and gateways over every KEM, KDF, and AEAD of the hpke package: 99 suites. A gateway accepts only what its keys advertise, and reports everything that a peer can cause as one error.
• Provide the post-quantum KEMs of draft-ietf-hpke-pq-05 through hpke: MLKEM768-X25519 (X-Wing), MLKEM768-P256, MLKEM1024-P384, and ML-KEM-512, 768, and 1024, beside the Diffie-Hellman KEMs, X448 among them. X-Wing is the one to choose. The one-stage SHAKE KDFs of the same draft are read in a key configuration but never chosen, since RFC 9458 derives the response keys with Extract and Expand.
• Add Ohttp.Replay, the defences of RFC 9458 Section 6.5 without I/O: a bounded cache of the encapsulated keys of recent requests, the check of a request's date field in the three formats of RFC 9110, and the date problem type, through which a client learns the gateway's time and retries. Gateway.encapsulated_key and Chunked.Gateway.encapsulated_key give the key to remember. The cohttp examples apply both sides.
• Add Ohttp.Http_message and Ohttp.Http_binding: exchanges of Binary HTTP messages, and the fields, checks, and error responses of RFC 9458 Section 5, without I/O. Examples over cohttp-lwt-unix show a client, a relay, a gateway, and a target, and run end to end with dune build @e2e.
• Add Ohttp.Service: the client, relay, and gateway of RFC 9458 Section 5 as steps from HTTP messages to HTTP messages, without I/O. The client adds a date field and retries once, encapsulated anew, with the gateway's time when the gateway refuses its date; the relay passes on the content and its type and nothing else; the gateway serves its key configurations, checks for replay, forwards only to the targets it lists, and seals every answer once the encapsulation is off.
• Add adapters for HTTP libraries, one package each, built on Ohttp.Service: ohttp-cohttp-lwt for any client of cohttp-lwt, with targets in the same process; ohttp-cohttp-eio; and ohttp-piaf, over HTTP/1.1 and HTTP/2. Each has a client that fetches key configurations and calls through a relay, a relay handler, a gateway handler, and forwarding to targets. ohttp-cohttp has the conversions between the types of the http package and those of bhttp that the two cohttp adapters share. The cohttp examples now use ohttp-cohttp-lwt.
• Bound what a relay or a gateway holds. Ohttp.Service.Gateway.create and the new Ohttp.Service.Relay.create take the longest request to read, 1 MiB by default, and how many requests to handle at once, 256; a relay also takes the longest answer to read from its gateway, 8 MiB. The adapters' relay handlers take an Ohttp.Service.Relay.t, and their clients and Target.forward a ?max_response_size, 8 MiB by default. A message over its limit is refused from its content-length or once its content has been counted past the limit, with a 413, a 502, or Error.Content_too_large, and a request beyond the number in flight with a 503. Rates and timeouts remain the deployment's.
• Add Ohttp.Chunked, an experimental implementation of chunked Oblivious HTTP (draft-ietf-ohai-chunked-ohttp-08): incremental senders and receivers for requests and responses, which take a stream in whatever slices a transport delivers and detect truncation. The interface may change before the draft is published as an RFC.
• Reproduce the examples of RFC 9292 Section 5, RFC 9458 Appendix A, and the draft's Appendix A byte for byte, in both directions, from values that a script extracts from the pinned text of each document.
• Validate both packages against chris-wood/ohttp-go and martinthomson/ohttp with a differential harness, in both roles and for every suite in common, X448 and X-Wing with ohttp-go included, and replay what they produced in the test suites.
• Require hpke 0.4.0, for the post-quantum KEMs, the suite's KDF and AEAD, and the deterministic senders of hpke.for_testing. Like hpke since 0.3.0, ohttp needs a 64-bit OCaml. bhttp still has no dependencies.
• Remain an unaudited, non-production release intended for interoperability review.