go/api
Roland Shoemaker 9eeb627f60 crypto/tls: add ech client support
This CL adds a (very opinionated) client-side ECH implementation.

In particular, if a user configures a ECHConfigList, by setting the
Config.EncryptedClientHelloConfigList, but we determine that none of
the configs are appropriate, we will not fallback to plaintext SNI, and
will instead return an error. It is then up to the user to decide if
they wish to fallback to plaintext themselves (by removing the config
list).

Additionally if Config.EncryptedClientHelloConfigList is provided, we
will not offer TLS support lower than 1.3, since negotiating any other
version, while offering ECH, is a hard error anyway. Similarly, if a
user wishes to fallback to plaintext SNI by using 1.2, they may do so
by removing the config list.

With regard to PSK GREASE, we match the boringssl  behavior, which does
not include PSK identities/binders in the outer hello when doing ECH.

If the server rejects ECH, we will return a ECHRejectionError error,
which, if provided by the server, will contain a ECHConfigList in the
RetryConfigList field containing configs that should be used if the user
wishes to retry. It is up to the user to replace their existing
Config.EncryptedClientHelloConfigList with the retry config list.

Fixes #63369

Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
Change-Id: I9bc373c044064221a647a388ac61624efd6bbdbf
Reviewed-on: https://go-review.googlesource.com/c/go/+/578575
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-05-23 03:10:12 +00:00
..
next crypto/tls: add ech client support 2024-05-23 03:10:12 +00:00
except.txt crypto/tls: implement Extended Master Secret 2023-05-25 00:13:30 +00:00
go1.1.txt strconv: quote rune 007F as \x7f, not \u007f 2022-03-31 20:37:15 +00:00
go1.2.txt
go1.3.txt
go1.4.txt [release-branch.go1.4] api: create go1.4.txt 2014-12-12 14:01:01 +11:00
go1.5.txt api: update go1.5.txt 2015-07-30 21:14:09 +00:00
go1.6.txt go/types: rename Importer2 to ImporterFrom 2016-01-13 23:40:13 +00:00
go1.7.txt unicode: upgrade to version 9.0.0 2016-06-28 15:08:11 +00:00
go1.8.txt Revert "cmd/go: note when some Go files were ignored on no-Go-files errors" 2016-12-21 05:25:57 +00:00
go1.9.txt cmd/api: set architecture sizes when type checking 2021-10-04 20:20:20 +00:00
go1.10.txt text/template: revert CL 66410 "add break, continue actions in ranges" 2018-02-06 05:00:01 +00:00
go1.11.txt crypto/tls: make ConnectionState.ExportKeyingMaterial a method 2018-08-22 03:48:56 +00:00
go1.12.txt api: add os.(*File).SyscallConn to go1.12.txt 2019-01-02 21:21:53 +00:00
go1.13.txt api/go1.13: add debug/elf.Symbol fields added in CL 184099 2019-08-08 18:44:16 +00:00
go1.14.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.15.txt go/printer: remove exported StdFormat flag 2020-07-17 02:15:01 +00:00
go1.16.txt cmd/api: track darwin arm64 port 2022-12-02 16:30:41 +00:00
go1.17.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.18.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.19.txt cmd/api: track deprecations 2022-12-02 16:29:41 +00:00
go1.20.txt cmd/api: add API checks for freebsd/riscv64 2023-02-17 21:23:32 +00:00
go1.21.txt go/ast: deprecate Object 2023-08-07 09:39:17 +00:00
go1.22.txt Revert "archive/tar: add FileInfoNames interface" 2024-01-24 20:54:27 +00:00
go1.txt
README api/README: refer to doc/README.md 2024-01-31 19:22:50 +00:00

Files in this directory are data for Go's API checker ("go tool api", in src/cmd/api).

Each file is a list of API features, one per line.

go1.txt (and similarly named files) are frozen once a version has been
shipped. Each file adds new lines but does not remove any.

except.txt lists features that may disappear without breaking true
compatibility.

Starting with go1.19.txt, each API feature line must end in "#nnnnn"
giving the GitHub issue number of the proposal issue that accepted
the new API. This helps with our end-of-cycle audit of new APIs.
The same requirement applies to next/* (described below), which will
become a go1.XX.txt for XX >= 19.

The next/ directory contains the only files intended to be mutated.
Each file in that directory contains a list of features that may be added
to the next release of Go. The files in this directory only affect the
warning output from the go api tool. Each file should be named
nnnnn.txt, after the issue number for the accepted proposal.
(The #nnnnn suffix must also appear at the end of each line in the file;
that will be preserved when next/*.txt is concatenated into go1.XX.txt.)

When you add a file to the api/next directory, you must add at least one file
under doc/next. See doc/README.md for details.