cybercyst/go
1
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-05-05 15:43:04 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[release-branch.go1.24] crypto/tls: fix ECH compatibility

Browse Source 
Previously, the code only checked supportedVersions[0] for TLS 1.3
However, Chromium-based
browsers may list TLS 1.3 at different positions, causing ECH failures.
This fix:
    Iterates through supportedVersions to accept connections as long as TLS 1.3 is present.
    Improves ECH compatibility, ensuring Chrome, Edge, and other browsers work properly.

Fixes #73118

Change-Id: I32f4219fb6654d5cc22c7f33497c6142c0acb4f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/648015
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
(cherry picked from commit cd2f347c61bd9f41e977d74dc2dd3a1f36b65800)
Reviewed-on: https://go-review.googlesource.com/c/go/+/661936
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: 古大羊 <lj1788@gmail.com>
This commit is contained in:
古大羊 2025-02-10 12:49:15 +08:00 committed by Carlos Amedee
parent a9d9b55709
commit b2c005e7b2
1 changed files with 22 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
src/crypto/tls/ech.go
View File

@ -381,8 +381,28 @@ func decodeInnerClientHello(outer *clientHelloMsg, encoded []byte) (*clientHello
return nil, errInvalidECHExt
}
if len(inner.supportedVersions) != 1 || (len(inner.supportedVersions) >= 1 && inner.supportedVersions[0] != VersionTLS13) {
return nil, errors.New("tls: client sent encrypted_client_hello extension and offered incompatible versions")
hasTLS13 := false
for _, v := range inner.supportedVersions {
// Skip GREASE values (values of the form 0x?A0A).
// GREASE (Generate Random Extensions And Sustain Extensibility) is a mechanism used by
// browsers like Chrome to ensure TLS implementations correctly ignore unknown values.
// GREASE values follow a specific pattern: 0x?A0A, where ? can be any hex digit.
// These values should be ignored when processing supported TLS versions.
if v&0x0F0F == 0x0A0A && v&0xff == v>>8 {
continue
}
// Ensure at least TLS 1.3 is offered.
if v == VersionTLS13 {
hasTLS13 = true
} else if v < VersionTLS13 {
// Reject if any non-GREASE value is below TLS 1.3, as ECH requires TLS 1.3+.
return nil, errors.New("tls: client sent encrypted_client_hello extension with unsupported versions")
}
}
if !hasTLS13 {
return nil, errors.New("tls: client sent encrypted_client_hello extension but did not offer TLS 1.3")
}
return inner, nil