| commit | 9d2ee975ef9fe627bf0a6f01c1f69e8ef1d4f05d | [log] [tgz] |
|---|---|---|
| author | Roland Shoemaker <bracewell@google.com> | Mon Nov 20 12:06:18 2023 -0800 |
| committer | Roland Shoemaker <roland@golang.org> | Mon Dec 18 16:33:08 2023 +0000 |
| tree | c9b72524f94ca6c058ed9f39c72188f02ff08804 | |
| parent | 4e5a26183ecb4f9a0f85c8f8dbe7982885435436 [diff] |
ssh: implement strict KEX protocol changes
Implement the "strict KEX" protocol changes, as described in section
1.9 of the OpenSSH PROTOCOL file (as of OpenSSH version 9.6/9.6p1).
Namely this makes the following changes:
* Both the server and the client add an additional algorithm to the
initial KEXINIT message, indicating support for the strict KEX mode.
* When one side of the connection sees the strict KEX extension
algorithm, the strict KEX mode is enabled for messages originating
from the other side of the connection. If the sequence number for
the side which requested the extension is not 1 (indicating that it
has already received non-KEXINIT packets), the connection is
terminated.
* When strict kex mode is enabled, unexpected messages during the
handshake are considered fatal. Additionally when a key change
occurs (on the receipt of the NEWKEYS message) the message sequence
numbers are reset.
Thanks to Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk from Ruhr
University Bochum for reporting this issue.
Fixes CVE-2023-48795
Fixes golang/go#64784
Change-Id: I96b53afd2bd2fb94d2b6f2a46a5dacf325357604
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/550715
Reviewed-by: Nicola Murino <nicola.murino@gmail.com>
Reviewed-by: Tatiana Bradley <tatianabradley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Roland Shoemaker <roland@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This repository holds supplementary Go cryptography libraries.
The easiest way to install is to run go get -u golang.org/x/crypto/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/crypto.
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