Skip the key exchange test when using the system's ssh CLI if the
required KEX algorithm (e.g., mlkem768x25519-sha256) is not supported.
This is determined by running ssh -Q kex and checking for the presence
of the target algorithm.
Prevents false test failures in CI environments with older or limited
SSH implementations.
Cq-Include-Trybots: luci.golang.try:x_crypto-gotip-darwin-amd64-longtest,x_crypto-gotip-linux-amd64-longtest,x_crypto-gotip-windows-amd64-longtest
Change-Id: I3fac703ec70559e18b30d5fff88274335a7c3952
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/679195
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
We add this support for the following reasons:
- We are planning to expose recommended (secure) vs. supported (works,
not necessarily recommended) algorithms. The DHGEX kex is currently
only exposed as a client-side kex. To simplify the calling convention
for this follow-on, we expose the server side too.
- Some clients are quite inflexible with reference to kex algorithms
choice, for example they offer:
diffie-hellman-group-exchange-sha256, diffie-hellman-group-exchange-sha1,
diffie-hellman-group14-sha1, diffie-hellman-group1-sha1
therefore DHGEX helps interoperability.
We do not recommend the DHGEX kex as a whole:
- the negotiation requires an extra round trip
- the server must generate parameters (slow) or hardcode them, which
defeats the security benefit over traditional DH.
In this implementation we hardcode sending Oakley Group 14, Oakley
Group 15 or Oakley Group 16 based on the requested max size.
Users that are concerned with security of classical DH kex should
migrate to kex based on EC or Ed25519.
Fixesgolang/go#54743
Change-Id: I127822e90efc36821af4aca679931f40a2023021
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/532415
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Nicola Murino <nicola.murino@gmail.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
These tests try to ensure better compatibility of our server implementation
with the ssh CLI.
With these tests in place:
1) before merging CL 447757 we would have noticed that our server
implementation was broken with OpenSSH 8.8+
2) after merging CL 447757 we would have noticed that our server
implementation was broken with OpenSSH 7.2-7.7
The ssh CLI from $PATH is used by default, but can be overridden using
the SSH_CLI_PATH environment variable.
Change-Id: I93d64be41c7613132b0364afac8397f57c2dcbca
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/506837
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Nicola Murino <nicola.murino@gmail.com>
dingandCyrus Katrak
Nicola Murino
Heschi Kreinick