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>
This is a follow-up to CL 317169, which dropped go1.12 compatibility,
and made the golang.org/x/crypto/ed25519 package an alias / wrapper for
crypto/ed25519 in stdlib.
This patch updates uses within this repository to use stdlib instead of
depending on the wrapper. With this patch applied, the only remaining
use of the wrapper is in ed25519_test, which appears to be in place to
verify compatibility of the wrapper itself.
Change-Id: I0195396102a75ae20bdd82ca8ab59855c0eb5cea
GitHub-Last-Rev: 24dbec563cbd84bc47bdc7736b0245fc83dd3353
GitHub-Pull-Request: golang/crypto#238
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/448238
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Nicola Murino <nicola.murino@gmail.com>
Reviewed-by: Nicola Murino <nicola.murino@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Joedian Reid <joedian@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Tighter validation could cause backwards incompatibility issues, eg
configurations with valid and invalid MACs, KEXs, ciphers currently work
if a supported algorithm is negotiated and that's also the scenario of
removing support for an existing algorithm.
Fixesgolang/go#39397
Change-Id: If90253ba89e1d8f732cc1e1c3d24fe0a1e2dac71
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/512175
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
After adding support for rsa-sha2-256/512 on the server side some edge
cases started to arise with old clients:
1) public key authentication with gpg-agent < 2.2.6 fails because we
receive ssh-rsa as signature format and rsa-sha2-256 or rsa-sha2-512
as algorithm.
This is a bug in gpg-agent fixed in this commit:
https://github.com/gpg/gnupg/commit/80b775bdbb852aa4a80292c9357e5b1876110c00
2) certificate authentication fails with OpenSSH 7.2-7.7 because we
receive ssh-rsa-cert-v01@openssh.com as algorithm and rsa-sha2-256
or rsa-sha2-512 as signature format.
This patch is based on CL 412854 and has been tested with every version
of OpenSSH from 7.1 to 7.9 and OpenSSH 9.3.
Fixesgolang/go#53391
Change-Id: Id71f596f73d84efb5c76d6d5388432cccad3e3b1
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/506835
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
This uses a copy of testenv.Command copied from the main repo, with
light edits to allow the testenv helpers to build with Go 1.19.
The testenv helper revealed an exec.Command leak in TestCertLogin, so
we also fix that leak and simplify server cleanup using
testing.T.Cleanup.
For golang/go#60099.
Fixesgolang/go#60343.
Change-Id: I7f79fcdb559498b987ee7689972ac53b83870aaf
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/496935
Auto-Submit: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Run-TryBot: Bryan Mills <bcmills@google.com>
This fixes a data race in the tests for x/crypto/ssh, which expects to
be able to examine a transport's read and write counters without
locking after closing it.
(Given the number of goroutines, channels, and mutexes used in this
package, I wouldn't be surprised if other concurrency bugs remain.
I would suggest simplifying the concurrency in this package, but I
don't intend to follow up on that myself at the moment.)
Fixesgolang/go#56957.
Change-Id: Ib1f1390b66707c66a3608e48f3f52483cff3c1f5
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/456758
Reviewed-by: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
In accordance to RFC8308, send ext-info-c only during the first key
exchange. Some server implementations such as OpenSSH 7 will send an
extInfoMsg message each time when ext-info-c is received. This results
in a closed connection, as our client does not expect this message while
handling the mux.
See https://bugzilla.mindrot.org/show_bug.cgi?id=2929 regarding the
behaviour of OpenSSH if it sees ext-info-c in later key exchanges.
Fixesgolang/go#51808
Change-Id: Id94f1ef73cec6147136246b0b6048b57db92660d
GitHub-Last-Rev: fcfe5ed37306136219854031abc809e0dc9b3124
GitHub-Pull-Request: golang/crypto#208
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/394134
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Trust: Roland Shoemaker <roland@golang.org>
CL 220037 had implemented support for host authentication using
rsa-sha2-256/512, but not client public key authentication. OpenSSH
disabled the SHA-1 based ssh-rsa by default in version 8.8 (after
pre-announcing it in versions 8.2, 8.3, 8.4, 8.5, 8.6, and 8.7) although
some distributions re-enable it. GitHub will start rejecting ssh-rsa for
keys uploaded before November 2, 2021 on March 15, 2022.
https://github.blog/2021-09-01-improving-git-protocol-security-github/
The server side already worked, as long as the client selected one of
the SHA-2 algorithms, because the signature flowed freely to Verify.
There was however nothing verifying that the signature algorithm matched
the advertised one. The comment suggested the check was being performed,
but it got lost back in CL 86190043. Not a security issue because the
signature had to pass the callback's Verify method regardless, and both
values were checked to be acceptable.
Tested with OpenSSH 8.8 configured with "PubkeyAcceptedKeyTypes -ssh-rsa"
and no application-side changes.
The Signers returned by ssh/agent (when backed by an agent client)
didn't actually implement AlgorithmSigner but ParameterizedSigner, an
interface defined in an earlier version of CL 123955.
Updates golang/go#49269Fixesgolang/go#39885
For golang/go#49952
Change-Id: I13b41db8041f1112a70f106c55f077b904b12cb8
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/392394
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
The server side implementation was not actually populating the
SSH_MSG_USERAUTH_INFO_REQUEST field with the
KeyboardInteractiveChallenge argument, although the client side was
deserializing it and passing it to the KeyboardInteractiveChallenge
callback.
Anyway, the first field of SSH_MSG_USERAUTH_INFO_REQUEST is "name", not
"user". Maybe the confusion was due to the first field of
SSH_MSG_USERAUTH_REQUEST being the user.
RFC 4256, Section 3.3, says this about it
One possibility is to use the name field (possibly
prefixed with the application's name) as the title of a dialog window
in which the prompt(s) are presented.
and examples include "CRYPTOCard Authentication", "Password
Authentication", and "Password Expired".
Co-authored-by: Kevin Wallace <kevin@pentabarf.net>
Change-Id: Ic6ec0dfea2122704603c44f42898a980689a15c9
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/372234
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
The server implementation looks at the HostKeys to advertise and
negotiate host key signature algorithms. A fundamental issue of the
Signer and AlgorithmSigner interfaces is that they don't expose the
supported signature algorithms, so really the server has to guess.
Currently, it would guess exclusively based on the PublicKey.Type,
regardless of whether the host key implemented AlgorithmSigner. This
means that a legacy Signer that only supports ssh-rsa still led the
server to negotiate rsa-sha2 algorithms. The server would then fail to
find a suitable host key to make the signature and crash.
This won't happen if only Signers from this package are used, but if a
custom Signer that doesn't support SignWithAlgorithm() but returns
"ssh-rsa" from PublicKey().Type() is used as a HostKey, the server is
vulnerable to DoS.
The only workable rules to determine what to advertise seems to be:
1. a pure Signer will always Sign with the PublicKey.Type
2. an AlgorithmSigner supports all algorithms associated with the
PublicKey.Type
Rule number two means that we can't add new supported algorithms in the
future, which is not great, but it's too late to fix that.
rsaSigner was breaking rule number one, and although it would have been
fine where it's used, I didn't want to break our own interface contract.
It's unclear why we had separate test key entries for rsa-sha2
algorithms, since we can use the ssh-rsa key for those. The only test
that used them, TestCertTypes, seemed broken: the init was actually
failing at making the corresponding signers rsaSigners, and indeed the
test for the SHA-256 signer expected and checked a SHA-512 signature.
Pending CVE
For golang/go#49952
Change-Id: Ie658eefcadd87906e63fc7faae8249376aa96c79
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/392355
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Heschi Kreinick
Randy Reddig
Nicola Murino
Matt Dainty
Bryan C. Mills
Dmitri Shuralyov
Sebastiaan van Stijn
Mariano Cano
Boshi Lian
Stan Hu
Stefan Klein
Tobias Klauser
cui fliter
Anmol Sethi
Park Zhou
Axel Wagner
Brad Fitzpatrick
edef
Russ Cox
Peter Verraedt
