Dialing the 0.0.0.0 address (as returned by net.Addr().String() for a
net.Listen("tcp", ":1") address) is not yet guaranteed to work. It's
currently OS-dependent.
For some reason it works on Go 1.8+, but it hasn't yet been defined to
work reliably.
Fix the tests for now (since we need to support older Go releases),
even if this might work in the future.
Updates golang/go#18806
Change-Id: I2f0476b1d4f2673ab64ffedfa733f2d92fceb6ff
Reviewed-on: https://go-review.googlesource.com/42496
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
This change breaks existing behavior.
Before, a missing ClientConfig.HostKeyCallback would cause host key
checking to be disabled. In this configuration, establishing a
connection to any host just works, so today, most SSH client code in
the wild does not perform any host key checks.
This makes it easy to perform a MITM attack:
* SSH installations that use keyboard-interactive or password
authentication can be attacked with MITM, thereby stealing
passwords.
* Clients that use public-key authentication with agent forwarding are
also vulnerable: the MITM server could allow the login to succeed, and
then immediately ask the agent to authenticate the login to the real
server.
* Clients that use public-key authentication without agent forwarding
are harder to attack unnoticedly: an attacker cannot authenticate the
login to the real server, so it cannot in general present a convincing
server to the victim.
Now, a missing HostKeyCallback will cause the handshake to fail. This
change also provides InsecureIgnoreHostKey() and FixedHostKey(key) as
ready made host checkers.
A simplistic parser for OpenSSH's known_hosts file is given as an
example. This change does not provide a full-fledged parser, as it
has complexity (wildcards, revocation, hashed addresses) that will
need further consideration.
When introduced, the host checking feature maintained backward
compatibility at the expense of security. We have decided this is not
the right tradeoff for the SSH library.
Fixesgolang/go#19767
Change-Id: I45fc7ba9bd1ea29c31ec23f115cdbab99913e814
Reviewed-on: https://go-review.googlesource.com/38701
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
If a key is added to an agent keyring with constraints, honor them.
This will remove keys when they've been on the keyring for
LifetimeSecs seconds or longer and will ask the user to confirm a
signing operation if ConfirmBeforeUse is set.
Change-Id: I633713c5f78b13a628a5d752f11b306b6e16a2ef
Reviewed-on: https://go-review.googlesource.com/28956
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The ssh-agent protocol allows the usage of keys and certs added to a
given agent to be constrained in certain ways. The only constraints
currently supported are lifetime (keys expire after some number of
seconds) and confirmation (the agent requires user confirmation before
performing any operations with the private key).
Change-Id: Idba5760db929805bf3da43fdcaca53ae6c479ca4
Reviewed-on: https://go-review.googlesource.com/12260
Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Peter Moody <pmoody@uber.com>
Brad Fitzpatrick
Han-Wen Nienhuys
Heschi Kreinick
Peter Moody
Niall Sheridan
Andrew Gerrand
Adam Langley