Have ssh-add accept a list of "destination constraints" that allow
restricting where keys may be used in conjunction with a ssh-agent/ssh
that supports session ID/hostkey binding.
Constraints are specified as either "[user@]host-pattern" or
"host-pattern>[user@]host-pattern".
The first form permits a key to be used to authenticate as the
specified user to the specified host.
The second form permits a key that has previously been permitted
for use at a host to be available via a forwarded agent to an
additional host.
For example, constraining a key with "user1@host_a" and
"host_a>host_b". Would permit authentication as "user1" at
"host_a", and allow the key to be available on an agent forwarded
to "host_a" only for authentication to "host_b". The key would not
be visible on agent forwarded to other hosts or usable for
authentication there.
Internally, destination constraints use host keys to identify hosts.
The host patterns are used to obtain lists of host keys for that
destination that are communicated to the agent. The user/hostkeys are
encoded using a new restrict-destination-v00@openssh.com key
constraint.
host keys are looked up in the default client user/system known_hosts
files. It is possible to override this set on the command-line.
feedback Jann Horn & markus@
ok markus@
OpenBSD-Commit-ID: ef47fa9ec0e3c2a82e30d37ef616e245df73163e
when it encounters an unquoted comment.
Add some additional utility function for working with argument
vectors, since we'll be switching to using them to parse
ssh/sshd_config shortly.
ok markus@ as part of a larger diff; tested in snaps
OpenBSD-Commit-ID: fd9c108cef2f713f24e3bc5848861d221bb3a1ac
to obtain known_hosts data from a command in addition to the usual files.
The command accepts bunch of %-expansions, including details of the
connection and the offered server host key. Note that the command may
be invoked up to three times per connection (see the manpage for
details).
ok markus@
OpenBSD-Commit-ID: 2433cff4fb323918ae968da6ff38feb99b4d33d0
Add load_hostkeys_file() and hostkeys_foreach_file() that accept a
FILE* argument instead of opening the file directly.
Original load_hostkeys() and hostkeys_foreach() are implemented using
these new interfaces.
Add a u_int note field to the hostkey_entry and hostkey_foreach_line
structs that is passed directly from the load_hostkeys() and
hostkeys_foreach() call. This is a lightweight way to annotate results
between different invocations of load_hostkeys().
ok markus@
OpenBSD-Commit-ID: 6ff6db13ec9ee4edfa658b2c38baad0f505d8c20
TCP connect. The connection phase of the SSH session is time-sensitive (due
to server side login grace periods) and is frequently interactive (e.g.
entering passwords). The ultimate interactive/bulk TOS/DSCP will be set after
authentication completes.
ok dtucker@
OpenBSD-Commit-ID: f31ab10d9233363a6d2c9996007083ba43a093f1
report the type because it is ambiguous as to whether it referred to the
known or new host key. bz3216; ok dtucker@
OpenBSD-Commit-ID: 2d5ce4a83dbcf44e340a572e361decad8aab7bad
find_by_key_ctx struct. Initializing a single member should be enough
(the spec says the remainder should be initialized as per the static
rules) but some GCCs warn on this which prevents us testing with -Werror
on those. ok deraadt@ djm@
OpenBSD-Commit-ID: 687126e60a27d30f02614760ef3c3ae4e8d6af28
any other host names/addresses already associated with the key. E.g.
> The authenticity of host 'test (10.0.0.1)' can't be established.
> ECDSA key fingerprint is SHA256:milU4MODXm8iJQI18wlsbPG7Yup+34fuNNmV08qDnax.
> This host key is known by the following other names/addresses:
> ~/.ssh/known_hosts:1: host.example.org,10.0.0.1
> ~/.ssh/known_hosts:2: [hashed name]
> ~/.ssh/known_hosts:3: [hashed name]
> ~/.ssh/known_hosts:4: host
> ~/.ssh/known_hosts:5: [host]:2222
> Are you sure you want to continue connecting (yes/no/[fingerprint])?
feedback and ok markus@
OpenBSD-Commit-ID: f6f58a77b49f1368b5883b3a1f776447cfcc7ef4
If host key checking fails (i.e. a wrong host key is recorded for the
server) and the user elects to continue (via StrictHostKeyChecking=no),
then disable UpdateHostkeys for the session.
reminded by Mark D. Baushke; ok markus@
OpenBSD-Commit-ID: 98b524f121f4252309dd21becd8c4cacb0c6042a
GlobalKnownHostsFile file, support only UserKnownHostsFile matches
suggested by Mark D. Baushke; feedback and ok markus@
OpenBSD-Commit-ID: eabb771a6add676c398d38a143a1aff5f04abbb9
key (commitid VtF8vozGOF8DMKVg). We now do this a simpler way that needs less
plumbing.
ok markus@
OpenBSD-Commit-ID: fb92d25b216bff8c136da818ac2221efaadf18ed
successfully authenticated the host; simpler than the complicated plumbing
via kex->flags we have now.
ok markus@
OpenBSD-Commit-ID: 80e39644eed75717d563a7f177e8117a0e14f42c
stdout and/or stderr to /dev/null. Factor all these out to a single
stdfd_devnull() function that allows selection of which of these to redirect.
ok markus@
OpenBSD-Commit-ID: 3033ba5a4c47cacfd5def020d42cabc52fad3099
certificate host key to a plain key. This occurs when the user connects to a
host with a certificate host key but no corresponding CA key configured in
known_hosts; feedback and ok markus@
OpenBSD-Commit-ID: 2ada81853ff9ee7824c62f440bcf4ad62030c901
> Are you sure you want to continue connecting (yes/no/[fingerprint])?
compare the fingerprint case sensitively; spotted Patrik Lundin
ok dtucker
OpenBSD-Commit-ID: 73097afee1b3a5929324e345ba4a4a42347409f2
limit for keys in addition to its current flag options. Time-limited keys
will automatically be removed from ssh-agent after their expiry time has
passed; ok markus@
OpenBSD-Commit-ID: 792e71cacbbc25faab5424cf80bee4a006119f94
the destination. This allows, eg, keeping host keys in individual files
using "UserKnownHostsFile ~/.ssh/known_hosts.d/%k". bz#1654, ok djm@, jmc@
(man page bits)
OpenBSD-Commit-ID: 7084d723c9cc987a5c47194219efd099af5beadc
errors. This ensures that the logged errors are consistent with other
transport- layer errors and that the relevant IP addresses are logged. bz3129
ok dtucker@
OpenBSD-Commit-ID: 2c22891f0b9e1a6cd46771cedbb26ac96ec2e6ab
sigaction(2). This wrapper blocks all other signals during the handler
preventing races between handlers, and sets SA_RESTART which should reduce
the potential for short read/write operations.
OpenBSD-Commit-ID: 5e047663fd77a40d7b07bdabe68529df51fd2519
When confirming a host key using the fingerprint itself, ignore leading and
trailing whitespace. ok deraadt@ djm@
OpenBSD-Commit-ID: cafd7f803bbdcd40c3a8f8f1a77747e6b6d8c011
expand_proxy_command()
Always put 'host' before 'host_arg' for consistency. ok markus@ djm@
OpenBSD-Commit-ID: 1ba5b25472779f1b1957295fcc6907bb961472a3
some arbitrary value < 0. errno is only updated in this case. Change all
(most?) callers of syscalls to follow this better, and let's see if this
strictness helps us in the future.
OpenBSD-Commit-ID: 48081f00db7518e3b712a49dca06efc2a5428075
speculation and memory sidechannel attacks like Spectre, Meltdown, Rowhammer
and Rambleed. This change encrypts private keys when they are not in use with
a symmetic key that is derived from a relatively large "prekey" consisting of
random data (currently 16KB).
Attackers must recover the entire prekey with high accuracy before
they can attempt to decrypt the shielded private key, but the current
generation of attacks have bit error rates that, when applied
cumulatively to the entire prekey, make this unlikely.
Implementation-wise, keys are encrypted "shielded" when loaded and then
automatically and transparently unshielded when used for signatures or
when being saved/serialised.
Hopefully we can remove this in a few years time when computer
architecture has become less unsafe.
been in snaps for a bit already; thanks deraadt@
ok dtucker@ deraadt@
OpenBSD-Commit-ID: 19767213c312e46f94b303a512ef8e9218a39bd4
when accepting an unknown host key. This allows you to paste a fingerprint
obtained out of band into the yes/no prompt and have the client do the
comparison for you. ok markus@ djm@
OpenBSD-Commit-ID: 3c47d10b9f43d3d345e044fd9ec09709583a2767
API, started almost exactly six years ago.
This change stops including the old packet_* API by default and makes
each file that requires the old API include it explicitly. We will
commit file-by-file refactoring to remove the old API in consistent
steps.
with & ok markus@
OpenBSD-Commit-ID: 93c98a6b38f6911fd1ae025a1ec57807fb4d4ef4
