This adds a protocol extension to improve the integrity of the SSH
transport protocol, particular in and around the initial key exchange
(KEX) phase.
Full details of the extension are in the PROTOCOL file.
with markus@
OpenBSD-Commit-ID: 2a66ac962f0a630d7945fee54004ed9e9c439f14
This attempts to hide inter-keystroke timings by sending interactive
traffic at fixed intervals (default: every 20ms) when there is only a
small amount of data being sent. It also sends fake "chaff" keystrokes
for a random interval after the last real keystroke. These are
controlled by a new ssh_config ObscureKeystrokeTiming keyword/
feedback/ok markus@
OpenBSD-Commit-ID: 02231ddd4f442212820976068c34a36e3c1b15be
a fd directly into the transport input buffer.
Use this in the client and server mainloops to avoid unnecessary
copying. It also lets us use a more greedy read size without penalty.
Yields a 2-3% performance gain on cipher-speed.sh (in a fairly
unscientific test tbf)
feedback dtucker@ ok markus@
OpenBSD-Commit-ID: df4112125bf79d8e38e79a77113e1b373078e632
client and server mainloops.
Previously the rekey timeout could expire but rekeying would not start
until a packet was sent or received. This could cause us to spin in
select() on the rekey timeout if the connection was quiet.
ok markus@
OpenBSD-Commit-ID: 4356cf50d7900f3df0a8f2117d9e07c91b9ff987
parsing rather than make the caller do it. Saves a lot of boilerplate code.
from markus@ ok djm@
OpenBSD-Commit-ID: 576bf784f9a240f5a1401f7005364e59aed3bce9
use this to give packet-related fatal error messages more context (esp. the
remote endpoint) ok markus@
OpenBSD-Commit-ID: de57211f9543426b515a8a10a4f481666b2b2a50
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
Put remote client info back into the ClientAlive
connection termination message. Based in part on diff from lars.nooden at
gmail, ok djm
OpenBSD-Commit-ID: 80a0f619a29bbf2f32eb5297a69978a0e05d0ee0
add sshd_config RDomain keyword to place sshd and the
subsequent user session (including the shell and any TCP/IP forwardings) into
the specified rdomain(4)
ok markus@
Upstream-ID: be2358e86346b5cacf20d90f59f980b87d1af0f5
refactor channels.c
Move static state to a "struct ssh_channels" that is allocated at
runtime and tracked as a member of struct ssh.
Explicitly pass "struct ssh" to all channels functions.
Replace use of the legacy packet APIs in channels.c.
Rework sshd_config PermitOpen handling: previously the configuration
parser would call directly into the channels layer. After the refactor
this is not possible, as the channels structures are allocated at
connection time and aren't available when the configuration is parsed.
The server config parser now tracks PermitOpen itself and explicitly
configures the channels code later.
ok markus@
Upstream-ID: 11828f161656b965cc306576422613614bea2d8f
add ssh_packet_set_log_preamble() to allow inclusion of a
preamble string in disconnect messages; ok markus@
Upstream-ID: 34cb41182cd76d414c214ccb01c01707849afead
Make ssh_packet_set_rekey_limits take u32 for the number of
seconds until rekeying (negative values are rejected at config parse time).
This allows the removal of some casts and a signed vs unsigned comparison
warning.
rekey_time is cast to int64 for the comparison which is a no-op
on OpenBSD, but should also do the right thing in -portable on
anything still using 32bit time_t (until the system time actually
wraps, anyway).
some early guidance deraadt@, ok djm@
Upstream-ID: c9f18613afb994a07e7622eb326f49de3d123b6c
Add a per-packet input hook that is called with the
decrypted packet contents. This will be used for fuzzing; ok markus@
Upstream-ID: a3221cee6b1725dd4ae1dd2c13841b4784cb75dc
ssh proxy mux mode (-O proxy; idea from Simon Tatham): - mux
client speaks the ssh-packet protocol directly over unix-domain socket. - mux
server acts as a proxy, translates channel IDs and relays to the server. - no
filedescriptor passing necessary. - combined with unix-domain forwarding it's
even possible to run mux client and server on different machines. feedback
& ok djm@
Upstream-ID: 666a2fb79f58e5c50e246265fb2b9251e505c25b
Remove support for pre-authentication compression. Doing
compression early in the protocol probably seemed reasonable in the 1990s,
but today it's clearly a bad idea in terms of both cryptography (cf. multiple
compression oracle attacks in TLS) and attack surface.
Moreover, to support it across privilege-separation zlib needed
the assistance of a complex shared-memory manager that made the
required attack surface considerably larger.
Prompted by Guido Vranken pointing out a compiler-elided security
check in the shared memory manager found by Stack
(http://css.csail.mit.edu/stack/); ok deraadt@ markus@
NB. pre-auth authentication has been disabled by default in sshd
for >10 years.
Upstream-ID: 32af9771788d45a0779693b41d06ec199d849caf
refactor canohost.c: move functions that cache results closer
to the places that use them (authn and session code). After this, no state is
cached in canohost.c
feedback and ok markus@
Upstream-ID: 5f2e4df88d4803fc8ec59ec53629105e23ce625e
refactor activation of rekeying
This makes automatic rekeying internal to the packet code (previously
the server and client loops needed to assist). In doing to it makes
application of rekey limits more accurate by accounting for packets
about to be sent as well as packets queued during rekeying events
themselves.
Based on a patch from dtucker@ which was in turn based on a patch
Aleksander Adamowski in bz#2521; ok markus@
Upstream-ID: a441227fd64f9739850ca97b4cf794202860fcd8
Allow RekeyLimits in excess of 4G up to 2**63 bits
(limited by the return type of scan_scaled). Part of bz#2521, ok djm.
Upstream-ID: 13bea82be566b9704821b1ea05bf7804335c7979
include remote port number in a few more messages; makes
tying log messages together into a session a bit easier; bz#2503 ok dtucker@
Upstream-ID: 9300dc354015f7a7368d94a8ff4a4266a69d237e
update packet.c & isolate, introduce struct ssh a) switch
packet.c to buffer api and isolate per-connection info into struct ssh b)
(de)serialization of the state is moved from monitor to packet.c c) the old
packet.c API is implemented in opacket.[ch] d) compress.c/h is removed and
integrated into packet.c with and ok djm@
[monitor.c packet.c packet.h]
unbreak compression, by re-init-ing the compression code in the
post-auth child. the new buffer code is more strict, and requires
buffer_init() while the old code was happy after a bzero();
originally from djm@
[authfile.c bufaux.c buffer.h channels.c krl.c mux.c packet.c packet.h]
[ssh-keygen.c]
buffer_get_string_ptr's return should be const to remind
callers that futzing with it will futz with the actual buffer
contents
[ssh_config sshconnect2.c packet.c readconf.h readconf.c clientloop.c
ssh_config.5 packet.h]
Add an optional second argument to RekeyLimit in the client to allow
rekeying based on elapsed time in addition to amount of traffic.
with djm@ jmc@, ok djm
[clientloop.c misc.c misc.h packet.c packet.h readconf.c readconf.h]
[servconf.c servconf.h session.c ssh.c ssh_config.5 sshd_config.5]
allow ssh and sshd to set arbitrary TOS/DSCP/QoS values instead of
hardcoding lowdelay/throughput.
bz#1733 patch from philipp AT redfish-solutions.com; ok markus@ deraadt@
[PROTOCOL PROTOCOL.agent PROTOCOL.certkeys auth2-jpake.c authfd.c]
[authfile.c buffer.h dns.c kex.c kex.h key.c key.h monitor.c]
[monitor_wrap.c myproposal.h packet.c packet.h pathnames.h readconf.c]
[ssh-add.1 ssh-add.c ssh-agent.1 ssh-agent.c ssh-keygen.1 ssh-keygen.c]
[ssh-keyscan.1 ssh-keyscan.c ssh-keysign.8 ssh.1 ssh.c ssh2.h]
[ssh_config.5 sshconnect.c sshconnect2.c sshd.8 sshd.c sshd_config.5]
[uuencode.c uuencode.h bufec.c kexecdh.c kexecdhc.c kexecdhs.c ssh-ecdsa.c]
Implement Elliptic Curve Cryptography modes for key exchange (ECDH) and
host/user keys (ECDSA) as specified by RFC5656. ECDH and ECDSA offer
better performance than plain DH and DSA at the same equivalent symmetric
key length, as well as much shorter keys.
Only the mandatory sections of RFC5656 are implemented, specifically the
three REQUIRED curves nistp256, nistp384 and nistp521 and only ECDH and
ECDSA. Point compression (optional in RFC5656 is NOT implemented).
Certificate host and user keys using the new ECDSA key types are supported.
Note that this code has not been tested for interoperability and may be
subject to change.
feedback and ok markus@
[auth-options.c auth1.c auth2.c bufaux.c buffer.h kex.c key.c packet.c]
[packet.h ssh-dss.c ssh-rsa.c]
Add buffer_get_cstring() and related functions that verify that the
string extracted from the buffer contains no embedded \0 characters*
This prevents random (possibly malicious) crap from being appended to
strings where it would not be noticed if the string is used with
a string(3) function.
Use the new API in a few sensitive places.
* actually, we allow a single one at the end of the string for now because
we don't know how many deployed implementations get this wrong, but don't
count on this to remain indefinitely.
[packet.h packet.c]
packet_bacup_state() and packet_restore_state() will be used to
temporarily save the current state ren resuming a suspended connection.
ok markus@
[sshconnect.h sshconnect.c]
Un-static ssh_exchange_identification(), part of a larger change from
Martin Forssen and needed for upcoming changes.
ok markus@
djm@openbsd.org
markus@openbsd.org
sf@openbsd.org
dtucker@openbsd.org
naddy@openbsd.org
Tim Rice
Damien Miller
Darren Tucker