Add a ProxyJump ssh_config(5) option and corresponding -J
ssh(1) command-line flag to allow simplified indirection through a SSH
bastion or "jump host".
These options construct a proxy command that connects to the
specified jump host(s) (more than one may be specified) and uses
port-forwarding to establish a connection to the next destination.
This codifies the safest way of indirecting connections through SSH
servers and makes it easy to use.
ok markus@
Upstream-ID: fa899cb8b26d889da8f142eb9774c1ea36b04397
Move the host and port used by ssh -W into the Options
struct. This will make future changes a bit easier. ok djm@
Upstream-ID: 151bce5ecab2fbedf0d836250a27968d30389382
Add an AddKeysToAgent client option which can be set to
'yes', 'no', 'ask', or 'confirm', and defaults to 'no'. When enabled, a
private key that is used during authentication will be added to ssh-agent if
it is running (with confirmation enabled if set to 'confirm').
Initial version from Joachim Schipper many years ago.
ok markus@
Upstream-ID: a680db2248e8064ec55f8be72d539458c987d5f4
add ssh_config CertificateFile option to explicitly list
a certificate; patch from Meghana Bhat on bz#2436; ok markus@
Upstream-ID: 58648ec53c510b41c1f46d8fe293aadc87229ab8
Turn off DSA by default; add HostKeyAlgorithms to the
server and PubkeyAcceptedKeyTypes to the client side, so it still can be
tested or turned back on; feedback and ok djm@
Upstream-ID: 8450a9e6d83f80c9bfed864ff061dfc9323cec21
Revise hostkeys@openssh.com hostkey learning extension.
The client will not ask the server to prove ownership of the private
halves of any hitherto-unseen hostkeys it offers to the client.
Allow UpdateHostKeys option to take an 'ask' argument to let the
user manually review keys offered.
ok markus@
Add a ssh_config HostbasedKeyType option to control which
host public key types are tried during hostbased authentication.
This may be used to prevent too many keys being sent to the server,
and blowing past its MaxAuthTries limit.
bz#2211 based on patch by Iain Morgan; ok markus@
Host key rotation support.
Add a hostkeys@openssh.com protocol extension (global request) for
a server to inform a client of all its available host key after
authentication has completed. The client may record the keys in
known_hosts, allowing it to upgrade to better host key algorithms
and a server to gracefully rotate its keys.
The client side of this is controlled by a UpdateHostkeys config
option (default on).
ok markus@
Add FingerprintHash option to control algorithm used for
key fingerprints. Default changes from MD5 to SHA256 and format from hex to
base64.
Feedback and ok naddy@ markus@
Tweak config reparsing with host canonicalisation
Make the second pass through the config files always run when
hostname canonicalisation is enabled.
Add a "Match canonical" criteria that allows ssh_config Match
blocks to trigger only in the second config pass.
Add a -G option to ssh that causes it to parse its configuration
and dump the result to stdout, similar to "sshd -T"
Allow ssh_config Port options set in the second config parse
phase to be applied (they were being ignored).
bz#2267 bz#2286; ok markus
[PROTOCOL auth-options.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c]
[auth-rsa.c auth.c auth1.c auth2-hostbased.c auth2-kbdint.c auth2-none.c]
[auth2-passwd.c auth2-pubkey.c auth2.c canohost.c channels.c channels.h]
[clientloop.c misc.c misc.h monitor.c mux.c packet.c readconf.c]
[readconf.h servconf.c servconf.h serverloop.c session.c ssh-agent.c]
[ssh.c ssh_config.5 sshconnect.c sshconnect1.c sshconnect2.c sshd.c]
[sshd_config.5 sshlogin.c]
Add support for Unix domain socket forwarding. A remote TCP port
may be forwarded to a local Unix domain socket and vice versa or
both ends may be a Unix domain socket. This is a reimplementation
of the streamlocal patches by William Ahern from:
http://www.25thandclement.com/~william/projects/streamlocal.html
OK djm@ markus@
[readconf.c readconf.h ssh.c ssh_config.5]
reparse ssh_config and ~/.ssh/config if hostname canonicalisation changes
the hostname. This allows users to write configurations that always
refer to canonical hostnames, e.g.
CanonicalizeHostname yes
CanonicalDomains int.example.org example.org
CanonicalizeFallbackLocal no
Host *.int.example.org
Compression off
Host *.example.org
User djm
ok markus@
[readconf.c readconf.h ssh.1 ssh.c ssh_config.5]
s/canonicalise/canonicalize/ for consistency with existing spelling,
e.g. authorized_keys; pointed out by naddy@
[readconf.c readconf.h roaming_client.c ssh.1 ssh.c ssh_config.5]
[sshconnect.c sshconnect.h]
Implement client-side hostname canonicalisation to allow an explicit
search path of domain suffixes to use to convert unqualified host names
to fully-qualified ones for host key matching.
This is particularly useful for host certificates, which would otherwise
need to list unqualified names alongside fully-qualified ones (and this
causes a number of problems).
"looks fine" markus@
[readconf.c readconf.h ssh-keysign.c ssh.c ssh_config.5]
add a "Match" keyword to ssh_config that allows matching on hostname,
user and result of arbitrary commands. "nice work" markus@
[readconf.c readconf.h ssh_config.5 sshconnect.c]
Add a ssh_config ProxyUseFDPass option that supports the use of
ProxyCommands that establish a connection and then pass a connected
file descriptor back to ssh(1). This allows the ProxyCommand to exit
rather than have to shuffle data back and forth and enables ssh to use
getpeername, etc. to obtain address information just like it does with
regular directly-connected sockets. ok markus@
[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
[readconf.c ssh.c readconf.h sshconnect2.c]
Keep track of which IndentityFile options were manually supplied and which
were default options, and don't warn if the latter are missing.
ok markus@
[mux.c readconf.h channels.h compat.h compat.c ssh.c readconf.c channels.c version.h]
unbreak remote portforwarding with dynamic allocated listen ports:
1) send the actual listen port in the open message (instead of 0).
this allows multiple forwardings with a dynamic listen port
2) update the matching permit-open entry, so we can identify where
to connect to
report: den at skbkontur.ru and P. Szczygielski
feedback and ok djm@
[readconf.c readconf.h ssh.c ssh_config.5 sshconnect.c sshconnect2.c]
Remove undocumented legacy options UserKnownHostsFile2 and
GlobalKnownHostsFile2 by making UserKnownHostsFile/GlobalKnownHostsFile
accept multiple paths per line and making their defaults include
known_hosts2; ok markus
[clientloop.c mux.c readconf.c readconf.h ssh.c ssh_config.5]
Add a RequestTTY ssh_config option to allow configuration-based
control over tty allocation (like -t/-T); ok markus@
[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@
[kex.c kex.h kexecdh.c kexecdhc.c kexecdhs.c readconf.c readconf.h]
[servconf.c servconf.h ssh_config.5 sshconnect2.c sshd.c sshd_config.5]
add a KexAlgorithms knob to the client and server configuration to allow
selection of which key exchange methods are used by ssh(1) and sshd(8)
and their order of preference.
ok markus@
[clientloop.c readconf.c readconf.h ssh.c ssh_config.5]
add a "ControlPersist" option that automatically starts a background
ssh(1) multiplex master when connecting. This connection can stay alive
indefinitely, or can be set to automatically close after a user-specified
duration of inactivity. bz#1330 - patch by dwmw2 AT infradead.org, but
further hacked on by wmertens AT cisco.com, apb AT cequrux.com,
martin-mindrot-bugzilla AT earth.li and myself; "looks ok" markus@
[ssh.c]
log the hostname and address that we connected to at LogLevel=verbose
after authentication is successful to mitigate "phishing" attacks by
servers with trusted keys that accept authentication silently and
automatically before presenting fake password/passphrase prompts;
"nice!" markus@
[channels.c mux.c readconf.c readconf.h ssh.h]
bz#1327: remove hardcoded limit of 100 permitopen clauses and port
forwards per direction; ok markus@ stevesk@
[PROTOCOL.mux clientloop.h mux.c readconf.c readconf.h ssh.1 ssh.c]
mux support for remote forwarding with dynamic port allocation,
use with
LPORT=`ssh -S muxsocket -R0:localhost:25 -O forward somehost`
feedback and ok djm@
[pathnames.h readconf.c readconf.h scp.1 sftp.1 ssh-add.1 ssh-add.c]
[ssh-agent.c ssh-keygen.1 ssh-keygen.c ssh.1 ssh.c ssh_config.5]
replace our obsolete smartcard code with PKCS#11.
ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-11/v2-20/pkcs-11v2-20.pdf
ssh(1) and ssh-keygen(1) use dlopen(3) directly to talk to a PKCS#11
provider (shared library) while ssh-agent(1) delegates PKCS#11 to
a forked a ssh-pkcs11-helper process.
PKCS#11 is currently a compile time option.
feedback and ok djm@; inspired by patches from Alon Bar-Lev
`
[channels.c ssh.1 servconf.c sshd_config.5 sshd.c channels.h servconf.h
ssh-keyscan.1 ssh-keyscan.c readconf.c sshconnect.c misc.c ssh.c
readconf.h scp.1 sftp.1 ssh_config.5 misc.h]
Remove RoutingDomain from ssh since it's now not needed. It can be
replaced with "route exec" or "nc -V" as a proxycommand. "route exec"
also ensures that trafic such as DNS lookups stays withing the specified
routingdomain. For example (from reyk):
# route -T 2 exec /usr/sbin/sshd
or inherited from the parent process
$ route -T 2 exec sh
$ ssh 10.1.2.3
ok deraadt@ markus@ stevesk@ reyk@
[ssh_config.5 sshd.c misc.h ssh-keyscan.1 readconf.h sshconnect.c
channels.c channels.h servconf.h servconf.c ssh.1 ssh-keyscan.c scp.1
sftp.1 sshd_config.5 readconf.c ssh.c misc.c]
Allow to set the rdomain in ssh/sftp/scp/sshd and ssh-keyscan.
ok markus@
[readconf.h readconf.c]
Add client option UseRoaming. It doesn't do anything yet but will
control whether the client tries to use roaming if enabled on the
server. From Martin Forssen.
ok markus@
[canohost.c canohost.h channels.c channels.h clientloop.c readconf.c]
[readconf.h serverloop.c ssh.c]
support remote port forwarding with a zero listen port (-R0:...) to
dyamically allocate a listen port at runtime (this is actually
specified in rfc4254); bz#1003 ok markus@
[clientloop.c misc.c readconf.c readconf.h servconf.c servconf.h]
[serverloop.c ssh-keyscan.c ssh.c sshd.c]
make a2port() return -1 when it encounters an invalid port number
rather than 0, which it will now treat as valid (needed for future work)
adjust current consumers of a2port() to check its return value is <= 0,
which in turn required some things to be converted from u_short => int
make use of int vs. u_short consistent in some other places too
feedback & ok markus@
[auth.h auth2.c monitor.c monitor.h monitor_wrap.c monitor_wrap.h]
[readconf.c readconf.h servconf.c servconf.h ssh2.h ssh_config.5]
[sshconnect2.c sshd_config.5 jpake.c jpake.h schnorr.c auth2-jpake.c]
[Makefile.in]
Add support for an experimental zero-knowledge password authentication
method using the J-PAKE protocol described in F. Hao, P. Ryan,
"Password Authenticated Key Exchange by Juggling", 16th Workshop on
Security Protocols, Cambridge, April 2008.
This method allows password-based authentication without exposing
the password to the server. Instead, the client and server exchange
cryptographic proofs to demonstrate of knowledge of the password while
revealing nothing useful to an attacker or compromised endpoint.
This is experimental, work-in-progress code and is presently
compiled-time disabled (turn on -DJPAKE in Makefile.inc).
"just commit it. It isn't too intrusive." deraadt@
[readconf.c readconf.h ssh.1 ssh_config.5 sshconnect.c]
Move SSH Fingerprint Visualization away from sharing the config option
CheckHostIP to an own config option named VisualHostKey.
While there, fix the behaviour that ssh would draw a random art picture
on every newly seen host even when the option was not enabled.
prodded by deraadt@, discussions,
help and ok markus@ djm@ dtucker@
[ssh_config.5 key.h readconf.c readconf.h ssh-keygen.1 ssh-keygen.c key.c
sshconnect.c]
Introduce SSH Fingerprint ASCII Visualization, a technique inspired by the
graphical hash visualization schemes known as "random art", and by
Dan Kaminsky's musings on the subject during a BlackOp talk at the
23C3 in Berlin.
Scientific publication (original paper):
"Hash Visualization: a New Technique to improve Real-World Security",
Perrig A. and Song D., 1999, International Workshop on Cryptographic
Techniques and E-Commerce (CrypTEC '99)
http://sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
The algorithm used here is a worm crawling over a discrete plane,
leaving a trace (augmenting the field) everywhere it goes.
Movement is taken from dgst_raw 2bit-wise. Bumping into walls
makes the respective movement vector be ignored for this turn,
thus switching to the other color of the chessboard.
Graphs are not unambiguous for now, because circles in graphs can be
walked in either direction.
discussions with several people,
help, corrections and ok markus@ djm@
[readconf.c readconf.h sshconnect2.c]
promote rekeylimit to a int64 so it can hold the maximum useful limit
of 2^32; report and patch from Jan.Pechanec AT Sun.COM, ok dtucker@
[clientloop.c ssh.1 ssh.c channels.c ssh_config.5 readconf.h session.c
channels.h readconf.c]
add ExitOnForwardFailure: terminate the connection if ssh(1)
cannot set up all requested dynamic, local, and remote port
forwardings. ok djm, dtucker, stevesk, jmc
[auth-options.c auth-options.h channels.c channels.h clientloop.c]
[misc.c misc.h readconf.c readconf.h scp.c servconf.c servconf.h]
[serverloop.c sftp.c ssh.1 ssh.c ssh_config ssh_config.5 sshconnect.c]
[sshconnect.h sshd.8 sshd_config sshd_config.5]
Add support for tun(4) forwarding over OpenSSH, based on an idea and
initial channel code bits by markus@. This is a simple and easy way to
use OpenSSH for ad hoc virtual private network connections, e.g.
administrative tunnels or secure wireless access. It's based on a new
ssh channel and works similar to the existing TCP forwarding support,
except that it depends on the tun(4) network interface on both ends of
the connection for layer 2 or layer 3 tunneling. This diff also adds
support for LocalCommand in the ssh(1) client.
ok djm@, markus@, jmc@ (manpages), tested and discussed with others
