ssh->kex and factor out the banner exchange. This eliminates some common code
from the client and server.
Also be more strict about handling \r characters - these should only
be accepted immediately before \n (pointed out by Jann Horn).
Inspired by a patch from Markus Schmidt.
(lots of) feedback and ok markus@
OpenBSD-Commit-ID: 1cc7885487a6754f63641d7d3279b0941890275b
KEX. It shouldn't be sent in subsequent ones, but if it is present we should
ignore it.
This prevents sshd from sending a SSH_MSG_EXT_INFO for REKEX for buggy
these clients. Reported by Jakub Jelen via bz2929; ok dtucker@
OpenBSD-Commit-ID: 91564118547f7807030ec537480303e2371902f9
This time, make sure to not remove things that are necessary for
pre-auth compression on the client. Add a comment that pre-auth
compression is still supported in the client.
ok markus@
OpenBSD-Commit-ID: 282c6fec7201f18a5c333bbb68d9339734d2f784
It turns out we still support pre-auth compression on the client.
Therefore revert the previous two commits:
date: 2018/07/06 09:06:14; author: sf; commitid: yZVYKIRtUZWD9CmE;
Rename COMP_DELAYED to COMP_ZLIB
Only delayed compression is supported nowadays.
ok markus@
date: 2018/07/06 09:05:01; author: sf; commitid: rEGuT5UgI9f6kddP;
Remove leftovers from pre-authentication compression
Support for this has been removed in 2016.
COMP_DELAYED will be renamed in a later commit.
ok markus@
OpenBSD-Commit-ID: cdfef526357e4e1483c86cf599491b2dafb77772
Support for this has been removed in 2016.
COMP_DELAYED will be renamed in a later commit.
ok markus@
OpenBSD-Commit-ID: 6a99616c832627157113fcb0cf5a752daf2e6b58
signature work - returns ability to add/remove/specify algorithms by
wildcard.
Algorithm lists are now fully expanded when the server/client configs
are finalised, so errors are reported early and the config dumps
(e.g. "ssh -G ...") now list the actual algorithms selected.
Clarify that, while wildcards are accepted in algorithm lists, they
aren't full pattern-lists that support negation.
(lots of) feedback, ok markus@
OpenBSD-Commit-ID: a8894c5c81f399a002f02ff4fe6b4fa46b1f3207
In ssh, when an agent fails to return a RSA-SHA2 signature when
requested and falls back to RSA-SHA1 instead, retry the signature to
ensure that the public key algorithm sent in the SSH_MSG_USERAUTH
matches the one in the signature itself.
In sshd, strictly enforce that the public key algorithm sent in the
SSH_MSG_USERAUTH message matches what appears in the signature.
Make the sshd_config PubkeyAcceptedKeyTypes and
HostbasedAcceptedKeyTypes options control accepted signature algorithms
(previously they selected supported key types). This allows these
options to ban RSA-SHA1 in favour of RSA-SHA2.
Add new signature algorithms "rsa-sha2-256-cert-v01@openssh.com" and
"rsa-sha2-512-cert-v01@openssh.com" to force use of RSA-SHA2 signatures
with certificate keys.
feedback and ok markus@
OpenBSD-Commit-ID: c6e9f6d45eed8962ad502d315d7eaef32c419dde
put back some pre-auth zlib bits that I shouldn't have
removed - they are still used by the client. Spotted by naddy@
Upstream-ID: 80919468056031037d56a1f5b261c164a6f90dc2
restore pre-auth compression support in the client -- the
previous commit was intended to remove it from the server only.
remove a few server-side pre-auth compression bits that escaped
adjust wording of Compression directive in sshd_config(5)
pointed out by naddy@ ok markus@
Upstream-ID: d23696ed72a228dacd4839dd9f2dec424ba2016b
add support for additional fixed DH groups from
draft-ietf-curdle-ssh-kex-sha2-03
diffie-hellman-group14-sha256 (2K group)
diffie-hellman-group16-sha512 (4K group)
diffie-hellman-group18-sha512 (8K group)
based on patch from Mark D. Baushke and Darren Tucker
ok markus@
Upstream-ID: ac00406ada4f0dfec41585ca0839f039545bc46f
fix signed/unsigned errors reported by clang-3.7; add
sshbuf_dup_string() to replace a common idiom of strdup(sshbuf_ptr()) with
better safety checking; feedback and ok markus@
Upstream-ID: 71f926d9bb3f1efed51319a6daf37e93d57c8820
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
implement SHA2-{256,512} for RSASSA-PKCS1-v1_5 signatures
(user and host auth) based on draft-rsa-dsa-sha2-256-03.txt and
draft-ssh-ext-info-04.txt; with & ok djm@
Upstream-ID: cf82ce532b2733e5c4b34bb7b7c94835632db309
Allow ssh_config and sshd_config kex parameters options be
prefixed by a '+' to indicate that the specified items be appended to the
default rather than replacing it.
approach suggested by dtucker@, feedback dlg@, ok markus@
Upstream-ID: 0f901137298fc17095d5756ff1561a7028e8882a
include the peer's offer when logging a failure to
negotiate a mutual set of algorithms (kex, pubkey, ciphers, etc.) ok markus@
Upstream-ID: bbb8caabf5c01790bb845f5ce135565248d7c796
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@
correctly match ECDSA subtype (== curve) for
offered/recevied host keys. Fixes connection-killing host key mismatches when
a server offers multiple ECDSA keys with different curve type (an extremely
unlikely configuration).
ok markus, "looks mechanical" deraadt@
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@
[chacha.h cipher-chachapoly.h digest.h hmac.h kex.h kexc25519.c]
[misc.h poly1305.h ssh-pkcs11.c defines.h]
revert __bounded change; it causes way more problems for portable than
it solves; pointed out by dtucker@
[chacha.h cipher-chachapoly.h digest.h hmac.h kex.h kexc25519.c
[misc.h poly1305.h ssh-pkcs11.c]
use __bounded(...) attribute recently added to sys/cdefs.h instead of
longform __attribute__(__bounded(...));
for brevity and a warning free compilation with llvm/clang
[Makefile.in digest.c digest.h hostfile.c kex.h mac.c hmac.c hmac.h]
replace openssl HMAC with an implementation based on our ssh_digest_*
ok and feedback djm@
[cipher.c cipher.h kex.c kex.h kexgexc.c]
Add a special case for the DH group size for 3des-cbc, which has an
effective strength much lower than the key size. This causes problems
with some cryptlib implementations, which don't support group sizes larger
than 4k but also don't use the largest group size it does support as
specified in the RFC. Based on a patch from Petr Lautrbach at Redhat,
reduced by me with input from Markus. ok djm@ markus@
[bufaux.c buffer.h kex.c kex.h kexc25519.c kexc25519c.c kexc25519s.c]
[kexdhc.c kexdhs.c kexecdhc.c kexecdhs.c kexgexc.c kexgexs.c]
avoid use of OpenSSL BIGNUM type and functions for KEX with
Curve25519 by adding a buffer_put_bignum2_from_string() that stores
a string using the bignum encoding rules. Will make it easier to
build a reduced-feature OpenSSH without OpenSSL in the future;
ok markus@
[digest.c digest.h hostfile.c kex.c kex.h kexc25519.c kexc25519c.c]
[kexc25519s.c kexdh.c kexecdh.c kexecdhc.c kexecdhs.c kexgex.c kexgexc.c]
[kexgexs.c key.c key.h roaming_client.c roaming_common.c schnorr.c]
[schnorr.h ssh-dss.c ssh-ecdsa.c ssh-rsa.c sshconnect2.c]
Introduce digest API and use it to perform all hashing operations
rather than calling OpenSSL EVP_Digest* directly. Will make it easier
to build a reduced-feature OpenSSH without OpenSSL in future;
feedback, ok markus@
[cipher.c cipher.h kex.c kex.h mac.c mac.h servconf.c ssh.c]
Output the effective values of Ciphers, MACs and KexAlgorithms when
the default has not been overridden. ok markus@
[kex.c kex.h myproposal.h ssh-keyscan.c sshconnect2.c sshd.c]
use curve25519 for default key exchange (curve25519-sha256@libssh.org);
initial patch from Aris Adamantiadis; ok djm@
[auth.h kex.h kexdhs.c kexecdhs.c kexgexs.c monitor.c servconf.c]
[servconf.h session.c sshd.c sshd_config.5]
add ssh-agent(1) support to sshd(8); allows encrypted hostkeys,
or hostkeys on smartcards; most of the work by Zev Weiss; bz #1974
ok djm@
[authfile.c cipher.c cipher.h kex.c kex.h kexecdh.c kexecdhc.c kexecdhs.c]
[key.c key.h mac.c mac.h packet.c ssh.1 ssh.c]
add the ability to query supported ciphers, MACs, key type and KEX
algorithms to ssh. Includes some refactoring of KEX and key type handling
to be table-driven; ok markus@
[PROTOCOL authfile.c cipher.c cipher.h kex.c kex.h monitor_wrap.c]
[myproposal.h packet.c ssh_config.5 sshd_config.5]
support AES-GCM as defined in RFC 5647 (but with simpler KEX handling)
ok and feedback djm@
[PROTOCOL authfile.c cipher.c cipher.h kex.h mac.c myproposal.h]
[packet.c ssh_config.5 sshd_config.5]
add encrypt-then-mac (EtM) modes to openssh by defining new mac algorithms
that change the packet format and compute the MAC over the encrypted
message (including the packet size) instead of the plaintext data;
these EtM modes are considered more secure and used by default.
feedback and ok djm@
[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@
[kexecdhc.c kexecdhs.c key.c key.h myproposal.h packet.c readconf.c]
[ssh-agent.c ssh-ecdsa.c ssh-keygen.c ssh.c] Disable ECDH and ECDSA on
platforms that don't have the requisite OpenSSL support. ok dtucker@
[kex.c kex.h kexecdh.c key.c key.h monitor.c ssh-ecdsa.c]
ECDH/ECDSA compliance fix: these methods vary the hash function they use
(SHA256/384/512) depending on the length of the curve in use. The previous
code incorrectly used SHA256 in all cases.
This fix will cause authentication failure when using 384 or 521-bit curve
keys if one peer hasn't been upgraded and the other has. (256-bit curve
keys work ok). In particular you may need to specify HostkeyAlgorithms
when connecting to a server that has not been upgraded from an upgraded
client.
ok naddy@
[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@
- djm@cvs.openbsd.org 2010/02/26 20:29:54
[PROTOCOL PROTOCOL.agent PROTOCOL.certkeys addrmatch.c auth-options.c]
[auth-options.h auth.h auth2-pubkey.c authfd.c dns.c dns.h hostfile.c]
[hostfile.h kex.h kexdhs.c kexgexs.c key.c key.h match.h monitor.c]
[myproposal.h servconf.c servconf.h ssh-add.c ssh-agent.c ssh-dss.c]
[ssh-keygen.1 ssh-keygen.c ssh-rsa.c ssh.1 ssh.c ssh2.h sshconnect.c]
[sshconnect2.c sshd.8 sshd.c sshd_config.5]
Add support for certificate key types for users and hosts.
OpenSSH certificate key types are not X.509 certificates, but a much
simpler format that encodes a public key, identity information and
some validity constraints and signs it with a CA key. CA keys are
regular SSH keys. This certificate style avoids the attack surface
of X.509 certificates and is very easy to deploy.
Certified host keys allow automatic acceptance of new host keys
when a CA certificate is marked as sh/known_hosts.
see VERIFYING HOST KEYS in ssh(1) for details.
Certified user keys allow authentication of users when the signing
CA key is marked as trusted in authorized_keys. See "AUTHORIZED_KEYS
FILE FORMAT" in sshd(8) for details.
Certificates are minted using ssh-keygen(1), documentation is in
the "CERTIFICATES" section of that manpage.
Documentation on the format of certificates is in the file
PROTOCOL.certkeys
feedback and ok markus@
djm@openbsd.org
Damien Miller
markus@openbsd.org
sf@openbsd.org
naddy@openbsd.org
Darren Tucker