ECDH/x25519 + Streamlined NTRU Prime post-quantum KEX to the default
KEXAlgorithms list (after the ECDH methods but before the prime-group DH
ones).
ok markus@
OpenBSD-Commit-ID: 22b77e27a04e497a10e22f138107579652854210
signature algorithm by default. It is feasible to create colliding SHA1
hashes, so we need to deprecate its use.
RSA/SHA-256/512 remains available and will be transparently selected
instead of RSA/SHA1 for most SSH servers released in the last five+
years. There is no need to regenerate RSA keys.
The use of RSA/SHA1 can be re-enabled by adding "ssh-rsa" to the
PubkeyAcceptedAlgorithms directives on the client and server.
ok dtucker deraadt
OpenBSD-Commit-ID: 189bcc4789c7254e09e23734bdd5def8354ff1d5
time and remove ifdef and distinct settings for OPENSSL=no case.
This will make things much simpler for -portable where the exact set
of algos depends on the configuration of both OpenSSH and the libcrypto
it's linked against (if any). ok djm@
OpenBSD-Commit-ID: e0116d0183dcafc7a9c40ba5fe9127805c5dfdd2
keys.
Previously we didn't do this because we didn't want to expose
the attack surface presented by USB and FIDO protocol handling,
but now that this is insulated behind ssh-sk-helper there is
less risk.
ok markus@
OpenBSD-Commit-ID: 77b068dd133b8d87e0f010987bd5131e640ee64c
U2F/FIDO keys are not supported for host authentication, so we need
a separate list for user keys.
feedback & ok markus@
OpenBSD-Commit-ID: 7fe2e6ab85f9f2338866e5af8ca2d312abbf0429
in the client for KEX, ciphers and MACs. The ciphers and MACs were identical
between the client and server, but the error accidentially disabled the
diffie-hellman-group-exchange-sha1 KEX method.
This fixes the client code to use the correct method list, but
because nobody complained, it also disables the
diffie-hellman-group-exchange-sha1 KEX method.
Reported by nuxi AT vault24.org via bz#2697; ok dtucker
OpenBSD-Commit-ID: e30c33a23c10fd536fefa120e86af1842e33fd57
signature algorithms that are allowed for CA signatures. Notably excludes
ssh-dsa.
ok markus@
OpenBSD-Commit-ID: 1628e4181dc8ab71909378eafe5d06159a22deb4
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
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
support plain curve25519-sha256 KEX algorithm now that it
is approaching standardisation (same algorithm is currently supported as
curve25519-sha256@libssh.org)
Upstream-ID: 5e2b6db2e72667048cf426da43c0ee3fc777baa2
remove 3des-cbc from the client's default proposal;
64-bit block ciphers are not safe in 2016 and we don't want to wait until
attacks like sweet32 are extended to SSH.
As 3des-cbc was the only mandatory cipher in the SSH RFCs, this may
cause problems connecting to older devices using the defaults, but
it's highly likely that such devices already need explicit
configuration for KEX and hostkeys anyway.
ok deraadt, markus, dtucker
Upstream-ID: a505dfe65c6733af0f751b64cbc4bb7e0761bc2f
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
turn off more old crypto in the client: hmac-md5, ripemd,
truncated HMACs, RC4, blowfish. ok markus@ dtucker@
Upstream-ID: 96aa11c2c082be45267a690c12f1d2aae6acd46e
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
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
turn off 1024 bit diffie-hellman-group1-sha1 key
exchange method (already off in server, this turns it off in the client by
default too) ok dtucker@
Upstream-ID: f59b88f449210ab7acf7d9d88f20f1daee97a4fa
Reorder client proposal to prefer
diffie-hellman-group-exchange-sha1 over diffie-hellman-group14-sha1. ok djm@
Upstream-ID: 552c08d47347c3ee1a9a57d88441ab50abe17058
[mac.c myproposal.h umac.c]
UMAC can use our local fallback implementation of AES when OpenSSL isn't
available. Glue code straight from Ted Krovetz's original umac.c.
ok markus@
repeatedly):
- markus@cvs.openbsd.org 2014/03/25 09:40:03
[myproposal.h]
trimm default proposals.
This commit removes the weaker pre-SHA2 hashes, the broken ciphers
(arcfour), and the broken modes (CBC) from the default configuration
(the patch only changes the default, all the modes are still available
for the config files).
ok djm@, reminded by tedu@ & naddy@ and discussed with many
- deraadt@cvs.openbsd.org 2014/03/26 17:16:26
[myproposal.h]
The current sharing of myproposal[] between both client and server code
makes the previous diff highly unpallatable. We want to go in that
direction for the server, but not for the client. Sigh.
Brought up by naddy.
- markus@cvs.openbsd.org 2014/03/27 23:01:27
[myproposal.h ssh-keyscan.c sshconnect2.c sshd.c]
disable weak proposals in sshd, but keep them in ssh; ok djm@
[Makefile.in PROTOCOL PROTOCOL.chacha20poly1305 authfile.c chacha.c]
[chacha.h cipher-chachapoly.c cipher-chachapoly.h cipher.c cipher.h]
[dh.c myproposal.h packet.c poly1305.c poly1305.h servconf.c ssh.1]
[ssh.c ssh_config.5 sshd_config.5] Add a new protocol 2 transport
cipher "chacha20-poly1305@openssh.com" that combines Daniel
Bernstein's ChaCha20 stream cipher and Poly1305 MAC to build an
authenticated encryption mode.
Inspired by and similar to Adam Langley's proposal for TLS:
http://tools.ietf.org/html/draft-agl-tls-chacha20poly1305-03
but differs in layout used for the MAC calculation and the use of a
second ChaCha20 instance to separately encrypt packet lengths.
Details are in the PROTOCOL.chacha20poly1305 file.
Feedback markus@, naddy@; manpage bits Loganden Velvindron @ AfriNIC
ok markus@ naddy@
NID_X9_62_prime256v1, NID_secp384r1 and NID_secp521r1 and test that the
latter actually works before using it. Fedora (at least) has NID_secp521r1
that doesn't work (see https://bugzilla.redhat.com/show_bug.cgi?id=1021897).
[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@
[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@
