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openssh (1:7.6p1-1) unstable; urgency=medium
OpenSSH 7.6 includes a number of changes that may affect existing
configurations:
* ssh(1): Delete SSH protocol version 1 support, associated configuration
options and documentation.
* ssh(1)/sshd(8): Remove support for the hmac-ripemd160 MAC.
* ssh(1)/sshd(8): Remove support for the arcfour, blowfish and CAST
ciphers.
* Refuse RSA keys <1024 bits in length and improve reporting for keys
that do not meet this requirement.
* ssh(1): Do not offer CBC ciphers by default.
-- Colin Watson <cjwatson@debian.org> Fri, 06 Oct 2017 12:36:48 +0100
openssh (1:7.5p1-1) experimental; urgency=medium
OpenSSH 7.5 includes a number of changes that may affect existing
configurations:
* This release deprecates the sshd_config UsePrivilegeSeparation option,
thereby making privilege separation mandatory.
* The format of several log messages emitted by the packet code has
changed to include additional information about the user and their
authentication state. Software that monitors ssh/sshd logs may need to
account for these changes. For example:
Connection closed by user x 1.1.1.1 port 1234 [preauth]
Connection closed by authenticating user x 10.1.1.1 port 1234 [preauth]
Connection closed by invalid user x 1.1.1.1 port 1234 [preauth]
Affected messages include connection closure, timeout, remote
disconnection, negotiation failure and some other fatal messages
generated by the packet code.
-- Colin Watson <cjwatson@debian.org> Sun, 02 Apr 2017 02:58:01 +0100
openssh (1:7.4p1-7) unstable; urgency=medium
This version restores the default for AuthorizedKeysFile to search both
~/.ssh/authorized_keys and ~/.ssh/authorized_keys2, as was the case in
Debian configurations before 1:7.4p1-1. Upstream intends to phase out
searching ~/.ssh/authorized_keys2 by default, so you should ensure that
you are only using ~/.ssh/authorized_keys, at least for critical
administrative access; do not assume that the current default will remain
in place forever.
-- Colin Watson <cjwatson@debian.org> Sun, 05 Mar 2017 02:12:42 +0000
openssh (1:7.4p1-1) unstable; urgency=medium
OpenSSH 7.4 includes a number of changes that may affect existing
configurations:
* ssh(1): 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 default configuration, but it's highly likely
that such devices already need explicit configuration for key exchange
and hostkey algorithms already anyway.
* sshd(8): 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.
Pre-auth compression support has been disabled by default for >10
years. Support remains in the client.
* ssh-agent will refuse to load PKCS#11 modules outside a whitelist of
trusted paths by default. The path whitelist may be specified at
run-time.
* sshd(8): When a forced-command appears in both a certificate and an
authorized keys/principals command= restriction, sshd will now refuse
to accept the certificate unless they are identical. The previous
(documented) behaviour of having the certificate forced-command
override the other could be a bit confusing and error-prone.
* sshd(8): Remove the UseLogin configuration directive and support for
having /bin/login manage login sessions.
The unprivileged sshd process that deals with pre-authentication network
traffic is now subject to additional sandboxing restrictions by default:
that is, the default sshd_config now sets UsePrivilegeSeparation to
"sandbox" rather than "yes". This has been the case upstream for a while,
but until now the Debian configuration diverged unnecessarily.
-- Colin Watson <cjwatson@debian.org> Tue, 27 Dec 2016 18:01:46 +0000
openssh (1:7.2p1-1) unstable; urgency=medium
OpenSSH 7.2 disables a number of legacy cryptographic algorithms by
default in ssh:
* Several ciphers blowfish-cbc, cast128-cbc, all arcfour variants and the
rijndael-cbc aliases for AES.
* MD5-based and truncated HMAC algorithms.
These algorithms are already disabled by default in sshd.
-- Colin Watson <cjwatson@debian.org> Tue, 08 Mar 2016 11:47:20 +0000
openssh (1:7.1p1-2) unstable; urgency=medium
OpenSSH 7.0 disables several pieces of weak, legacy, and/or unsafe
cryptography.
* Support for the legacy SSH version 1 protocol is disabled by default at
compile time. Note that this also means that the Cipher keyword in
ssh_config(5) is effectively no longer usable; use Ciphers instead for
protocol 2. The openssh-client-ssh1 package includes "ssh1", "scp1",
and "ssh-keygen1" binaries which you can use if you have no alternative
way to connect to an outdated SSH1-only server; please contact the
server administrator or system vendor in such cases and ask them to
upgrade.
* Support for the 1024-bit diffie-hellman-group1-sha1 key exchange is
disabled by default at run-time. It may be re-enabled using the
instructions at http://www.openssh.com/legacy.html
* Support for ssh-dss, ssh-dss-cert-* host and user keys is disabled by
default at run-time. These may be re-enabled using the instructions at
http://www.openssh.com/legacy.html
* Support for the legacy v00 cert format has been removed.
Future releases will retire more legacy cryptography, including:
* Refusing all RSA keys smaller than 1024 bits (the current minimum is
768 bits).
* Several ciphers will be disabled by default: blowfish-cbc, cast128-cbc,
all arcfour variants, and the rijndael-cbc aliases for AES.
* MD5-based HMAC algorithms will be disabled by default.
-- Colin Watson <cjwatson@debian.org> Tue, 08 Dec 2015 15:33:08 +0000
openssh (1:6.9p1-1) unstable; urgency=medium
UseDNS now defaults to 'no'. Configurations that match against the client
host name (via sshd_config or authorized_keys) may need to re-enable it or
convert to matching against addresses.
-- Colin Watson <cjwatson@debian.org> Thu, 20 Aug 2015 10:38:58 +0100
openssh (1:6.7p1-5) unstable; urgency=medium
openssh-server 1:6.7p1-4 changed the default setting of AcceptEnv to list
a number of specific LC_FOO variables rather than the wildcard LC_*. I
have since been persuaded that this was a bad idea and have reverted it,
but it is difficult to automatically undo the change to
/etc/ssh/sshd_config without compounding the problem (that of modifying
configuration that some users did not want to be modified) further. Most
users who upgraded via version 1:6.7p1-4 should restore the previous value
of "AcceptEnv LANG LC_*" in /etc/ssh/sshd_config.
-- Colin Watson <cjwatson@debian.org> Sun, 22 Mar 2015 23:09:32 +0000
openssh (1:5.4p1-2) unstable; urgency=low
Smartcard support is now available using PKCS#11 tokens. If you were
previously using an unofficial build of Debian's OpenSSH package with
OpenSC-based smartcard support added, then note that commands like
'ssh-add -s 0' will no longer work; you need to use 'ssh-add -s
/usr/lib/opensc-pkcs11.so' instead.
-- Colin Watson <cjwatson@debian.org> Sat, 10 Apr 2010 01:08:59 +0100
openssh (1:3.8.1p1-9) experimental; urgency=low
The ssh package has been split into openssh-client and openssh-server. If
you had previously requested that the sshd server should not be run, then
that request will still be honoured. However, the recommended approach is
now to remove the openssh-server package if you do not want to run sshd.
You can remove the old /etc/ssh/sshd_not_to_be_run marker file after doing
that.
-- Colin Watson <cjwatson@debian.org> Mon, 2 Aug 2004 20:48:54 +0100
openssh (1:3.5p1-1) unstable; urgency=low
This version of OpenSSH disables the environment option for public keys by
default, in order to avoid certain attacks (for example, LD_PRELOAD). If
you are using this option in an authorized_keys file, beware that the keys
in question will no longer work until the option is removed.
To re-enable this option, set "PermitUserEnvironment yes" in
/etc/ssh/sshd_config after the upgrade is complete, taking note of the
warning in the sshd_config(5) manual page.
-- Colin Watson <cjwatson@debian.org> Sat, 26 Oct 2002 19:41:51 +0100
openssh (1:3.0.1p1-1) unstable; urgency=high
As of version 3, OpenSSH no longer uses separate files for ssh1 and ssh2
keys. This means the authorized_keys2 and known_hosts2 files are no longer
needed. They will still be read in order to maintain backward
compatibility.
-- Matthew Vernon <matthew@debian.org> Thu, 28 Nov 2001 17:43:01 +0000
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