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 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 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 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 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 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 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 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 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 Thu, 28 Nov 2001 17:43:01 +0000