SlackwareThis Forum is for the discussion of Slackware Linux.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
With today's release of OpenSSH 6.5, the OpenSSH development team reminds us why they've enjoyed such remarkable success since
project inception in late 1999.
OpenSSH 6.5 (sig) unveils an impressive number of new cryptographic primitives. Most noteworthy:
Key Exchange
ECDH over Curve25519 (curve25519-sha256@libssh.org), contributed by the libssh project, was added to complement existing
key exchange algorithms.
Bernstein's Curve25519 is resistant to twist and Pohlig-Hellman attacks and its prime (2²⁵⁵-19) is considered large enough to
adequately mitigate other attacks against ECC such as baby-step/giant-step, negating ρ, Pollard's ρ, and Oorschot-Wiener
parallel ρ. This makes it a particularly good choice for ECDH.
In addition, the DH group exchange algorithm was modified so clients request larger DH groups for each symmetric key size
(improving security associated with key agreement when using DH GEX).
Ciphers
chacha20-poly1305@openssh.com, a new authenticated encryption mode cipher, augments the current cipher set.
This AE cipher is a combination of ChaCha, a stream cipher which was used as the basis for the BLAKE hash (top five SHA-3
finalist), and Poly1305-AES, a MAC considered equal in cryptographic strength to AES.
Keys
A new Ed25519 public-key format (which can be used for both user and server keys) provides cryptographic security roughly
equivalent to 3072-bit RSA keys. Ed25519 signatures, generated deterministically unlike ECDSA, avoid certain attack vectors
associated with poor quality entropy sources (cf. Sony PS3 ECDSA security breach).
Private Key Format
A bcrypt KDF private key format provides significantly greater at-rest brute force resistance than the traditional PEM format.
The new format, automatically used for Ed25519 keys, can also be used with other key types (RSA, DSA, ECDSA) through the
"-o" ssh-keygen flag.
Note: existing keys can easily be upgraded to bcrypt KDF format with:
Code:
$ ssh-keygen -o -p -f $KEYNAME [-a $ROUNDS]
Congratulations and thanks to the entire OpenSSH team (Markus Friedl, Niels Provos, Theo de Raadt, Kevin Steves, Damien Miller,
Darren Tucker, Jason McIntyre, Tim Rice, and Ben Lindstrom) for a stellar release!
--mancha
Last edited by mancha; 02-01-2014 at 07:23 PM.
Reason: superscript
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.