OpenBSD Journal

SSH Protocol 1 Now Disabled at Compile Time

Contributed by pitrh on from the two-versions-enter-one-version-leaves dept.

As Damien Miller (djm@) announced on tech@, support for SSH version 1 is now no longer being included in OpenBSD SSH:


I just committed a change to src/usr.bin/ssh/ to compile- time disable SSH protocol 1. This protocol is old, unsafe and really, really shouldn't be used at all any more.

If you have need of it, then you can re-enable it for yourself using the knob in

If you run into bugs related to this change, please tell and we'll fix them quickly. We're deliberately doing this change early in the release cycle to flush out bugs and find out how many people are still using this terrible old protocol.


Like the man says, report any bugs found! And this might be a good time to offer the hand of friendship and understanding to any and all vendors/packagers who still support v1 to join the rest of us in deprecating the lesser protocols.

(Comments are closed)

  1. By Renaud Allard (renaud) on

    I was wondering when/if it would be removed. That's really good news security wise. People still using old ssh1 could as well use telnet nowadays.


Copyright © - Daniel Hartmeier. All rights reserved. Articles and comments are copyright their respective authors, submission implies license to publish on this web site. Contents of the archive prior to as well as images and HTML templates were copied from the fabulous original with Jose's and Jim's kind permission. This journal runs as CGI with httpd(8) on OpenBSD, the source code is BSD licensed. undeadly \Un*dead"ly\, a. Not subject to death; immortal. [Obs.]