Bug 1529

Summary:	Need a method to add new configuration options in a backwards-compatible fashion (avoiding "Bad configuration option")
Product:	Portable OpenSSH	Reporter:	nectar
Component:	Miscellaneous	Assignee:	Assigned to nobody <unassigned-bugs>
Status:	CLOSED DUPLICATE
Severity:	normal	CC:	djm
Priority:	P2
Version:	5.1p1
Hardware:	All
OS:	All

Description nectar 2008-10-03 10:25:12 AEST

Currently the OpenSSH configuration options parser terminates when an unknown configuration option is encountered.  For example, OpenSSH implementations without Simon Wilkinson's Kerberos support patch will choke on user’s ssh_config files that contain Kerberos options.  This can be problematic for heterogenous environments, where configuration files might be shared (e.g. network home directory).

Another example are new extensions.  OpenSSH now has some platform-independent keychain support (although the only implementation is currently on Mac OS X).  There is no option to disable that support for certain hosts or globally.  Such an option cannot be added without making it impossible to share an ssh_config with older versions of OpenSSH or platforms without keychain support.

Comment 1 nectar 2008-10-03 10:35:33 AEST

Perhaps there should be some way to annotate “non-critical“ options that would not cause OpenSSH to barf if they were not understood, or a way to annotate minimum version required.  Folks who do not share configuration files can ignore the existence of such annotations.

Comment 2 Damien Miller 2015-05-01 15:03:19 AEST

There has been an IgnoreUnknown option in ssh_config for a while. E.g. you can stick something like this at the start of ~/.ssh/config:

IgnoreUnknown GSSAPI*

*** This bug has been marked as a duplicate of bug 866 ***

Comment 3 Damien Miller 2015-08-11 23:04:32 AEST

Set all RESOLVED bugs to CLOSED with release of OpenSSH 7.1