diff options
| author | djm@openbsd.org <djm@openbsd.org> | 2017-09-03 23:33:13 +0000 |
|---|---|---|
| committer | Damien Miller <djm@mindrot.org> | 2017-09-04 09:38:57 +1000 |
| commit | 22376d27a349f62c502fec3396dfe0fdcb2a40b7 (patch) | |
| tree | 8368234874273df676d62ffab3bfc184ef58405f /ssh_config.5 | |
| parent | ff3c42384033514e248ba5d7376aa033f4a2b99a (diff) | |
| download | openssh-git-22376d27a349f62c502fec3396dfe0fdcb2a40b7.tar.gz | |
upstream commit
Expand ssh_config's StrictModes option with two new
settings:
StrictModes=accept-new will automatically accept hitherto-unseen keys
but will refuse connections for changed or invalid hostkeys.
StrictModes=off is the same as StrictModes=no
Motivation:
StrictModes=no combines two behaviours for host key processing:
automatically learning new hostkeys and continuing to connect to hosts
with invalid/changed hostkeys. The latter behaviour is quite dangerous
since it removes most of the protections the SSH protocol is supposed to
provide.
Quite a few users want to automatically learn hostkeys however, so
this makes that feature available with less danger.
At some point in the future, StrictModes=no will change to be a synonym
for accept-new, with its current behaviour remaining available via
StrictModes=off.
bz#2400, suggested by Michael Samuel; ok markus
Upstream-ID: 0f55502bf75fc93a74fb9853264a8276b9680b64
Diffstat (limited to 'ssh_config.5')
| -rw-r--r-- | ssh_config.5 | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/ssh_config.5 b/ssh_config.5 index 15ca0b4f..3823da6f 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -33,8 +33,8 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: ssh_config.5,v 1.253 2017/07/23 23:37:02 djm Exp $ -.Dd $Mdocdate: July 23 2017 $ +.\" $OpenBSD: ssh_config.5,v 1.254 2017/09/03 23:33:13 djm Exp $ +.Dd $Mdocdate: September 3 2017 $ .Dt SSH_CONFIG 5 .Os .Sh NAME @@ -1459,9 +1459,17 @@ frequently made. This option forces the user to manually add all new hosts. If this flag is set to -.Cm no , -ssh will automatically add new host keys to the -user known hosts files. +.Dq accept-new +then ssh will automatically add new new host keys to the user +known hosts files, but will not permit connections to hosts with +changed host keys. +If this flag is set to +.Dq no +or +.Dq off , +ssh will automatically add new host keys to the user known hosts files, +and allow connections to hosts with changed hostkeys to proceed subject +to some restrictions. If this flag is set to .Cm ask (the default), |