ssh-copy-id hangs when using ControlMaster auto

[Gabriele Vivinetto]

[Workaround]

ssh -O exit hostname # this will kill all ssh connection to that host
ssh-copy-id username@hostname # now it works because it's the first connection
# continue using ssh as normal.

Thanks to Ruben Laguna (ecerulm) in comment 7.

[Original Description]

On ubuntu 14.04 amd 64, running openssh-client 1:6.6p1-2ubuntu2, when using in ~/ssh/config
  ControlMaster auto

If you open an ssh connection to an host, and after try to run ssh-copy-id on the same host, trying to reuse the already opened connection, ssh-copy-id hangs.
If you press CTRL-D, the script goes on, without installing any key.

It seems that the script hangs at lines
 REMOTE_VERSION=$(ssh -v -o PreferredAuthentications=',' "$@" 2>&1 |
                  sed -ne 's/.*remote software version //p')

Found another bug report here: http://www.gossamer-threads.com/lists/openssh/bugs/57363

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: openssh-client 1:6.6p1-2ubuntu2
ProcVersionSignature: Ubuntu 3.13.0-32.56-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Jul 16 01:15:34 2014
InstallationDate: Installed on 2013-10-12 (276 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
RelatedPackageVersions:
 ssh-askpass N/A
 libpam-ssh N/A
 keychain N/A
 ssh-askpass-gnome 1:6.6p1-2ubuntu2
SSHClientVersion: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2, OpenSSL 1.0.1f 6 Jan 2014
SourcePackage: openssh
UpgradeStatus: Upgraded to trusty on 2014-06-10 (35 days ago)
modified.conffile..etc.ssh.ssh.config: [modified]
mtime.conffile..etc.ssh.ssh.config: 2014-06-19T17:39:06.965908

[Robie Basak (racb)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

I can see why it would hang on the line you've said - I presume the client will never see "remote software version" in this case.

I wonder if a fix would be to have line add "-Snone" to the ssh call, so that no control socket is ever used.

[Gabriele Vivinetto (gabriele.vivinetto)]

It would be nice to use control socket, because in this way, you don't have to enter password again to copy the ssh-key if you have an already connected session.

[Gabriele Vivinetto (gabriele.vivinetto)]

The problem is that when connecting using a control socket, it's not printed the line like:

 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3

So the variable REMOTE_VERSION is not set.

[Gabriele Vivinetto (gabriele.vivinetto)]

The version in saucy works perfectly:
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/saucy/openssh/saucy/view/head:/contrib/ssh-copy-id
It seems that the current is a huge rewrite ...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ruben Laguna (ecerulm)]

For reference to those that land here looking for a quick solution.

ssh -O exit hostname # this will kill all ssh connection to that host
ssh-copy-id username@hostname # now it works because it's the first connection
# continue using ssh as normal.

[Wil Tan (wil)]

You could also do:

ssh-copy-id -o ControlPath=none username@hostname

without killing the existing SSH connection.