macbook promacosssh
There seems to be two different SSH client versions on my Macbook Pro running Sierra (10.12.4). If I do the following:
$> ssh dev
It works just fine. However, if I do the following:
$> open ssh://dev
It opens a new terminal which then complains about the encryption settings in my ssh_config file. Researching the specific complaints, I found out that opening through the protocol handler is using an older version of SSH.
How do I change which SSH client the protocol redirects to?
Here's what happened. On the machines I was trying to reach (10.x.y.182 and 10.x.y.194), in the time when I was not using them they had their hard disks replaced and the OS reinstalled. This gave them new SSH keys, invalidating the ones I had in my ~/.ssh/known_hosts file. Unfortunately, Terminal.app did not surface this problem to me.
By deleting the entries for those machines in ~/.ssh/known_hosts, I forced the system to pull down the new keys and ask me if I wanted to use them. With this done, connections worked perfectly as usual. Oddly, however, even before I changed ~/.ssh/known_hosts, connections using the DNS name of the machine (svr10 and svr20) worked. Weird.
Thanks, everyone, who looked at this problem.
Turns out there were two problems here:
First, PuTTY wasn't actually sending any locale information. Apparently the Linux servers were configuring the locale automatically, or based on TERM or something. I fixed PuTTY by configuring environment variables for it to send:
Second, I'm using MacPorts (updated question since this was missing in the original), and MacPorts ssh does not send locale variables. I can't imagine why MacPorts configures SSH this way, but I had to add the following to /opt/local/etc/ssh/ssh_config:
Host *
SendEnv LANG LC_*
That really ought to be the default MacPorts config; it's the default on any standard Linux system, and it's even the default in OSX's own SSH. Figured out that MacPorts was part of the problem when SSH from Linux to OSX did set the locale.
I've filed a ticket with MacPorts suggesting the default be changed.
Best Answer
You can use a tool that is very comfortable to change the default app for specific URL handlers.
Change the ssh URL scheme with RCDefaultApp
It will look very similar to this screenshot: