mjhjmtu

I'm creating a Perl program that adds the specified host in root's known_hosts file. The program works in AIX and Linux, but not in Solaris and sadly, I can't find its equivalent command.

Sample line:

system("ssh-keyscan -H www.myserver.domain >> /.ssh/known_hosts");

Output:

ssh-keyscan: illegal option -- H
Usage: ssh-keyscan [-v46] [-p port] [-T timeout] [-f file]
[host | addrlist namelist] [...]

Update 1:

I tried the following command but it still asks for authenticity:

system("ssh-keyscan -t rsa www.myserver.domain >> /.ssh/known_hosts");

Update 2:
Output outside Perl:

# ssh-keyscan -t rsa www.myserver.domain >> /.ssh/test123.text 
# www.myserver.domain SSH-2.0-OpenSSH_6.7p1 Debian-5+deb8u3 
# less test123.text
# www.myserver.domain ssh-rsa KEY 
# ssh www.myserver.domain
# The authenticity of host 'www.myserver.domain (IP)' can't be established. RSA key fingerprint is FINGERPRINT. Are you sure you want to continue connecting (yes/no)?

Looking at the man page for ssh-keyscan on Solaris 10/11 doesn't look to support that switch.

ssh-keyscan [-v46] [-p port] [-T timeout] [-t type] 
 [-f file] [-] [host... | addrlist namelist] [...]

I think you can just do ssh-keyscan <hostname> however to retrieve the keys and then write them to your ~/.ssh/known_hosts file. This will still work but just won't put all the names that the host goes by on a single line like this:

hostname1, hostname1.fqdn.com .....

So you might have some cleanup work to do on the resulting known_hosts file.

Host authenticity

If you find you're encountering this issue which amounts to a catch 22, where you cannot scan a host that's not yet present in your known_hosts file:

The authenticity of host 'www.myserver.domain (IP)' can't be established. RSA key fingerprint is FINGERPRINT. Are you sure you want to continue connecting (yes/no)?

You can work around this issue by temporarily disabling StrictHostKeyChecking:

$ cat ~/.ssh/config
...
StrictHostKeyChecking no
...

Then do your keyscan <host> ... command again. Once you're complete, be sure to remove the StrictHostKeyChecking from your ~/.ssh/config.

References

• ssh_config man page