Nmap: Get SSH issue banner message with Nmap

[manmolecular]

Greetings.

I am trying to get an issue.net message (Welcome or Warning banner message from /etc/issue.net file) from a remote SSH server, this message appears immediately after connecting to the server (before the password login prompt, so we don't need to enter a password - we just need to connect to the SSH server).

For example, it looks looks like this:

user@user-pc:~& ssh root@localhost
Ubuntu 18.04.1 LTS
root@localhost's password: 

As you can see, issue welcome message "Ubuntu 18.04.1 LTS" appears before password prompt.

I wanted to ask if there is a way to get this SSH issue.net banner message with Nmap or maybe with some NSE scripts without login? Can this be done with Nmap?

Thanks in advance.

[dmiller-nmap]

This is the SSH_MESSAGE_USERAUTH_BANNER message, which is delivered encrypted during authentication. We rely on libssh2 for SSH communication, and libssh2 does not currently support retrieving the banner. But I did take some time and implement it: libssh2/libssh2#274

I also have some private code to use this in NSE, but I can't release it until I have configure checks and preprocessor guards for the appropriate code, since it wouldn't build against anything but my patched version of libssh2. I hope to find a bit more time to work on this soon. Thanks for the idea!

[thesubtlety]

I'm interested in this feature as well. It looks like this is still pending an update to the libssh2 library -any plans to revisit? Thanks!

[heruan]

I'm also interested on this, is it currently possible?