Re: Can an SSH_MSG_EXT_INFO have zero entries?

Peter Gutmann <[email protected]> Mon, 3 Apr 2023 10:53:06 +0000
Newsgroups gmane.ietf.secsh
Message-ID <SY4PR01MB62515F6B6932F6CFB66F106BEE929@SY4PR01MB6251.ausprd01.prod.outlook.com>
I wrote:

>It's technically legal according to the spec, but then so is a message with
>four billion extensions (assuming the packet length requirement is met).
>However, both of those values indicate that there's something severely wrong
>with the implementation sending it, sort of like running into someone wearing
>their underpants on their head the instinctive response is to cross the
>street to avoid them.

Just got a debug trace for the server that does this:

Read SSH ID string:
0000: 53 53 48 2D 32 2E 30 2D 41 7A 75 72 65 53 53 48 SSH-2.0-AzureSSH
0016: 5F 31 2E 30 2E 30                               _1.0.0

So Microsoft have done their own SSH implementation, and it's the one sending
this nonsensical message.

Of course it would be.

Peter.