Fixed crash when receiving unexpected response during host key test.

README.md

@@ -159,6 +159,7 @@ For convenience, a web front-end on top of the command-line tool is available at
 ## ChangeLog
 ### v2.4.0-dev (???)
  - Added version check for OpenSSH user enumeration (CVE-2018-15473).
+ - Fixed crash when receiving unexpected response during host key test.
 
 ### v2.3.1 (2020-10-28)
  - Now parses public key sizes for `rsa-sha2-256-cert-v01@openssh.com` and `rsa-sha2-512-cert-v01@openssh.com` host key types.

src/ssh_audit/hostkeytest.py

@@ -135,9 +135,12 @@ class HostKeyTest:
                 # Do the initial DH exchange.  The server responds back
                 # with the host key and its length.  Bingo.  We also get back the host key fingerprint.
                 kex_group.send_init(s)
+                try:
                     host_key = kex_group.recv_reply(s, variable_key_len)
                     if host_key is not None:
                         server_kex.set_host_key(host_key_type, host_key)
+                except Exception:
+                    pass
 
                 hostkey_modulus_size = kex_group.get_hostkey_size()
                 ca_modulus_size = kex_group.get_ca_size()