Fixed invalid JSON output when a socket error occurs while performing a client audit. (#295)

README.md

@@ -221,6 +221,7 @@ For convenience, a web front-end on top of the command-line tool is available at
  - Fixed crash when running with `-P` and `-T` options simultaneously.
  - Fixed host key tests from only reporting a key type at most once despite multiple hosts supporting it; credit [Daniel Lenski](https://github.com/dlenskiSB).
  - Fixed DHEat connection rate testing on MacOS X and BSD platforms; credit [Drew Noel](https://github.com/drewmnoel) and [Michael Osipov](https://github.com/michael-o).
+ - Fixed invalid JSON output when a socket error occurs while performing a client audit.
  - Added 1 new cipher: `grasshopper-ctr128`.
  - Added 2 new key exchanges: `mlkem768x25519-sha256`, `sntrup761x25519-sha512`.
 

src/ssh_audit/ssh_socket.py

@@ -108,7 +108,7 @@ class SSH_Socket(ReadBuf, WriteBuf):
             s.listen()
             self.__sock_map[s.fileno()] = s
         except Exception as e:
-            print("Warning: failed to listen on any IPv4 interfaces: %s" % str(e))
+            print("Warning: failed to listen on any IPv4 interfaces: %s" % str(e), file=sys.stderr)
 
         try:
             # Socket to listen on all IPv6 addresses.
@@ -119,11 +119,11 @@ class SSH_Socket(ReadBuf, WriteBuf):
             s.listen()
             self.__sock_map[s.fileno()] = s
         except Exception as e:
-            print("Warning: failed to listen on any IPv6 interfaces: %s" % str(e))
+            print("Warning: failed to listen on any IPv6 interfaces: %s" % str(e), file=sys.stderr)
 
         # If we failed to listen on any interfaces, terminate.
         if len(self.__sock_map.keys()) == 0:
-            print("Error: failed to listen on any IPv4 and IPv6 interfaces!")
+            print("Error: failed to listen on any IPv4 and IPv6 interfaces!", file=sys.stderr)
             sys.exit(exitcodes.CONNECTION_ERROR)
 
         # Wait for an incoming connection.  If a timeout was explicitly