Fix SSH brute-force success detection and error handling

nettacker/core/lib/ssh.py

@@ -1,41 +1,57 @@
 import logging
-
-from paramiko import SSHClient, AutoAddPolicy
+import socket
+from paramiko import SSHClient, AutoAddPolicy, AuthenticationException, SSHException
 from paramiko.auth_strategy import NoneAuth, Password
-
 from nettacker.core.lib.base import BaseEngine, BaseLibrary
 
 logging.getLogger("paramiko.transport").disabled = True
 
-
 class SshLibrary(BaseLibrary):
     client = SSHClient
 
     def brute_force(self, *args, **kwargs):
         host = kwargs["host"]
         port = kwargs["port"]
         username = kwargs["username"]
-        password = kwargs["password"]
+        password = kwargs.get("password")
+        timeout = kwargs.get("timeout", 3)
 
         connection = self.client()
         connection.set_missing_host_key_policy(AutoAddPolicy())
-        connection.connect(
-            **{
-                "hostname": host,
+
+        try:
+            connection.connect(
+                hostname=host,
+                port=port,
+                auth_strategy=Password(username=username, password_getter=lambda: password) if password else NoneAuth(username=username),
+                timeout=timeout,
+                look_for_keys=False,
+                allow_agent=False,
+                banner_timeout=timeout,
+            )
+            transport = connection.get_transport()
+            if not transport or not transport.is_active():
+                return {}
+            return {
+                "host": host,
                 "port": port,
-                "auth_strategy": Password(username=username, password_getter=lambda: password)
-                if password
-                else NoneAuth(username=username),
+                "username": username,
+                "password": password if password else "",
             }
-        )
-
-        return {
-            "host": host,
-            "port": port,
-            "username": username,
-            "password": password,
-        }
 
+        except AuthenticationException:
+            return {}
+        except SSHException:
+            return {}
+        except (socket.timeout, socket.error, ConnectionRefusedError, OSError):
+            return {}
+        except Exception:
+            return {}
+        finally:
+            try:
+                connection.close()
+            except Exception:
+                pass
 
 class SshEngine(BaseEngine):
     library = SshLibrary