Added check for correct paramiko version at runtime to mitigate version problems.

pwncat/__main__.py

@@ -4,9 +4,11 @@ import selectors
 import shlex
 import sys
 import warnings
+import inspect
 
 from sqlalchemy import exc as sa_exc
 from sqlalchemy.exc import InvalidRequestError
+from paramiko.buffered_pipe import BufferedPipe
 
 import pwncat
 from pwncat.util import console
@@ -15,71 +17,79 @@ from pwncat.remote import Victim
 
 def main():
 
-    # Default log-level is "INFO"
-    logging.getLogger().setLevel(logging.INFO)
+    params = inspect.signature(BufferedPipe.read).parameters
 
-    # Build the victim object
-    pwncat.victim = Victim()
-
-    # Arguments to `pwncat` are considered arguments to `connect`
-    # We use the `prog_name` argument to make the help for "connect"
-    # display "pwncat" in the usage. This is just a visual fix, and
-    # isn't used anywhere else.
-    pwncat.victim.command_parser.dispatch_line(
-        shlex.join(["connect"] + sys.argv[1:]), prog_name="pwncat"
-    )
-
-    # Only continue if we successfully connected
-    if not pwncat.victim.connected:
-        exit(0)
-
-    # Setup the selector to wait for data asynchronously from both streams
-    selector = selectors.DefaultSelector()
-    selector.register(sys.stdin, selectors.EVENT_READ, None)
-    selector.register(pwncat.victim.client, selectors.EVENT_READ, "read")
-
-    # Initialize our state
-    done = False
-
-    try:
-        # This loop is only used to funnel data between the local
-        # and remote hosts when in raw mode. During the `pwncat`
-        # prompt, the main loop is handled by the CommandParser
-        # class `run` method.
-        while not done:
-            for k, _ in selector.select():
-                if k.fileobj is sys.stdin:
-                    data = sys.stdin.buffer.read(1)
-                    pwncat.victim.process_input(data)
-                else:
-                    data = pwncat.victim.recv()
-                    if data is None or len(data) == 0:
-                        done = True
-                        break
-                    sys.stdout.buffer.write(data)
-                    sys.stdout.flush()
-    except ConnectionResetError:
-        pwncat.victim.restore_local_term()
-        console.log("[yellow]warning[/yellow]: connection reset by remote host")
-    except SystemExit:
-        console.log("closing connection")
-    finally:
-        # Restore the shell
-        pwncat.victim.restore_local_term()
-        try:
-            # Make sure everything was committed
-            pwncat.victim.session.commit()
-        except InvalidRequestError:
-            pass
-        console.log("local terminal restored")
-
-
-if __name__ == "__main__":
+    if "flags" not in params:
+        console.log(
+            f"[red]error[/red]: pwncat requires a custom fork of paramiko. This can be installed with `pip install -U git+https://github.com/calebstewart/paramiko`"
+        )
+        sys.exit(1)
 
     # Ignore SQL Alchemy warnings
     with warnings.catch_warnings():
         warnings.simplefilter("ignore", category=sa_exc.SAWarning)
 
-        main()
+        # Default log-level is "INFO"
+        logging.getLogger().setLevel(logging.INFO)
+
+        # Build the victim object
+        pwncat.victim = Victim()
+
+        # Arguments to `pwncat` are considered arguments to `connect`
+        # We use the `prog_name` argument to make the help for "connect"
+        # display "pwncat" in the usage. This is just a visual fix, and
+        # isn't used anywhere else.
+        pwncat.victim.command_parser.dispatch_line(
+            shlex.join(["connect"] + sys.argv[1:]), prog_name="pwncat"
+        )
+
+        # Only continue if we successfully connected
+        if not pwncat.victim.connected:
+            exit(0)
+
+        # Setup the selector to wait for data asynchronously from both streams
+        selector = selectors.DefaultSelector()
+        selector.register(sys.stdin, selectors.EVENT_READ, None)
+        selector.register(pwncat.victim.client, selectors.EVENT_READ, "read")
+
+        # Initialize our state
+        done = False
+
+        try:
+            # This loop is only used to funnel data between the local
+            # and remote hosts when in raw mode. During the `pwncat`
+            # prompt, the main loop is handled by the CommandParser
+            # class `run` method.
+            while not done:
+                for k, _ in selector.select():
+                    if k.fileobj is sys.stdin:
+                        data = sys.stdin.buffer.read(1)
+                        pwncat.victim.process_input(data)
+                    else:
+                        data = pwncat.victim.recv()
+                        if data is None or len(data) == 0:
+                            done = True
+                            break
+                        sys.stdout.buffer.write(data)
+                        sys.stdout.flush()
+        except ConnectionResetError:
+            pwncat.victim.restore_local_term()
+            console.log("[yellow]warning[/yellow]: connection reset by remote host")
+        except SystemExit:
+            console.log("closing connection")
+        finally:
+            # Restore the shell
+            pwncat.victim.restore_local_term()
+            try:
+                # Make sure everything was committed
+                pwncat.victim.session.commit()
+            except InvalidRequestError:
+                pass
+                console.log("local terminal restored")
+
+
+if __name__ == "__main__":
+
+    main()
 
     sys.exit(0)