drive.

src/snekssh/app4.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3.7
+#
+# Copyright (c) 2013-2024 by Ron Frederick <ronf@timeheart.net> and others.
+#
+# This program and the accompanying materials are made available under
+# the terms of the Eclipse Public License v2.0 which accompanies this
+# distribution and is available at:
+#
+#     http://www.eclipse.org/legal/epl-2.0/
+#
+# This program may also be made available under the following secondary
+# licenses when the conditions for such availability set forth in the
+# Eclipse Public License v2.0 are satisfied:
+#
+#    GNU General Public License, Version 2.0, or any later versions of
+#    that license
+#
+# SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
+#
+# Contributors:
+#     Ron Frederick - initial implementation, API, and documentation
+
+# To run this program, the file ``ssh_host_key`` must exist with an SSH
+# private key in it to use as a server host key. An SSH host certificate
+# can optionally be provided in the file ``ssh_host_key-cert.pub``.
+
+import asyncio, asyncssh, bcrypt, sys
+from typing import Optional
+
+passwords = {'guest': b'',                # guest account with no password
+             'user': bcrypt.hashpw(b'user', bcrypt.gensalt()),
+            }
+
+def handle_client(process: asyncssh.SSHServerProcess) -> None:
+    username = process.get_extra_info('username')
+    process.stdout.write(f'Welcome to my SSH server, {username}!\n')
+    #process.exit(0)
+
+class MySSHServer(asyncssh.SSHServer):
+    def connection_made(self, conn: asyncssh.SSHServerConnection) -> None:
+        peername = conn.get_extra_info('peername')[0]
+        print(f'SSH connection received from {peername}.')
+
+    def connection_lost(self, exc: Optional[Exception]) -> None:
+        if exc:
+            print('SSH connection error: ' + str(exc), file=sys.stderr)
+        else:
+            print('SSH connection closed.')
+
+    def begin_auth(self, username: str) -> bool:
+        # If the user's password is the empty string, no auth is required
+        return passwords.get(username) != b''
+
+    def password_auth_supported(self) -> bool:
+        return True
+
+    def validate_password(self, username: str, password: str) -> bool:
+        if username not in passwords:
+            return False
+        pw = passwords[username]
+        if not password and not pw:
+            return True
+        return bcrypt.checkpw(password.encode('utf-8'), pw)
+
+async def start_server() -> None:
+    await asyncssh.create_server(MySSHServer, '', 2231,
+                                 server_host_keys=['ssh_host_key'],
+                                 process_factory=handle_client)
+
+loop = asyncio.new_event_loop()
+
+try:
+    loop.run_until_complete(start_server())
+except (OSError, asyncssh.Error) as exc:
+    sys.exit('Error starting server: ' + str(exc))
+
+loop.run_forever()