Fix issue with SSH config reloading with Hostname aliases

This commit fixes an issue where SSH config was not evaluating properly
when "Match final" was combined with Hostname directives. Thanks go to
GitHub user commonism for reporting this issue and coming up with a
reproducible test case and a potential fix.

Author: ronf

asyncssh/connection.py

@@ -282,7 +282,7 @@ async def _canonicalize_host(loop: asyncio.AbstractEventLoop,
                              options: 'SSHConnectionOptions') -> Optional[str]:
     """Canonicalize a host name"""
 
-    host = options.host
+    host = options.orig_host
 
     if not options.canonicalize_hostname or not options.canonical_domains:
         logger.info('Host canonicalization disabled')
@@ -474,7 +474,7 @@ async def _connect(options: _Options, config: DefTuple[ConfigPaths],
 
     canon_host = await _canonicalize_host(loop, options)
 
-    host = canon_host if canon_host else options.host
+    host = canon_host if canon_host else options.orig_host
     canonical = bool(canon_host)
     final = options.config.has_match_final()
 
@@ -7295,6 +7295,7 @@ class SSHConnectionOptions(Options, Generic[_Options]):
     waiter: Optional[asyncio.Future]
     protocol_factory: _ProtocolFactory
     version: bytes
+    orig_host: str
     host: str
     port: int
     tunnel: object
@@ -7387,6 +7388,7 @@ def _split_cname_patterns(
         self.protocol_factory = protocol_factory
         self.version = _validate_version(version)
 
+        self.orig_host = host
         self.host = cast(str, config.get('Hostname', host))
         self.port = cast(int, port if port != () else
             config.get('Port', DEFAULT_PORT))

tests/test_forward.py

@@ -435,6 +435,30 @@ async def test_proxy_jump_encrypted_key_missing_passphrase(self):
         finally:
             os.remove('.ssh/config')
 
+    @asynctest
+    async def test_proxy_jump_config(self):
+        """Test ProxyJump to a host with config options"""
+
+        jump_host = await self.create_server(
+            _TCPConnectionServer, authorized_client_keys='authorized_keys')
+        jump_port = jump_host.get_port()
+
+        try:
+            write_file('.ssh/config',
+                       'Host jumphost\n'
+                       '  Hostname localhost\n'
+                       f'  Port {jump_port}\n'
+                       'Match final host  target\n'
+                       '  Hostname localhost\n'
+                       f'  Port {self._server_port}\n'
+                       '  ProxyJump jumphost\n', 'w')
+
+            async with self.connect(host='target', username='ckey'):
+                pass
+        finally:
+            jump_host.close()
+            os.remove('.ssh/config')
+
     @asynctest
     async def test_ssh_connect_reverse_tunnel(self):
         """Test creating a tunneled reverse direction SSH connection"""