Connecting through SSH tunnels fails for Mac

[mmuszkow]

Connecting to macOS (via asyncssh) with SSH tunnel fails every time, connecting without tunnel works fine. The behaviour is consistent on macOS 12, 13, 14.

async with asyncssh.connect(client.hostname, username=client.username, password=client.password, known_hosts=None) as ssh_conn:
    result = await ssh_conn.run('uname -a', check=True)
    print(client.username, client.hostname, result.stdout, end='')
    async with asyncvnc.connect(client.hostname, port=client.port, username=client.username, password=client.password, opener=ssh_conn.open_connection) as vnc_client:

The VNC server drops connection (<class 'asyncio.exceptions.IncompleteReadError'> 0 bytes read on a total of 4 expected bytes):

1. After client sends \x00\x00\x00\x0a\x01\x00RSA1\x00\x00\x00\x00 if no host key specified.
2. After client sends \x00\x00\x01\x8a\x01\x00RSA1 + credentials if host key specified.

I tried to put localhost instead of hostname in asyncssh.connect - result is the same.