from paramiko import SSHClient, AutoAddPolicy
from sys import exit

def connect(host, port, username, password):
    ssh_client = SSHClient()
    ssh_client.set_missing_host_key_policy(AutoAddPolicy())
    ssh_client.connect(host, port=port, username=username, password=password)
    return ssh_client.invoke_shell('raw')

def write_line(channel, line):
    channel.send(line + '\n')

def read_line(channel):
    if not hasattr(channel, 'line_buffer'):
        channel.line_buffer = ""
    while True:
        end_of_line = channel.line_buffer.find('\n\r')
        if not end_of_line == -1:
            line = channel.line_buffer[0:end_of_line]
            channel.line_buffer = channel.line_buffer[end_of_line+2:]
            return line
        channel.line_buffer += channel.recv(4096)

def execute(channel, command):
    result = []
    write_line(channel, command)
    while True:
        line = read_line(channel)
        result.append(line)
        if line.startswith('error'):
            return result

if __name__ == '__main__':
    channel = connect('localhost', 10022, 'serveradmin', 'secret')
    header = read_line(channel)
    if not header == 'TS3':
        exit('Not a TS3-Server...')
    motd = read_line(channel)

    result = execute(channel, 'whoami')
    print(result)

    execute(channel, 'quit')