def authentication_ok(self):
"""Checks the authentication and sets the username of the currently connected terminal.
Returns True or False"""
username = None
password = None
if self.authCallback:
if self.authNeedUser:
username = self.readline(prompt=str_to_bytes(self.PROMPT_USER),
use_history=False)
if self.authNeedPass:
password = self.readline(echo=False,
prompt=str_to_bytes(self.PROMPT_PASS),
use_history=False)
if self.DOECHO:
self.write(b"\n")
try:
self.authCallback(username, password)
except:
self.username = None
return False
else:
# Successful authentication
self.username = username
return True
else:
# No authentication desired
self.username = None
return True
def handle(self):
"""The actual service to which the user has connected."""
if self.TELNET_ISSUE:
self.writeline(self.TELNET_ISSUE)
if not self.authentication_ok():
return
if self.DOECHO:
self.writeline(self.WELCOME)
self.session_start()
while self.RUNSHELL:
raw_input = self.readline(prompt=str_to_bytes(self.PROMPT),
echo=True)
raw_input = raw_input.strip()
self.input = self.input_reader(self, raw_input)
self.raw_input = self.input.raw
if self.input.cmd:
cmd = bytes_to_str(self.input.cmd.upper())
params = [bytes_to_str(i) for i in self.input.params]
if cmd in self.COMMANDS:
try:
self.COMMANDS[cmd](params)
except:
log.exception('Error calling %s.' % cmd)
(t, p, tb) = sys.exc_info()
if self.handleException(t, p, tb):
break
else:
self.writeerror("Unknown command '%s'" % cmd)
log.debug("Exiting handler")
def writecooked(self, text):
"""Put data directly into the output queue (bypass output cooker)"""
self.sock.sendall(str_to_bytes(text))
def write(self, text):
"""Send a packet to the socket. This function cooks output."""
text = str_to_bytes(text) # eliminate any unicode or other snigglets
text = text.replace(IAC, IAC + IAC)
text = text.replace(chr_py3(10), chr_py3(13) + chr_py3(10))
self.writecooked(text)
def writemessage(self, text):
"""Write out an asynchr_py3onous message, then reconstruct the prompt and entered text."""
log.debug('writing message %r', text)
self.write(chr_py3(10) + str_to_bytes(text) + chr_py3(10))
self.write(self._current_prompt +
b''.join([chr_py3(i) for i in self._current_line]))
def writeline(self, text):
"""Send a packet with line ending."""
text = str_to_bytes(text) if isinstance(text, str) else text
log.debug('writing line %r' % text)
self.write(text + chr_py3(10))
def readline(self, echo=None, prompt='', use_history=True):
"""Return a line of text, including the terminating LF
If echo is true always echo, if echo is false never echo
If echo is None follow the negotiated setting.
prompt is the current prompt to write (and rewrite if needed)
use_history controls if this current line uses (and adds to) the command history.
"""
line = []
insptr = 0
ansi = 0
histptr = len(self.history)
prompt = str_to_bytes(prompt) if isinstance(prompt, str) else prompt
if self.DOECHO:
self.write(prompt)
self._current_prompt = prompt
else:
self._current_prompt = b''
self._current_line = b''
while True:
c = self.getc(block=True)
c = self.ansi_to_curses(c)
if c == theNULL:
continue
elif c == curses.KEY_LEFT:
if insptr > 0:
insptr = insptr - 1
self._readline_echo(self.CODES['CSRLEFT'], echo)
else:
self._readline_echo(BELL, echo)
continue
elif c == curses.KEY_RIGHT:
if insptr < len(line):
insptr = insptr + 1
self._readline_echo(self.CODES['CSRRIGHT'], echo)
else:
self._readline_echo(BELL, echo)
continue
elif c == curses.KEY_UP or c == curses.KEY_DOWN:
if not use_history:
self._readline_echo(BELL, echo)
continue
if c == curses.KEY_UP:
if histptr > 0:
histptr = histptr - 1
else:
self._readline_echo(BELL, echo)
continue
elif c == curses.KEY_DOWN:
if histptr < len(self.history):
histptr = histptr + 1
else:
self._readline_echo(BELL, echo)
continue
line = []
if histptr < len(self.history):
line.extend(self.history[histptr])
for char in range(insptr):
self._readline_echo(self.CODES['CSRLEFT'], echo)
self._readline_echo(self.CODES['DEOL'], echo)
self._readline_echo(b''.join([chr_py3(i) for i in line]), echo)
insptr = len(line)
continue
elif c == chr_py3(3):
self._readline_echo(
b'\n' + str_to_bytes(curses.ascii.unctrl(ord(c))) +
b' ABORT\n', echo)
return b''
elif c == chr_py3(4):
if len(line) > 0:
self._readline_echo(
b'\n' + str_to_bytes(curses.ascii.unctrl(ord(c))) +
b' ABORT (QUIT)\n', echo)
return b''
self._readline_echo(
b'\n' + str_to_bytes(curses.ascii.unctrl(ord(c))) +
b' QUIT\n', echo)
return b'QUIT'
elif c == chr_py3(10):
self._readline_echo(c, echo)
result = b''.join([chr_py3(i) for i in line])
if use_history:
self.history.append(result)
if echo is False:
if prompt:
self.write(chr_py3(10))
log.debug('readline: %s(hidden text)',
bytes_to_str(prompt))
else:
log.debug('readline: %s%r', bytes_to_str(prompt),
bytes_to_str(result))
return result
elif c == curses.KEY_BACKSPACE or c == chr_py3(
127) or c == chr_py3(8):
if insptr > 0:
self._readline_echo(
self.CODES['CSRLEFT'] + self.CODES['DEL'], echo)
insptr = insptr - 1
del line[insptr]
else:
self._readline_echo(BELL, echo)
continue
elif c == curses.KEY_DC:
if insptr < len(line):
self._readline_echo(self.CODES['DEL'], echo)
del line[insptr]
else:
self._readline_echo(BELL, echo)
continue
else:
if ord(c) < 32:
c = curses.ascii.unctrl(ord(c))
if len(line) > insptr:
self._readline_insert(c, echo, insptr, line)
else:
self._readline_echo(c, echo)
line[insptr:insptr] = c
insptr = insptr + len(c)
if self._readline_do_echo(echo):
self._current_line = line