tahoe-lafs/allmydata/manhole.py
2006-12-02 16:28:46 -07:00

272 lines
10 KiB
Python

# this is adapted from my code in Buildbot -warner
import os.path
import binascii, base64
from twisted.python import log
from twisted.application import service, strports
from twisted.cred import checkers, portal
from twisted.conch import manhole, telnet, manhole_ssh, checkers as conchc
from twisted.conch.insults import insults
from twisted.internet import protocol
from zope.interface import implements
# makeTelnetProtocol and _TelnetRealm are for the TelnetManhole
class makeTelnetProtocol:
# this curries the 'portal' argument into a later call to
# TelnetTransport()
def __init__(self, portal):
self.portal = portal
def __call__(self):
auth = telnet.AuthenticatingTelnetProtocol
return telnet.TelnetTransport(auth, self.portal)
class _TelnetRealm:
implements(portal.IRealm)
def __init__(self, namespace_maker):
self.namespace_maker = namespace_maker
def requestAvatar(self, avatarId, *interfaces):
if telnet.ITelnetProtocol in interfaces:
namespace = self.namespace_maker()
p = telnet.TelnetBootstrapProtocol(insults.ServerProtocol,
manhole.ColoredManhole,
namespace)
return (telnet.ITelnetProtocol, p, lambda: None)
raise NotImplementedError()
class chainedProtocolFactory:
# this curries the 'namespace' argument into a later call to
# chainedProtocolFactory()
def __init__(self, namespace):
self.namespace = namespace
def __call__(self):
return insults.ServerProtocol(manhole.ColoredManhole, self.namespace)
class AuthorizedKeysChecker(conchc.SSHPublicKeyDatabase):
"""Accept connections using SSH keys from a given file.
SSHPublicKeyDatabase takes the username that the prospective client has
requested and attempts to get a ~/.ssh/authorized_keys file for that
username. This requires root access, so it isn't as useful as you'd
like.
Instead, this subclass looks for keys in a single file, given as an
argument. This file is typically kept in the buildmaster's basedir. The
file should have 'ssh-dss ....' lines in it, just like authorized_keys.
"""
def __init__(self, authorized_keys_file):
self.authorized_keys_file = os.path.expanduser(authorized_keys_file)
def checkKey(self, credentials):
f = open(self.authorized_keys_file)
for l in f.readlines():
l2 = l.split()
if len(l2) < 2:
continue
try:
if base64.decodestring(l2[1]) == credentials.blob:
return 1
except binascii.Error:
continue
return 0
class ModifiedColoredManhole(manhole.ColoredManhole):
def connectionMade(self):
manhole.ColoredManhole.connectionMade(self)
self.keyHandlers["\x08"] = self.handle_BACKSPACE
self.keyHandlers["\x15"] = self.handle_KILLLINE
def handle_KILLLINE(self):
self.handle_END()
for i in range(len(self.lineBuffer)):
self.handle_BACKSPACE()
class _BaseManhole(service.MultiService):
"""This provides remote access to a python interpreter (a read/exec/print
loop) embedded in the buildmaster via an internal SSH server. This allows
detailed inspection of the buildmaster state. It is of most use to
buildbot developers. Connect to this by running an ssh client.
"""
def __init__(self, port, checker, using_ssh=True):
"""
@type port: string or int
@param port: what port should the Manhole listen on? This is a
strports specification string, like 'tcp:12345' or
'tcp:12345:interface=127.0.0.1'. Bare integers are treated as a
simple tcp port.
@type checker: an object providing the
L{twisted.cred.checkers.ICredentialsChecker} interface
@param checker: if provided, this checker is used to authenticate the
client instead of using the username/password scheme. You must either
provide a username/password or a Checker. Some useful values are::
import twisted.cred.checkers as credc
import twisted.conch.checkers as conchc
c = credc.AllowAnonymousAccess # completely open
c = credc.FilePasswordDB(passwd_filename) # file of name:passwd
c = conchc.UNIXPasswordDatabase # getpwnam() (probably /etc/passwd)
@type using_ssh: bool
@param using_ssh: If True, accept SSH connections. If False, accept
regular unencrypted telnet connections.
"""
# unfortunately, these don't work unless we're running as root
#c = credc.PluggableAuthenticationModulesChecker: PAM
#c = conchc.SSHPublicKeyDatabase() # ~/.ssh/authorized_keys
# and I can't get UNIXPasswordDatabase to work
service.MultiService.__init__(self)
if type(port) is int:
port = "tcp:%d" % port
self.port = port # for comparison later
self.checker = checker # to maybe compare later
def makeNamespace():
# close over 'self' so we can get access to .parent later
import debugshell
debugshell.app = self.parent # make client/queen accesible via 'app'
namespace = {}
for sym in dir(debugshell):
if sym.startswith('__') and sym.endswith('__'):
continue
namespace[sym] = getattr(debugshell, sym)
return namespace
def makeProtocol():
namespace = makeNamespace()
p = insults.ServerProtocol(ModifiedColoredManhole, namespace)
return p
self.using_ssh = using_ssh
if using_ssh:
r = manhole_ssh.TerminalRealm()
r.chainedProtocolFactory = makeProtocol
p = portal.Portal(r, [self.checker])
f = manhole_ssh.ConchFactory(p)
else:
r = _TelnetRealm(makeNamespace)
p = portal.Portal(r, [self.checker])
f = protocol.ServerFactory()
f.protocol = makeTelnetProtocol(p)
s = strports.service(self.port, f)
s.setServiceParent(self)
def startService(self):
service.MultiService.startService(self)
if self.using_ssh:
via = "via SSH"
else:
via = "via telnet"
log.msg("Manhole listening %s on port %s" % (via, self.port))
class TelnetManhole(_BaseManhole):
"""This Manhole accepts unencrypted (telnet) connections, and requires a
username and password authorize access. You are encouraged to use the
encrypted ssh-based manhole classes instead."""
def __init__(self, port, username, password):
"""
@type port: string or int
@param port: what port should the Manhole listen on? This is a
strports specification string, like 'tcp:12345' or
'tcp:12345:interface=127.0.0.1'. Bare integers are treated as a
simple tcp port.
@param username:
@param password: username= and password= form a pair of strings to
use when authenticating the remote user.
"""
self.username = username
self.password = password
c = checkers.InMemoryUsernamePasswordDatabaseDontUse()
c.addUser(username, password)
_BaseManhole.__init__(self, port, c, using_ssh=False)
class PasswordManhole(_BaseManhole):
"""This Manhole accepts encrypted (ssh) connections, and requires a
username and password to authorize access.
"""
def __init__(self, port, username, password):
"""
@type port: string or int
@param port: what port should the Manhole listen on? This is a
strports specification string, like 'tcp:12345' or
'tcp:12345:interface=127.0.0.1'. Bare integers are treated as a
simple tcp port.
@param username:
@param password: username= and password= form a pair of strings to
use when authenticating the remote user.
"""
self.username = username
self.password = password
c = checkers.InMemoryUsernamePasswordDatabaseDontUse()
c.addUser(username, password)
_BaseManhole.__init__(self, port, c)
class AuthorizedKeysManhole(_BaseManhole):
"""This Manhole accepts ssh connections, and requires that the
prospective client have an ssh private key that matches one of the public
keys in our authorized_keys file. It is created with the name of a file
that contains the public keys that we will accept."""
def __init__(self, port, keyfile):
"""
@type port: string or int
@param port: what port should the Manhole listen on? This is a
strports specification string, like 'tcp:12345' or
'tcp:12345:interface=127.0.0.1'. Bare integers are treated as a
simple tcp port.
@param keyfile: the name of a file (relative to the buildmaster's
basedir) that contains SSH public keys of authorized
users, one per line. This is the exact same format
as used by sshd in ~/.ssh/authorized_keys .
"""
# TODO: expanduser this, and make it relative to the buildmaster's
# basedir
self.keyfile = keyfile
c = AuthorizedKeysChecker(keyfile)
_BaseManhole.__init__(self, port, c)
class ArbitraryCheckerManhole(_BaseManhole):
"""This Manhole accepts ssh connections, but uses an arbitrary
user-supplied 'checker' object to perform authentication."""
def __init__(self, port, checker):
"""
@type port: string or int
@param port: what port should the Manhole listen on? This is a
strports specification string, like 'tcp:12345' or
'tcp:12345:interface=127.0.0.1'. Bare integers are treated as a
simple tcp port.
@param checker: an instance of a twisted.cred 'checker' which will
perform authentication
"""
_BaseManhole.__init__(self, port, checker)