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# Copyright (c) 2001-2007 Twisted Matrix Laboratories.
# See LICENSE for details.
from twisted.cred import portal
from twisted.python import components, log
from twisted.internet.error import ProcessExitedAlready
from zope import interface
from ssh import session, forwarding, filetransfer
from ssh.filetransfer import FXF_READ, FXF_WRITE, FXF_APPEND, FXF_CREAT, FXF_TRUNC, FXF_EXCL
from twisted.conch.ls import lsLine
from avatar import ConchUser
from error import ConchError
from interfaces import ISession, ISFTPServer, ISFTPFile
import struct, os, time, socket
import fcntl, tty
import pwd, grp
import pty
import ttymodes
try:
import utmp
except ImportError:
utmp = None
class UnixSSHRealm:
interface.implements(portal.IRealm)
def requestAvatar(self, username, mind, *interfaces):
user = UnixConchUser(username)
return interfaces[0], user, user.logout
class UnixConchUser(ConchUser):
def __init__(self, username):
ConchUser.__init__(self)
self.username = username
self.pwdData = pwd.getpwnam(self.username)
l = [self.pwdData[3]]
for groupname, password, gid, userlist in grp.getgrall():
if username in userlist:
l.append(gid)
self.otherGroups = l
self.listeners = {} # dict mapping (interface, port) -> listener
self.channelLookup.update(
{"session": session.SSHSession,
"direct-tcpip": forwarding.openConnectForwardingClient})
self.subsystemLookup.update(
{"sftp": filetransfer.FileTransferServer})
def getUserGroupId(self):
return self.pwdData[2:4]
def getOtherGroups(self):
return self.otherGroups
def getHomeDir(self):
return self.pwdData[5]
def getShell(self):
return self.pwdData[6]
def global_tcpip_forward(self, data):
hostToBind, portToBind = forwarding.unpackGlobal_tcpip_forward(data)
from twisted.internet import reactor
try: listener = self._runAsUser(
reactor.listenTCP, portToBind,
forwarding.SSHListenForwardingFactory(self.conn,
(hostToBind, portToBind),
forwarding.SSHListenServerForwardingChannel),
interface = hostToBind)
except:
return 0
else:
self.listeners[(hostToBind, portToBind)] = listener
if portToBind == 0:
portToBind = listener.getHost()[2] # the port
return 1, struct.pack('>L', portToBind)
else:
return 1
def global_cancel_tcpip_forward(self, data):
hostToBind, portToBind = forwarding.unpackGlobal_tcpip_forward(data)
listener = self.listeners.get((hostToBind, portToBind), None)
if not listener:
return 0
del self.listeners[(hostToBind, portToBind)]
self._runAsUser(listener.stopListening)
return 1
def logout(self):
# remove all listeners
for listener in self.listeners.itervalues():
self._runAsUser(listener.stopListening)
log.msg('avatar %s logging out (%i)' % (self.username, len(self.listeners)))
def _runAsUser(self, f, *args, **kw):
euid = os.geteuid()
egid = os.getegid()
groups = os.getgroups()
uid, gid = self.getUserGroupId()
os.setegid(0)
os.seteuid(0)
os.setgroups(self.getOtherGroups())
os.setegid(gid)
os.seteuid(uid)
try:
f = iter(f)
except TypeError:
f = [(f, args, kw)]
try:
for i in f:
func = i[0]
args = len(i)>1 and i[1] or ()
kw = len(i)>2 and i[2] or {}
r = func(*args, **kw)
finally:
os.setegid(0)
os.seteuid(0)
os.setgroups(groups)
os.setegid(egid)
os.seteuid(euid)
return r
class SSHSessionForUnixConchUser:
interface.implements(ISession)
def __init__(self, avatar):
self.avatar = avatar
self. environ = {'PATH':'/bin:/usr/bin:/usr/local/bin'}
self.pty = None
self.ptyTuple = 0
def addUTMPEntry(self, loggedIn=1):
if not utmp:
return
ipAddress = self.avatar.conn.transport.transport.getPeer().host
packedIp ,= struct.unpack('L', socket.inet_aton(ipAddress))
ttyName = self.ptyTuple[2][5:]
t = time.time()
t1 = int(t)
t2 = int((t-t1) * 1e6)
entry = utmp.UtmpEntry()
entry.ut_type = loggedIn and utmp.USER_PROCESS or utmp.DEAD_PROCESS
entry.ut_pid = self.pty.pid
entry.ut_line = ttyName
entry.ut_id = ttyName[-4:]
entry.ut_tv = (t1,t2)
if loggedIn:
entry.ut_user = self.avatar.username
entry.ut_host = socket.gethostbyaddr(ipAddress)[0]
entry.ut_addr_v6 = (packedIp, 0, 0, 0)
a = utmp.UtmpRecord(utmp.UTMP_FILE)
a.pututline(entry)
a.endutent()
b = utmp.UtmpRecord(utmp.WTMP_FILE)
b.pututline(entry)
b.endutent()
def getPty(self, term, windowSize, modes):
self.environ['TERM'] = term
self.winSize = windowSize
self.modes = modes
master, slave = pty.openpty()
ttyname = os.ttyname(slave)
self.environ['SSH_TTY'] = ttyname
self.ptyTuple = (master, slave, ttyname)
def openShell(self, proto):
from twisted.internet import reactor
if not self.ptyTuple: # we didn't get a pty-req
log.msg('tried to get shell without pty, failing')
raise ConchError("no pty")
uid, gid = self.avatar.getUserGroupId()
homeDir = self.avatar.getHomeDir()
shell = self.avatar.getShell()
self.environ['USER'] = self.avatar.username
self.environ['HOME'] = homeDir
self.environ['SHELL'] = shell
shellExec = os.path.basename(shell)
peer = self.avatar.conn.transport.transport.getPeer()
host = self.avatar.conn.transport.transport.getHost()
self.environ['SSH_CLIENT'] = '%s %s %s' % (peer.host, peer.port, host.port)
self.getPtyOwnership()
self.pty = reactor.spawnProcess(proto, \
shell, ['-%s' % shellExec], self.environ, homeDir, uid, gid,
usePTY = self.ptyTuple)
self.addUTMPEntry()
fcntl.ioctl(self.pty.fileno(), tty.TIOCSWINSZ,
struct.pack('4H', *self.winSize))
if self.modes:
self.setModes()
self.oldWrite = proto.transport.write
proto.transport.write = self._writeHack
self.avatar.conn.transport.transport.setTcpNoDelay(1)
def execCommand(self, proto, cmd):
from twisted.internet import reactor
uid, gid = self.avatar.getUserGroupId()
homeDir = self.avatar.getHomeDir()
shell = self.avatar.getShell() or '/bin/sh'
command = (shell, '-c', cmd)
peer = self.avatar.conn.transport.transport.getPeer()
host = self.avatar.conn.transport.transport.getHost()
self.environ['SSH_CLIENT'] = '%s %s %s' % (peer.host, peer.port, host.port)
if self.ptyTuple:
self.getPtyOwnership()
self.pty = reactor.spawnProcess(proto, \
shell, command, self.environ, homeDir,
uid, gid, usePTY = self.ptyTuple or 0)
if self.ptyTuple:
self.addUTMPEntry()
if self.modes:
self.setModes()
# else:
# tty.setraw(self.pty.pipes[0].fileno(), tty.TCSANOW)
self.avatar.conn.transport.transport.setTcpNoDelay(1)
def getPtyOwnership(self):
ttyGid = os.stat(self.ptyTuple[2])[5]
uid, gid = self.avatar.getUserGroupId()
euid, egid = os.geteuid(), os.getegid()
os.setegid(0)
os.seteuid(0)
try:
os.chown(self.ptyTuple[2], uid, ttyGid)
finally:
os.setegid(egid)
os.seteuid(euid)
def setModes(self):
pty = self.pty
attr = tty.tcgetattr(pty.fileno())
for mode, modeValue in self.modes:
if not ttymodes.TTYMODES.has_key(mode): continue
ttyMode = ttymodes.TTYMODES[mode]
if len(ttyMode) == 2: # flag
flag, ttyAttr = ttyMode
if not hasattr(tty, ttyAttr): continue
ttyval = getattr(tty, ttyAttr)
if modeValue:
attr[flag] = attr[flag]|ttyval
else:
attr[flag] = attr[flag]&~ttyval
elif ttyMode == 'OSPEED':
attr[tty.OSPEED] = getattr(tty, 'B%s'%modeValue)
elif ttyMode == 'ISPEED':
attr[tty.ISPEED] = getattr(tty, 'B%s'%modeValue)
else:
if not hasattr(tty, ttyMode): continue
ttyval = getattr(tty, ttyMode)
attr[tty.CC][ttyval] = chr(modeValue)
tty.tcsetattr(pty.fileno(), tty.TCSANOW, attr)
def eofReceived(self):
if self.pty:
self.pty.closeStdin()
def closed(self):
if self.ptyTuple and os.path.exists(self.ptyTuple[2]):
ttyGID = os.stat(self.ptyTuple[2])[5]
os.chown(self.ptyTuple[2], 0, ttyGID)
if self.pty:
try:
self.pty.signalProcess('HUP')
except (OSError,ProcessExitedAlready):
pass
self.pty.loseConnection()
self.addUTMPEntry(0)
log.msg('shell closed')
def windowChanged(self, winSize):
self.winSize = winSize
fcntl.ioctl(self.pty.fileno(), tty.TIOCSWINSZ,
struct.pack('4H', *self.winSize))
def _writeHack(self, data):
"""
Hack to send ignore messages when we aren't echoing.
"""
if self.pty is not None:
attr = tty.tcgetattr(self.pty.fileno())[3]
if not attr & tty.ECHO and attr & tty.ICANON: # no echo
self.avatar.conn.transport.sendIgnore('\x00'*(8+len(data)))
self.oldWrite(data)
class SFTPServerForUnixConchUser:
interface.implements(ISFTPServer)
def __init__(self, avatar):
self.avatar = avatar
def _setAttrs(self, path, attrs):
"""
NOTE: this function assumes it runs as the logged-in user:
i.e. under _runAsUser()
"""
if attrs.has_key("uid") and attrs.has_key("gid"):
os.chown(path, attrs["uid"], attrs["gid"])
if attrs.has_key("permissions"):
os.chmod(path, attrs["permissions"])
if attrs.has_key("atime") and attrs.has_key("mtime"):
os.utime(path, (attrs["atime"], attrs["mtime"]))
def _getAttrs(self, s):
return {
"size" : s.st_size,
"uid" : s.st_uid,
"gid" : s.st_gid,
"permissions" : s.st_mode,
"atime" : int(s.st_atime),
"mtime" : int(s.st_mtime)
}
def _absPath(self, path):
home = self.avatar.getHomeDir()
return os.path.abspath(os.path.join(home, path))
def gotVersion(self, otherVersion, extData):
return {}
def openFile(self, filename, flags, attrs):
return UnixSFTPFile(self, self._absPath(filename), flags, attrs)
def removeFile(self, filename):
filename = self._absPath(filename)
return self.avatar._runAsUser(os.remove, filename)
def renameFile(self, oldpath, newpath):
oldpath = self._absPath(oldpath)
newpath = self._absPath(newpath)
return self.avatar._runAsUser(os.rename, oldpath, newpath)
def makeDirectory(self, path, attrs):
path = self._absPath(path)
return self.avatar._runAsUser([(os.mkdir, (path,)),
(self._setAttrs, (path, attrs))])
def removeDirectory(self, path):
path = self._absPath(path)
self.avatar._runAsUser(os.rmdir, path)
def openDirectory(self, path):
return UnixSFTPDirectory(self, self._absPath(path))
def getAttrs(self, path, followLinks):
path = self._absPath(path)
if followLinks:
s = self.avatar._runAsUser(os.stat, path)
else:
s = self.avatar._runAsUser(os.lstat, path)
return self._getAttrs(s)
def setAttrs(self, path, attrs):
path = self._absPath(path)
self.avatar._runAsUser(self._setAttrs, path, attrs)
def readLink(self, path):
path = self._absPath(path)
return self.avatar._runAsUser(os.readlink, path)
def makeLink(self, linkPath, targetPath):
linkPath = self._absPath(linkPath)
targetPath = self._absPath(targetPath)
return self.avatar._runAsUser(os.symlink, targetPath, linkPath)
def realPath(self, path):
return os.path.realpath(self._absPath(path))
def extendedRequest(self, extName, extData):
raise NotImplementedError
class UnixSFTPFile:
interface.implements(ISFTPFile)
def __init__(self, server, filename, flags, attrs):
self.server = server
openFlags = 0
if flags & FXF_READ == FXF_READ and flags & FXF_WRITE == 0:
openFlags = os.O_RDONLY
if flags & FXF_WRITE == FXF_WRITE and flags & FXF_READ == 0:
openFlags = os.O_WRONLY
if flags & FXF_WRITE == FXF_WRITE and flags & FXF_READ == FXF_READ:
openFlags = os.O_RDWR
if flags & FXF_APPEND == FXF_APPEND:
openFlags |= os.O_APPEND
if flags & FXF_CREAT == FXF_CREAT:
openFlags |= os.O_CREAT
if flags & FXF_TRUNC == FXF_TRUNC:
openFlags |= os.O_TRUNC
if flags & FXF_EXCL == FXF_EXCL:
openFlags |= os.O_EXCL
if attrs.has_key("permissions"):
mode = attrs["permissions"]
del attrs["permissions"]
else:
mode = 0777
fd = server.avatar._runAsUser(os.open, filename, openFlags, mode)
if attrs:
server.avatar._runAsUser(server._setAttrs, filename, attrs)
self.fd = fd
def close(self):
return self.server.avatar._runAsUser(os.close, self.fd)
def readChunk(self, offset, length):
return self.server.avatar._runAsUser([ (os.lseek, (self.fd, offset, 0)),
(os.read, (self.fd, length)) ])
def writeChunk(self, offset, data):
return self.server.avatar._runAsUser([(os.lseek, (self.fd, offset, 0)),
(os.write, (self.fd, data))])
def getAttrs(self):
s = self.server.avatar._runAsUser(os.fstat, self.fd)
return self.server._getAttrs(s)
def setAttrs(self, attrs):
raise NotImplementedError
class UnixSFTPDirectory:
def __init__(self, server, directory):
self.server = server
self.files = server.avatar._runAsUser(os.listdir, directory)
self.dir = directory
def __iter__(self):
return self
def next(self):
try:
f = self.files.pop(0)
except IndexError:
raise StopIteration
else:
s = self.server.avatar._runAsUser(os.lstat, os.path.join(self.dir, f))
longname = lsLine(f, s)
attrs = self.server._getAttrs(s)
return (f, longname, attrs)
def close(self):
self.files = []
components.registerAdapter(SFTPServerForUnixConchUser, UnixConchUser, filetransfer.ISFTPServer)
components.registerAdapter(SSHSessionForUnixConchUser, UnixConchUser, session.ISession)
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