我目前正在通过蛮力学习 ssh/只是继续破解，直到我理解它的方法。经过反复试验，我已经能够成功发送“pty-req”，然后是“shell”请求，我可以获得登录前导码，发送命令并接收标准输出，但我不确定如何告诉SSH 服务 我想接收标准错误和状态消息。目前，通读其他 SSH 实现（paramiko、Net::SSH）并没有太多指导意义。
也就是说，查看 SSH 的 RFC 之一，我相信列出的请求之一可能是我正在寻找的：https ://www.rfc-editor.org/rfc/rfc4250#section-4.9.3
#!/usr/bin/env python
from twisted.conch.ssh import transport
from twisted.conch.ssh import userauth
from twisted.conch.ssh import connection
from twisted.conch.ssh import common
from twisted.conch.ssh.common import NS
from twisted.conch.ssh import keys
from twisted.conch.ssh import channel
from twisted.conch.ssh import session
from twisted.internet import defer
from twisted.internet import defer, protocol, reactor
from twisted.python import log
import struct, sys, getpass, os
log.startLogging(sys.stdout)
USER = 'dward'
HOST = '192.168.0.19' # pristine.local
PASSWD = "password"
PRIVATE_KEY = "~/id_rsa"
class SimpleTransport(transport.SSHClientTransport):
def verifyHostKey(self, hostKey, fingerprint):
print 'host key fingerprint: %s' % fingerprint
return defer.succeed(1)
def connectionSecure(self):
self.requestService(
SimpleUserAuth(USER,
SimpleConnection()))
class SimpleUserAuth(userauth.SSHUserAuthClient):
def getPassword(self):
return defer.succeed(PASSWD)
def getGenericAnswers(self, name, instruction, questions):
print name
print instruction
answers = []
for prompt, echo in questions:
if echo:
answer = raw_input(prompt)
else:
answer = getpass.getpass(prompt)
answers.append(answer)
return defer.succeed(answers)
def getPublicKey(self):
path = os.path.expanduser(PRIVATE_KEY)
# this works with rsa too
# just change the name here and in getPrivateKey
if not os.path.exists(path) or self.lastPublicKey:
# the file doesn't exist, or we've tried a public key
return
return keys.Key.fromFile(filename=path+'.pub').blob()
def getPrivateKey(self):
path = os.path.expanduser(PRIVATE_KEY)
return defer.succeed(keys.Key.fromFile(path).keyObject)
class SimpleConnection(connection.SSHConnection):
def serviceStarted(self):
self.openChannel(SmartChannel(2**16, 2**15, self))
class SmartChannel(channel.SSHChannel):
name = "session"
def getResponse(self, timeout = 10):
self.onData = defer.Deferred()
self.timeout = reactor.callLater( timeout, self.onData.errback, Exception("Timeout") )
return self.onData
def openFailed(self, reason):
print "Failed", reason
@defer.inlineCallbacks
def channelOpen(self, ignoredData):
self.data = ''
self.oldData = ''
self.onData = None
self.timeout = None
term = os.environ.get('TERM', 'xterm')
#winsz = fcntl.ioctl(fd, tty.TIOCGWINSZ, '12345678')
winSize = (25,80,0,0) #struct.unpack('4H', winsz)
ptyReqData = session.packRequest_pty_req(term, winSize, '')
try:
result = yield self.conn.sendRequest(self, 'pty-req', ptyReqData, wantReply = 1 )
except Exception as e:
print "Failed with ", e
try:
result = yield self.conn.sendRequest(self, "shell", '', wantReply = 1)
except Exception as e:
print "Failed shell with ", e
#fetch preample
data = yield self.getResponse()
"""
Welcome to Ubuntu 11.04 (GNU/Linux 2.6.38-8-server x86_64)
* Documentation: http://www.ubuntu.com/server/doc
System information as of Sat Oct 29 13:09:50 MDT 2011
System load: 0.0 Processes: 111
Usage of /: 48.0% of 6.62GB Users logged in: 1
Memory usage: 39% IP address for eth1: 192.168.0.19
Swap usage: 3%
Graph this data and manage this system at https://landscape.canonical.com/
New release 'oneiric' available.
Run 'do-release-upgrade' to upgrade to it.
Last login: Sat Oct 29 01:23:16 2011 from 192.168.0.17
"""
print data
while data != "" and data.strip().endswith("~$") == False:
try:
data = yield self.getResponse()
print repr(data)
"""
\x1B]0;dward@pristine: ~\x07dward@pristine:~$
"""
except Exception as e:
print e
break
self.write("false\n")
#fetch response
try:
data = yield self.getResponse()
except Exception as e:
print "Failed to catch response?", e
else:
print data
"""
false
\x1B]0;dward@pristine: ~\x07dward@pristine:~$
"""
self.write("true\n")
#fetch response
try:
data = yield self.getResponse()
except Exception as e:
print "Failed to catch response?", e
else:
print data
"""
true
\x1B]0;dward@pristine: ~\x07dward@pristine:~$
"""
self.write("echo Hello World\n\x00")
try:
data = yield self.getResponse()
except Exception as e:
print "Failed to catch response?", e
else:
print data
"""
echo Hello World
Hello World
\x1B]0;dward@pristine: ~\x07dward@pristine:~$
"""
#Close up shop
self.loseConnection()
dbgp = 1
def request_exit_status(self, data):
status = struct.unpack('>L', data)[0]
print 'status was: %s' % status
def dataReceived(self, data):
self.data += data
if self.onData is not None:
if self.timeout and self.timeout.active():
self.timeout.cancel()
if self.onData.called == False:
self.onData.callback(data)
def extReceived(self, dataType, data):
dbgp = 1
print "Extended Data recieved! dataType = %s , data = %s " % ( dataType, data, )
self.extendData = data
def closed(self):
print 'got data : %s' % self.data.replace("\\r\\n","\r\n")
self.loseConnection()
reactor.stop()
protocol.ClientCreator(reactor, SimpleTransport).connectTCP(HOST, 22)
reactor.run()
此外，我尝试向远程 shell 添加显式错误命令：
self.write("ls -alF badPathHere\n\x00")
try:
data = yield self.getResponse()
except Exception as e:
print "Failed to catch response?", e
else:
print data
"""
ls -alF badPathHere
ls: cannot access badPathHere: No such file or directory
\x1B]0;dward@pristine: ~\x07dward@pristine:~$
"""
看起来 stderr 正在混入 stderr