Tftp implementation (#330)

* ed:   cowrie/commands/tftp.py
	deleted:    cowrie/core/CustomParser.py

* Added TFTP implementation
This now needs tftpy from pip

* Added tftpy

cowrie/commands/__init__.py

@@ -30,5 +30,6 @@ __all__ = [
     'which',
     'perl',
     'uptime',
-    'python'
+    'python',
+    'tftp'
     ]

cowrie/commands/tftp.py

@@ -0,0 +1,128 @@
+#!/usr/bin/env python
+
+import time
+import re
+import tftpy
+import os
+from cowrie.core.customparser import CustomParser
+from cowrie.core.customparser import OptionNotFound
+from cowrie.core.customparser import ExitException
+from cowrie.core.honeypot import HoneyPotCommand
+from cowrie.core.fs import *
+
+
+commands = {}
+
+
+class Progress(object):
+
+    def __init__(self, protocol):
+
+        self.progress = 0
+        self.out = protocol
+
+
+    def progresshook(self, pkt):
+
+        if isinstance(pkt, tftpy.TftpPacketDAT):
+            self.progress += len(pkt.data)
+            self.out.write("Transferred %d bytes" % self.progress + "\n")
+        elif isinstance(pkt, tftpy.TftpPacketOACK):
+            self.out.write("Received OACK, options are: %s" % pkt.options + "\n")
+
+
+class command_tftp(HoneyPotCommand):
+
+    port = 69
+
+    hostname = None
+    file_to_get = None
+
+    def makeTftpRetrieval(self):
+
+        progresshook = Progress(self).progresshook
+
+        tclient = tftpy.TftpClient(self.hostname,
+                                   int(self.port))
+        cfg = self.protocol.cfg
+        if cfg.has_option('honeypot', 'download_limit_size'):
+            self.limit_size = int(cfg.get('honeypot', 'download_limit_size'))
+
+        self.download_path = cfg.get('honeypot', 'download_path')
+
+        self.safeoutfile = '%s/%s_%s' % \
+                           (self.download_path,
+                            time.strftime('%Y%m%d%H%M%S'),
+                            re.sub('[^A-Za-z0-9]', '_', self.file_to_get))
+
+        self.protocol.logDispatch(eventid='cowrie.session.file_download',
+                                  format='Downloaded tftpFile to %(outfile)s',
+                                  outfile=self.safeoutfile
+                                  )
+
+        log.msg(eventid='cowrie.session.file_download',
+                format='Downloaded tftpFile to %(outfile)s',
+                outfile=self.safeoutfile
+                )
+
+        try:
+            tclient.download(self.file_to_get, self.safeoutfile, progresshook)
+            self.file_to_get = self.fs.resolve_path(self.file_to_get, self.protocol.cwd)
+            self.fs.mkfile(self.file_to_get, 0, 0, tclient.context.metrics.bytes, 33188)
+            self.fs.update_realfile(self.fs.getfile(self.file_to_get), self.safeoutfile)
+            f = self.fs.getfile(self.file_to_get)
+            f[A_REALFILE] = self.safeoutfile
+
+        except tftpy.TftpException, err:
+            return
+
+        except KeyboardInterrupt:
+            pass
+
+
+    def start(self):
+
+        parser = CustomParser(self)
+        parser.prog = "tftp"
+        parser.add_argument("hostname", nargs='?', default=None)
+        parser.add_argument("-c", nargs=2)
+        parser.add_argument("-l")
+        parser.add_argument("-g")
+        parser.add_argument("-p")
+        parser.add_argument("-r")
+
+        try:
+            args = parser.parse_args(self.args)
+            if args.c:
+                if len(args.c) > 1:
+                    command = args.c[0]
+                    self.file_to_get = args.c[1]
+                    if args.hostname is None:
+                        raise OptionNotFound("Hostname is invalid")
+                    self.hostname = args.hostname
+
+            elif args.r:
+                self.file_to_get = args.r
+                self.hostname = args.g
+            else:
+                parser.print_usage()
+                raise OptionNotFound("Missing!!")
+
+            if self.hostname is None:
+                raise OptionNotFound("Hostname is invalid")
+
+            self.makeTftpRetrieval()
+
+        except OptionNotFound:
+            self.exit()
+            return
+        except ExitException:
+            self.exit()
+            return
+        except Exception:
+            self.exit()
+            return
+
+        self.exit()
+
+commands['/usr/bin/tftp'] = command_tftp

cowrie/core/customparser.py

@@ -0,0 +1,59 @@
+import argparse
+
+
+class OptionNotFound(Exception):
+
+    def __init__(self, value):
+        self.value = value
+
+    def __str__(self):
+        return repr(self.value)
+
+
+class ExitException(Exception):
+
+    def __init__(self, value):
+        self.value = value
+
+    def __str__(self):
+        return repr(self.value)
+
+
+class CustomParser(argparse.ArgumentParser):
+    def __init__(self, protocol,
+                 prog=None,
+                 usage=None,
+                 description=None,
+                 epilog=None,
+                 version=None,
+                 parents=[],
+                 formatter_class=argparse.HelpFormatter,
+                 prefix_chars='-',
+                 fromfile_prefix_chars=None,
+                 argument_default=None,
+                 conflict_handler='error',
+                 add_help=True):
+        self.protocol = protocol
+        super(CustomParser, self).__init__(prog,
+                                           usage,
+                                           description,
+                                           epilog,
+                                           version,
+                                           parents,
+                                           formatter_class,
+                                           prefix_chars,
+                                           fromfile_prefix_chars,
+                                           argument_default,
+                                           conflict_handler,
+                                           add_help)
+
+    def exit(self, status=0, message=None):
+        raise ExitException("Exiting...")
+
+
+    def _print_message(self, message, file=None):
+        super(CustomParser,self)._print_message(message, self.protocol)
+
+    def error(self, message):
+        self.print_usage(self.protocol)
+        raise OptionNotFound("Sorry no option found")

requirements.txt

@@ -6,3 +6,4 @@ gmpy2
 service_identity
 pycrypto
 python-dateutil
+tftpy