upgrade to python3.6+ syntax using pyupgrade --py36-plus (#1502)

src/backend_pool/libvirt/guest_handler.py

@@ -48,7 +48,7 @@ def create_guest(connection, mac_address, guest_unique_id):
         snapshot_path = os.getcwd()
 
     # create a disk snapshot to be used by the guest
-    disk_img = os.path.join(snapshot_path, 'snapshot-{0}-{1}.qcow2'.format(version_tag, guest_unique_id))
+    disk_img = os.path.join(snapshot_path, f'snapshot-{version_tag}-{guest_unique_id}.qcow2')
 
     if not backend_pool.libvirt.snapshot_handler.create_disk_snapshot(base_image, disk_img):
         log.msg(eventid='cowrie.backend_pool.guest_handler',

src/backend_pool/pool_server.py

@@ -47,7 +47,7 @@ class PoolServer(Protocol):
             recv = struct.unpack('!H', data[1:3])
             ip_len = recv[0]
 
-            recv = struct.unpack('!{0}s'.format(ip_len), data[3:])
+            recv = struct.unpack(f'!{ip_len}s', data[3:])
             attacker_ip = recv[0].decode()
 
             log.msg(eventid='cowrie.backend_pool.server',
@@ -69,11 +69,11 @@ class PoolServer(Protocol):
                     nat_ssh_port, nat_telnet_port = self.factory.nat.request_binding(guest_id, guest_ip,
                                                                                      ssh_port, telnet_port)
 
-                    fmt = '!cIIH{0}sHHH{1}s'.format(len(self.nat_public_ip), len(guest_snapshot))
+                    fmt = '!cIIH{}sHHH{}s'.format(len(self.nat_public_ip), len(guest_snapshot))
                     response = struct.pack(fmt, b'r', 0, guest_id, len(self.nat_public_ip), self.nat_public_ip.encode(),
                                            nat_ssh_port, nat_telnet_port, len(guest_snapshot), guest_snapshot.encode())
                 else:
-                    fmt = '!cIIH{0}sHHH{1}s'.format(len(guest_ip), len(guest_snapshot))
+                    fmt = '!cIIH{}sHHH{}s'.format(len(guest_ip), len(guest_snapshot))
                     response = struct.pack(fmt, b'r', 0, guest_id, len(guest_ip), guest_ip.encode(),
                                            ssh_port, telnet_port, len(guest_snapshot), guest_snapshot.encode())
             except NoAvailableVMs:

src/backend_pool/ssh_exec.py

@@ -3,20 +3,20 @@ from twisted.internet import defer, protocol, reactor
 
 
 # object is added for Python 2.7 compatibility (#1198) - as is super with args
-class PasswordAuth(userauth.SSHUserAuthClient, object):
+class PasswordAuth(userauth.SSHUserAuthClient):
     def __init__(self, user, password, conn):
-        super(PasswordAuth, self).__init__(user, conn)
+        super().__init__(user, conn)
         self.password = password
 
     def getPassword(self, prompt=None):
         return defer.succeed(self.password)
 
 
-class CommandChannel(channel.SSHChannel, object):
+class CommandChannel(channel.SSHChannel):
     name = 'session'
 
     def __init__(self, command, done_deferred, callback, *args, **kwargs):
-        super(CommandChannel, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self.command = command
         self.done_deferred = done_deferred
         self.callback = callback
@@ -41,9 +41,9 @@ class CommandChannel(channel.SSHChannel, object):
             self.callback(self.data)
 
 
-class ClientConnection(connection.SSHConnection, object):
+class ClientConnection(connection.SSHConnection):
     def __init__(self, cmd, done_deferred, callback):
-        super(ClientConnection, self).__init__()
+        super().__init__()
         self.command = cmd
         self.done_deferred = done_deferred
         self.callback = callback

src/backend_pool/util.py

@@ -20,7 +20,7 @@ def nmap_port(guest_ip, port):
 
 
 def read_file(file_name):
-    with open(file_name, 'r') as file:
+    with open(file_name) as file:
         return file.read()
 
 

src/cowrie/commands/adduser.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2010 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import random
 

src/cowrie/commands/apt.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import random
 import re
@@ -14,12 +13,12 @@ from cowrie.shell.command import HoneyPotCommand
 commands = {}
 
 
-class command_faked_package_class_factory(object):
+class command_faked_package_class_factory:
     @staticmethod
     def getCommand(name):
         class command_faked_installation(HoneyPotCommand):
             def call(self):
-                self.write("{}: Segmentation fault\n".format(name))
+                self.write(f"{name}: Segmentation fault\n")
 
         return command_faked_installation
 
@@ -122,7 +121,7 @@ pages for more information and options.
         packages = {}
         for y in [re.sub('[^A-Za-z0-9]', '', x) for x in self.args[1:]]:
             packages[y] = {
-                'version': '{0}.{1}-{2}'.format(random.choice([0, 1]), random.randint(1, 40), random.randint(1, 10)),
+                'version': '{}.{}-{}'.format(random.choice([0, 1]), random.randint(1, 40), random.randint(1, 10)),
                 'size': random.randint(100, 900)
             }
         totalsize = sum([packages[x]['size'] for x in packages])
@@ -134,7 +133,7 @@ pages for more information and options.
         self.write('  %s ' % ' '.join(packages) + '\n')
         self.write('0 upgraded, %d newly installed, 0 to remove and 259 not upgraded.\n' % len(packages))
         self.write('Need to get %s.2kB of archives.\n' % (totalsize))
-        self.write('After this operation, %skB of additional disk space will be used.\n' % (totalsize * 2.2,))
+        self.write('After this operation, {}kB of additional disk space will be used.\n'.format(totalsize * 2.2))
         i = 1
         for p in packages:
             self.write('Get:%d http://ftp.debian.org stable/main %s %s [%s.2kB]\n' %
@@ -148,12 +147,12 @@ pages for more information and options.
         self.write('(Reading database ... 177887 files and directories currently installed.)\n')
         yield self.sleep(1, 2)
         for p in packages:
-            self.write('Unpacking %s (from .../archives/%s_%s_i386.deb) ...\n' % (p, p, packages[p]['version']))
+            self.write('Unpacking {} (from .../archives/{}_{}_i386.deb) ...\n'.format(p, p, packages[p]['version']))
             yield self.sleep(1, 2)
         self.write('Processing triggers for man-db ...\n')
         yield self.sleep(2)
         for p in packages:
-            self.write('Setting up %s (%s) ...\n' % (p, packages[p]['version']))
+            self.write('Setting up {} ({}) ...\n'.format(p, packages[p]['version']))
             self.fs.mkfile('/usr/bin/%s' % p, 0, 0, random.randint(10000, 90000), 33188)
             self.protocol.commands['/usr/bin/%s' % p] = \
                 command_faked_package_class_factory.getCommand(p)

src/cowrie/commands/awk.py

@@ -8,7 +8,6 @@ awk command
 limited implementation that only supports `print` command.
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 import re
@@ -72,7 +71,7 @@ class command_awk(HoneyPotCommand):
                 pname = self.fs.resolve_path(arg, self.protocol.cwd)
 
                 if self.fs.isdir(pname):
-                    self.errorWrite("awk: {}: Is a directory\n".format(arg))
+                    self.errorWrite(f"awk: {arg}: Is a directory\n")
                     continue
 
                 try:
@@ -82,7 +81,7 @@ class command_awk(HoneyPotCommand):
                     else:
                         raise FileNotFound
                 except FileNotFound:
-                    self.errorWrite("awk: {}: No such file or directory\n".format(arg))
+                    self.errorWrite(f"awk: {arg}: No such file or directory\n")
 
         else:
             self.output(self.input_data)

src/cowrie/commands/base.py

@@ -3,7 +3,6 @@
 
 # coding=utf-8
 
-from __future__ import absolute_import, division
 
 import codecs
 import datetime
@@ -25,7 +24,7 @@ commands = {}
 class command_whoami(HoneyPotCommand):
 
     def call(self):
-        self.write('{0}\n'.format(self.protocol.user.username))
+        self.write(f'{self.protocol.user.username}\n')
 
 
 commands['/usr/bin/whoami'] = command_whoami
@@ -228,7 +227,7 @@ class command_hostname(HoneyPotCommand):
             else:
                 self.write("hostname: you must be root to change the host name\n")
         else:
-            self.write('{0}\n'.format(self.protocol.hostname))
+            self.write(f'{self.protocol.hostname}\n')
 
 
 commands['/bin/hostname'] = command_hostname
@@ -460,7 +459,7 @@ class command_ps(HoneyPotCommand):
             s = ''.join([output[i][x] for x in line])
             if 'w' not in args:
                 s = s[:(int(self.environ['COLUMNS']) if 'COLUMNS' in self.environ else 80)]
-            self.write('{0}\n'.format(s))
+            self.write(f'{s}\n')
 
 
 commands['/bin/ps'] = command_ps
@@ -532,19 +531,19 @@ class command_shutdown(HoneyPotCommand):
                 "** the \"time\" argument is mandatory! (try \"now\") **",
             )
             for line in output:
-                self.write('{0}\n'.format(line))
+                self.write(f'{line}\n')
             self.exit()
         elif len(self.args) > 1 and self.args[0].strip().count('-h') \
                 and self.args[1].strip().count('now'):
             self.write('\n')
-            self.write('Broadcast message from root@{} (pts/0) ({}):\n'.format(self.protocol.hostname, time.ctime()))
+            self.write(f'Broadcast message from root@{self.protocol.hostname} (pts/0) ({time.ctime()}):\n')
             self.write('\n')
             self.write('The system is going down for maintenance NOW!\n')
             reactor.callLater(3, self.finish)
         elif len(self.args) > 1 and self.args[0].strip().count('-r') \
                 and self.args[1].strip().count('now'):
             self.write('\n')
-            self.write('Broadcast message from root@{} (pts/0) ({}):\n'.format(self.protocol.hostname, time.ctime()))
+            self.write(f'Broadcast message from root@{self.protocol.hostname} (pts/0) ({time.ctime()}):\n')
             self.write('\n')
             self.write('The system is going down for reboot NOW!\n')
             reactor.callLater(3, self.finish)
@@ -569,7 +568,7 @@ class command_reboot(HoneyPotCommand):
 
     def start(self):
         self.write('\n')
-        self.write('Broadcast message from root@{} (pts/0) ({}):\n\n'.format(self.protocol.hostname, time.ctime()))
+        self.write(f'Broadcast message from root@{self.protocol.hostname} (pts/0) ({time.ctime()}):\n\n')
         self.write('The system is going down for reboot NOW!\n')
         reactor.callLater(3, self.finish)
 
@@ -592,7 +591,7 @@ class command_history(HoneyPotCommand):
                 return
             count = 1
             for line in self.protocol.historyLines:
-                self.write(' %s  %s\n' % (str(count).rjust(4), line))
+                self.write(' {}  {}\n'.format(str(count).rjust(4), line))
                 count += 1
         except Exception:
             # Non-interactive shell, do nothing
@@ -606,7 +605,7 @@ class command_date(HoneyPotCommand):
 
     def call(self):
         time = datetime.datetime.utcnow()
-        self.write('{0}\n'.format(time.strftime("%a %b %d %H:%M:%S UTC %Y")))
+        self.write('{}\n'.format(time.strftime("%a %b %d %H:%M:%S UTC %Y")))
 
 
 commands['/bin/date'] = command_date
@@ -620,7 +619,7 @@ class command_yes(HoneyPotCommand):
 
     def y(self):
         if len(self.args):
-            self.write("{0}\n".format(' '.join(self.args, '\n')))
+            self.write("{}\n".format(' '.join(self.args, '\n')))
         else:
             self.write('y\n')
         self.scheduled = reactor.callLater(0.01, self.y)
@@ -681,7 +680,7 @@ class command_php(HoneyPotCommand):
                 'Copyright (c) 1997-2010 The PHP Group'
             )
             for line in output:
-                self.write('{0}\n'.format(line))
+                self.write(f'{line}\n')
             self.exit()
         elif self.args[0] == '-h':
             output = (
@@ -725,7 +724,7 @@ class command_php(HoneyPotCommand):
                 ''
             )
             for line in output:
-                self.write('{0}\n'.format(line))
+                self.write(f'{line}\n')
             self.exit()
         else:
             self.exit()
@@ -767,7 +766,7 @@ class command_set(HoneyPotCommand):
     # With enhancements it should work like env when -o posix is used
     def call(self):
         for i in sorted(list(self.environ.keys())):
-            self.write('{0}={1}\n'.format(i, self.environ[i]))
+            self.write('{}={}\n'.format(i, self.environ[i]))
 
 
 commands['set'] = command_set

src/cowrie/commands/base64.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import getopt
 
 from twisted.python import log

src/cowrie/commands/busybox.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 from twisted.python import log
 
 from cowrie.shell.command import HoneyPotCommand
@@ -57,7 +55,7 @@ class command_busybox(HoneyPotCommand):
 
     def help(self):
         for ln in busybox_help:
-            self.errorWrite('{0}\n'.format(ln))
+            self.errorWrite(f'{ln}\n')
 
     def call(self):
         if len(self.args) == 0:
@@ -85,7 +83,7 @@ class command_busybox(HoneyPotCommand):
             if self.input_data:
                 self.write(self.input_data)
         else:
-            self.write('{}: applet not found\n'.format(cmd))
+            self.write(f'{cmd}: applet not found\n')
 
 
 commands['/bin/busybox'] = command_busybox

src/cowrie/commands/cat.py

@@ -6,7 +6,6 @@ cat command
 
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 
@@ -30,7 +29,7 @@ class command_cat(HoneyPotCommand):
         try:
             optlist, args = getopt.gnu_getopt(self.args, 'AbeEnstTuv', ['help', 'number', 'version'])
         except getopt.GetoptError as err:
-            self.errorWrite("cat: invalid option -- '{}'\nTry 'cat --help' for more information.\n".format(err.opt))
+            self.errorWrite(f"cat: invalid option -- '{err.opt}'\nTry 'cat --help' for more information.\n")
             self.exit()
             return
 
@@ -51,7 +50,7 @@ class command_cat(HoneyPotCommand):
                 pname = self.fs.resolve_path(arg, self.protocol.cwd)
 
                 if self.fs.isdir(pname):
-                    self.errorWrite('cat: {}: Is a directory\n'.format(arg))
+                    self.errorWrite(f'cat: {arg}: Is a directory\n')
                     continue
 
                 try:
@@ -61,7 +60,7 @@ class command_cat(HoneyPotCommand):
                     else:
                         raise FileNotFound
                 except FileNotFound:
-                    self.errorWrite('cat: {}: No such file or directory\n'.format(arg))
+                    self.errorWrite(f'cat: {arg}: No such file or directory\n')
             self.exit()
         elif self.input_data is not None:
             self.output(self.input_data)
@@ -86,7 +85,7 @@ class command_cat(HoneyPotCommand):
             lines.pop()
         for line in lines:
             if self.number:
-                self.write('{:>6}  '.format(self.linenumber))
+                self.write(f'{self.linenumber:>6}  ')
                 self.linenumber = self.linenumber + 1
             self.writeBytes(line + b'\n')
 

src/cowrie/commands/chmod.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2020 Peter Sufliarsky <sufliarskyp@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import getopt
 import re
@@ -69,12 +68,12 @@ class command_chmod(HoneyPotCommand):
             self.write('chmod: missing operand\n' + TRY_CHMOD_HELP_MSG)
             return
         if mode and not files:
-            self.write('chmod: missing operand after ‘{}’\n'.format(mode) + TRY_CHMOD_HELP_MSG)
+            self.write(f'chmod: missing operand after ‘{mode}’\n' + TRY_CHMOD_HELP_MSG)
             return
 
         # mode has to match the regex
         if not re.fullmatch(MODE_REGEX, mode):
-            self.write('chmod: invalid mode: ‘{}’\n'.format(mode) + TRY_CHMOD_HELP_MSG)
+            self.write(f'chmod: invalid mode: ‘{mode}’\n' + TRY_CHMOD_HELP_MSG)
             return
 
         # go through the list of files and check whether they exist
@@ -87,7 +86,7 @@ class command_chmod(HoneyPotCommand):
             else:
                 path = self.fs.resolve_path(file, self.protocol.cwd)
                 if not self.fs.exists(path):
-                    self.write('chmod: cannot access \'{}\': No such file or directory\n'.format(file))
+                    self.write(f'chmod: cannot access \'{file}\': No such file or directory\n')
 
     def parse_args(self):
         mode = None
@@ -109,9 +108,9 @@ class command_chmod(HoneyPotCommand):
         except getopt.GetoptError as err:
             failed_opt = err.msg.split(' ')[1]
             if failed_opt.startswith("--"):
-                self.errorWrite("chmod: unrecognized option '--{}'\n".format(err.opt) + TRY_CHMOD_HELP_MSG)
+                self.errorWrite(f"chmod: unrecognized option '--{err.opt}'\n" + TRY_CHMOD_HELP_MSG)
             else:
-                self.errorWrite("chmod: invalid option -- '{}'\n".format(err.opt) + TRY_CHMOD_HELP_MSG)
+                self.errorWrite(f"chmod: invalid option -- '{err.opt}'\n" + TRY_CHMOD_HELP_MSG)
             return [], None, [], True
 
         # if mode was not found before, use the first arg as mode

src/cowrie/commands/chpasswd.py

@@ -6,7 +6,6 @@
 This module contains the chpasswd commnad
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 
@@ -43,7 +42,7 @@ class command_chpasswd(HoneyPotCommand):
                 if len(line):
                     u, p = line.split(b':')
                     if not len(p):
-                        self.write('chpasswd: line {}: missing new password\n'.format(c))
+                        self.write(f'chpasswd: line {c}: missing new password\n')
                     else:
                         """
                         TODO:
@@ -54,7 +53,7 @@ class command_chpasswd(HoneyPotCommand):
                         pass
                 c += 1
         except Exception:
-            self.write('chpasswd: line {}: missing new password\n'.format(c))
+            self.write(f'chpasswd: line {c}: missing new password\n')
 
     def start(self):
         try:
@@ -73,7 +72,7 @@ class command_chpasswd(HoneyPotCommand):
                 return
             elif o in "-c":
                 if args not in ["NONE", "DES", "MD5", "SHA256", "SHA512"]:
-                    self.errorWrite("chpasswd: unsupported crypt method: {}\n".format(a))
+                    self.errorWrite(f"chpasswd: unsupported crypt method: {a}\n")
                     self.help()
                     self.exit()
 

src/cowrie/commands/crontab.py

@@ -6,7 +6,6 @@
 This module contains the crontab commnad
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 
@@ -36,7 +35,7 @@ class command_crontab(HoneyPotCommand):
         try:
             opts, args = getopt.getopt(self.args, 'u:elri')
         except getopt.GetoptError as err:
-            self.write("crontab: invalid option -- \'{0}\'\n".format(err.opt))
+            self.write(f"crontab: invalid option -- \'{err.opt}\'\n")
             self.write("crontab: usage error: unrecognized option\n")
             self.help()
             self.exit()
@@ -52,11 +51,11 @@ class command_crontab(HoneyPotCommand):
                 opt = o
 
         if opt == "-e":
-            self.write("must be privileged to use {0}\n".format(opt))
+            self.write(f"must be privileged to use {opt}\n")
             self.exit()
             return
         elif opt in ["-l", "-r", "-i"]:
-            self.write("no crontab for {0}\n".format(user))
+            self.write(f"no crontab for {user}\n")
             self.exit()
             return
 

src/cowrie/commands/curl.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import getopt
 import os
@@ -186,7 +185,7 @@ class command_curl(HoneyPotCommand):
             optlist, args = getopt.getopt(self.args, 'sho:O', ['help', 'manual', 'silent'])
         except getopt.GetoptError as err:
             # TODO: should be 'unknown' instead of 'not recognized'
-            self.write("curl: {}\n".format(err))
+            self.write(f"curl: {err}\n")
             self.write("curl: try 'curl --help' or 'curl --manual' for more information\n")
             self.exit()
             return
@@ -252,7 +251,7 @@ class command_curl(HoneyPotCommand):
             if scheme != b'http' and scheme != b'https':
                 raise NotImplementedError
         except Exception:
-            self.errorWrite('curl: (1) Protocol "{}" not supported or disabled in libcurl\n'.format(scheme))
+            self.errorWrite(f'curl: (1) Protocol "{scheme}" not supported or disabled in libcurl\n')
             self.exit()
             return None
 

src/cowrie/commands/dd.py

@@ -5,7 +5,6 @@
 dd commands
 """
 
-from __future__ import absolute_import, division
 
 import re
 
@@ -30,11 +29,11 @@ class command_dd(HoneyPotCommand):
 
         for arg in self.args:
             if arg.find('=') == -1:
-                self.write('unknown operand: {}'.format(arg))
+                self.write(f'unknown operand: {arg}')
                 HoneyPotCommand.exit(self)
             operand, value = arg.split('=')
             if operand not in ('if', 'bs', 'of', 'count'):
-                self.write('unknown operand: {}'.format(operand))
+                self.write(f'unknown operand: {operand}')
                 self.exit(success=False)
             self.ddargs[operand] = value
 
@@ -48,21 +47,21 @@ class command_dd(HoneyPotCommand):
                 iname = self.ddargs['if']
                 pname = self.fs.resolve_path(iname, self.protocol.cwd)
                 if self.fs.isdir(pname):
-                    self.errorWrite('dd: {}: Is a directory\n'.format(iname))
+                    self.errorWrite(f'dd: {iname}: Is a directory\n')
                     bSuccess = False
 
                 if bSuccess:
                     if 'bs' in self.ddargs:
                         block = parse_size(self.ddargs['bs'])
                         if block <= 0:
-                            self.errorWrite('dd: invalid number \'{}\'\n'.format(block))
+                            self.errorWrite(f'dd: invalid number \'{block}\'\n')
                             bSuccess = False
 
                 if bSuccess:
                     if 'count' in self.ddargs:
                         c = int(self.ddargs['count'])
                         if c < 0:
-                            self.errorWrite('dd: invalid number \'{}\'\n'.format(c))
+                            self.errorWrite(f'dd: invalid number \'{c}\'\n')
                             bSuccess = False
 
                 if bSuccess:
@@ -78,7 +77,7 @@ class command_dd(HoneyPotCommand):
                             else:
                                 self.writeBytes(data)
                     except FileNotFound:
-                        self.errorWrite('dd: {}: No such file or directory\n'.format(iname))
+                        self.errorWrite(f'dd: {iname}: No such file or directory\n')
                         bSuccess = False
 
                 self.exit(success=bSuccess)

src/cowrie/commands/du.py

@@ -1,8 +1,6 @@
-# -*- coding: utf-8 -*-
 # Copyright (c) 2018 Danilo Vargas <danilo.vargas@csiete.org>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import os
 
@@ -112,7 +110,7 @@ or available locally via: info '(coreutils) du invocation'\n"""
                 files = (self.protocol.fs.getfile(path)[:],)
         except Exception:
             self.write(
-                'ls: cannot access %s: No such file or directory\n' % (path,))
+                f'ls: cannot access {path}: No such file or directory\n')
             return
 
         filenames = [x[A_NAME] for x in files]
@@ -122,10 +120,10 @@ or available locally via: info '(coreutils) du invocation'\n"""
             if all:
                 isdir = self.protocol.fs.isdir(os.path.join(path, filename))
                 if isdir:
-                    filename = "4       ./{0}\n".format(filename)
+                    filename = f"4       ./{filename}\n"
                     self.write(filename)
             else:
-                filename = "4       {0}\n".format(filename)
+                filename = f"4       {filename}\n"
                 self.write(filename)
         if all:
             self.write("36      .\n")

src/cowrie/commands/env.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 from cowrie.shell.command import HoneyPotCommand
 
 commands = {}
@@ -31,7 +29,7 @@ class command_env(HoneyPotCommand):
     def call(self):
         # This only show environ vars, not the shell vars. Need just to mimic real systems
         for i in list(self.protocol.environ.keys()):
-            self.write('{0}={1}\n'.format(i, self.protocol.environ[i]))
+            self.write('{}={}\n'.format(i, self.protocol.environ[i]))
 
 
 commands['/usr/bin/env'] = command_env

src/cowrie/commands/ethtool.py

@@ -1,8 +1,6 @@
-# -*- coding: utf-8 -*-
 # Copyright (c) 2014 Peter Reuterås <peter@reuteras.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 from cowrie.shell.command import HoneyPotCommand
 

src/cowrie/commands/free.py

@@ -5,7 +5,6 @@
 This module ...
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 
@@ -81,7 +80,7 @@ class command_free(HoneyPotCommand):
         """
         needed_keys = ["Buffers", "Cached", "MemTotal", "MemFree", "SwapTotal", "SwapFree", "Shmem", "MemAvailable"]
         mem_info_map = {}
-        with open('/proc/meminfo', 'r') as proc_file:
+        with open('/proc/meminfo') as proc_file:
             for line in proc_file:
                 tokens = line.split(':')
 

src/cowrie/commands/fs.py

@@ -6,7 +6,6 @@
 Filesystem related commands
 """
 
-from __future__ import absolute_import, division
 
 import copy
 import getopt
@@ -31,7 +30,7 @@ class command_grep(HoneyPotCommand):
             contents = self.fs.file_contents(filename)
             self.grep_application(contents, match)
         except Exception:
-            self.errorWrite("grep: {}: No such file or directory\n".format(filename))
+            self.errorWrite(f"grep: {filename}: No such file or directory\n")
 
     def grep_application(self, contents, match):
         match = os.path.basename(match).replace('\"', '').encode('utf8')
@@ -60,7 +59,7 @@ class command_grep(HoneyPotCommand):
             try:
                 optlist, args = getopt.getopt(self.args, 'abcDEFGHhIiJLlmnOoPqRSsUVvwxZA:B:C:e:f:')
             except getopt.GetoptError as err:
-                self.errorWrite("grep: invalid option -- {}\n".format(err.opt))
+                self.errorWrite(f"grep: invalid option -- {err.opt}\n")
                 self.help()
                 self.exit()
                 return
@@ -104,7 +103,7 @@ class command_tail(HoneyPotCommand):
             contents = self.fs.file_contents(filename)
             self.tail_application(contents)
         except Exception:
-            self.errorWrite("tail: cannot open `{}' for reading: No such file or directory\n".format(filename))
+            self.errorWrite(f"tail: cannot open `{filename}' for reading: No such file or directory\n")
 
     def tail_application(self, contents):
         contentsplit = contents.split(b'\n')
@@ -126,7 +125,7 @@ class command_tail(HoneyPotCommand):
             try:
                 optlist, args = getopt.getopt(self.args, 'n:')
             except getopt.GetoptError as err:
-                self.errorWrite("tail: invalid option -- '{}'\n".format(err.opt))
+                self.errorWrite(f"tail: invalid option -- '{err.opt}'\n")
                 self.exit()
                 return
 
@@ -178,7 +177,7 @@ class command_head(HoneyPotCommand):
             contents = self.fs.file_contents(filename)
             self.head_application(contents)
         except Exception:
-            self.errorWrite("head: cannot open `{}' for reading: No such file or directory\n".format(filename))
+            self.errorWrite(f"head: cannot open `{filename}' for reading: No such file or directory\n")
 
     def start(self):
         self.n = 10
@@ -188,7 +187,7 @@ class command_head(HoneyPotCommand):
             try:
                 optlist, args = getopt.getopt(self.args, 'n:')
             except getopt.GetoptError as err:
-                self.errorWrite("head: invalid option -- '{}'\n".format(err.opt))
+                self.errorWrite(f"head: invalid option -- '{err.opt}'\n")
                 self.exit()
                 return
 
@@ -239,10 +238,10 @@ class command_cd(HoneyPotCommand):
             self.errorWrite('bash: cd: OLDPWD not set\n')
             return
         if inode is None or inode is False:
-            self.errorWrite('bash: cd: {}: No such file or directory\n'.format(pname))
+            self.errorWrite(f'bash: cd: {pname}: No such file or directory\n')
             return
         if inode[fs.A_TYPE] != fs.T_DIR:
-            self.errorWrite('bash: cd: {}: Not a directory\n'.format(pname))
+            self.errorWrite(f'bash: cd: {pname}: Not a directory\n')
             return
         self.protocol.cwd = newpath
 
@@ -310,7 +309,7 @@ or available locally via: info '(coreutils) rm invocation'\n"""
         try:
             optlist, args = getopt.gnu_getopt(self.args, 'rTfvh', ['help', 'recursive', 'force', 'verbose'])
         except getopt.GetoptError as err:
-            self.errorWrite("rm: invalid option -- '{}'\n".format(err.opt))
+            self.errorWrite(f"rm: invalid option -- '{err.opt}'\n")
             self.paramError()
             self.exit()
             return
@@ -336,7 +335,7 @@ or available locally via: info '(coreutils) rm invocation'\n"""
             except (IndexError, fs.FileNotFound):
                 if not force:
                     self.errorWrite(
-                        'rm: cannot remove `{}\': No such file or directory\n'.format(f))
+                        f'rm: cannot remove `{f}\': No such file or directory\n')
                 continue
             basename = pname.split('/')[-1]
             for i in dir[:]:
@@ -386,13 +385,13 @@ class command_cp(HoneyPotCommand):
             return
         sources, dest = args[:-1], args[-1]
         if len(sources) > 1 and not self.fs.isdir(resolv(dest)):
-            self.errorWrite("cp: target `{}' is not a directory\n".format(dest))
+            self.errorWrite(f"cp: target `{dest}' is not a directory\n")
             return
 
         if dest[-1] == '/' and not self.fs.exists(resolv(dest)) and \
                 not recursive:
             self.errorWrite(
-                "cp: cannot create regular file `{}': Is a directory\n".format(dest))
+                f"cp: cannot create regular file `{dest}': Is a directory\n")
             return
 
         if self.fs.isdir(resolv(dest)):
@@ -401,16 +400,16 @@ class command_cp(HoneyPotCommand):
             isdir = False
             parent = os.path.dirname(resolv(dest))
             if not self.fs.exists(parent):
-                self.errorWrite("cp: cannot create regular file " + "`{}': No such file or directory\n".format(dest))
+                self.errorWrite("cp: cannot create regular file " + f"`{dest}': No such file or directory\n")
                 return
 
         for src in sources:
             if not self.fs.exists(resolv(src)):
                 self.errorWrite(
-                    "cp: cannot stat `{}': No such file or directory\n".format(src))
+                    f"cp: cannot stat `{src}': No such file or directory\n")
                 continue
             if not recursive and self.fs.isdir(resolv(src)):
-                self.errorWrite("cp: omitting directory `{}'\n".format(src))
+                self.errorWrite(f"cp: omitting directory `{src}'\n")
                 continue
             s = copy.deepcopy(self.fs.getfile(resolv(src)))
             if isdir:
@@ -455,12 +454,12 @@ class command_mv(HoneyPotCommand):
             return
         sources, dest = args[:-1], args[-1]
         if len(sources) > 1 and not self.fs.isdir(resolv(dest)):
-            self.errorWrite("mv: target `{}' is not a directory\n".format(dest))
+            self.errorWrite(f"mv: target `{dest}' is not a directory\n")
             return
 
         if dest[-1] == '/' and not self.fs.exists(resolv(dest)) and len(sources) != 1:
             self.errorWrite(
-                "mv: cannot create regular file `{}': Is a directory\n".format(dest))
+                f"mv: cannot create regular file `{dest}': Is a directory\n")
             return
 
         if self.fs.isdir(resolv(dest)):
@@ -469,13 +468,13 @@ class command_mv(HoneyPotCommand):
             isdir = False
             parent = os.path.dirname(resolv(dest))
             if not self.fs.exists(parent):
-                self.errorWrite("mv: cannot create regular file " + "`{}': No such file or directory\n".format(dest))
+                self.errorWrite("mv: cannot create regular file " + f"`{dest}': No such file or directory\n")
                 return
 
         for src in sources:
             if not self.fs.exists(resolv(src)):
                 self.errorWrite(
-                    "mv: cannot stat `{}': No such file or directory\n".format(src))
+                    f"mv: cannot stat `{src}': No such file or directory\n")
                 continue
             s = self.fs.getfile(resolv(src))
             if isdir:
@@ -507,12 +506,12 @@ class command_mkdir(HoneyPotCommand):
             pname = self.fs.resolve_path(f, self.protocol.cwd)
             if self.fs.exists(pname):
                 self.errorWrite(
-                    'mkdir: cannot create directory `{}\': File exists\n'.format(f))
+                    f'mkdir: cannot create directory `{f}\': File exists\n')
                 return
             try:
                 self.fs.mkdir(pname, 0, 0, 4096, 16877)
             except (fs.FileNotFound):
-                self.errorWrite('mkdir: cannot create directory `{}\': No such file or directory\n'.format(f))
+                self.errorWrite(f'mkdir: cannot create directory `{f}\': No such file or directory\n')
             return
 
 
@@ -531,7 +530,7 @@ class command_rmdir(HoneyPotCommand):
             try:
                 if len(self.fs.get_path(pname)):
                     self.errorWrite(
-                        'rmdir: failed to remove `{}\': Directory not empty\n'.format(f))
+                        f'rmdir: failed to remove `{f}\': Directory not empty\n')
                     continue
                 dir = self.fs.get_path('/'.join(pname.split('/')[:-1]))
             except (IndexError, fs.FileNotFound):
@@ -539,12 +538,12 @@ class command_rmdir(HoneyPotCommand):
             fname = os.path.basename(f)
             if not dir or fname not in [x[fs.A_NAME] for x in dir]:
                 self.errorWrite(
-                    'rmdir: failed to remove `{}\': No such file or directory\n'.format(f))
+                    f'rmdir: failed to remove `{f}\': No such file or directory\n')
                 continue
             for i in dir[:]:
                 if i[fs.A_NAME] == fname:
                     if i[fs.A_TYPE] != fs.T_DIR:
-                        self.errorWrite("rmdir: failed to remove '{}': Not a directory\n".format(f))
+                        self.errorWrite(f"rmdir: failed to remove '{f}': Not a directory\n")
                         return
                     dir.remove(i)
                     break
@@ -581,7 +580,7 @@ class command_touch(HoneyPotCommand):
             pname = self.fs.resolve_path(f, self.protocol.cwd)
             if not self.fs.exists(os.path.dirname(pname)):
                 self.errorWrite(
-                    'touch: cannot touch `{}`: No such file or directory\n'.format(pname))
+                    f'touch: cannot touch `{pname}`: No such file or directory\n')
                 return
             if self.fs.exists(pname):
                 # FIXME: modify the timestamp here
@@ -589,7 +588,7 @@ class command_touch(HoneyPotCommand):
             # can't touch in special directories
             if any([pname.startswith(_p) for _p in fs.SPECIAL_PATHS]):
                 self.errorWrite(
-                    'touch: cannot touch `{}`: Permission denied\n'.format(pname))
+                    f'touch: cannot touch `{pname}`: Permission denied\n')
                 return
 
             self.fs.mkfile(pname, 0, 0, 0, 33188)

src/cowrie/commands/ftpget.py

@@ -1,7 +1,5 @@
-# -*- coding: utf-8 -*-
 # Author: Claud Xiao
 
-from __future__ import absolute_import, division
 
 import ftplib
 import getopt
@@ -148,14 +146,14 @@ Download a file via FTP
 
         self.url_log = 'ftp://'
         if self.username:
-            self.url_log = '{}{}'.format(self.url_log, self.username)
+            self.url_log = f'{self.url_log}{self.username}'
             if self.password:
-                self.url_log = '{}:{}'.format(self.url_log, self.password)
+                self.url_log = f'{self.url_log}:{self.password}'
-            self.url_log = '{}@'.format(self.url_log)
+            self.url_log = f'{self.url_log}@'
-        self.url_log = '{}{}'.format(self.url_log, self.host)
+        self.url_log = f'{self.url_log}{self.host}'
         if self.port != 21:
-            self.url_log = '{}:{}'.format(self.url_log, self.port)
+            self.url_log = f'{self.url_log}:{self.port}'
-        self.url_log = '{}/{}'.format(self.url_log, self.remote_path)
+        self.url_log = f'{self.url_log}/{self.remote_path}'
 
         self.artifactFile = Artifact(self.local_file)
 
@@ -208,7 +206,7 @@ Download a file via FTP
         try:
             ftp.connect(host=self.host, port=self.port, timeout=30)
         except Exception as e:
-            log.msg('FTP connect failed: host=%s, port=%s, err=%s' % (self.host, self.port, str(e)))
+            log.msg('FTP connect failed: host={}, port={}, err={}'.format(self.host, self.port, str(e)))
             self.write('ftpget: can\'t connect to remote host: Connection refused\n')
             return False
 
@@ -227,7 +225,7 @@ Download a file via FTP
         try:
             ftp.login(user=self.username, passwd=self.password)
         except Exception as e:
-            log.msg('FTP login failed: user=%s, passwd=%s, err=%s' % (self.username, self.password, str(e)))
+            log.msg('FTP login failed: user={}, passwd={}, err={}'.format(self.username, self.password, str(e)))
             self.write('ftpget: unexpected server response to USER: %s\n' % str(e))
             try:
                 ftp.quit()

src/cowrie/commands/gcc.py

@@ -1,6 +1,5 @@
 # Copyright (c) 2013 Bas Stottelaar <basstottelaar [AT] gmail [DOT] com>
 
-from __future__ import absolute_import, division
 
 import getopt
 import os
@@ -115,7 +114,7 @@ class command_gcc(HoneyPotCommand):
                 if self.fs.exists(sourcefile):
                     input_files = input_files + 1
                 else:
-                    self.write("%s: %s: No such file or directory\n" % (command_gcc.APP_NAME, value))
+                    self.write(f"{command_gcc.APP_NAME}: {value}: No such file or directory\n")
                     complete = False
 
         # To generate, or not
@@ -168,7 +167,7 @@ Thread model: posix
 gcc version {} (Debian {}-5)""".format(version, version_short, version_short, version_short, version, version))  # noqa: E501
 
         # Write
-        self.write('{0}\n'.format(data))
+        self.write(f'{data}\n')
         self.exit()
 
     def generate_file(self, outfile):
@@ -216,7 +215,7 @@ gcc version {} (Debian {}-5)""".format(version, version_short, version_short, ve
         """
         Print missing argument message, and exit
         """
-        self.write("%s: argument to '%s' is missing\n" % (command_gcc.APP_NAME, arg))
+        self.write(f"{command_gcc.APP_NAME}: argument to '{arg}' is missing\n")
         self.exit()
 
     def help(self):

src/cowrie/commands/ifconfig.py

@@ -1,17 +1,15 @@
-# -*- coding: utf-8 -*-
 # Copyright (c) 2014 Peter Reuterås <peter@reuteras.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 from random import randint, randrange
 
 from cowrie.shell.command import HoneyPotCommand
 
-HWaddr = "%02x:%02x:%02x:%02x:%02x:%02x" % (
+HWaddr = "{:02x}:{:02x}:{:02x}:{:02x}:{:02x}:{:02x}".format(
     randint(0, 255), randint(0, 255), randint(0, 255), randint(0, 255), randint(0, 255), randint(0, 255))
 
-inet6 = "fe%02x::%02x:%02xff:fe%02x:%02x01/64" % (
+inet6 = "fe{:02x}::{:02x}:{:02x}ff:fe{:02x}:{:02x}01/64".format(
     randint(0, 255), randrange(111, 888), randint(0, 255), randint(0, 255), randint(0, 255))
 
 commands = {}
@@ -26,7 +24,7 @@ class command_ifconfig(HoneyPotCommand):
     @staticmethod
     def convert_bytes_to_mx(bytes_eth0):
         mb = float(bytes_eth0) / 1000 / 1000
-        return "{0:.1f}".format(mb)
+        return f"{mb:.1f}"
 
     def calculate_rx(self):
         rx_bytes = randrange(111111111, 555555555)
@@ -68,7 +66,7 @@ lo        Link encap:Local Loopback
                   self.protocol.kippoIP.rsplit('.', 1)[0], inet6, rx_packets,
                   tx_packets, rx_bytes_eth0, rx_mb_eth0, tx_bytes_eth0, tx_mb_eth0,
                   lo_bytes, lo_mb, lo_bytes, lo_mb)
-        self.write('{0}\n'.format(result))
+        self.write(f'{result}\n')
 
 
 commands['/sbin/ifconfig'] = command_ifconfig

src/cowrie/commands/iptables.py

@@ -1,6 +1,5 @@
 # Copyright (c) 2013 Bas Stottelaar <basstottelaar [AT] gmail [DOT] com>
 
-from __future__ import absolute_import, division
 
 import optparse
 
@@ -204,8 +203,8 @@ class command_iptables(HoneyPotCommand):
         if self.user_is_root():
             # Verify table existence
             if table not in list(self.tables.keys()):
-                self.write("""%s: can\'t initialize iptables table \'%s\': Table does not exist (do you need to insmod?)
+                self.write("""{}: can\'t initialize iptables table \'{}\': Table does not exist (do you need to insmod?)
-Perhaps iptables or your kernel needs to be upgraded.\n""" % (command_iptables.APP_NAME, table))
+Perhaps iptables or your kernel needs to be upgraded.\n""".format(command_iptables.APP_NAME, table))
                 self.exit()
             else:
                 # Exists
@@ -230,7 +229,7 @@ Perhaps iptables or your kernel needs to be upgraded.\n""" % (command_iptables.A
         """
         Show version and exit
         """
-        self.write('%s %s\n' % (command_iptables.APP_NAME, command_iptables.APP_VERSION))
+        self.write(f'{command_iptables.APP_NAME} {command_iptables.APP_VERSION}\n')
         self.exit()
 
     def show_help(self):
@@ -238,7 +237,7 @@ Perhaps iptables or your kernel needs to be upgraded.\n""" % (command_iptables.A
         Show help and exit
         """
 
-        self.write("""%s %s'
+        self.write("""{} {}'
 
 Usage: iptables -[AD] chain rule-specification [options]
        iptables -I chain [rulenum] rule-specification [options]
@@ -300,7 +299,7 @@ Options:
 [!] --fragment -f      match second or further fragments only
   --modprobe=<command>     try to insert modules using this command
   --set-counters PKTS BYTES    set the counter during insert/append
-[!] --version  -V      print package version.\n""" % (command_iptables.APP_NAME, command_iptables.APP_VERSION))
+[!] --version  -V      print package version.\n""".format(command_iptables.APP_NAME, command_iptables.APP_VERSION))
         self.exit()
 
     def list_rules(self, chain):
@@ -326,7 +325,7 @@ Options:
                 output.append("-P %s ACCEPT" % chain)
 
             # Done
-            self.write('{0}\n'.format('\n'.join(output)))
+            self.write('{}\n'.format('\n'.join(output)))
             self.exit()
         else:
             self.no_permission()
@@ -365,7 +364,7 @@ Options:
                 output.append("\n".join(chain_output))
 
             # Done
-            self.write("{0}\n".format('\n\n'.join(output)))
+            self.write("{}\n".format('\n\n'.join(output)))
             self.exit()
         else:
             self.no_permission()
@@ -394,8 +393,10 @@ Options:
             self.no_permission()
 
     def no_permission(self):
-        self.write("""%s %s: can\'t initialize iptables table \'filter\': Permission denied (you must be root)
+        self.write("{} {}: ".format(command_iptables.APP_NAME, command_iptables.APP_VERSION) +
-Perhaps iptables or your kernel needs to be upgraded.\n""" % (command_iptables.APP_NAME, command_iptables.APP_VERSION))
+                   "can\'t initialize iptables table \'filter\': " +
+                   "Permission denied (you must be root)\n" +
+                   "Perhaps iptables or your kernel needs to be upgraded.\n")
         self.exit()
 
     def no_command(self):

src/cowrie/commands/last.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import time
 

src/cowrie/commands/ls.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import getopt
 import os.path
@@ -41,7 +40,7 @@ class command_ls(HoneyPotCommand):
             opts, args = getopt.gnu_getopt(self.args, '1@ABCFGHLOPRSTUWabcdefghiklmnopqrstuvwx',
                                            ['help', 'version', 'param'])
         except getopt.GetoptError as err:
-            self.write("ls: {}\n".format(err))
+            self.write(f"ls: {err}\n")
             self.write("Try 'ls --help' for more information.\n")
             return
 
@@ -82,7 +81,7 @@ class command_ls(HoneyPotCommand):
                 files = (self.protocol.fs.getfile(path)[:],)
         except Exception:
             self.write(
-                'ls: cannot access %s: No such file or directory\n' % (path,))
+                f'ls: cannot access {path}: No such file or directory\n')
             return
         return files
 
@@ -172,7 +171,7 @@ class command_ls(HoneyPotCommand):
                 perms[0] = 'd'
             elif file[fs.A_TYPE] == fs.T_LINK:
                 perms[0] = 'l'
-                linktarget = ' -> %s' % (file[fs.A_TARGET],)
+                linktarget = ' -> {}'.format(file[fs.A_TARGET])
 
             perms = ''.join(perms)
             ctime = time.localtime(file[fs.A_CTIME])
@@ -186,7 +185,7 @@ class command_ls(HoneyPotCommand):
                  file[fs.A_NAME],
                  linktarget)
 
-            self.write('{0}\n'.format(line))
+            self.write(f'{line}\n')
 
 
 commands['/bin/ls'] = command_ls

src/cowrie/commands/nc.py

@@ -1,15 +1,11 @@
-from __future__ import absolute_import, division
-
 import getopt
 import re
 import socket
 import struct
-import sys
 
 from cowrie.core.config import CowrieConfig
 from cowrie.shell.command import HoneyPotCommand
 
-if sys.version_info > (3,):
 long = int
 
 commands = {}
@@ -74,7 +70,7 @@ usage: nc [-46bCDdhjklnrStUuvZz] [-I length] [-i interval] [-O length]
         port = args[1]
 
         if not re.match(r'^\d+$', port):
-            self.errorWrite('nc: port number invalid: {}\n'.format(port))
+            self.errorWrite(f'nc: port number invalid: {port}\n')
             self.exit()
             return
 

src/cowrie/commands/netstat.py

@@ -1,6 +1,5 @@
 # Based on work by Peter Reuteras (https://bitbucket.org/reuteras/kippo/)
 
-from __future__ import absolute_import, division
 
 import socket
 
@@ -69,13 +68,13 @@ Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface\n
         destination = self.protocol.kippoIP.rsplit('.', 1)[0] + ".0"
         gateway = self.protocol.kippoIP.rsplit('.', 1)[0] + ".1"
         l1 = "%s%s0.0.0.0         UG        0 0          0 eth0" % \
-             ('{:<16}'.format(default),
+             (f'{default:<16}',
-              '{:<16}'.format(gateway))
+              f'{gateway:<16}')
         l2 = "%s%s255.255.255.0   U         0 0          0 eth0" % \
-             ('{:<16}'.format(destination),
+             (f'{destination:<16}',
-              '{:<16}'.format(lgateway))
+              f'{lgateway:<16}')
-        self.write('{0}\n'.format(l1))
+        self.write(f'{l1}\n')
-        self.write('{0}\n'.format(l2))
+        self.write(f'{l2}\n')
 
     def do_netstat_normal(self):
         self.write("""Active Internet connections (w/o servers)
@@ -99,7 +98,7 @@ Proto Recv-Q Send-Q Local Address           Foreign Address         State\n""")
                 (s_name, s_port, " " * (24 - len(s_name + s_port) - 1),
                  c_name, c_port, " " * (24 - len(c_name + c_port) - 1),
                  "ESTABLISHED")
-            self.write('{0}\n'.format(line))
+            self.write(f'{line}\n')
         if self.show_listen or self.show_all:
             self.write("tcp6       0      0 [::]:ssh                [::]:*                  LISTEN\n")
         self.write("""Active UNIX domain sockets (only servers)

src/cowrie/commands/nohup.py

@@ -1,8 +1,6 @@
-# -*- coding: utf-8 -*-
 # Copyright (c) 2014 Peter Reuterås <peter@reuteras.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 from cowrie.shell.command import HoneyPotCommand
 

src/cowrie/commands/perl.py

@@ -5,7 +5,6 @@
 This module contains the perl command
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 

src/cowrie/commands/ping.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import getopt
 import hashlib
@@ -33,7 +32,7 @@ class command_ping(HoneyPotCommand):
         try:
             optlist, args = getopt.gnu_getopt(self.args, "c:")
         except getopt.GetoptError as err:
-            self.write('ping: %s\n' % (err,))
+            self.write(f'ping: {err}\n')
             self.exit()
             return
 
@@ -55,7 +54,7 @@ class command_ping(HoneyPotCommand):
                     '            [-M mtu discovery hint] [-S sndbuf]',
                     '            [ -T timestamp option ] [ -Q tos ] [hop1 ...] destination',
             ):
-                self.write('{0}\n'.format(line))
+                self.write(f'{line}\n')
             self.exit()
             return
         self.host = args[0].strip()
@@ -64,14 +63,14 @@ class command_ping(HoneyPotCommand):
             if self.valid_ip(self.host):
                 self.ip = self.host
             else:
-                self.write('ping: unknown host %s\n' % (self.host,))
+                self.write(f'ping: unknown host {self.host}\n')
                 self.exit()
         else:
             s = hashlib.md5((self.host).encode("utf-8")).hexdigest()
             self.ip = '.'.join([str(int(x, 16)) for x in (s[0:2], s[2:4], s[4:6], s[6:8])])
 
         self.running = True
-        self.write('PING %s (%s) 56(84) bytes of data.\n' % (self.host, self.ip))
+        self.write(f'PING {self.host} ({self.ip}) 56(84) bytes of data.\n')
         self.scheduled = reactor.callLater(0.2, self.showreply)
         self.count = 0
 
@@ -89,7 +88,7 @@ class command_ping(HoneyPotCommand):
             self.scheduled = reactor.callLater(1, self.showreply)
 
     def printstatistics(self):
-        self.write('--- %s ping statistics ---\n' % (self.host,))
+        self.write(f'--- {self.host} ping statistics ---\n')
         self.write('%d packets transmitted, %d received, 0%% packet loss, time 907ms\n' % (self.count, self.count))
         self.write('rtt min/avg/max/mdev = 48.264/50.352/52.441/2.100 ms\n')
 

src/cowrie/commands/python.py

@@ -5,7 +5,6 @@
 This module contains the python commnad
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 
@@ -76,7 +75,7 @@ class command_python(HoneyPotCommand):
         try:
             opts, args = getopt.gnu_getopt(self.args, 'BdEhiORsStuvVx3c:m:Q:W:', ['help', 'version'])
         except getopt.GetoptError as err:
-            self.write("Unknown option: -{0}\n".format(err.opt))
+            self.write(f"Unknown option: -{err.opt}\n")
             self.write("usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ... \n")
             self.write("Try `python -h' for more information.\n")
             self.exit()

src/cowrie/commands/scp.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 import getopt
 import hashlib
@@ -75,7 +74,7 @@ class command_scp(HoneyPotCommand):
             outdir = self.fs.resolve_path(self.out_dir, self.protocol.cwd)
 
             if not self.fs.exists(outdir):
-                self.errorWrite('-scp: {}: No such file or directory\n'.format(self.out_dir))
+                self.errorWrite(f'-scp: {self.out_dir}: No such file or directory\n')
                 self.exit()
 
         self.write('\x00')
@@ -175,7 +174,7 @@ class command_scp(HoneyPotCommand):
                         self.fs.mkfile(outfile, 0, 0, r.group(2), r.group(1))
                     except fs.FileNotFound:
                         # The outfile locates at a non-existing directory.
-                        self.errorWrite('-scp: {}: No such file or directory\n'.format(outfile))
+                        self.errorWrite(f'-scp: {outfile}: No such file or directory\n')
                         self.safeoutfile = None
                         return ''
 

src/cowrie/commands/service.py

@@ -5,7 +5,6 @@
 This module contains the service commnad
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 

src/cowrie/commands/sleep.py

@@ -5,7 +5,6 @@
 This module contains the sleep command
 """
 
-from __future__ import absolute_import, division
 
 import re
 

src/cowrie/commands/ssh.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import getopt
 import hashlib
@@ -53,7 +52,7 @@ class command_ssh(HoneyPotCommand):
                 return
         if not len(args):
             for line in OUTPUT:
-                self.write('{0}\n'.format(line))
+                self.write(f'{line}\n')
             self.exit()
             return
         user, host = 'root', args[0]
@@ -67,8 +66,8 @@ class command_ssh(HoneyPotCommand):
             if self.valid_ip(host):
                 self.ip = host
             else:
-                self.write('ssh: Could not resolve hostname %s: \
+                self.write('ssh: Could not resolve hostname {}: \
-                    Name or service not known\n' % (host,))
+                    Name or service not known\n'.format(host))
                 self.exit()
         else:
             s = hashlib.md5(host.encode()).hexdigest()
@@ -78,8 +77,8 @@ class command_ssh(HoneyPotCommand):
         self.host = host
         self.user = user
 
-        self.write('The authenticity of host \'%s (%s)\' \
+        self.write('The authenticity of host \'{} ({})\' \
-            can\'t be established.\n' % (self.host, self.ip))
+            can\'t be established.\n'.format(self.host, self.ip))
         self.write('RSA key fingerprint is \
             9d:30:97:8a:9e:48:0d:de:04:8d:76:3a:7b:4b:30:f8.\n')
         self.write('Are you sure you want to continue connecting (yes/no)? ')
@@ -88,7 +87,7 @@ class command_ssh(HoneyPotCommand):
     def yesno(self, line):
         self.write('Warning: Permanently added \'{}\' (RSA) to the \
             list of known hosts.\n'.format(self.host))
-        self.write('%s@%s\'s password: ' % (self.user, self.host))
+        self.write(f'{self.user}@{self.host}\'s password: ')
         self.protocol.password_input = True
 
     def wait(self, line):

src/cowrie/commands/sudo.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import getopt
 
 from cowrie.shell.command import HoneyPotCommand
@@ -57,12 +55,12 @@ class command_sudo(HoneyPotCommand):
 
     def short_help(self):
         for ln in sudo_shorthelp:
-            self.errorWrite('{0}\n'.format(ln))
+            self.errorWrite(f'{ln}\n')
         self.exit()
 
     def long_help(self):
         for ln in sudo_longhelp:
-            self.errorWrite('{0}\n'.format(ln))
+            self.errorWrite(f'{ln}\n')
         self.exit()
 
     def version(self):

src/cowrie/commands/tar.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import os
 import tarfile
@@ -64,7 +63,7 @@ class command_tar(HoneyPotCommand):
         for f in t:
             dest = self.fs.resolve_path(f.name.strip('/'), self.protocol.cwd)
             if verbose:
-                self.write('{0}\n'.format(f.name))
+                self.write(f'{f.name}\n')
             if not extract or not len(dest):
                 continue
             if f.isdir():
@@ -73,7 +72,7 @@ class command_tar(HoneyPotCommand):
                 self.mkfullpath(os.path.dirname(dest), f)
                 self.fs.mkfile(dest, 0, 0, f.size, f.mode, f.mtime)
             else:
-                log.msg("tar: skipping [{}]".format(f.name))
+                log.msg(f"tar: skipping [{f.name}]")
 
 
 commands['/bin/tar'] = command_tar

src/cowrie/commands/tee.py

@@ -5,7 +5,6 @@ tee command
 
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 import os
@@ -32,7 +31,7 @@ class command_tee(HoneyPotCommand):
         try:
             optlist, args = getopt.gnu_getopt(self.args, 'aip', ['help', 'append', 'version'])
         except getopt.GetoptError as err:
-            self.errorWrite("tee: invalid option -- '{}'\nTry 'tee --help' for more information.\n".format(err.opt))
+            self.errorWrite(f"tee: invalid option -- '{err.opt}'\nTry 'tee --help' for more information.\n")
             self.exit()
             return
 
@@ -50,7 +49,7 @@ class command_tee(HoneyPotCommand):
             pname = self.fs.resolve_path(arg, self.protocol.cwd)
 
             if self.fs.isdir(pname):
-                self.errorWrite('tee: {}: Is a directory\n'.format(arg))
+                self.errorWrite(f'tee: {arg}: Is a directory\n')
                 continue
 
             try:
@@ -65,7 +64,7 @@ class command_tee(HoneyPotCommand):
                 self.fs.mkfile(pname, 0, 0, 0, 0o644)
 
             except FileNotFound:
-                self.errorWrite('tee: {}: No such file or directory\n'.format(arg))
+                self.errorWrite(f'tee: {arg}: No such file or directory\n')
 
         if self.input_data:
             self.output(self.input_data)

src/cowrie/commands/tftp.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import tftpy
 
 try:
@@ -17,7 +15,7 @@ from cowrie.shell.customparser import CustomParser
 commands = {}
 
 
-class Progress(object):
+class Progress:
 
     def __init__(self, protocol):
         self.progress = 0
@@ -52,7 +50,7 @@ class command_tftp(HoneyPotCommand):
             # so we have to convert unicode type to str type
             tclient.download(str(self.file_to_get), self.artifactFile, progresshook)
 
-            url = 'tftp://%s/%s' % (self.hostname, self.file_to_get.strip('/'))
+            url = 'tftp://{}/{}'.format(self.hostname, self.file_to_get.strip('/'))
 
             self.file_to_get = self.fs.resolve_path(self.file_to_get, self.protocol.cwd)
 

src/cowrie/commands/ulimit.py

@@ -5,7 +5,6 @@
 This module ...
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 
@@ -26,7 +25,7 @@ class command_ulimit(HoneyPotCommand):
         try:
             opts, args = getopt.getopt(self.args, 'SHacdfilmnpqstuvx')
         except getopt.GetoptError as err:
-            self.errorWrite("-bash: ulimit: {}\n".format(err))
+            self.errorWrite(f"-bash: ulimit: {err}\n")
             self.write("ulimit: usage: ulimit [-SHacdfilmnpqstuvx] [limit]\n")
             return
 

src/cowrie/commands/uname.py

@@ -5,7 +5,6 @@
 uname command
 """
 
-from __future__ import absolute_import, division
 
 from cowrie.core.config import CowrieConfig
 from cowrie.shell.command import HoneyPotCommand
@@ -80,7 +79,7 @@ class command_uname(HoneyPotCommand):
             }
         if not self.args:
             # IF no params output default
-            self.write('{}\n'.format(kernel_name()))
+            self.write(f'{kernel_name()}\n')
         else:
             # I have parameter to parse
             for a in self.args:
@@ -107,17 +106,17 @@ class command_uname(HoneyPotCommand):
             I have all the option set
             '''
             if opts['name']:
-                self.write('{} '.format(kernel_name()))
+                self.write(f'{kernel_name()} ')
             if opts['node']:
-                self.write('{} '.format(self.protocol.hostname))
+                self.write(f'{self.protocol.hostname} ')
             if opts['release']:
-                self.write('{} '.format(kernel_version()))
+                self.write(f'{kernel_version()} ')
             if opts['version']:
-                self.write('{} '.format(kernel_build_string()))
+                self.write(f'{kernel_build_string()} ')
             if opts['machine']:
-                self.write('{} '.format(hardware_platform()))
+                self.write(f'{hardware_platform()} ')
             if opts['os']:
-                self.write('{} '.format(operating_system()))
+                self.write(f'{operating_system()} ')
             self.write('\n')
 
 

src/cowrie/commands/uniq.py

@@ -5,7 +5,6 @@
 uniq command
 """
 
-from __future__ import absolute_import, division
 
 from twisted.python import log
 

src/cowrie/commands/unzip.py

@@ -2,7 +2,6 @@
 # Based on code made by Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import os
 import zipfile
@@ -90,11 +89,11 @@ class command_unzip(HoneyPotCommand):
             self.write(
                 'unzip:   cannot find zipfile directory in one of {0}, {0}.zip or {0}.ZIP.\n'.format(filename))
             return
-        self.write('Archive:  {}\n'.format(filename))
+        self.write(f'Archive:  {filename}\n')
         for f in t:
             dest = self.fs.resolve_path(
                 f.filename.strip('/'), self.protocol.cwd)
-            self.write('  inflating: {0}\n'.format(f.filename))
+            self.write(f'  inflating: {f.filename}\n')
             if not len(dest):
                 continue
             if f.is_dir():
@@ -103,7 +102,7 @@ class command_unzip(HoneyPotCommand):
                 self.mkfullpath(os.path.dirname(dest), f)
                 self.fs.mkfile(dest, 0, 0, f.file_size, 33188)
             else:
-                log.msg("  skipping: {}\n".format(f.name))
+                log.msg(f"  skipping: {f.name}\n")
 
 
 commands['/bin/unzip'] = command_unzip

src/cowrie/commands/uptime.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import time
 

src/cowrie/commands/wc.py

@@ -6,7 +6,6 @@
 This module contains the wc commnad
 """
 
-from __future__ import absolute_import, division
 
 import getopt
 import re
@@ -54,7 +53,7 @@ class command_wc(HoneyPotCommand):
             contents = self.fs.file_contents(filename)
             self.wc_application(contents, optlist)
         except Exception:
-            self.errorWrite("wc: {}: No such file or directory\n".format(filename))
+            self.errorWrite(f"wc: {filename}: No such file or directory\n")
 
     def wc_application(self, contents, optlist):
         for opt, arg in optlist:
@@ -82,7 +81,7 @@ class command_wc(HoneyPotCommand):
             try:
                 optlist, args = getopt.getopt(self.args, 'cmlLwhv')
             except getopt.GetoptError as err:
-                self.errorWrite("wc: invalid option -- {}\n".format(err.opt))
+                self.errorWrite(f"wc: invalid option -- {err.opt}\n")
                 self.help()
                 self.exit()
                 return

src/cowrie/commands/wget.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import getopt
 import os
@@ -134,7 +133,7 @@ class command_wget(HoneyPotCommand):
             if not host:
                 return None
         except Exception:
-            self.errorWrite('%s: Unsupported scheme.\n' % (url,))
+            self.errorWrite(f'{url}: Unsupported scheme.\n')
             return None
 
         # File in host's fs that will hold content of the downloaded file
@@ -142,7 +141,7 @@ class command_wget(HoneyPotCommand):
         self.artifactFile = Artifact(self.outfile)
 
         if not self.quiet:
-            self.errorWrite('--%s--  %s\n' % (time.strftime('%Y-%m-%d %H:%M:%S'), url.decode('utf8')))
+            self.errorWrite('--{}--  {}\n'.format(time.strftime('%Y-%m-%d %H:%M:%S'), url.decode('utf8')))
             self.errorWrite('Connecting to %s:%d... connected.\n' % (host, port))
             self.errorWrite('HTTP request sent, awaiting response... ')
 
@@ -198,9 +197,9 @@ class command_wget(HoneyPotCommand):
     def error(self, error, url):
         # we need to handle 301 redirects separately
         if hasattr(error, 'webStatus') and error.webStatus.decode() == '301':
-            self.errorWrite('{} {}\n'.format(error.webStatus.decode(), error.webMessage.decode()))
+            self.errorWrite(f'{error.webStatus.decode()} {error.webMessage.decode()}\n')
             https_url = error.getErrorMessage().replace('301 Moved Permanently to ', '')
-            self.errorWrite('Location {} [following]\n'.format(https_url))
+            self.errorWrite(f'Location {https_url} [following]\n')
 
             # do the download again with the https URL
             self.deferred = self.download(https_url.encode('utf8'), self.outfile)
@@ -276,15 +275,15 @@ class HTTPProgressDownloader(client.HTTPDownloader):
                                                                          self.contenttype))
             else:
                 if not self.quiet:
-                    self.wget.errorWrite('Length: unspecified [{}]\n'.format(self.contenttype))
+                    self.wget.errorWrite(f'Length: unspecified [{self.contenttype}]\n')
             if 0 < self.wget.limit_size < self.totallength:
-                log.msg('Not saving URL ({}) due to file size limit'.format(self.wget.url))
+                log.msg(f'Not saving URL ({self.wget.url}) due to file size limit')
                 self.nomore = True
             if not self.quiet:
                 if self.fakeoutfile == '-':
                     self.wget.errorWrite('Saving to: `STDOUT\'\n\n')
                 else:
-                    self.wget.errorWrite('Saving to: `{}\'\n\n'.format(self.fakeoutfile))
+                    self.wget.errorWrite(f'Saving to: `{self.fakeoutfile}\'\n\n')
 
         return client.HTTPDownloader.gotHeaders(self, headers)
 
@@ -300,7 +299,7 @@ class HTTPProgressDownloader(client.HTTPDownloader):
                 return client.HTTPDownloader.pagePart(self, data)
             if self.totallength:
                 percent = int(self.currentlength / self.totallength * 100)
-                spercent = "{}%".format(percent)
+                spercent = f"{percent}%"
             else:
                 spercent = '%dK' % (self.currentlength / 1000)
                 percent = 0

src/cowrie/commands/which.py

@@ -1,6 +1,5 @@
 # Copyright (c) 2013 Bas Stottelaar <basstottelaar [AT] gmail [DOT] com>
 
-from __future__ import absolute_import, division
 
 from cowrie.shell.command import HoneyPotCommand
 
@@ -26,7 +25,7 @@ class command_which(HoneyPotCommand):
                 resolved = self.fs.resolve_path(f, path)
 
                 if self.fs.exists(resolved):
-                    self.write("%s/%s\n" % (path, f))
+                    self.write(f"{path}/{f}\n")
 
 
 commands['which'] = command_which

src/cowrie/commands/yum.py

@@ -4,7 +4,6 @@
 
 # Modified by Fabiola Buschendorf, https://github.com/FabiolaBusch
 
-from __future__ import absolute_import, division
 
 import hashlib
 import random
@@ -20,7 +19,7 @@ arch = 'x86_64'
 commands = {}
 
 
-class command_faked_package_class_factory(object):
+class command_faked_package_class_factory:
     @staticmethod
     def getCommand(name):
         class command_faked_installation(HoneyPotCommand):
@@ -63,8 +62,8 @@ class command_yum(HoneyPotCommand):
         randhash = hashlib.sha1(b'{}'.format(randnum)).hexdigest()
         randhash2 = hashlib.sha1(b'{}'.format(randnum2)).hexdigest()
         yield self.sleep(1, 2)
-        self.write('Installed: 7/{0}  {1}:{2}\n'.format(arch, random.randint(500, 800), randhash))
+        self.write('Installed: 7/{}  {}:{}\n'.format(arch, random.randint(500, 800), randhash))
-        self.write('Group-Installed: yum 13:{}\n'.format(randhash2))
+        self.write(f'Group-Installed: yum 13:{randhash2}\n')
         self.write('version\n')
         self.exit()
 
@@ -193,9 +192,9 @@ Options:
         packages = {}
         for y in [re.sub('[^A-Za-z0-9]', '', x) for x in self.args[1:]]:
             packages[y] = {
-                'version': '{0}.{1}-{2}'.format(random.choice([0, 1]), random.randint(1, 40), random.randint(1, 10)),
+                'version': '{}.{}-{}'.format(random.choice([0, 1]), random.randint(1, 40), random.randint(1, 10)),
                 'size': random.randint(100, 900),
-                'release': '{0}.el7'.format(random.randint(1, 15))
+                'release': '{}.el7'.format(random.randint(1, 15))
             }
         totalsize = sum([packages[x]['size'] for x in packages])
         repository = 'base'
@@ -209,7 +208,7 @@ Options:
         self.write('Resolving Dependencies\n')
         self.write('--> Running transaction check\n')
         for p in packages:
-            self.write('---> Package {0}.{1} {2}.{3} will be installed\n'.format(p, packages[p]['version'], arch,
+            self.write('---> Package {}.{} {}.{} will be installed\n'.format(p, packages[p]['version'], arch,
                        packages[p]['release']))
         self.write('--> Finished Dependency Resolution\n')
         self.write('Beginning Kernel Module Plugin\n')
@@ -225,16 +224,15 @@ Options:
         self.write('{}\n'.format('=' * 176))
         self.write('Installing:\n')
         for p in packages:
-            self.write(' {0}\t\t\t\t{1}\t\t\t{2}-{3}\t\t\t{4}\t\t\t\t{5} k\n'.format(p, arch, packages[p]['version'],
+            self.write(' {}\t\t\t\t{}\t\t\t{}-{}\t\t\t{}\t\t\t\t{} k\n'.format(p, arch, packages[p]['version'],
-                                                                                     packages[p]['release'], repository,
+                       packages[p]['release'], repository, packages[p]['size']))
-                                                                                     packages[p]['size']))
         self.write('\n')
         self.write('Transaction Summary\n')
         self.write('{}\n'.format('=' * 176))
-        self.write('Install  {0} Packages\n\n'.format(len(packages)))
+        self.write('Install  {} Packages\n\n'.format(len(packages)))
 
-        self.write('Total download size: {0} k\n'.format(totalsize))
+        self.write(f'Total download size: {totalsize} k\n')
-        self.write('Installed size: {:.1f} M\n'.format((totalsize * 0.0032)))
+        self.write('Installed size: {:.1f} M\n'.format(totalsize * 0.0032))
         self.write('Is this ok [y/d/N]: ')
         # Assume 'yes'
 
@@ -251,20 +249,20 @@ Options:
         self.write('Running transaction\n')
         i = 1
         for p in packages:
-            self.write('  Installing : {0}-{1}-{2}.{3} \t\t\t\t {4}/{5} \n'.format
+            self.write('  Installing : {}-{}-{}.{} \t\t\t\t {}/{} \n'.format
                        (p, packages[p]['version'], packages[p]['release'], arch, i, len(packages)))
             yield self.sleep(0.5, 1)
             i += 1
         i = 1
         for p in packages:
-            self.write('  Verifying : {0}-{1}-{2}.{3} \t\t\t\t {4}/{5} \n'.format
+            self.write('  Verifying : {}-{}-{}.{} \t\t\t\t {}/{} \n'.format
                        (p, packages[p]['version'], packages[p]['release'], arch, i, len(packages)))
             yield self.sleep(0.5, 1)
             i += 1
         self.write('\n')
         self.write('Installed:\n')
         for p in packages:
-            self.write('  {0}.{1} {2}:{3}-{4} \t\t'.format
+            self.write('  {}.{} {}:{}-{} \t\t'.format
                        (p, arch, random.randint(0, 2), packages[p]['version'], packages[p]['release']))
         self.write('\n')
         self.write('Complete!\n')

src/cowrie/core/artifact.py

@@ -20,7 +20,6 @@ or:
 
 """
 
-from __future__ import absolute_import, division
 
 import hashlib
 import os

src/cowrie/core/auth.py

@@ -5,7 +5,6 @@
 This module contains authentication code
 """
 
-from __future__ import absolute_import, division
 
 import json
 import re
@@ -27,7 +26,7 @@ _USERDB_DEFAULTS = [
 ]
 
 
-class UserDB(object):
+class UserDB:
     """
     By Walter de Jong <walter@sara.nl>
     """
@@ -42,9 +41,9 @@ class UserDB(object):
         """
 
         try:
-            with open('{}/userdb.txt'.format(CowrieConfig().get('honeypot', 'etc_path')), 'r') as db:
+            with open('{}/userdb.txt'.format(CowrieConfig().get('honeypot', 'etc_path'))) as db:
                 userdb = db.readlines()
-        except IOError:
+        except OSError:
             log.msg("Could not read etc/userdb.txt, default database activated")
             userdb = _USERDB_DEFAULTS
 
@@ -108,7 +107,7 @@ class UserDB(object):
         self.userdb[(login, passwd)] = policy
 
 
-class AuthRandom(object):
+class AuthRandom:
     """
     Alternative class that defines the checklogin() method.
     Users will be authenticated after a random number of attempts.
@@ -129,7 +128,7 @@ class AuthRandom(object):
 
         if self.maxtry < self.mintry:
             self.maxtry = self.mintry + 1
-            log.msg("maxtry < mintry, adjusting maxtry to: {}".format(self.maxtry))
+            log.msg(f"maxtry < mintry, adjusting maxtry to: {self.maxtry}")
         self.uservar = {}
         self.uservar_file = '{}/auth_random.json'.format(CowrieConfig().get('honeypot', 'state_path'))
         self.loadvars()
@@ -139,7 +138,7 @@ class AuthRandom(object):
         Load user vars from json file
         """
         if path.isfile(self.uservar_file):
-            with open(self.uservar_file, 'r') as fp:
+            with open(self.uservar_file) as fp:
                 try:
                     self.uservar = json.load(fp)
                 except Exception:
@@ -178,7 +177,7 @@ class AuthRandom(object):
             ipinfo = self.uservar[src_ip]
             ipinfo['try'] = 0
             if userpass in cache:
-                log.msg("first time for {}, found cached: {}".format(src_ip, userpass))
+                log.msg(f"first time for {src_ip}, found cached: {userpass}")
                 ipinfo['max'] = 1
                 ipinfo['user'] = str(thelogin)
                 ipinfo['pw'] = str(thepasswd)
@@ -191,7 +190,7 @@ class AuthRandom(object):
         else:
             if userpass in cache:
                 ipinfo = self.uservar[src_ip]
-                log.msg("Found cached: {}".format(userpass))
+                log.msg(f"Found cached: {userpass}")
                 ipinfo['max'] = 1
                 ipinfo['user'] = str(thelogin)
                 ipinfo['pw'] = str(thepasswd)
@@ -218,7 +217,7 @@ class AuthRandom(object):
         ipinfo['try'] += 1
         attempts = ipinfo['try']
         need = ipinfo['max']
-        log.msg("login attempt: {}".format(attempts))
+        log.msg(f"login attempt: {attempts}")
 
         # Check if enough login attempts are tried
         if attempts < need:

src/cowrie/core/cef.py

@@ -26,8 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
-
 
 #  cowrie.client.fingerprint
 #  cowrie.client.size
@@ -45,7 +43,6 @@ from __future__ import absolute_import, division
 #  cowrie.session.file_download
 #  cowrie.session.file_upload
 
-
 def formatCef(logentry):
     """
     Take logentry and turn into CEF string
@@ -93,7 +90,7 @@ def formatCef(logentry):
     cefList = []
     for key in list(cefExtensions.keys()):
         value = str(cefExtensions[key])
-        cefList.append('{}={}'.format(key, value))
+        cefList.append(f'{key}={value}')
 
     cefExtension = ' '.join(cefList)
 

src/cowrie/core/checkers.py

@@ -5,7 +5,6 @@
 This module contains ...
 """
 
-from __future__ import absolute_import, division
 
 from sys import modules
 
@@ -25,7 +24,7 @@ from cowrie.core.config import CowrieConfig
 
 
 @implementer(ICredentialsChecker)
-class HoneypotPublicKeyChecker(object):
+class HoneypotPublicKeyChecker:
     """
     Checker that accepts, logs and denies public key authentication attempts
     """
@@ -45,7 +44,7 @@ class HoneypotPublicKeyChecker(object):
 
 
 @implementer(ICredentialsChecker)
-class HoneypotNoneChecker(object):
+class HoneypotNoneChecker:
     """
     Checker that does no authentication check
     """
@@ -57,7 +56,7 @@ class HoneypotNoneChecker(object):
 
 
 @implementer(ICredentialsChecker)
-class HoneypotPasswordChecker(object):
+class HoneypotPasswordChecker:
     """
     Checker that accepts "keyboard-interactive" and "password"
     """
@@ -99,7 +98,7 @@ class HoneypotPasswordChecker(object):
             if hasattr(modules[authmodule], authclass):
                 authname = getattr(modules[authmodule], authclass)
             else:
-                log.msg('auth_class: %s not found in %s' % (authclass, authmodule))
+                log.msg(f'auth_class: {authclass} not found in {authmodule}')
 
         theauth = authname()
 

src/cowrie/core/config.py

@@ -5,7 +5,6 @@
 This module contains code to deal with Cowrie's configuration
 """
 
-from __future__ import absolute_import, division
 
 import configparser
 from os import environ
@@ -16,7 +15,7 @@ def to_environ_key(key):
     return key.upper()
 
 
-class CowrieConfig(object):
+class CowrieConfig:
     """
     Singleton class for configuration data
     """
@@ -38,13 +37,13 @@ class EnvironmentConfigParser(configparser.ConfigParser):
     def has_option(self, section, option):
         if to_environ_key('_'.join(("cowrie", section, option))) in environ:
             return True
-        return super(EnvironmentConfigParser, self).has_option(section, option)
+        return super().has_option(section, option)
 
     def get(self, section, option, raw=False, **kwargs):
         key = to_environ_key('_'.join(("cowrie", section, option)))
         if key in environ:
             return environ[key]
-        return super(EnvironmentConfigParser, self).get(section, option, raw=raw, **kwargs)
+        return super().get(section, option, raw=raw, **kwargs)
 
 
 def readConfigFile(cfgfile):

src/cowrie/core/credentials.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 from twisted.cred.credentials import ICredentials, IUsernamePassword
 
@@ -64,7 +63,7 @@ class IPluggableAuthenticationModulesIP(ICredentials):
 
 
 @implementer(IPluggableAuthenticationModulesIP)
-class PluggableAuthenticationModulesIP(object):
+class PluggableAuthenticationModulesIP:
     """
     Twisted removed IPAM in 15, adding in Cowrie now
     """
@@ -76,14 +75,14 @@ class PluggableAuthenticationModulesIP(object):
 
 
 @implementer(IUsername)
-class Username(object):
+class Username:
 
     def __init__(self, username):
         self.username = username
 
 
 @implementer(IUsernamePasswordIP)
-class UsernamePasswordIP(object):
+class UsernamePasswordIP:
     """
     This credential interface also provides an IP address
     """

src/cowrie/core/output.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 import abc
 import re
@@ -78,7 +77,7 @@ def convert(input):
         return input
 
 
-class Output(object):
+class Output:
     """
     This is the abstract base class intended to be inherited by
     cowrie output plugins. Plugins require the mandatory

src/cowrie/core/realm.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 from twisted.conch import interfaces as conchinterfaces
 from twisted.conch.telnet import ITelnetProtocol
@@ -40,7 +39,7 @@ from cowrie.telnet import session
 
 
 @implementer(IRealm)
-class HoneyPotRealm(object):
+class HoneyPotRealm:
     def __init__(self):
         pass
 

src/cowrie/core/ttylog.py

@@ -7,7 +7,6 @@
 Should be compatible with user mode linux
 """
 
-from __future__ import absolute_import, division
 
 import hashlib
 import struct

src/cowrie/core/utils.py

@@ -2,7 +2,6 @@
 # Copyright (c) 2010-2014 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import sys
 
@@ -27,16 +26,16 @@ def durationHuman(seconds):
 
     duration = []
     if years > 0:
-        duration.append('{0} year{1} '.format(syears, 's' * (years != 1)))
+        duration.append('{} year{} '.format(syears, 's' * (years != 1)))
     else:
         if days > 0:
-            duration.append('{0} day{1} '.format(days, 's' * (days != 1)))
+            duration.append('{} day{} '.format(days, 's' * (days != 1)))
         if hours > 0:
-            duration.append('{0}:'.format(shours))
+            duration.append(f'{shours}:')
         if minutes >= 0:
-            duration.append('{0}:'.format(sminutes))
+            duration.append(f'{sminutes}:')
         if seconds >= 0:
-            duration.append('{0}'.format(sseconds))
+            duration.append(f'{sseconds}')
 
     return ''.join(duration)
 
@@ -85,7 +84,7 @@ def uptime(total_seconds):
     if days > 0:
         s += str(days) + " " + (days == 1 and "day" or "days") + ", "
     if len(s) > 0 or hours > 0:
-        s += '%s:%s' % (str(hours).rjust(2), str(minutes).rjust(2, '0'))
+        s += '{}:{}'.format(str(hours).rjust(2), str(minutes).rjust(2, '0'))
     else:
         s += '{} min'.format(str(minutes))
     return s
@@ -107,7 +106,7 @@ def get_endpoints_from_section(cfg, section, default_port):
 
     listen_endpoints = []
     for i in listen_addr.split():
-        listen_endpoints.append('tcp:{}:interface={}'.format(listen_port, i))
+        listen_endpoints.append(f'tcp:{listen_port}:interface={i}')
 
     return listen_endpoints
 

src/cowrie/insults/insults.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009-2014 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import hashlib
 import os
@@ -135,7 +134,7 @@ class LoggingServerProtocol(insults.ServerProtocol):
                         outfile=shasumfile,
                         shasum=shasum,
                         destfile='')
-            except IOError:
+            except OSError:
                 pass
             finally:
                 self.stdinlogOpen = False
@@ -173,7 +172,7 @@ class LoggingServerProtocol(insults.ServerProtocol):
                             outfile=shasumfile,
                             shasum=shasum,
                             destfile=url)
-                except IOError:
+                except OSError:
                     pass
             self.redirFiles.clear()
 

src/cowrie/output/abuseipdb.py

@@ -128,7 +128,7 @@ class Output(output.Output):
 
         log.msg(
             eventid='cowrie.abuseipdb.started',
-            format='AbuseIPDB Plugin version {} started. Currently in beta.'.format(__version__),
+            format=f'AbuseIPDB Plugin version {__version__} started. Currently in beta.',
         )
 
     def stop(self):

src/cowrie/output/crashreporter.py

@@ -6,7 +6,6 @@ It has its own emit() function and does not use cowrie eventid's
 to avoid circular calls
 """
 
-from __future__ import absolute_import, division
 
 import json
 
@@ -19,7 +18,7 @@ import cowrie.core.output
 from cowrie._version import __version__
 from cowrie.core.config import CowrieConfig
 
-COWRIE_USER_AGENT = 'Cowrie Honeypot {}'.format(__version__).encode('ascii')
+COWRIE_USER_AGENT = f'Cowrie Honeypot {__version__}'.encode('ascii')
 COWRIE_URL = 'https://api.cowrie.org/v1/crash'
 
 

src/cowrie/output/csirtg.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import os
 from datetime import datetime
 

src/cowrie/output/cuckoo.py

@@ -30,7 +30,6 @@
 Send downloaded/uplaoded files to Cuckoo
 """
 
-from __future__ import absolute_import, division
 
 import os
 
@@ -93,11 +92,11 @@ class Output(cowrie.core.output.Output):
         """
         res = None
         try:
-            print("Looking for tasks for: {}".format(sha256))
+            print(f"Looking for tasks for: {sha256}")
             res = requests.get(
                 urljoin(
                     self.url_base,
-                    "/files/view/sha256/{}".format(sha256)
+                    f"/files/view/sha256/{sha256}"
                 ),
                 verify=False,
                 auth=HTTPBasicAuth(
@@ -135,9 +134,9 @@ class Output(cowrie.core.output.Output):
             if res and res.ok:
                 print("Cuckoo Request: {}, Task created with ID: {}".format(res.status_code, res.json()["task_id"]))
             else:
-                print("Cuckoo Request failed: {}".format(res.status_code))
+                print(f"Cuckoo Request failed: {res.status_code}")
         except Exception as e:
-            print("Cuckoo Request failed: {}".format(e))
+            print(f"Cuckoo Request failed: {e}")
 
     def posturl(self, scanUrl):
         """
@@ -160,6 +159,6 @@ class Output(cowrie.core.output.Output):
             if res and res.ok:
                 print("Cuckoo Request: {}, Task created with ID: {}".format(res.status_code, res.json()["task_id"]))
             else:
-                print("Cuckoo Request failed: {}".format(res.status_code))
+                print(f"Cuckoo Request failed: {res.status_code}")
         except Exception as e:
-            print("Cuckoo Request failed: {}".format(e))
+            print(f"Cuckoo Request failed: {e}")

src/cowrie/output/dshield.py

@@ -3,7 +3,6 @@ Send SSH logins to SANS DShield.
 See https://isc.sans.edu/ssh.html
 """
 
-from __future__ import absolute_import, division
 
 import base64
 import hashlib
@@ -70,9 +69,9 @@ class Output(cowrie.core.output.Output):
         # fixed nonce to mix up the limited userid.
         _nonceb64 = 'ElWO1arph+Jifqme6eXD8Uj+QTAmijAWxX1msbJzXDM='
 
-        log_output = u''
+        log_output = ''
         for attempt in self.batch:
-            log_output += u'{0}\t{1}\t{2}\t{3}\t{4}\t{5}\n'.format(
+            log_output += '{}\t{}\t{}\t{}\t{}\t{}\n'.format(
                 attempt['date'],
                 attempt['time'],
                 attempt['timezone'],
@@ -88,7 +87,7 @@ class Output(cowrie.core.output.Output):
                 base64.b64decode(self.auth_key),
                 hashlib.sha256).digest()
         )
-        auth_header = 'credentials={0} nonce={1} userid={2}'.format(digest.decode('ascii'), _nonceb64, self.userid)
+        auth_header = 'credentials={} nonce={} userid={}'.format(digest.decode('ascii'), _nonceb64, self.userid)
         headers = {
             'X-ISC-Authorization': auth_header,
             'Content-Type': 'text/plain'
@@ -96,7 +95,7 @@ class Output(cowrie.core.output.Output):
 
         if self.debug:
             log.msg('dshield: posting: {}'.format(repr(headers)))
-            log.msg('dshield: posting: {}'.format(log_output))
+            log.msg(f'dshield: posting: {log_output}')
 
         req = threads.deferToThread(
             requests.request,
@@ -112,20 +111,20 @@ class Output(cowrie.core.output.Output):
             response = resp.content.decode('utf8')
 
             if self.debug:
-                log.msg("dshield: status code {}".format(resp.status_code))
+                log.msg(f"dshield: status code {resp.status_code}")
-                log.msg("dshield: response {}".format(resp.content))
+                log.msg(f"dshield: response {resp.content}")
 
             if resp.status_code == requests.codes.ok:
                 sha1_regex = re.compile(r'<sha1checksum>([^<]+)<\/sha1checksum>')
                 sha1_match = sha1_regex.search(response)
                 if sha1_match is None:
-                    log.msg('dshield: ERROR: Could not find sha1checksum in response: {0}'.format(repr(response)))
+                    log.msg('dshield: ERROR: Could not find sha1checksum in response: {}'.format(repr(response)))
                     failed = True
                 sha1_local = hashlib.sha1()
                 sha1_local.update(log_output.encode('utf8'))
                 if sha1_match.group(1) != sha1_local.hexdigest():
                     log.msg(
-                        'dshield: ERROR: SHA1 Mismatch {0} {1} .'.format(sha1_match.group(1), sha1_local.hexdigest()))
+                        'dshield: ERROR: SHA1 Mismatch {} {} .'.format(sha1_match.group(1), sha1_local.hexdigest()))
                     failed = True
                 md5_regex = re.compile(r'<md5checksum>([^<]+)<\/md5checksum>')
                 md5_match = md5_regex.search(response)
@@ -135,12 +134,12 @@ class Output(cowrie.core.output.Output):
                 md5_local = hashlib.md5()
                 md5_local.update(log_output.encode('utf8'))
                 if md5_match.group(1) != md5_local.hexdigest():
-                    log.msg('dshield: ERROR: MD5 Mismatch {0} {1} .'.format(md5_match.group(1), md5_local.hexdigest()))
+                    log.msg('dshield: ERROR: MD5 Mismatch {} {} .'.format(md5_match.group(1), md5_local.hexdigest()))
                     failed = True
-                log.msg('dshield: SUCCESS: Sent {0} bytes worth of data to secure.dshield.org'.format(len(log_output)))
+                log.msg('dshield: SUCCESS: Sent {} bytes worth of data to secure.dshield.org'.format(len(log_output)))
             else:
-                log.msg('dshield ERROR: error {0}.'.format(resp.status_code))
+                log.msg(f'dshield ERROR: error {resp.status_code}.')
-                log.msg('dshield response was {0}'.format(response))
+                log.msg(f'dshield response was {response}')
                 failed = True
 
             if failed:

src/cowrie/output/elasticsearch.py

@@ -1,6 +1,5 @@
 # Simple elasticsearch logger
 
-from __future__ import absolute_import, division
 
 from elasticsearch import Elasticsearch, NotFoundError
 
@@ -49,7 +48,7 @@ class Output(cowrie.core.output.Output):
                 options["ca_certs"] = self.ca_certs
 
         # connect
-        self.es = Elasticsearch("{0}:{1}".format(self.host, self.port), **options)
+        self.es = Elasticsearch(f"{self.host}:{self.port}", **options)
         # self.es = Elasticsearch('{0}:{1}'.format(self.host, self.port))
 
         self.check_index()

src/cowrie/output/greynoise.py

@@ -2,7 +2,6 @@
 Send attackers IP to GreyNoise
 """
 
-from __future__ import absolute_import, division
 
 import treq
 
@@ -55,7 +54,7 @@ class Output(cowrie.core.output.Output):
                 meta=query['metadata']
             )
 
-        gnUrl = '{0}query/ip'.format(GNAPI_URL).encode('utf8')
+        gnUrl = f'{GNAPI_URL}query/ip'.encode('utf8')
         headers = ({'User-Agent': [COWRIE_USER_AGENT]})
         fields = {'key': self.apiKey, 'ip': entry['src_ip']}
 
@@ -71,7 +70,7 @@ class Output(cowrie.core.output.Output):
 
         if response.code != 200:
             rsp = yield response.text()
-            log.error("greynoise: got error {}".format(rsp))
+            log.error(f"greynoise: got error {rsp}")
             return
 
         j = yield response.json()
@@ -87,4 +86,4 @@ class Output(cowrie.core.output.Output):
                 for query in j['records']:
                     message(query)
         else:
-            log.msg("greynoise: no results for for IP {0}".format(entry['src_ip']))
+            log.msg("greynoise: no results for for IP {}".format(entry['src_ip']))

src/cowrie/output/hpfeeds.py

@@ -2,7 +2,6 @@
 Output plugin for HPFeeds
 """
 
-from __future__ import absolute_import, division
 
 import hashlib
 import json
@@ -88,7 +87,7 @@ def msgauth(rand, ident, secret):
     return msghdr(OP_AUTH, strpack8(ident) + hash)
 
 
-class FeedUnpack(object):
+class FeedUnpack:
     def __init__(self):
         self.buf = bytearray()
 
@@ -120,9 +119,9 @@ class FeedUnpack(object):
         return opcode, data
 
 
-class hpclient(object):
+class hpclient:
     def __init__(self, server, port, ident, secret, debug):
-        log.msg('hpfeeds client init broker {0}:{1}, identifier {2}'.format(server, port, ident))
+        log.msg(f'hpfeeds client init broker {server}:{port}, identifier {ident}')
         self.server, self.port = server, int(port)
         self.ident, self.secret = ident.encode('latin1'), secret.encode('latin1')
         self.debug = debug
@@ -186,16 +185,16 @@ class hpclient(object):
         try:
             for opcode, data in self.unpacker:
                 if self.debug:
-                    log.msg('hpfeeds: msg opcode {0:x} data {1}'.format(
+                    log.msg('hpfeeds: msg opcode {:x} data {}'.format(
                         opcode,
-                        ''.join('{:02x}'.format(x) for x in data))
+                        ''.join(f'{x:02x}' for x in data))
                     )
                 if opcode == OP_INFO:
                     name, rand = strunpack8(data)
                     if self.debug:
-                        log.msg('hpfeeds: server name {0} rand {1}'.format(
+                        log.msg('hpfeeds: server name {} rand {}'.format(
                             name,
-                            ''.join('{:02x}'.format(x) for x in rand))
+                            ''.join(f'{x:02x}' for x in rand))
                         )
                     self.send(msgauth(rand, self.ident, self.secret))
                     self.state = 'GOTINFO'
@@ -205,12 +204,12 @@ class hpclient(object):
                     chan, data = strunpack8(data)
                     if self.debug:
                         log.msg(
-                            'hpfeeds: publish to {0} by {1}: {2}'.format(
+                            'hpfeeds: publish to {} by {}: {}'.format(
-                                chan, ident, ''.join('{:02x}'.format(x) for x in data)))
+                                chan, ident, ''.join(f'{x:02x}' for x in data)))
                 elif opcode == OP_ERROR:
-                    log.msg('hpfeeds: errormessage from server: {0}'.format(''.join('{:02x}'.format(x) for x in data)))
+                    log.msg('hpfeeds: errormessage from server: {}'.format(''.join(f'{x:02x}' for x in data)))
                 else:
-                    log.msg('hpfeeds: unknown opcode message: {0:x}'.format(opcode))
+                    log.msg(f'hpfeeds: unknown opcode message: {opcode:x}')
         except BadClient:
             log.msg('hpfeeds: unpacker error, disconnecting.')
             self.close()
@@ -219,7 +218,7 @@ class hpclient(object):
         try:
             self.send(msgpublish(self.ident, channel, json.dumps(kwargs, default=set2json).encode('latin1')))
         except Exception as e:
-            log.msg('hpfeeds: connection to hpfriends lost: {0}, reconnecting'.format(e))
+            log.msg(f'hpfeeds: connection to hpfriends lost: {e}, reconnecting')
             self.connect()
             self.send(msgpublish(self.ident, channel, json.dumps(kwargs, default=set2json).encode('latin1')))
 

src/cowrie/output/hpfeeds3.py

@@ -2,7 +2,6 @@
 Output plugin for HPFeeds
 """
 
-from __future__ import absolute_import, division
 
 import json
 import logging

src/cowrie/output/influx.py

@@ -22,7 +22,7 @@ class Output(cowrie.core.output.Output):
         try:
             self.client = InfluxDBClient(host=host, port=port, ssl=ssl, verify_ssl=ssl)
         except InfluxDBClientError as e:
-            log.msg("output_influx: I/O error({0}): '{1}'".format(
+            log.msg("output_influx: I/O error({}): '{}'".format(
                 e.code, e.message))
             return
 

src/cowrie/output/jsonlog.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 import json
 import os

src/cowrie/output/kafka.py

@@ -30,7 +30,6 @@
 Work in progress Kafka output. Not functional yet
 """
 
-from __future__ import absolute_import, division
 
 import json
 import logging

src/cowrie/output/localsyslog.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 import syslog
 

src/cowrie/output/malshare.py

@@ -31,7 +31,6 @@ Send files to https://malshare.com/
 More info https://malshare.com/doc.php
 """
 
-from __future__ import absolute_import, division
 
 import os
 
@@ -94,6 +93,6 @@ class Output(cowrie.core.output.Output):
             if res and res.ok:
                 log.msg("Submitted to MalShare")
             else:
-                log.msg("MalShare Request failed: {}".format(res.status_code))
+                log.msg(f"MalShare Request failed: {res.status_code}")
         except Exception as e:
-            log.msg("MalShare Request failed: {}".format(e))
+            log.msg(f"MalShare Request failed: {e}")

src/cowrie/output/mongodb.py

@@ -1,7 +1,3 @@
-# -*- coding: utf-8 -*-
-
-from __future__ import absolute_import, division
-
 import pymongo
 
 from twisted.python import log
@@ -19,14 +15,14 @@ class Output(cowrie.core.output.Output):
             object_id = collection.insert_one(event).inserted_id
             return object_id
         except Exception as e:
-            log.msg('mongo error - {0}'.format(e))
+            log.msg(f'mongo error - {e}')
 
     def update_one(self, collection, session, doc):
         try:
             object_id = collection.update({'session': session}, doc)
             return object_id
         except Exception as e:
-            log.msg('mongo error - {0}'.format(e))
+            log.msg(f'mongo error - {e}')
 
     def start(self):
         db_addr = CowrieConfig().get('output_mongodb', 'connection_string')
@@ -99,7 +95,7 @@ class Output(cowrie.core.output.Output):
         elif eventid == 'cowrie.client.size':
             doc = self.col_sessions.find_one({'session': entry['session']})
             if doc:
-                doc['termsize'] = '{0}x{1}'.format(entry['width'], entry['height'])
+                doc['termsize'] = '{}x{}'.format(entry['width'], entry['height'])
                 self.update_one(self.col_sessions, entry['session'], doc)
             else:
                 pass

src/cowrie/output/mysql.py

@@ -2,7 +2,6 @@
 MySQL output connector. Writes audit logs to MySQL database
 """
 
-from __future__ import absolute_import, division
 
 import MySQLdb
 
@@ -34,7 +33,7 @@ class ReconnectingConnectionPool(adbapi.ConnectionPool):
         except (MySQLdb.OperationalError, MySQLdb._exceptions.OperationalError) as e:
             if e.args[0] not in (2003, 2006, 2013):
                 raise e
-            log.msg("RCP: got error {0}, retrying operation".format(e))
+            log.msg(f"RCP: got error {e}, retrying operation")
             conn = self.connections.get(self.threadID())
             self.disconnect(conn)
             # Try the interaction again
@@ -78,10 +77,10 @@ class Output(cowrie.core.output.Output):
         1406, "Data too long for column '...' at row ..."
         """
         if error.value[0] in (1146, 1406):
-            log.msg("output_mysql: MySQL Error: {}".format(error.value))
+            log.msg(f"output_mysql: MySQL Error: {error.value}")
             log.msg("MySQL schema maybe misconfigured, doublecheck database!")
         else:
-            log.err("output_mysql: MySQL Error: {}".format(error.value))
+            log.err(f"output_mysql: MySQL Error: {error.value}")
 
     def simpleQuery(self, sql, args):
         """
@@ -188,7 +187,7 @@ class Output(cowrie.core.output.Output):
                 'UPDATE `sessions` '
                 'SET `termsize` = %s '
                 'WHERE `id` = %s',
-                ('%sx%s' % (entry['width'], entry['height']), entry["session"]))
+                ('{}x{}'.format(entry['width'], entry['height']), entry["session"]))
 
         elif entry["eventid"] == 'cowrie.session.closed':
             self.simpleQuery(

src/cowrie/output/redis.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import json
 from configparser import NoOptionError
 

src/cowrie/output/rethinkdblog.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import time
 from datetime import datetime
 

src/cowrie/output/reversedns.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 # `ipaddress` system library only on Python3.4+
 import ipaddress
 

src/cowrie/output/s3.py

@@ -2,7 +2,6 @@
 Send downloaded/uplaoded files to S3 (or compatible)
 """
 
-from __future__ import absolute_import, division
 
 from configparser import NoOptionError
 
@@ -71,16 +70,16 @@ class Output(cowrie.core.output.Output):
     @defer.inlineCallbacks
     def upload(self, shasum, filename):
         if shasum in self.seen:
-            print("Already uploaded file with sha {} to S3".format(shasum))
+            print(f"Already uploaded file with sha {shasum} to S3")
             return
 
         exists = yield self._object_exists_remote(shasum)
         if exists:
-            print("Somebody else already uploaded file with sha {} to S3".format(shasum))
+            print(f"Somebody else already uploaded file with sha {shasum} to S3")
             self.seen.add(shasum)
             return
 
-        print("Uploading file with sha {} ({}) to S3".format(shasum, filename))
+        print(f"Uploading file with sha {shasum} ({filename}) to S3")
         with open(filename, 'rb') as fp:
             yield threads.deferToThread(
                 self.client.put_object,

src/cowrie/output/slack.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 import json
 import time
@@ -59,5 +58,5 @@ class Output(cowrie.core.output.Output):
         self.sc.api_call(
             "chat.postMessage",
             channel=self.slack_channel,
-            text="%s %s" % (time.strftime('%Y-%m-%d %H:%M:%S'), json.dumps(logentry, indent=4, sort_keys=True))
+            text="{} {}".format(time.strftime('%Y-%m-%d %H:%M:%S'), json.dumps(logentry, indent=4, sort_keys=True))
         )

src/cowrie/output/socketlog.py

@@ -1,7 +1,3 @@
-# encoding: utf-8
-
-from __future__ import absolute_import, division
-
 import json
 import socket
 
@@ -37,7 +33,7 @@ class Output(cowrie.core.output.Output):
 
         try:
             self.sock.sendall(message.encode())
-        except socket.error as ex:
+        except OSError as ex:
             if ex.errno == 32:  # Broken pipe
                 self.start()
                 self.sock.sendall(message.encode())

src/cowrie/output/splunk.py

@@ -6,7 +6,6 @@ Not ready for production use.
 JSON log file is still recommended way to go
 """
 
-from __future__ import absolute_import, division
 
 import json
 
@@ -90,7 +89,7 @@ class Output(cowrie.core.output.Output):
             if response.code == 200:
                 return
             else:
-                log.msg("SplunkHEC response: {} {}".format(response.code, response.phrase))
+                log.msg(f"SplunkHEC response: {response.code} {response.phrase}")
                 d = client.readBody(response)
                 d.addCallback(cbBody)
                 d.addErrback(cbPartial)

src/cowrie/output/sqlite.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import sqlite3
 
 from twisted.enterprise import adbapi
@@ -148,7 +146,7 @@ class Output(cowrie.core.output.Output):
                 'UPDATE `sessions` '
                 'SET `termsize` = ? '
                 'WHERE `id` = ?',
-                ('%sx%s' % (entry['width'], entry['height']), entry["session"]))
+                ('{}x{}'.format(entry['width'], entry['height']), entry["session"]))
 
         elif entry["eventid"] == 'cowrie.session.closed':
             self.simpleQuery(

src/cowrie/output/textlog.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 import cowrie.core.cef
 import cowrie.core.output
@@ -47,10 +46,10 @@ class Output(cowrie.core.output.Output):
 
     def write(self, logentry):
         if self.format == 'cef':
-            self.outfile.write('{0} '.format(logentry['timestamp']))
+            self.outfile.write('{} '.format(logentry['timestamp']))
-            self.outfile.write('{0}\n'.format(cowrie.core.cef.formatCef(logentry)))
+            self.outfile.write('{}\n'.format(cowrie.core.cef.formatCef(logentry)))
         else:
-            self.outfile.write('{0} '.format(logentry['timestamp']))
+            self.outfile.write('{} '.format(logentry['timestamp']))
-            self.outfile.write('{0} '.format(logentry['session']))
+            self.outfile.write('{} '.format(logentry['session']))
-            self.outfile.write('{0}\n'.format(logentry['message']))
+            self.outfile.write('{}\n'.format(logentry['message']))
         self.outfile.flush()

src/cowrie/output/virustotal.py

@@ -30,7 +30,6 @@
 Send SSH logins to Virustotal
 """
 
-from __future__ import absolute_import, division
 
 import datetime
 import json
@@ -110,7 +109,7 @@ class Output(cowrie.core.output.Output):
         # If the file was first downloaded more than a "period of time" (e.g 1 min) ago -
         # it has been apparently scanned before in VT and therefore is not going to be checked again
         if file_modification_time < datetime.datetime.now()-TIME_SINCE_FIRST_DOWNLOAD:
-            log.msg("File with shasum '%s' was downloaded before" % (shasum, ))
+            log.msg(f"File with shasum '{shasum}' was downloaded before")
             return False
         return True
 
@@ -119,7 +118,7 @@ class Output(cowrie.core.output.Output):
         Check file scan report for a hash
         Argument is full event so we can access full file later on
         """
-        vtUrl = '{0}file/report'.format(VTAPI_URL).encode('utf8')
+        vtUrl = f'{VTAPI_URL}file/report'.encode('utf8')
         headers = http_headers.Headers({'User-Agent': [COWRIE_USER_AGENT]})
         fields = {'apikey': self.apiKey, 'resource': entry['shasum'], 'allinfo': 1}
         body = StringProducer(urlencode(fields).encode("utf-8"))
@@ -134,7 +133,7 @@ class Output(cowrie.core.output.Output):
                 d.addCallback(cbBody)
                 return d
             else:
-                log.msg("VT Request failed: {} {}".format(response.code, response.phrase))
+                log.msg(f"VT Request failed: {response.code} {response.phrase}")
 
         def cbBody(body):
             """
@@ -157,7 +156,7 @@ class Output(cowrie.core.output.Output):
             Extract the information we need from the body
             """
             if self.debug:
-                log.msg("VT scanfile result: {}".format(result))
+                log.msg(f"VT scanfile result: {result}")
             result = result.decode('utf8')
             j = json.loads(result)
             log.msg("VT: {}".format(j['verbose_msg']))
@@ -216,11 +215,11 @@ class Output(cowrie.core.output.Output):
         """
         Send a file to VirusTotal
         """
-        vtUrl = '{0}file/scan'.format(VTAPI_URL).encode('utf8')
+        vtUrl = f'{VTAPI_URL}file/scan'.encode('utf8')
         fields = {('apikey', self.apiKey)}
         files = {('file', fileName, open(artifact, 'rb'))}
         if self.debug:
-            log.msg("submitting to VT: {0}".format(repr(files)))
+            log.msg("submitting to VT: {}".format(repr(files)))
         contentType, body = encode_multipart_formdata(fields, files)
         producer = StringProducer(body)
         headers = http_headers.Headers({
@@ -247,14 +246,14 @@ class Output(cowrie.core.output.Output):
                 d.addErrback(cbPartial)
                 return d
             else:
-                log.msg("VT Request failed: {} {}".format(response.code, response.phrase))
+                log.msg(f"VT Request failed: {response.code} {response.phrase}")
 
         def cbError(failure):
             failure.printTraceback()
 
         def processResult(result):
             if self.debug:
-                log.msg("VT postfile result: {}".format(result))
+                log.msg(f"VT postfile result: {result}")
             result = result.decode('utf8')
             j = json.loads(result)
             # This is always a new resource, since we did the scan before
@@ -273,7 +272,7 @@ class Output(cowrie.core.output.Output):
         """
         Check url scan report for a hash
         """
-        vtUrl = '{0}url/report'.format(VTAPI_URL).encode('utf8')
+        vtUrl = f'{VTAPI_URL}url/report'.encode('utf8')
         headers = http_headers.Headers({'User-Agent': [COWRIE_USER_AGENT]})
         fields = {'apikey': self.apiKey, 'resource': entry['url'], 'scan': 1, 'allinfo': 1}
         body = StringProducer(urlencode(fields).encode("utf-8"))
@@ -288,7 +287,7 @@ class Output(cowrie.core.output.Output):
                 d.addCallback(cbBody)
                 return d
             else:
-                log.msg("VT Request failed: {} {}".format(response.code, response.phrase))
+                log.msg(f"VT Request failed: {response.code} {response.phrase}")
 
         def cbBody(body):
             """
@@ -311,7 +310,7 @@ class Output(cowrie.core.output.Output):
             Extract the information we need from the body
             """
             if self.debug:
-                log.msg("VT scanurl result: {}".format(result))
+                log.msg(f"VT scanurl result: {result}")
             result = result.decode('utf8')
             j = json.loads(result)
             log.msg("VT: {}".format(j['verbose_msg']))
@@ -361,7 +360,7 @@ class Output(cowrie.core.output.Output):
         """
         Send a comment to VirusTotal with Twisted
         """
-        vtUrl = '{0}comments/put'.format(VTAPI_URL).encode('utf8')
+        vtUrl = f'{VTAPI_URL}comments/put'.encode('utf8')
         parameters = {
             "resource": resource,
             "comment": self.commenttext,
@@ -387,14 +386,14 @@ class Output(cowrie.core.output.Output):
                 d.addErrback(cbPartial)
                 return d
             else:
-                log.msg("VT Request failed: {} {}".format(response.code, response.phrase))
+                log.msg(f"VT Request failed: {response.code} {response.phrase}")
 
         def cbError(failure):
             failure.printTraceback()
 
         def processResult(result):
             if self.debug:
-                log.msg("VT postcomment result: {}".format(result))
+                log.msg(f"VT postcomment result: {result}")
             result = result.decode('utf8')
             j = json.loads(result)
             return j['response_code']
@@ -411,7 +410,7 @@ class WebClientContextFactory(ClientContextFactory):
 
 
 @implementer(IBodyProducer)
-class StringProducer(object):
+class StringProducer:
 
     def __init__(self, body):
         self.body = body

src/cowrie/output/xmpp.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import json
 import string
 from random import choice
@@ -37,7 +35,7 @@ class XMPPLoggerProtocol(muc.MUCClient):
         self.join(self.jrooms, self.nick)
 
     def joinedRoom(self, room):
-        log.msg('Joined room {}'.format(room.name))
+        log.msg(f'Joined room {room.name}')
 
     def connectionMade(self):
         log.msg('Connected!')

src/cowrie/pool_interface/client.py

@@ -36,7 +36,7 @@ class PoolClient(Protocol):
         self.transport.write(buf)
 
     def send_vm_request(self, src_ip):
-        fmt = '!cH{0}s'.format(len(src_ip))
+        fmt = '!cH{}s'.format(len(src_ip))
         buf = struct.pack(fmt, b'r', len(src_ip), src_ip.encode())
 
         self.transport.write(buf)
@@ -84,7 +84,7 @@ class PoolClient(Protocol):
             ip_len = recv[0]
             data = data[2:]
 
-            recv = struct.unpack('!{0}s'.format(ip_len), data[:ip_len])
+            recv = struct.unpack(f'!{ip_len}s', data[:ip_len])
             honey_ip = recv[0]
             data = data[ip_len:]
 
@@ -99,7 +99,7 @@ class PoolClient(Protocol):
             snaphsot_len = recv[0]
             data = data[2:]
 
-            recv = struct.unpack('!{0}s'.format(snaphsot_len), data[:snaphsot_len])
+            recv = struct.unpack(f'!{snaphsot_len}s', data[:snaphsot_len])
             snapshot = recv[0]
             data = data[snaphsot_len:]
 

src/cowrie/pool_interface/handler.py

@@ -45,7 +45,7 @@ class PoolHandler:
         client.send_initialisation()
 
     def initial_pool_connection_error(self, reason):
-        log.err('Could not connect to VM pool: {0}'.format(reason.value))
+        log.err(f'Could not connect to VM pool: {reason.value}')
         os._exit(1)
 
     def initialisation_response(self, res_code):

src/cowrie/python/logfile.py

@@ -2,7 +2,6 @@
 # Copyright (c) 2017 Michel Oosterhof <michel@oosterhof.net>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 from os import environ
 

src/cowrie/shell/avatar.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009-2014 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 from twisted.conch import avatar
 from twisted.conch.error import ConchError
@@ -50,7 +49,7 @@ class CowrieUser(avatar.ConchUser):
             self.channelLookup[b'direct-tcpip'] = forwarding.cowrieOpenConnectForwardingClient
 
     def logout(self):
-        log.msg("avatar {} logging out".format(self.username))
+        log.msg(f"avatar {self.username} logging out")
 
     def lookupChannel(self, channelType, windowSize, maxPacket, data):
         """
@@ -58,7 +57,7 @@ class CowrieUser(avatar.ConchUser):
         """
         klass = self.channelLookup.get(channelType, None)
         if not klass:
-            raise ConchError(OPEN_UNKNOWN_CHANNEL_TYPE, "unknown channel: {}".format(channelType))
+            raise ConchError(OPEN_UNKNOWN_CHANNEL_TYPE, f"unknown channel: {channelType}")
         else:
             return klass(remoteWindow=windowSize,
                          remoteMaxPacket=maxPacket,

src/cowrie/shell/command.py

@@ -5,7 +5,6 @@
 This module contains code to run a command
 """
 
-from __future__ import absolute_import, division
 
 import os
 import re
@@ -26,7 +25,7 @@ else:
     from cowrie.shell import shlex
 
 
-class HoneyPotCommand(object):
+class HoneyPotCommand:
     """
     This is the super class for all commands in cowrie/commands
     """
@@ -109,7 +108,7 @@ class HoneyPotCommand(object):
         for arg in args:
             path = self.fs.resolve_path(arg, self.protocol.cwd)
             if self.fs.isdir(path):
-                self.errorWrite("{}: error reading `{}': Is a directory\n".format(application, arg))
+                self.errorWrite(f"{application}: error reading `{arg}': Is a directory\n")
                 continue
             files.append(path)
         return files
@@ -162,7 +161,7 @@ class HoneyPotCommand(object):
         self.exit()
 
     def lineReceived(self, line):
-        log.msg('QUEUED INPUT: {}'.format(line))
+        log.msg(f'QUEUED INPUT: {line}')
         # FIXME: naive command parsing, see lineReceived below
         # line = "".join(line)
         self.protocol.cmdstack[0].cmdpending.append(shlex.split(line, posix=True))

src/cowrie/shell/customparser.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import, division
-
 import argparse
 
 
@@ -35,7 +33,7 @@ class CustomParser(argparse.ArgumentParser):
                  conflict_handler='error',
                  add_help=True):
         self.protocol = protocol
-        super(CustomParser, self).__init__(prog=prog,
+        super().__init__(prog=prog,
                          usage=usage,
                          description=description,
                          epilog=epilog,
@@ -51,7 +49,7 @@ class CustomParser(argparse.ArgumentParser):
         raise ExitException("Exiting...")
 
     def _print_message(self, message, file=None):
-        super(CustomParser, self)._print_message(message, self.protocol)
+        super()._print_message(message, self.protocol)
 
     def error(self, message):
         self.print_usage(self.protocol)

src/cowrie/shell/filetransfer.py

@@ -5,7 +5,6 @@
 This module contains ...
 """
 
-from __future__ import absolute_import, division
 
 import os
 
@@ -24,7 +23,7 @@ from cowrie.core.config import CowrieConfig
 
 
 @implementer(ISFTPFile)
-class CowrieSFTPFile(object):
+class CowrieSFTPFile:
     """
     SFTPTFile
     """
@@ -88,7 +87,7 @@ class CowrieSFTPFile(object):
         raise NotImplementedError
 
 
-class CowrieSFTPDirectory(object):
+class CowrieSFTPDirectory:
 
     def __init__(self, server, directory):
         self.server = server
@@ -143,7 +142,7 @@ class CowrieSFTPDirectory(object):
 
 
 @implementer(ISFTPServer)
-class SFTPServerForCowrieUser(object):
+class SFTPServerForCowrieUser:
 
     def __init__(self, avatar):
         self.avatar = avatar
@@ -176,33 +175,33 @@ class SFTPServerForCowrieUser(object):
         return {}
 
     def openFile(self, filename, flags, attrs):
-        log.msg("SFTP openFile: {}".format(filename))
+        log.msg(f"SFTP openFile: {filename}")
         return CowrieSFTPFile(self, self._absPath(filename), flags, attrs)
 
     def removeFile(self, filename):
-        log.msg("SFTP removeFile: {}".format(filename))
+        log.msg(f"SFTP removeFile: {filename}")
         return self.fs.remove(self._absPath(filename))
 
     def renameFile(self, oldpath, newpath):
-        log.msg("SFTP renameFile: {} {}".format(oldpath, newpath))
+        log.msg(f"SFTP renameFile: {oldpath} {newpath}")
         return self.fs.rename(self._absPath(oldpath), self._absPath(newpath))
 
     def makeDirectory(self, path, attrs):
-        log.msg("SFTP makeDirectory: {}".format(path))
+        log.msg(f"SFTP makeDirectory: {path}")
         path = self._absPath(path)
         self.fs.mkdir2(path)
         self._setAttrs(path, attrs)
 
     def removeDirectory(self, path):
-        log.msg("SFTP removeDirectory: {}".format(path))
+        log.msg(f"SFTP removeDirectory: {path}")
         return self.fs.rmdir(self._absPath(path))
 
     def openDirectory(self, path):
-        log.msg("SFTP OpenDirectory: {}".format(path))
+        log.msg(f"SFTP OpenDirectory: {path}")
         return CowrieSFTPDirectory(self, self._absPath(path))
 
     def getAttrs(self, path, followLinks):
-        log.msg("SFTP getAttrs: {}".format(path))
+        log.msg(f"SFTP getAttrs: {path}")
         path = self._absPath(path)
         if followLinks:
             s = self.fs.stat(path)
@@ -211,17 +210,17 @@ class SFTPServerForCowrieUser(object):
         return self._getAttrs(s)
 
     def setAttrs(self, path, attrs):
-        log.msg("SFTP setAttrs: {}".format(path))
+        log.msg(f"SFTP setAttrs: {path}")
         path = self._absPath(path)
         return self._setAttrs(path, attrs)
 
     def readLink(self, path):
-        log.msg("SFTP readLink: {}".format(path))
+        log.msg(f"SFTP readLink: {path}")
         path = self._absPath(path)
         return self.fs.readlink(path)
 
     def makeLink(self, linkPath, targetPath):
-        log.msg("SFTP makeLink: {} {}".format(linkPath, targetPath))
+        log.msg(f"SFTP makeLink: {linkPath} {targetPath}")
         linkPath = self._absPath(linkPath)
         targetPath = self._absPath(targetPath)
         return self.fs.symlink(targetPath, linkPath)

src/cowrie/shell/fs.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009-2014 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 try:
     import cPickle as pickle
@@ -70,7 +69,7 @@ class PermissionDenied(Exception):
     pass
 
 
-class HoneyPotFilesystem(object):
+class HoneyPotFilesystem:
 
     def __init__(self, fs, arch, home):
 
@@ -144,7 +143,7 @@ class HoneyPotFilesystem(object):
                 continue
             cwd.append(piece)
 
-        return '/%s' % ('/'.join(cwd),)
+        return '/{}'.format('/'.join(cwd))
 
     def resolve_path_wc(self, path, cwd):
         """
@@ -160,7 +159,7 @@ class HoneyPotFilesystem(object):
 
         def foo(p, cwd):
             if not len(p):
-                found.append('/%s' % ('/'.join(cwd),))
+                found.append('/{}'.format('/'.join(cwd)))
             elif p[0] == '.':
                 foo(p[1:], cwd)
             elif p[0] == '..':
@@ -374,7 +373,7 @@ class HoneyPotFilesystem(object):
         if openFlags & os.O_WRONLY == os.O_WRONLY or openFlags & os.O_RDWR == os.O_RDWR:
             # strip executable bit
             hostmode = mode & ~(111)
-            hostfile = '%s/%s_sftp_%s' % (
+            hostfile = '{}/{}_sftp_{}'.format(
                 CowrieConfig().get('honeypot', 'download_path'),
                 time.strftime('%Y%m%d-%H%M%S'),
                 re.sub('[^A-Za-z0-9]', '_', filename)
@@ -537,7 +536,7 @@ class HoneyPotFilesystem(object):
         f[A_SIZE] = size
 
 
-class _statobj(object):
+class _statobj:
     """
     Transform a tuple into a stat object
     """

src/cowrie/shell/honeypot.py

@@ -1,7 +1,6 @@
 # Copyright (c) 2009-2014 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import copy
 import os
@@ -22,7 +21,7 @@ else:
     from cowrie.shell import shlex
 
 
-class HoneyPotShell(object):
+class HoneyPotShell:
 
     def __init__(self, protocol, interactive=True, redirect=False):
         self.protocol = protocol
@@ -51,27 +50,27 @@ class HoneyPotShell(object):
 
                 if tok == self.lexer.eof:
                     if tokens:
-                        self.cmdpending.append((tokens))
+                        self.cmdpending.append(tokens)
                     break
 
                 # For now, treat && and || same as ;, just execute without checking return code
                 if tok == '&&' or tok == '||':
                     if tokens:
-                        self.cmdpending.append((tokens))
+                        self.cmdpending.append(tokens)
                         tokens = []
                         continue
                     else:
                         self.protocol.terminal.write(
-                            '-bash: syntax error near unexpected token `{}\'\n'.format(tok).encode('utf8'))
+                            f'-bash: syntax error near unexpected token `{tok}\'\n'.encode('utf8'))
                         break
                 elif tok == ';':
                     if tokens:
-                        self.cmdpending.append((tokens))
+                        self.cmdpending.append(tokens)
                         tokens = []
                         continue
                     else:
                         self.protocol.terminal.write(
-                            '-bash: syntax error near unexpected token `{}\'\n'.format(tok).encode('utf8'))
+                            f'-bash: syntax error near unexpected token `{tok}\'\n'.encode('utf8'))
                         break
                 elif tok == '$?':
                     tok = "0"
@@ -105,7 +104,7 @@ class HoneyPotShell(object):
                 self.protocol.terminal.write(
                     b'-bash: syntax error: unexpected end of file\n')
                 # Could run runCommand here, but i'll just clear the list instead
-                log.msg("exception: {}".format(e))
+                log.msg(f"exception: {e}")
                 self.cmdpending = []
                 self.showPrompt()
                 return
@@ -324,7 +323,7 @@ class HoneyPotShell(object):
 
             # Example: [root@svr03 ~]#   (More of a "CentOS" feel)
             # Example: root@svr03:~#     (More of a "Debian" feel)
-            prompt = '{0}@{1}:{2}'.format(self.protocol.user.username, self.protocol.hostname, cwd)
+            prompt = f'{self.protocol.user.username}@{self.protocol.hostname}:{cwd}'
             if not self.protocol.user.uid:
                 prompt += '# '  # "Root" user
             else:
@@ -402,7 +401,7 @@ class HoneyPotShell(object):
 
         newbuf = ''
         if len(files) == 1:
-            newbuf = ' '.join(line.decode('utf8').split()[:-1] + ['%s%s' % (basedir, files[0][fs.A_NAME])])
+            newbuf = ' '.join(line.decode('utf8').split()[:-1] + ['{}{}'.format(basedir, files[0][fs.A_NAME])])
             if files[0][fs.A_TYPE] == fs.T_DIR:
                 newbuf += '/'
             else:
@@ -414,7 +413,7 @@ class HoneyPotShell(object):
             else:
                 prefix = ''
             first = line.decode('utf8').split(' ')[:-1]
-            newbuf = ' '.join(first + ['%s%s' % (basedir, prefix)])
+            newbuf = ' '.join(first + [f'{basedir}{prefix}'])
             newbuf = newbuf.encode('utf8')
             if newbuf == b''.join(self.protocol.lineBuffer):
                 self.protocol.terminal.write(b'\n')
@@ -435,7 +434,7 @@ class HoneyPotShell(object):
         self.protocol.terminal.write(newbuf)
 
 
-class StdOutStdErrEmulationProtocol(object):
+class StdOutStdErrEmulationProtocol:
     """
     Pipe support written by Dave Germiquet
     Support for commands chaining added by Ivan Korolev (@fe7ch)

src/cowrie/shell/protocol.py

@@ -2,7 +2,6 @@
 # Copyright (c) 2009-2014 Upi Tamminen <desaster@gmail.com>
 # See the COPYRIGHT file for more information
 
-from __future__ import absolute_import, division
 
 import os
 import socket
@@ -29,7 +28,7 @@ class HoneyPotBaseProtocol(insults.TerminalProtocol, TimeoutMixin):
     commands = {}
     for c in cowrie.commands.__all__:
         try:
-            module = __import__('cowrie.commands.%s' % (c,),
+            module = __import__(f'cowrie.commands.{c}',
                                 globals(), locals(), ['commands'])
             commands.update(module.commands)
         except Exception as e:
@@ -131,8 +130,8 @@ class HoneyPotBaseProtocol(insults.TerminalProtocol, TimeoutMixin):
     def txtcmd(self, txt):
         class command_txtcmd(command.HoneyPotCommand):
             def call(self):
-                log.msg('Reading txtcmd from "{}"'.format(txt))
+                log.msg(f'Reading txtcmd from "{txt}"')
-                with open(txt, 'r') as f:
+                with open(txt) as f:
                     self.write(f.read())
 
         return command_txtcmd
@@ -155,7 +154,7 @@ class HoneyPotBaseProtocol(insults.TerminalProtocol, TimeoutMixin):
                 return None
         else:
             for i in [
-                '%s/%s' % (self.fs.resolve_path(x, self.cwd), cmd)
+                '{}/{}'.format(self.fs.resolve_path(x, self.cwd), cmd)
                 for x in paths
             ]:
                 if self.fs.exists(i):
@@ -169,7 +168,7 @@ class HoneyPotBaseProtocol(insults.TerminalProtocol, TimeoutMixin):
         if path in self.commands:
             return self.commands[path]
 
-        log.msg("Can't find command {}".format(cmd))
+        log.msg(f"Can't find command {cmd}")
         return None
 
     def lineReceived(self, line):
@@ -183,7 +182,7 @@ class HoneyPotBaseProtocol(insults.TerminalProtocol, TimeoutMixin):
         if len(self.cmdstack):
             self.cmdstack[-1].lineReceived(line)
         else:
-            log.msg("discarding input {}".format(line))
+            log.msg(f"discarding input {line}")
 
     def call_command(self, pp, cmd, *args):
         self.pp = pp

src/cowrie/shell/pwd.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 from binascii import crc32
 from random import randint, seed
@@ -36,13 +35,13 @@ from twisted.python import log
 from cowrie.core.config import CowrieConfig
 
 
-class Passwd(object):
+class Passwd:
     """
     This class contains code to handle the users and their properties in
     /etc/passwd. Note that contrary to the name, it does not handle any
     passwords.
     """
-    passwd_file = '%s/etc/passwd' % (CowrieConfig().get('honeypot', 'contents_path'),)
+    passwd_file = '{}/etc/passwd'.format(CowrieConfig().get('honeypot', 'contents_path'))
 
     def __init__(self):
         self.load()
@@ -52,7 +51,7 @@ class Passwd(object):
         Load /etc/passwd
         """
         self.passwd = []
-        with open(self.passwd_file, 'r') as f:
+        with open(self.passwd_file) as f:
             while True:
                 rawline = f.readline()
                 if not rawline:
@@ -138,12 +137,12 @@ class Passwd(object):
         return e
 
 
-class Group(object):
+class Group:
     """
     This class contains code to handle the groups and their properties in
     /etc/group.
     """
-    group_file = '%s/etc/group' % (CowrieConfig().get('honeypot', 'contents_path'),)
+    group_file = '{}/etc/group'.format(CowrieConfig().get('honeypot', 'contents_path'))
 
     def __init__(self):
         self.load()
@@ -153,7 +152,7 @@ class Group(object):
         Load /etc/group
         """
         self.group = []
-        with open(self.group_file, 'r') as f:
+        with open(self.group_file) as f:
             while True:
                 rawline = f.readline()
                 if not rawline:

src/cowrie/shell/server.py

@@ -26,7 +26,6 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 
-from __future__ import absolute_import, division
 
 import json
 import random
@@ -38,7 +37,7 @@ from cowrie.core.config import CowrieConfig
 from cowrie.shell import fs
 
 
-class CowrieServer(object):
+class CowrieServer:
     """
     In traditional Kippo each connection gets its own simulated machine.
     This is not always ideal, sometimes two connections come from the same
@@ -59,7 +58,7 @@ class CowrieServer(object):
         except NoOptionError:
             self.arch = 'linux-x64-lsb'
 
-        log.msg("Initialized emulated server as architecture: {}".format(self.arch))
+        log.msg(f"Initialized emulated server as architecture: {self.arch}")
 
     def getCommandOutput(self, file):
         """