服务器评测
现在很多高校都是使用drcom客户端管理学生的上网流量等信息，在Linux下Drcom客户端版本有的学校可能没有发布，我们可以使用Python模拟登陆Drcom。
最主要的就是认证的服务器地址，这个需要抓包分析出ip，自行谷歌，很容易可以实现的
Linux下运行py脚本 (必须安装Python2)
命令行: python drclient.py
下面附drclient.py
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import socket, struct, time
from hashlib import md5
import sys
import os
import random
# CONFIG
server = ” #认证服务器地址
username=” #账号
password=” #密码
CONTROLCHECKSTATUS = ‘\x08’
ADAPTERNUM = ‘\x01’
host_ip = ” #ipv4地址
IPDOG = ‘\x01’
host_name = ‘DRCOMFUCKER’
PRIMARY_DNS = ” #DNS服务器
dhcp_server = ” #DHCP服务器
AUTH_VERSION = ‘\x08\x00’
mac = 0xMac地址 #Mac地址
host_os = ‘WINDIAOS’
KEEP_ALIVE_VERSION = ‘\xdc\x02’
AUTH_VERSION = ‘\x0a\x00’
IPDOG = ‘\x01’
# CONFIG_END
nic_name = ” #Indicate your nic, e.g. ‘eth0.2’.nic_name
bind_ip = ‘0.0.0.0’
class ChallengeException (Exception):
def __init__(self):
pass
class LoginException (Exception):
def __init__(self):
pass
def bind_nic():
try:
import fcntl
def get_ip_address(ifname):
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
return socket.inet_ntoa(fcntl.ioctl(
s.fileno(),
0x8915, # SIOCGIFADDR
struct.pack(‘256s’, ifname[:15])
)[20:24])
return get_ip_address(nic_name)
except ImportError as e:
print(‘Indicate nic feature need to be run under Unix based system.’)
return ‘0.0.0.0’
except IOError as e:
print(nic_name + ‘is unacceptable !’)
return ‘0.0.0.0’
finally:
return ‘0.0.0.0’
if nic_name != ”:
bind_ip = bind_nic()
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
# s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((bind_ip, 61440))
s.settimeout(3)
SALT = ”
IS_TEST = True
# specified fields based on version
CONF = “/etc/drcom.conf”
UNLIMITED_RETRY = True
EXCEPTION = False
DEBUG = False #log saves to file
LOG_PATH = ‘/var/log/drcom_client.log’
if IS_TEST:
DEBUG = True
LOG_PATH = ‘drcom_client.log’
def log(*args, **kwargs):
s = ‘ ‘.join(args)
print s
if DEBUG:
with open(LOG_PATH,’a’) as f:
f.write(s + ‘\n’)
def challenge(svr,ran):
while True:
t = struct.pack(“<H”, int(ran)%(0xFFFF))
s.sendto(“\x01\x02″+t+”\x09″+”\x00″*15, (svr, 61440))
try:
data, address = s.recvfrom(1024)
log(‘[challenge] recv’,data.encode(‘hex’))
except:
log(‘[challenge] timeout, retrying…’)
continue
if address == (svr, 61440):
break
else:
continue
log(‘[DEBUG] challenge:\n’ + data.encode(‘hex’))
if data[0] != ‘\x02’:
raise ChallengeException
log(‘[challenge] challenge packet sent.’)
return data[4:8]
def md5sum(s):
m = md5()
m.update(s)
return m.digest()
def dump(n):
s = ‘%x’ % n
if len(s) & 1:
s = ‘0’ + s
return s.decode(‘hex’)
# def ror(md5, pwd):
# ret = ”
# for i in range(len(pwd)):
# x = ord(md5[i]) ^ ord(pwd[i])
# ret += chr(((x<<3)&0xFF) + (x>>5))
# return ret
def keep_alive_package_builder(number,random,tail,type=1,first=False):
data = ‘\x07’+ chr(number) + ‘\x28\x00\x0b’ + chr(type)
if first :
data += ‘\x0f\x27’
else:
data += KEEP_ALIVE_VERSION
data += ‘\x2f\x12’ + ‘\x00’ * 6
data += tail
data += ‘\x00’ * 4
#data += struct.pack(“!H”,0xdc02)
if type == 3:
foo = ”.join([chr(int(i)) for i in host_ip.split(‘.’)]) # host_ip
#CRC
# edited on 2014/5/12, filled zeros to checksum
# crc = packet_CRC(data+foo)
crc = ‘\x00’ * 4
#data += struct.pack(“!I”,crc) + foo + ‘\x00’ * 8
data += crc + foo + ‘\x00’ * 8
else: #packet type = 1
data += ‘\x00’ * 16
return data
# def packet_CRC(s):
# ret = 0
# for i in re.findall(‘..’, s):
# ret ^= struct.unpack(‘>h’, i)[0]
# ret &= 0xFFFF
# ret = ret * 0x2c7
# return ret
def keep_alive2(*args):
#first keep_alive:
#number = number (mod 7)
#status = 1: first packet user sended
# 2: first packet user recieved
# 3: 2nd packet user sended
# 4: 2nd packet user recieved
# Codes for test
tail = ”
packet = ”
svr = server
ran = random.randint(0,0xFFFF)
ran += random.randint(1,10)
# 2014/10/15 add by latyas, maybe svr sends back a file packet
svr_num = 0
packet = keep_alive_package_builder(svr_num,dump(ran),’\x00’*4,1,True)
while True:
log(‘[keep-alive2] send1’,packet.encode(‘hex’))
s.sendto(packet, (svr, 61440))
data, address = s.recvfrom(1024)
log(‘[keep-alive2] recv1’,data.encode(‘hex’))
if data.startswith(‘\x07\x00\x28\x00’) or data.startswith(‘\x07’ + chr(svr_num) + ‘\x28\x00’):
break
elif data[0] == ‘\x07’ and data[2] == ‘\x10’:
log(‘[keep-alive2] recv file, resending..’)
svr_num = svr_num + 1
packet = keep_alive_package_builder(svr_num,dump(ran),’\x00’*4,1, False)
else:
log(‘[keep-alive2] recv1/unexpected’,data.encode(‘hex’))
#log(‘[keep-alive2] recv1’,data.encode(‘hex’))
ran += random.randint(1,10)
packet = keep_alive_package_builder(svr_num, dump(ran),’\x00’*4,1,False)
log(‘[keep-alive2] send2’,packet.encode(‘hex’))
s.sendto(packet, (svr, 61440))
while True:
data, address = s.recvfrom(1024)
if data[0] == ‘\x07’:
svr_num = svr_num + 1
break
else:
log(‘[keep-alive2] recv2/unexpected’,data.encode(‘hex’))
log(‘[keep-alive2] recv2’,data.encode(‘hex’))
tail = data[16:20]
ran += random.randint(1,10)
packet = keep_alive_package_builder(svr_num,dump(ran),tail,3,False)
log(‘[keep-alive2] send3’,packet.encode(‘hex’))
s.sendto(packet, (svr, 61440))
while True:
data, address = s.recvfrom(1024)
if data[0] == ‘\x07’:
svr_num = svr_num + 1
break
else:
log(‘[keep-alive2] recv3/unexpected’,data.encode(‘hex’))
log(‘[keep-alive2] recv3’,data.encode(‘hex’))
tail = data[16:20]
log(“[keep-alive2] keep-alive2 loop was in daemon.”)
i = svr_num
while True:
try:
ran += random.randint(1,10)
packet = keep_alive_package_builder(i,dump(ran),tail,1,False)
#log(‘DEBUG: keep_alive2,packet 4\n’,packet.encode(‘hex’))
log(‘[keep_alive2] send’,str(i),packet.encode(‘hex’))
s.sendto(packet, (svr, 61440))
data, address = s.recvfrom(1024)
log(‘[keep_alive2] recv’,data.encode(‘hex’))
tail = data[16:20]
#log(‘DEBUG: keep_alive2,packet 4 return\n’,data.encode(‘hex’))
ran += random.randint(1,10)
packet = keep_alive_package_builder(i+1,dump(ran),tail,3,False)
#log(‘DEBUG: keep_alive2,packet 5\n’,packet.encode(‘hex’))
s.sendto(packet, (svr, 61440))
log(‘[keep_alive2] send’,str(i+1),packet.encode(‘hex’))
data, address = s.recvfrom(1024)
log(‘[keep_alive2] recv’,data.encode(‘hex’))
tail = data[16:20]
#log(‘DEBUG: keep_alive2,packet 5 return\n’,data.encode(‘hex’))
i = (i+2) % 0xFF
time.sleep(20)
keep_alive1(*args)
except:
pass
import re
def checksum(s):
ret = 1234
for i in re.findall(‘….’, s):
ret ^= int(i[::-1].encode(‘hex’), 16)
ret = (1968 * ret) & 0xffffffff
return struct.pack(‘<I’, ret)
def mkpkt(salt, usr, pwd, mac):
data = ‘\x03\x01\x00’+chr(len(usr)+20)
data += md5sum(‘\x03\x01’+salt+pwd)
data += usr.ljust(36, ‘\x00’)
data += CONTROLCHECKSTATUS
data += ADAPTERNUM
data += dump(int(data[4:10].encode(‘hex’),16)^mac).rjust(6,’\x00′) #mac xor md51
data += md5sum(“\x01” + pwd + salt + ‘\x00’*4) #md52
data += ‘\x01’ # number of ip
#data += ‘\x0a\x1e\x16\x11’ #your ip address1, 10.30.22.17
data += ”.join([chr(int(i)) for i in host_ip.split(‘.’)]) #x.x.x.x ->
data += ‘\00’*4 #your ipaddress 2
data += ‘\00’*4 #your ipaddress 3
data += ‘\00’*4 #your ipaddress 4
data += md5sum(data + ‘\x14\x00\x07\x0b’)[:8] #md53
data += IPDOG
data += ‘\x00’*4 #delimeter
data += host_name.ljust(32, ‘\x00’)
data += ”.join([chr(int(i)) for i in PRIMARY_DNS.split(‘.’)]) #primary dns
data += ”.join([chr(int(i)) for i in dhcp_server.split(‘.’)]) #DHCP server
data += ‘\x00\x00\x00\x00’ #secondary dns:0.0.0.0
data += ‘\x00’ * 8 #delimeter
data += ‘\x94\x00\x00\x00’ # unknow
data += ‘\x05\x00\x00\x00’ # os major
data += ‘\x01\x00\x00\x00’ # os minor
data += ‘\x28\x0a\x00\x00’ # OS build
data += ‘\x02\x00\x00\x00’ #os unknown
data += host_os.ljust(32,’\x00′)
data += ‘\x00’ * 96
#data += ‘\x01’ + host_os.ljust(128, ‘\x00’)
#data += ‘\x0a\x00\x00’+chr(len(pwd)) # \0x0a represents version of client, algorithm: DRCOM_VER + 100
#data += ror(md5sum(‘\x03\x01’+salt+pwd), pwd)
data += AUTH_VERSION
data += ‘\x02\x0c’
data += checksum(data+’\x01\x26\x07\x11\x00\x00’+dump(mac))
data += ‘\x00\x00’ #delimeter
data += dump(mac)
data += ‘\x00’ # auto logout / default: False
data += ‘\x00’ # broadcast mode / default : False
data += ‘\xe9\x13’ #unknown, filled numbers randomly =w=
log(‘[mkpkt]’,data.encode(‘hex’))
return data
def login(usr, pwd, svr):
import random
global SALT
i = 0
while True:
salt = challenge(svr,time.time()+random.randint(0xF,0xFF))
SALT = salt
packet = mkpkt(salt, usr, pwd, mac)
log(‘[login] send’,packet.encode(‘hex’))
s.sendto(packet, (svr, 61440))
data, address = s.recvfrom(1024)
log(‘[login] recv’,data.encode(‘hex’))
log(‘[login] packet sent.’)
if address == (svr, 61440):
if data[0] == ‘\x04’:
log(‘[login] loged in’)
break
else:
log(‘[login] login failed.’)
if IS_TEST:
time.sleep(3)
else:
time.sleep(30)
continue
else:
if i >= 5 and UNLIMITED_RETRY == False :
log(‘[login] exception occured.’)
sys.exit(1)
else:
continue
log(‘[login] login sent’)
#0.8 changed:
return data[23:39]
#return data[-22:-6]
def keep_alive1(salt,tail,pwd,svr):
foo = struct.pack(‘!H’,int(time.time())%0xFFFF)
data = ‘\xff’ + md5sum(‘\x03\x01’+salt+pwd) + ‘\x00\x00\x00’
data += tail
data += foo + ‘\x00\x00\x00\x00’
log(‘[keep_alive1] send’,data.encode(‘hex’))
s.sendto(data, (svr, 61440))
while True:
data, address = s.recvfrom(1024)
if data[0] == ‘\x07’:
break
else:
log(‘[keep-alive1]recv/not expected’,data.encode(‘hex’))
log(‘[keep-alive1] recv’,data.encode(‘hex’))
def empty_socket_buffer():
#empty buffer for some fucking schools
log(‘starting to empty socket buffer’)
try:
while True:
data, address = s.recvfrom(1024)
log(‘recived sth unexpected’,data.encode(‘hex’))
if s == ”:
break
except:
# get exception means it has done.
log(‘exception in empty_socket_buffer’)
pass
log(’emptyed’)
def daemon():
with open(‘/var/run/jludrcom.pid’,’w’) as f:
f.write(str(os.getpid()))
def main():
if not IS_TEST:
daemon()
execfile(CONF, globals())
log(“auth svr:”+server+”\nusername:”+username+”\npassword:”+password+”\nmac:”+str(hex(mac)))
log(bind_ip)
while True:
try:
package_tail = login(username, password, server)
except LoginException:
continue
log(‘package_tail’,package_tail.encode(‘hex’))
#keep_alive1 is fucking bullshit!
empty_socket_buffer()
keep_alive1(SALT,package_tail,password,server)
keep_alive2(SALT,package_tail,password,server)
if __name__ == “__main__”:
main()
本文永久更新链接地址：http://www.linuxidc.com/Linux/2016-12/138766.htm
