This is a very old post. Reposting it since while migrating it from blogger.com to here it got lost. Found it recently. Not sure how relevant or correct is this now.

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My college uses the software Cyberoam for controlling the bandwidth and timing allocated to us for surfing the internet. If you don’t know what is it then visit here. So, to access the internet we all need to install the client software and login via that. But I don’t like to install it because it feels like a college spy on my computer, you may find it irrational but I can’t help being a paranoid. I have always used the web login page of Cyberoam but it is not a very good solution, first because I will always need to keep the browser open. (The Cyberoam page refreshes at a specific time periodically. If it fails to do so then you get logged out.) Second problem is that on my Linux platform if I work from console mode then I can’t login because no browser can run without GUI support (I know of Lynx but I haven’t been able to use it for it.)

Recently I thought of investigating the working of the web login page of Cyberoam. After bringing up the login page of Cyberoam I changed the value of attribute method of form tag to GET from POST. So after filling-up the username and password when I hit enter key, there it was all the details that are sent from my browser to Cyberoam server in my browser address bar. I thought of simulating the POST action using a Python code. It required only a pinch of Python to do this. I tried the following Python code to simulate that and it worked, as it should. You too can try the following code and login to Cyberoam.

[code lang=”python” wraplines=”false”]
import urllib
urllib.urlopen("http://192.168.5.10:8090/corporate/servlet/CyberoamHTTPClient","mode=191&isAccessDenied=null&url=null&message=&username=YourUserName&password=YourPassword&saveinfo=saveinfo&login=Login")[/code]

Be sure to substitute YourUserName and YourPasswordfor your username and password respectively. The above will get you logged in but won’t keep you logged it because you need to re-post the login data at every (usually) 3 minutes. So, I got down to work again. Below is quick and dirty shell script to get around this problem. Note the above code has been distorted and compressed into single line and passed via piping to Python in script below.

[code lang=”bash” wraplines=”false”]
while [[ 1 == 1 ]]
do
printf "%s\n%s\n" "import urllib" "urllib.urlopen(\"http://192.168.5.10:8090/corporate/servlet/CyberoamHTTPClient\",\"mode=191&isAccessDenied=null&url=null&message=&username=YourUserName&password=YourPassword&saveinfo=saveinfo&login=Login\")" |python
sleep 3m
done[/code]

Again in the above code do replace YourUserName and YourPassword for your actual username and password respectively. Well now it was working great. 🙂 As usual I was again not satisfied because how will I know if I have logged in successfully or not? The only way for that was by parsing the returned page after logging-in for the message. I noticed that returned page’s source code contained…

[code lang=”html”][/code]

Please notice the part message. The value after that is the message I was seeking. So, all I needed is to parse this page for the value of attribute src of the tag frame. Also, note this very string also contains some more very useful values, viz. – loginstatus and liverequesttime. I noticed that value of loginstatus becomes true when logged in otherwise it remains false, and the value of liverequesttimegiave the time (in seconds) in which to re-post the login data.

The HTML parsing class in the Python script (which I wrote) below is based on the code from the great HTML parsing tutorial located here. Note the script uses the zenity command to display GUI dialog boxes. If you do not have this installed or simply don’t want to display GUI dialog boxes then start the script with -nogui argument. If you want the script to remain completely silent then use the -silent argument. I call this script Cyberthon (=Cyberoam+Python) 😉

[code lang=”python” wraplines=”false”]#!/usr/bin/python
#!/usr/bin/python

#Program Name: Cyberthon (Python Cyberoam Client)
#Coder AppleGrew
#License GPL
#Version 1.2
cyberroamIP = "192.168.5.10" #The IP of the Cyberoam site.
cyberroamPort = "8090" #Set to "" if not using.
username = "your_username" #Your username
passwordFile = "/home/you/.passwd" #Path file containing a single string, your password.
sleeptime = 0 #in minutes or set to 0, it will then parse this value from the cyberoam returned page dynamically.
never_quit = True #Once started cyberthon will never, even when the cyberoam server cannot be connected.

import sys

silent = False
nogui = False
for arg in sys.argv:
if "-silent" == arg:
silent = True
if "-nogui" == arg:
nogui = True

#Parsing and logging in too.
import sgmllib

class MyCyberroamParser(sgmllib.SGMLParser):
"A simple parser class."

def parse(self, s):
"Parse the given string ‘s’."
self.feed(s)
self.close()

def __init__(self, verbose=0):
"Initialise an object, passing ‘verbose’ to the superclass."

sgmllib.SGMLParser.__init__(self, verbose)
self.required_entities = [‘message’,’loginstatus’,’liverequesttime’]
self.frames_attr = []
self.in_required_entity = False
self.current_entity = ""
self.entity_values = {}

def do_frame(self, attributes):
for name, value in attributes:
if name == "src":
self.frames_attr.append(value)

def unknown_entityref(self,ref):
self.current_entity = ref
if ref in self.required_entities:
self.in_required_entity=True

def handle_data(self, data):
"Try to get the value of entity &message. Used in 2nd pass of parsing."

if self.in_required_entity:
self.entity_values[self.current_entity] = data[1:] #To remove the preceeding =
self.in_required_entity = False

def get_src(self,index=-1):
"Return the list of src targets."
if index == -1:
return self.frames_attr
else:
return self.frames_attr[index]

import urllib, sgmllib,time,commands,os

pf = open(passwordFile)
passwd = pf.readline()
pf.close()
if passwd[-1] == ‘\n’: #Removing terminating newline character.
passwd = passwd[:-1]

cyberroamAddress = cyberroamIP
if cyberroamPort != "":
cyberroamAddress = cyberroamAddress+":"+cyberroamPort

sec2sleep = 60*sleeptime
lastmsg = ""
msgChanged = True
lastMsgWasFailMsg = False
sec2sleepOnError = 6
while True:
try:
# Logging in and fetching the Cyberroam login page.
f = urllib.urlopen("http://"+cyberroamAddress+"/corporate/servlet/CyberoamHTTPClient","mode=191&isAccessDenied=null&url=null&message=&username="+username+"&password="+passwd+"&saveinfo=saveinfo&login=Login")
sec2sleepOnError = 6
except IOError, (errno, strerror):
if not silent:
print "Connection to Cyberoam server timed out. Error(%s): %s" % (errno, strerror)

if sec2sleepOnError > 30:
if not silent:
if nogui:
print "Quitting program."
else:
if never_quit:
if not lastMsgWasFailMsg:
os.popen(‘zenity –info –text="Failed to connect to server, but I am NOT quitting." –title="Cyberthon" >/dev/null’)
lastMsgWasFailMsg = True
else:
commands.getoutput(‘zenity –info –text="Could not connect to the server. Quitting program." –title="Cyberthon"’)
if not never_quit:
sys.exit(1)
else:
sec2sleepOnError = 6

if not silent:
print "Retrying in %s seconds" % sec2sleepOnError

time.sleep(sec2sleepOnError)
sec2sleepOnError = sec2sleepOnError*2
continue

s = f.read()

# Try and process the page.
# The class should have been defined first, remember.
myparser = MyCyberroamParser()
myparser.parse(s)

# Get the the src targets. It contains the status message. And then parse it again for entity &message.
qindex = myparser.get_src(1).index(‘?’)
srcstr = myparser.get_src(1)[:qindex+1]+’&’+myparser.get_src(1)[qindex+1:]

myparser.parse(srcstr)

message = myparser.entity_values[‘message’]
if lastmsg != message or lastMsgWasFailMsg:
lastmsg = message
msgChanged = True
lastMsgWasFailMsg = False

if (not silent) and msgChanged:
msgChanged = False

msg=”
i=0
while i < len(message): #Converting hex nos. to characters. t=message[i] if message[i]==’%’: no=int(message[i+1:i+3],16) t=chr(no) i=i+2 msg=msg+t i=i+1 message = "" for x in msg:#Changing all + to space. if x == ‘+’: x = " " message=message+x if nogui: print message else: os.popen(‘zenity –info –text="From Cyberoam: ‘+message+’" –title="Cyberthon" >/dev/null’)

if myparser.entity_values[‘loginstatus’].lower()!="true":
break;

if sleeptime==0:
sec2sleep = int(myparser.entity_values[‘liverequesttime’])
time.sleep(sec2sleep)
[/code]

Please copy the file very carefully. A single extra space here and there may throw Python haywire, making it throw up all sorts of nasty syntax errors. Paste the contents of this code in a file and name it – Cyberthon.py.