SpyGuard/server/frontend/app/classes/capture.py
2022-11-06 15:51:33 +01:00

162 lines
5.6 KiB
Python
Executable File

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import subprocess as sp
from app.utils import stop_monitoring, read_config, get_iocs, get_device_uuid
from app.classes.network import Network
from os import mkdir, path, chmod
import sys
import json
import random
class Capture(object):
def __init__(self):
self.random_choice_alphabet = "ABCDEF1234567890"
self.rules_file = "/tmp/rules"
self.generate_rule_file()
def start_capture(self) -> dict:
"""Start a dumpcap capture on the created AP interface and save
the generated pcap in a temporary directory under /tmp/.
Returns:
dict: Capture token and operation status.
"""
# Few context variable assignment
self.capture_token = "".join([random.choice(self.random_choice_alphabet) for i in range(8)])
self.capture_dir = "/tmp/{}/".format(self.capture_token)
self.assets_dir = "/tmp/{}/assets/".format(self.capture_token)
self.iface = read_config(("network", "in"))
self.pcap = self.capture_dir + "capture.pcap"
self.rules_file = "/tmp/rules"
# For packets monitoring
self.list_pkts = []
self.last_pkts = 0
# Make the capture and the assets directory
mkdir(self.capture_dir)
chmod(self.capture_dir, 0o777)
mkdir(self.assets_dir)
chmod(self.assets_dir, 0o777)
# Kill possible potential process
stop_monitoring()
# Writing the instance UUID for reporting.
with open("/tmp/{}/assets/instance.json".format(self.capture_token), "w") as f:
f.write(json.dumps({ "instance_uuid" : get_device_uuid().strip() }))
try:
sp.Popen(["dumpcap", "-n", "-i", self.iface, "-w", self.pcap])
sp.Popen(["suricata", "-c", "/etc/suricata/suricata.yaml", "-i", self.iface, "-l", self.assets_dir, "-S", self.rules_file])
return { "status": True,
"message": "Capture started",
"capture_token": self.capture_token }
except:
return { "status": False,
"message": f"Unexpected error: {sys.exc_info()[0]}"}
def get_capture_stats(self) -> dict:
""" Get some dirty capture statistics in order to have a sparkline
in the background of capture view.
Returns:
dict: dict containing stats associated to the capture
"""
with open("/sys/class/net/{}/statistics/tx_packets".format(self.iface)) as f:
tx_pkts = int(f.read())
with open("/sys/class/net/{}/statistics/rx_packets".format(self.iface)) as f:
rx_pkts = int(f.read())
if self.last_pkts == 0:
self.last_pkts = tx_pkts + rx_pkts
return {"status": True,
"packets": [0*400]}
else:
curr_pkts = (tx_pkts + rx_pkts) - self.last_pkts
self.last_pkts = tx_pkts + rx_pkts
self.list_pkts.append(curr_pkts)
return {"status": True,
"packets": self.beautify_stats(self.list_pkts)}
@staticmethod
def beautify_stats(data) -> list:
"""Add 0 at the end of the array if the len of the array is less
than max_len. Else, get the last 100 stats. This allows to
show a kind of "progressive chart" in the background for
the first packets.
Args:
data (list): list of integers
Returns:
list: list of integers
"""
max_len = 400
if len(data) >= max_len:
return data[-max_len:]
else:
return data + [1] * (max_len - len(data))
def stop_capture(self) -> dict:
"""Stop dumpcap & suricata if any instance present & ask create_capinfos.
Returns:
dict: operation status
"""
network = Network()
# We stop the monitoring and the associated hotspot.
if stop_monitoring():
if network.delete_hotspot():
self.create_capinfos()
return {"status": True,
"message": "Capture stopped"}
else:
return {"status": False,
"message": "No active hotspot"}
else:
return {"status": False,
"message": "No active capture"}
def create_capinfos(self) -> bool:
"""Creates a capinfo json file.
Returns:
bool: True if everything worked well.
"""
self.pcap = self.capture_dir + "capture.pcap"
infos = sp.Popen(["capinfos", self.pcap], stdout=sp.PIPE, stderr=sp.PIPE)
infos = infos.communicate()[0]
data = {}
for l in infos.decode().splitlines():
try:
l = l.split(": ") if ": " in l else l.split("= ")
if len(l[0]) and len(l[1]):
data[l[0].strip()] = l[1].strip()
except:
continue
with open("{}capinfos.json".format(self.assets_dir), 'w') as f:
json.dump(data, f)
return True
def generate_rule_file(self) -> bool:
"""Generate a suricata rules files.
Returns:
bool: operation status.
"""
rules = [r[0] for r in get_iocs("snort")]
try:
with open(self.rules_file, "w+") as f:
f.write("\n".join(rules))
return True
except:
return False