Secure Source of Randomness

server/frontend/app/classes/capture.py

@@ -1,128 +1,128 @@
-#!/usr/bin/env python3
+#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
+# -*- coding: utf-8 -*-
-
+
-import subprocess as sp
+import subprocess as sp
-from app.utils import terminate_process, read_config
+from app.utils import terminate_process, read_config
-from os import mkdir, path
+from os import mkdir, path
-from flask import send_file, jsonify
+from flask import send_file, jsonify
-import datetime
+import datetime
-import shutil
+import shutil
-import json
+import json
-import random
+import sys
-import sys
+import re
-import re
+import secrets
-
+
-
+
-class Capture(object):
+class Capture(object):
-
+
-    def __init__(self):
+    def __init__(self):
-        self.random_choice_alphabet = "ABCDEF1234567890"
+        self.random_choice_alphabet = "ABCDEF1234567890"
-
+
-    def start_capture(self):
+    def start_capture(self):
-        """
+        """
-        Start a tshark capture on the created AP interface and save
+        Start a tshark capture on the created AP interface and save
-        it in a temporary directory under /tmp/.
+        it in a temporary directory under /tmp/.
-
+
-        :return: dict containing capture token and status. 
+        :return: dict containing capture token and status. 
-        """
+        """
-
+
-        # Kill potential tshark zombies instances, if any.
+        # Kill potential tshark zombies instances, if any.
-        terminate_process("tshark")
+        terminate_process("tshark")
-
+
-        # Few context variable assignment
+        # Few context variable assignment
-        self.capture_token = "".join(
+        self.capture_token = "".join(
-            [random.choice(self.random_choice_alphabet) for i in range(8)])
+            [secrets.choice(self.random_choice_alphabet) for i in range(8)])
-        self.capture_dir = "/tmp/{}/".format(self.capture_token)
+        self.capture_dir = "/tmp/{}/".format(self.capture_token)
-        self.assets_dir = "/tmp/{}/assets/".format(self.capture_token)
+        self.assets_dir = "/tmp/{}/assets/".format(self.capture_token)
-        self.pcap = self.capture_dir + "capture.pcap"
+        self.pcap = self.capture_dir + "capture.pcap"
-        self.iface = read_config(("network", "in"))
+        self.iface = read_config(("network", "in"))
-
+
-        # For packets monitoring
+        # For packets monitoring
-        self.list_pkts = []
+        self.list_pkts = []
-        self.last_pkts = 0
+        self.last_pkts = 0
-
+
-        # Make the capture and the assets directory
+        # Make the capture and the assets directory
-        mkdir(self.capture_dir)
+        mkdir(self.capture_dir)
-        mkdir(self.assets_dir)
+        mkdir(self.assets_dir)
-
+
-        try:
+        try:
-            sp.Popen(["tshark",  "-i", self.iface, "-w",
+            sp.Popen(["tshark",  "-i", self.iface, "-w",
-                      self.pcap, "-f", "tcp or udp"])
+                      self.pcap, "-f", "tcp or udp"])
-            return {"status": True,
+            return {"status": True,
-                    "message": "Capture started",
+                    "message": "Capture started",
-                    "capture_token": self.capture_token}
+                    "capture_token": self.capture_token}
-        except:
+        except:
-            return {"status": False,
+            return {"status": False,
-                    "message": "Unexpected error: %s" % sys.exc_info()[0]}
+                    "message": "Unexpected error: %s" % sys.exc_info()[0]}
-
+
-    def get_capture_stats(self):
+    def get_capture_stats(self):
-        """
+        """
-            Get some dirty capture statistics in order to have a sparkline 
+            Get some dirty capture statistics in order to have a sparkline 
-            in the background of capture view.
+            in the background of capture view.
-
+
-            :return: dict containing stats associated to the capture
+            :return: dict containing stats associated to the capture
-        """
+        """
-        with open("/sys/class/net/{}/statistics/tx_packets".format(self.iface)) as f:
+        with open("/sys/class/net/{}/statistics/tx_packets".format(self.iface)) as f:
-            tx_pkts = int(f.read())
+            tx_pkts = int(f.read())
-        with open("/sys/class/net/{}/statistics/rx_packets".format(self.iface)) as f:
+        with open("/sys/class/net/{}/statistics/rx_packets".format(self.iface)) as f:
-            rx_pkts = int(f.read())
+            rx_pkts = int(f.read())
-
+
-        if self.last_pkts == 0:
+        if self.last_pkts == 0:
-            self.last_pkts = tx_pkts + rx_pkts
+            self.last_pkts = tx_pkts + rx_pkts
-            return {"status": True,
+            return {"status": True,
-                    "packets": [0*400]}
+                    "packets": [0*400]}
-        else:
+        else:
-            curr_pkts = (tx_pkts + rx_pkts) - self.last_pkts
+            curr_pkts = (tx_pkts + rx_pkts) - self.last_pkts
-            self.last_pkts = tx_pkts + rx_pkts
+            self.last_pkts = tx_pkts + rx_pkts
-            self.list_pkts.append(curr_pkts)
+            self.list_pkts.append(curr_pkts)
-            return {"status": True,
+            return {"status": True,
-                    "packets": self.beautify_stats(self.list_pkts)}
+                    "packets": self.beautify_stats(self.list_pkts)}
-
+
-    @staticmethod
+    @staticmethod
-    def beautify_stats(data):
+    def beautify_stats(data):
-        """
+        """
-            Add 0 at the end of the array if the len of the array is less 
+            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 
+            than max_len. Else, get the last 100 stats. This allows to 
-            show a kind of "progressive chart" in the background for 
+            show a kind of "progressive chart" in the background for 
-            the first packets.
+            the first packets.
-
+
-            :return: a list of integers.
+            :return: a list of integers.
-        """
+        """
-        max_len = 400
+        max_len = 400
-        if len(data) >= max_len:
+        if len(data) >= max_len:
-            return data[-max_len:]
+            return data[-max_len:]
-        else:
+        else:
-            return data + [1] * (max_len - len(data))
+            return data + [1] * (max_len - len(data))
-
+
-    def stop_capture(self):
+    def stop_capture(self):
-        """
+        """
-            Stop tshark if any instance present & ask create_capinfos.
+            Stop tshark if any instance present & ask create_capinfos.
-            :return: dict as a small confirmation.
+            :return: dict as a small confirmation.
-        """
+        """
-        if terminate_process("tshark"):
+        if terminate_process("tshark"):
-            self.create_capinfos()
+            self.create_capinfos()
-            return {"status": True,
+            return {"status": True,
-                    "message": "Capture stopped"}
+                    "message": "Capture stopped"}
-        else:
+        else:
-            return {"status": False,
+            return {"status": False,
-                    "message": "No active capture"}
+                    "message": "No active capture"}
-
+
-    def create_capinfos(self):
+    def create_capinfos(self):
-        """
+        """
-            Creates a capinfo json file.
+            Creates a capinfo json file.
-            :return: dict as a small confirmation.
+            :return: dict as a small confirmation.
-        """
+        """
-        infos = sp.Popen(["capinfos", self.pcap],
+        infos = sp.Popen(["capinfos", self.pcap],
-                         stdout=sp.PIPE, stderr=sp.PIPE)
+                         stdout=sp.PIPE, stderr=sp.PIPE)
-        infos = infos.communicate()[0]
+        infos = infos.communicate()[0]
-        data = {}
+        data = {}
-        for l in infos.decode().splitlines():
+        for l in infos.decode().splitlines():
-            try:
+            try:
-                l = l.split(": ") if ": " in l else l.split("= ")
+                l = l.split(": ") if ": " in l else l.split("= ")
-                if len(l[0]) and len(l[1]):
+                if len(l[0]) and len(l[1]):
-                    data[l[0].strip()] = l[1].strip()
+                    data[l[0].strip()] = l[1].strip()
-            except:
+            except:
-                continue
+                continue
-        with open("{}capinfos.json".format(self.assets_dir), 'w') as f:
+        with open("{}capinfos.json".format(self.assets_dir), 'w') as f:
-            json.dump(data, f)
+            json.dump(data, f)
-            return True
+            return True

server/frontend/app/classes/network.py

@@ -9,13 +9,13 @@ import sys
 import time
 import qrcode
 import base64
-import random
 import requests
 
 from wifi import Cell
 from os import path, remove
 from io import BytesIO
 from app.utils import terminate_process, read_config
+import secrets
 
 
 class Network(object):
@@ -170,14 +170,14 @@ class Network(object):
 
         # Generate the hostapd configuration
         if read_config(("network", "tokenized_ssids")):
-            token = "".join([random.choice(self.random_choice_alphabet)
+            token = "".join([secrets.choice(self.random_choice_alphabet)
                              for i in range(4)])
-            self.AP_SSID = random.choice(read_config(
+            self.AP_SSID = secrets.choice(read_config(
                 ("network", "ssids"))) + "-" + token
         else:
-            self.AP_SSID = random.choice(read_config(("network", "ssids")))
+            self.AP_SSID = secrets.choice(read_config(("network", "ssids")))
         self.AP_PASS = "".join(
-            [random.choice(self.random_choice_alphabet) for i in range(8)])
+            [secrets.choice(self.random_choice_alphabet) for i in range(8)])
 
         # Launch hostapd
         if self.write_hostapd_config():