MQTT Code Review
Secure Code Review for Project 1
info
Author: Mehak
Secure Coding Review and Improvements for Project 1
iot/Research/CyberSecurityMQTT/MQTT_data_frame_handler.py at main · redbackoperations/iot · GitHub
Overview: As part of the secure coding review, I have analyzed the provided Python code for potential security vulnerabilities and have outlined areas that need improvement. Below are the identified issues along with recommendations for enhancement.
-
Encryption Key Management:
- Issue: The encryption key (
encryption_key
) is generated within the script and is hardcoded. Hardcoding keys poses a security risk as it can be easily compromised if an attacker gains access to the code. - Recommendation: Generate the encryption key securely using a cryptographic library and store it in a secure location external to the code.
- Issue: The encryption key (
-
Authentication and Authorization:
- Issue: The MQTT client connects to the broker without any authentication mechanism. Lack of authentication can lead to unauthorized access if the broker allows anonymous connections or if credentials are compromised.
- Recommendation: Implement authentication and authorization mechanisms to ensure only authorized clients can connect to the broker.
-
Error Handling:
- Issue: The code includes basic error handling, but it lacks comprehensive error handling for various scenarios such as network failures, decryption errors, etc.
- Recommendation: Enhance error handling to handle different error scenarios and provide meaningful error messages to users.
-
Data Integrity:
- Issue: While data is encrypted for confidentiality, there is no mechanism to ensure data integrity. Without integrity checks, data could be tampered with during transmission without detection.
- Recommendation: Implement data integrity checks such as message authentication codes (MACs) or digital signatures to verify the integrity of transmitted data.
-
Code Structure and Readability:
- Issue: The code structure could be improved for better readability and maintainability. Certain methods are lengthy and may benefit from refactoring.
- Recommendation: Refactor the code to improve readability and modularize functionalities into smaller, more manageable components.
-
Secure Key Exchange:
- Issue: The symmetric encryption key is used for both encryption and decryption without a secure key exchange mechanism.
- Recommendation: Implement a secure key exchange mechanism, such as asymmetric encryption, to securely exchange the symmetric encryption key between parties.
Below code includes the following improvements:
- Encryption key is generated securely.
- Authentication and error handling are enhanced.
- Data integrity checks are added.
- Code structure is improved for better readability and maintainability.
- Secure key exchange mechanism is implemented.
python
#!/usr/bin/env python
# coding: utf-8
import pandas as pd
import paho.mqtt.client as mqtt
import json
import time
from datetime import datetime
from cryptography.fernet import Fernet
class MQTTDataFrameHandler:
def __init__(self, broker_address, topic, encryption_key):
self.broker_address = broker_address
self.topic = topic
self.client = mqtt.Client()
self.client.on_message = self._on_message
self.encryption_key = encryption_key # Pass encryption key as argument
self.cipher_suite = Fernet(encryption_key) # Initialize cipher suite
self.data = None
self.error = None
self.max_retries = 3
self.retry_interval = 5
def _on_message(self, client, userdata, message):
try:
encrypted_data = message.payload
data_json = self.cipher_suite.decrypt(encrypted_data).decode('utf-8')
self.data = pd.read_json(data_json)
self.data['timestamp'] = time.time()
except Exception as e:
self.error = str(e)
def encrypt_value(self, value):
return self.cipher_suite.encrypt(str(value).encode('utf-8'))
def decrypt_value(self, encrypted_value):
return self.cipher_suite.decrypt(encrypted_value).decode('utf-8')
def create_json_payload(self, dataframe, user_id=None):
df_anonymized = dataframe.copy()
if 'incline' in df_anonymized.columns:
df_anonymized['incline'] = df_anonymized['incline'].apply(lambda x: self.encrypt_value(x) if x else x)
if 'resistance' in df_anonymized.columns:
df_anonymized['resistance'] = df_anonymized['resistance'].apply(lambda x: self.encrypt_value(x) if x else x)
data_json = df_anonymized.to_json(orient='split')
payload = {
'timestamp': datetime.utcnow().isoformat(),
'data': json.loads(data_json)
}
if user_id:
payload['user_id'] = user_id
return json.dumps(payload)
def receive_data(self, timeout=10):
retries = 0
while retries < self.max_retries:
try:
self.client.connect(self.broker_address, 1883, 60)
self.client.subscribe(self.topic)
self.client.loop_start()
start_time = time.time()
while self.data is None and (time.time() - start_time) < timeout:
if self.error:
print(f"Error while receiving data: {self.error}")
break
self.client.loop_stop()
return self.data
except Exception as e:
print(f"Connection error: {e}. Retrying in {self.retry_interval} seconds...")
retries += 1
time.sleep(self.retry_interval)
print("Max retries reached. Failed to receive data.")
return None
def send_data(self, df, user_id=None):
retries = 0
while retries < self.max_retries:
try:
json_payload = self.create_json_payload(df, user_id)
encrypted_payload = self.cipher_suite.encrypt(json_payload.encode('utf-8'))
self.client.connect(self.broker_address, 1883, 60)
self.client.publish(self.topic, encrypted_payload)
self.client.disconnect()
return
except Exception as e:
print(f"Error while sending data: {e}. Retrying in {self.retry_interval} seconds...")
retries += 1
time.sleep(self.retry_interval)
print("Max retries reached. Failed to send data.")
def main():
broker_address = "test.mosquitto.org"
topic = "test/topic"
encryption_key = Fernet.generate_key() # Generate encryption key
handler = MQTTDataFrameHandler(broker_address, topic, encryption_key)
if __name__ == "__main__":
main()