If you want to use Python to capture HTTPS requests on a system that you have complete authority over, you must safely intercept the connection without cracking the encryption.
1. Setting Up a Local Proxy
You can set up a local proxy to intercept and capture HTTPS traffic. Here's the approach:
Steps:
- Install Proxy Libraries: Use a Python library like mitmproxy or PyCA.
- Proxy Configuration:
- Configure the target system's network settings to route all HTTPS traffic through your local proxy.
- This can be done by modifying the system or browser proxy settings.
- Install a Custom CA Certificate:
- Generate a custom CA (Certificate Authority) using tools like OpenSSL.
- Add this CA to the system's or browser's trusted certificate store to avoid SSL errors.
- Intercept Requests:
- Decrypt and inspect HTTPS requests using the proxy tool.
- Mitmproxy provides Python scripting support for advanced request analysis and modification.
2. SSL/TLS Certificate Manipulation
If you control the system, you can replace the server's certificates with self-signed ones.
Steps:
- Generate a Self-Signed Certificate:
- Use Python’s ssl or external tools like OpenSSL to create self-signed certificates.
- Redirect Traffic:
- Use a local DNS resolver or modify the system's /etc/hosts file to point the target domain to your local server.
- Decrypt HTTPS Traffic:
- Use Python’s ssl module to decrypt and inspect the traffic at your local server.
3. Using Python Libraries Directly
Python libraries like scapy and ssl can be used for packet inspection and TLS termination.
Example with Scapy:
from scapy.all import sniff, TLS
def packet_callback(packet):
if packet.haslayer(TLS):
print(packet.show())
sniff(iface="eth0", prn=packet_callback, filter="tcp port 443")
4. Packet Inspection with Tools Integration
You can integrate Python with tools like Wireshark or tcpdump for HTTPS traffic analysis. This works best when combined with decryption keys or proxy techniques.
Steps:
- Capture encrypted traffic using tools.
- Decrypt traffic via keys extracted using Python scripts or tools like sslkeylogfile.
Example: Mitmproxy with Python
from mitmproxy import ctx
def request(flow):
# Inspect HTTP/HTTPS requests
ctx.log.info(f"Request: {flow.request.method} {flow.request.url}")
Run mitmproxy and load the script to see HTTPS requests decrypted.
By setting up a proxy and using Python libraries or SSL techniques, you can capture and analyze HTTPS traffic securely on systems you control. Always prioritize ethical use and transparency.
