misc mitmproxy testing. wipe UA, print headers, kill connection, inject error

mitmproxyIntecept.py

from mitmproxy import http

''' dns intercept not working... why?
from mitmproxy import dns

def request(flow: dns.DNSFlow):
    print(f"DNS Request: {flow.request.qname}")

def response(flow: dns.DNSFlow):
    print(f"DNS Response: {flow.response.qname}")
'''


printHeader = True
printRequestContent = False
printResponseContent = False
clearUserAgent = True
injectError = False
injectReplaceKeyWord = False
killConnection = False

def request(flow: http.HTTPFlow) -> None:   
    if printHeader:
        ua = flow.request.headers["User-Agent"]
        print('user: ' + ua)
        print(f"Response:\n{flow.request.headers}")

    if printRequestContent:
        print(flow.request.content)    

    if killConnection:
        print(f"killed request to: {flow.request.pretty_url} ({flow.request.host })")
        flow.kill()
        return

    if clearUserAgent:
        flow.request.headers["User-Agent"] = ""
        flow.request.headers["x-requested-with"] = "" 
        # https://issues.chromium.org/issues/40626445
        # https://android-developers.googleblog.com/2023/02/improving-user-privacy-by-requiring-opt-in-to-send-x-requested-wih-header-from-webview.html

    
def response(flow: http.HTTPFlow) -> None:
    response_body = flow.response.get_text()
    
    if printResponseContent:
        print(f"Response: {flow.response.status_code}")
        try:         
            print(f"Response Body:\n{response_body}")
        except UnicodeDecodeError:
            print("Failed to decode response body as text.")

    if injectReplaceKeyWord:
        keyword = "the"
        replacement = "REPLACED!" #demo
        modified_body = response_body.replace(keyword, replacement)
        flow.response.set_text(modified_body)

    if injectError:
        flow.response.status_code = 400

SSLKEYLOGFILE="$PWD/.mitmproxy/sslkeylogfile.txt" mitmweb -p 9090 --ssl-insecure --scripts /home/user/Desktop/
mitmproxyIntecept.py