#!/usr/bin/env python3 """ website_debug.py - simple diagnostic scanner for a URL/host. Prints DNS resolution, TCP port checks, SSL cert info, redirect chain, HTTP status and headers, and robots.txt summary. Streams output line-by-line for the UI. """ import sys import socket import ssl import urllib.parse import http.client import time def print_flush(s=''): print(s) sys.stdout.flush() def resolve_host(host): print_flush(f"[DNS] Resolving {host}...") try: infos = socket.getaddrinfo(host, None) ips = [] for info in infos: ips.append(info[4][0]) ips = sorted(set(ips)) for ip in ips: print_flush(f"[DNS] -> {ip}") return ips except Exception as e: print_flush(f"[DNS] Error: {e}") return [] def tcp_check(host, port, timeout=3): print_flush(f"[TCP] Connecting to {host}:{port}...") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(timeout) try: start = time.time() s.connect((host, port)) elapsed = (time.time() - start) * 1000 print_flush(f"[TCP] Connected to {host}:{port} ({int(elapsed)}ms)") s.close() return True except Exception as e: print_flush(f"[TCP] Failed: {e}") try: s.close() except: pass return False def get_ssl_info(host, timeout=5): print_flush(f"[SSL] Retrieving certificate for {host}:443 ...") try: context = ssl.create_default_context() conn = context.wrap_socket(socket.socket(socket.AF_INET), server_hostname=host) conn.settimeout(timeout) conn.connect((host, 443)) cert = conn.getpeercert() conn.close() subj = cert.get('subject', ()) issuer = cert.get('issuer', ()) notBefore = cert.get('notBefore') notAfter = cert.get('notAfter') # try to get CN cn = None for part in subj: for k,v in part: if k == 'commonName': cn = v issuer_cn = None for part in issuer: for k,v in part: if k == 'commonName': issuer_cn = v print_flush(f"[SSL] Subject CN: {cn}") print_flush(f"[SSL] Issuer: {issuer_cn}") print_flush(f"[SSL] Valid: {notBefore} -> {notAfter}") return cert except Exception as e: print_flush(f"[SSL] Error: {e}") return None def fetch_url(url, max_redirects=8, timeout=8): visited = [] current = url for i in range(max_redirects+1): visited.append(current) parsed = urllib.parse.urlparse(current) scheme = parsed.scheme or 'http' host = parsed.hostname port = parsed.port path = parsed.path or '/' if parsed.query: path += '?' + parsed.query print_flush(f"[HTTP] {scheme.upper()} request to {host}{path} (redirect #{i})") try: if scheme == 'https': conn = http.client.HTTPSConnection(host, port or 443, timeout=timeout) else: conn = http.client.HTTPConnection(host, port or 80, timeout=timeout) conn.request('GET', path, headers={'User-Agent': 'Website-Debug/1.0'}) resp = conn.getresponse() status = resp.status reason = resp.reason headers = resp.getheaders() print_flush(f"[HTTP] Status: {status} {reason}") for h,v in headers: # only print key headers to reduce noise if h.lower() in ('server','content-type','content-length','location','set-cookie','cache-control','x-frame-options','strict-transport-security'): print_flush(f"[HTTP] Header: {h}: {v}") # read a small body preview try: body = resp.read(1024) if body: body_preview = body.decode('utf-8', errors='replace').strip().split('\n')[0] print_flush(f"[HTTP] Body Preview: {body_preview[:200]}") except Exception as e: print_flush(f"[HTTP] Body read error: {e}") conn.close() # follow redirect if status in (301,302,303,307,308): loc = dict(headers).get('Location') if not loc: print_flush('[HTTP] Redirect without Location header') break # make absolute loc = urllib.parse.urljoin(current, loc) print_flush(f"[HTTP] Redirect -> {loc}") current = loc continue else: return {'final_url': current, 'status': status, 'headers': headers} except Exception as e: print_flush(f"[HTTP] Error: {e}") return {'error': str(e)} print_flush('[HTTP] Too many redirects') return {'error': 'too many redirects'} def fetch_robots(host, scheme='http'): url = f"{scheme}://{host}/robots.txt" print_flush(f"[ROBOTS] Fetching {url}") try: parsed = urllib.parse.urlparse(url) conn = http.client.HTTPConnection(parsed.hostname, parsed.port or 80, timeout=6) conn.request('GET', '/robots.txt', headers={'User-Agent': 'Website-Debug/1.0'}) resp = conn.getresponse() status = resp.status print_flush(f"[ROBOTS] Status: {status}") if status == 200: body = resp.read(2048).decode('utf-8', errors='replace') lines = [l.strip() for l in body.splitlines() if l.strip()] for ln in lines[:20]: print_flush(f"[ROBOTS] {ln}") conn.close() except Exception as e: print_flush(f"[ROBOTS] Error: {e}") def main(): if len(sys.argv) < 2: print_flush('Usage: website_debug.py ') sys.exit(2) target = sys.argv[1] print_flush(f"[DEBUG] Starting diagnostics for: {target}") parsed = urllib.parse.urlparse(target) host = parsed.hostname or target scheme = parsed.scheme or 'http' # DNS ips = resolve_host(host) # TCP checks ports = [80, 443] open_ports = [] for p in ports: ok = tcp_check(host, p) if ok: open_ports.append(p) # SSL cert if 443 in open_ports: get_ssl_info(host) # HTTP fetch and redirect chain if scheme not in ('http','https'): scheme = 'http' http_res = fetch_url(f"{scheme}://{host}") if 'error' in http_res: print_flush(f"[DIAG] HTTP error: {http_res['error']}") else: print_flush(f"[DIAG] Final URL: {http_res.get('final_url')}") print_flush(f"[DIAG] Status: {http_res.get('status')}") # robots.txt fetch_robots(host, scheme=scheme) print_flush('[DEBUG] Diagnostics complete') if __name__ == '__main__': main()