dns_utils.py

from scapy.all import sniff, DNS, DNSQR, DNSRR
from datetime import datetime
import time
from utils import save_results

def safe_decode(data):
    if isinstance(data, bytes):
        try:
            return data.decode("utf-8")
        except UnicodeDecodeError:
            return repr(data)  # Representação em string dos bytes caso a decodificação falhe
    else:
        return data


def capture_dns_queries():
    dns_queries = []
    start_time = time.time()

    def packet_callback(packet):
        if packet.haslayer(DNSQR):
            dns_query_layer = packet[DNSQR]
            query_info = {
                "query_name": safe_decode(dns_query_layer.qname) if dns_query_layer.qname else "Desconhecido",
                "query_type": dns_query_layer.qtype,
                "responses": []
            }

            if packet.haslayer(DNSRR):
                for i in range(packet[DNS].ancount):
                    rr = packet[DNSRR][i]
                    response_name = safe_decode(rr.rrname) if rr.rrname else "Desconhecido"
                    response_data = safe_decode(rr.rdata) if rr.rdata else "Desconhecido"
                    query_info["responses"].append({
                        "response_name": response_name,
                        "response_type": rr.type,
                        "response_data": response_data,
                        "response_ttl": rr.ttl
                    })

            dns_queries.append(query_info)

    print("Capturando consultas DNS...")
    sniff(filter="port 53", prn=packet_callback, store=0)

    end_time = time.time()
    capture_duration = end_time - start_time

    print(f"Captura completada. Duração: {capture_duration} segundos, Total de consultas capturadas: {len(dns_queries)}")

    save = input("Deseja salvar os resultados? (s/n): ")
    if save.lower() == 's':
        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
        data_to_save = {
            'dns_queries': dns_queries,
            'capture_duration': capture_duration,
            'total_queries': len(dns_queries)
        }
        save_results(data_to_save, "captura_dns", f"captura_dns_{timestamp}.json")