DNS over HTTPS

import httpx  # pip install httpx
import json

# DoH 쿼리 (JSON API)
def doh_query_json(domain: str, record_type: str = "A") -> dict:
    """Cloudflare DoH JSON API로 DNS 쿼리"""
    url = "https://cloudflare-dns.com/dns-query"
    params = {"name": domain, "type": record_type}
    headers = {"accept": "application/dns-json"}

    response = httpx.get(url, params=params, headers=headers)
    return response.json()

# 사용 예시
result = doh_query_json("google.com", "A")
print(f"도메인: {result['Question'][0]['name']}")
for answer in result.get('Answer', []):
    print(f"  {answer['type']}: {answer['data']} (TTL: {answer['TTL']}s)")

# Google DoH 쿼리
def google_doh_query(domain: str) -> dict:
    """Google DoH JSON API"""
    url = f"https://dns.google/resolve?name={domain}&type=A"
    response = httpx.get(url)
    return response.json()

# DoH 서버 응답 속도 비교
import time

DOH_SERVERS = {
    "Cloudflare": "https://cloudflare-dns.com/dns-query?name=example.com&type=A",
    "Google": "https://dns.google/resolve?name=example.com&type=A",
    "Quad9": "https://dns.quad9.net:5053/dns-query?name=example.com&type=A"
}

for name, url in DOH_SERVERS.items():
    start = time.time()
    httpx.get(url, headers={"accept": "application/dns-json"})
    latency = (time.time() - start) * 1000
    print(f"{name}: {latency:.1f}ms")

// DoH 쿼리 (브라우저 / Node.js)
async function dohQuery(domain, type = 'A') {
    const url = `https://cloudflare-dns.com/dns-query?name=${domain}&type=${type}`;

    const response = await fetch(url, {
        headers: { 'accept': 'application/dns-json' }
    });

    return response.json();
}

// 사용 예시
const result = await dohQuery('google.com', 'A');
console.log('DNS 응답:', result);

result.Answer?.forEach(record => {
    console.log(`${record.name} -> ${record.data} (TTL: ${record.TTL}s)`);
});

// 여러 레코드 타입 조회
async function fullDnsLookup(domain) {
    const types = ['A', 'AAAA', 'MX', 'TXT', 'NS'];
    const results = {};

    await Promise.all(types.map(async type => {
        try {
            const data = await dohQuery(domain, type);
            results[type] = data.Answer || [];
        } catch (e) {
            results[type] = [];
        }
    }));

    return results;
}

// DNS 응답 시간 측정
async function measureDohLatency(server, domain) {
    const start = performance.now();
    await fetch(`${server}?name=${domain}&type=A`, {
        headers: { 'accept': 'application/dns-json' }
    });
    return performance.now() - start;
}

// 여러 DoH 서버 비교
const servers = {
    'Cloudflare': 'https://cloudflare-dns.com/dns-query',
    'Google': 'https://dns.google/resolve',
};

for (const [name, url] of Object.entries(servers)) {
    const latency = await measureDohLatency(url, 'example.com');
    console.log(`${name}: ${latency.toFixed(1)}ms`);
}