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| import asyncio
import aiohttp
import base64
import hashlib
from datetime import datetime
from cryptography import x509
from cryptography.hazmat.backends import default_backend
import psycopg2
from psycopg2.extras import execute_values
class CTLogCollector:
"""CT 日誌收集器"""
LOGS = [
{
'name': 'Google Argon 2024',
'url': 'https://ct.googleapis.com/logs/us1/argon2024/',
},
{
'name': 'Cloudflare Nimbus 2024',
'url': 'https://ct.cloudflare.com/logs/nimbus2024/',
},
]
def __init__(self, db_config):
self.db_config = db_config
self.batch_size = 256
async def get_tree_size(self, session, log_url):
"""取得日誌的當前大小"""
async with session.get(f"{log_url}ct/v1/get-sth") as response:
data = await response.json()
return data['tree_size']
async def get_entries(self, session, log_url, start, end):
"""取得日誌條目"""
url = f"{log_url}ct/v1/get-entries?start={start}&end={end}"
async with session.get(url) as response:
data = await response.json()
return data.get('entries', [])
def parse_certificate(self, entry):
"""解析憑證資料"""
leaf_input = base64.b64decode(entry['leaf_input'])
extra_data = base64.b64decode(entry['extra_data'])
# 略過 MerkleTreeLeaf 標頭
timestamp = int.from_bytes(leaf_input[2:10], 'big')
entry_type = int.from_bytes(leaf_input[10:12], 'big')
try:
if entry_type == 0: # X509LogEntry
cert_len = int.from_bytes(b'\x00' + leaf_input[12:15], 'big')
cert_der = leaf_input[15:15+cert_len]
else: # PrecertLogEntry
tbs_len = int.from_bytes(b'\x00' + leaf_input[44:47], 'big')
# 對於 precert，需要從 extra_data 取得完整憑證
cert_len = int.from_bytes(b'\x00' + extra_data[0:3], 'big')
cert_der = extra_data[3:3+cert_len]
cert = x509.load_der_x509_certificate(cert_der, default_backend())
# 提取 SAN
sans = []
try:
san_ext = cert.extensions.get_extension_for_oid(
x509.oid.ExtensionOID.SUBJECT_ALTERNATIVE_NAME
)
for name in san_ext.value:
if isinstance(name, x509.DNSName):
sans.append(('DNS', name.value))
elif isinstance(name, x509.IPAddress):
sans.append(('IP', str(name.value)))
except x509.ExtensionNotFound:
pass
return {
'timestamp': datetime.fromtimestamp(timestamp / 1000),
'common_name': self._get_common_name(cert),
'issuer': cert.issuer.rfc4514_string(),
'not_before': cert.not_valid_before,
'not_after': cert.not_valid_after,
'serial_number': format(cert.serial_number, 'x'),
'sha256_fingerprint': hashlib.sha256(cert_der).hexdigest(),
'raw_certificate': cert_der,
'sans': sans
}
except Exception as e:
return None
def _get_common_name(self, cert):
"""取得 Common Name"""
try:
cn = cert.subject.get_attributes_for_oid(
x509.oid.NameOID.COMMON_NAME
)
return cn[0].value if cn else None
except:
return None
async def collect_log(self, log_info, start_index=None):
"""收集單一日誌"""
async with aiohttp.ClientSession() as session:
tree_size = await self.get_tree_size(session, log_info['url'])
if start_index is None:
start_index = max(0, tree_size - 1000) # 從最後 1000 條開始
print(f"收集 {log_info['name']}: {start_index} -> {tree_size}")
conn = psycopg2.connect(**self.db_config)
cursor = conn.cursor()
for batch_start in range(start_index, tree_size, self.batch_size):
batch_end = min(batch_start + self.batch_size - 1, tree_size - 1)
entries = await self.get_entries(
session, log_info['url'], batch_start, batch_end
)
certs_to_insert = []
for i, entry in enumerate(entries):
parsed = self.parse_certificate(entry)
if parsed:
parsed['log_id'] = log_info['name']
parsed['log_index'] = batch_start + i
certs_to_insert.append(parsed)
if certs_to_insert:
self._batch_insert(cursor, certs_to_insert)
conn.commit()
print(f" 已處理: {batch_end}/{tree_size}")
cursor.close()
conn.close()
def _batch_insert(self, cursor, certs):
"""批次插入憑證"""
cert_values = [
(
c['log_id'], c['log_index'], c['timestamp'],
c['common_name'], c['issuer'], c['not_before'],
c['not_after'], c['serial_number'], c['sha256_fingerprint'],
psycopg2.Binary(c['raw_certificate'])
)
for c in certs
]
execute_values(
cursor,
"""
INSERT INTO certificates
(log_id, log_index, timestamp, common_name, issuer,
not_before, not_after, serial_number, sha256_fingerprint, raw_certificate)
VALUES %s
ON CONFLICT (sha256_fingerprint) DO NOTHING
RETURNING id, sha256_fingerprint
""",
cert_values
)
# 插入 SANs
inserted = {row[1]: row[0] for row in cursor.fetchall()}
san_values = []
for cert in certs:
cert_id = inserted.get(cert['sha256_fingerprint'])
if cert_id:
for san_type, san_value in cert['sans']:
san_values.append((cert_id, san_type, san_value))
if san_values:
execute_values(
cursor,
"""
INSERT INTO subject_alternative_names
(certificate_id, san_type, san_value)
VALUES %s
""",
san_values
)
# 執行收集
async def main():
db_config = {
'host': 'localhost',
'database': 'ct_monitor',
'user': 'ct_user',
'password': 'secret'
}
collector = CTLogCollector(db_config)
for log in collector.LOGS:
await collector.collect_log(log)
if __name__ == "__main__":
asyncio.run(main())
|