601 lines
25 KiB
Python
601 lines
25 KiB
Python
# dnsrecon/providers/crtsh_provider.py
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import json
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import re
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from pathlib import Path
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from typing import List, Dict, Any, Set, Optional
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from urllib.parse import quote
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from datetime import datetime, timezone
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import requests
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from .base_provider import BaseProvider
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from core.provider_result import ProviderResult
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from utils.helpers import _is_valid_domain
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from core.logger import get_forensic_logger
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class CrtShProvider(BaseProvider):
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"""
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Provider for querying crt.sh certificate transparency database.
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FIXED: Now properly creates domain and CA nodes instead of large entities.
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REMOVED: All PostgreSQL logic to rely exclusively on the HTTP API for stability.
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Returns standardized ProviderResult objects with caching support.
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"""
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def __init__(self, name=None, session_config=None):
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"""Initialize CrtSh provider with session-specific configuration."""
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super().__init__(
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name="crtsh",
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rate_limit=60,
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timeout=15,
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session_config=session_config
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)
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self.base_url = "https://crt.sh/"
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self._stop_event = None
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# Initialize cache directory
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self.domain_cache_dir = Path('cache') / 'crtsh'
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self.domain_cache_dir.mkdir(parents=True, exist_ok=True)
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# Compile regex for date filtering for efficiency
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self.date_pattern = re.compile(r'^\d{4}-\d{2}-\d{2}[ T]\d{2}:\d{2}:\d{2}')
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def get_name(self) -> str:
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"""Return the provider name."""
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return "crtsh"
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def get_display_name(self) -> str:
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"""Return the provider display name for the UI."""
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return "crt.sh"
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def requires_api_key(self) -> bool:
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"""Return True if the provider requires an API key."""
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return False
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def get_eligibility(self) -> Dict[str, bool]:
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"""Return a dictionary indicating if the provider can query domains and/or IPs."""
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return {'domains': True, 'ips': False}
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def is_available(self) -> bool:
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"""Check if the provider is configured to be used."""
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return True
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def _get_cache_file_path(self, domain: str) -> Path:
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"""Generate cache file path for a domain."""
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safe_domain = domain.replace('.', '_').replace('/', '_').replace('\\', '_')
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return self.domain_cache_dir / f"{safe_domain}.json"
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def _get_cache_status(self, cache_file_path: Path) -> str:
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"""
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Check cache status for a domain.
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Returns: 'not_found', 'fresh', or 'stale'
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"""
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if not cache_file_path.exists():
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return "not_found"
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try:
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with open(cache_file_path, 'r') as f:
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cache_data = json.load(f)
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last_query_str = cache_data.get("last_upstream_query")
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if not last_query_str:
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return "stale"
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last_query = datetime.fromisoformat(last_query_str.replace('Z', '+00:00'))
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hours_since_query = (datetime.now(timezone.utc) - last_query).total_seconds() / 3600
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cache_timeout = self.config.cache_timeout_hours
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if hours_since_query < cache_timeout:
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return "fresh"
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else:
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return "stale"
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except (json.JSONDecodeError, ValueError, KeyError) as e:
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self.logger.logger.warning(f"Invalid cache file format for {cache_file_path}: {e}")
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return "stale"
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def query_domain(self, domain: str) -> ProviderResult:
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"""
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Query crt.sh for certificates containing the domain via HTTP API.
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Args:
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domain: Domain to investigate
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Returns:
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ProviderResult containing discovered relationships and attributes
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"""
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if not _is_valid_domain(domain):
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return ProviderResult()
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if self._stop_event and self._stop_event.is_set():
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return ProviderResult()
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cache_file = self._get_cache_file_path(domain)
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cache_status = self._get_cache_status(cache_file)
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result = ProviderResult()
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try:
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if cache_status == "fresh":
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result = self._load_from_cache(cache_file)
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self.logger.logger.info(f"Using fresh cached crt.sh data for {domain}")
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return result
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# For "stale" or "not_found", we must query the API.
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new_raw_certs = self._query_crtsh_api(domain)
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if self._stop_event and self._stop_event.is_set():
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return ProviderResult()
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# Combine with old data if cache is stale
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if cache_status == "stale":
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old_raw_certs = self._load_raw_data_from_cache(cache_file)
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combined_certs = old_raw_certs + new_raw_certs
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# Deduplicate the combined list
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seen_ids = set()
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unique_certs = []
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for cert in combined_certs:
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cert_id = cert.get('id')
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if cert_id not in seen_ids:
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unique_certs.append(cert)
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seen_ids.add(cert_id)
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raw_certificates_to_process = unique_certs
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self.logger.logger.info(f"Refreshed and merged cache for {domain}. Total unique certs: {len(raw_certificates_to_process)}")
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else: # "not_found"
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raw_certificates_to_process = new_raw_certs
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result = self._process_certificates_to_result_fixed(domain, raw_certificates_to_process)
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self.logger.logger.info(f"Created fresh result for {domain} ({result.get_relationship_count()} relationships)")
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# Save the new result and the raw data to the cache
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self._save_result_to_cache(cache_file, result, raw_certificates_to_process, domain)
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except requests.exceptions.RequestException as e:
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self.logger.logger.error(f"Upstream query failed for {domain}: {e}")
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# **BUG FIX:** Always re-raise the exception. This signals a failure to the
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# scanner, allowing its retry logic to handle the transient error.
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raise e
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return result
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def query_ip(self, ip: str) -> ProviderResult:
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"""
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crt.sh does not support IP-based certificate queries effectively via its API.
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Args:
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ip: IP address to investigate
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Returns:
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Empty ProviderResult
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"""
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return ProviderResult()
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def _load_from_cache(self, cache_file_path: Path) -> ProviderResult:
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"""Load processed crt.sh data from a cache file."""
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try:
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with open(cache_file_path, 'r') as f:
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cache_content = json.load(f)
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result = ProviderResult()
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# Reconstruct relationships
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for rel_data in cache_content.get("relationships", []):
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result.add_relationship(
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source_node=rel_data["source_node"],
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target_node=rel_data["target_node"],
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relationship_type=rel_data["relationship_type"],
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provider=rel_data["provider"],
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confidence=rel_data["confidence"],
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raw_data=rel_data.get("raw_data", {})
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)
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# Reconstruct attributes
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for attr_data in cache_content.get("attributes", []):
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result.add_attribute(
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target_node=attr_data["target_node"],
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name=attr_data["name"],
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value=attr_data["value"],
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attr_type=attr_data["type"],
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provider=attr_data["provider"],
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confidence=attr_data["confidence"],
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metadata=attr_data.get("metadata", {})
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)
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return result
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except (json.JSONDecodeError, FileNotFoundError, KeyError) as e:
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self.logger.logger.error(f"Failed to load cached certificates from {cache_file_path}: {e}")
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return ProviderResult()
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def _load_raw_data_from_cache(self, cache_file_path: Path) -> List[Dict[str, Any]]:
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"""Load only the raw certificate data from a cache file."""
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try:
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with open(cache_file_path, 'r') as f:
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cache_content = json.load(f)
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return cache_content.get("raw_certificates", [])
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except (json.JSONDecodeError, FileNotFoundError):
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return []
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def _save_result_to_cache(self, cache_file_path: Path, result: ProviderResult, raw_certificates: List[Dict[str, Any]], domain: str) -> None:
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"""Save processed crt.sh result and raw data to a cache file."""
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try:
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cache_data = {
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"domain": domain,
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"last_upstream_query": datetime.now(timezone.utc).isoformat(),
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"raw_certificates": raw_certificates, # Store the raw data for deduplication
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"relationships": [
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{
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"source_node": rel.source_node,
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"target_node": rel.target_node,
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"relationship_type": rel.relationship_type,
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"confidence": rel.confidence,
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"provider": rel.provider,
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"raw_data": rel.raw_data
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} for rel in result.relationships
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],
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"attributes": [
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{
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"target_node": attr.target_node,
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"name": attr.name,
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"value": attr.value,
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"type": attr.type,
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"provider": attr.provider,
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"confidence": attr.confidence,
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"metadata": attr.metadata
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} for attr in result.attributes
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]
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}
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cache_file_path.parent.mkdir(parents=True, exist_ok=True)
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with open(cache_file_path, 'w') as f:
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json.dump(cache_data, f, separators=(',', ':'), default=str)
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except Exception as e:
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self.logger.logger.warning(f"Failed to save cache file for {domain}: {e}")
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def _query_crtsh_api(self, domain: str) -> List[Dict[str, Any]]:
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"""Query crt.sh API for raw certificate data."""
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url = f"{self.base_url}?q={quote(domain)}&output=json"
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response = self.make_request(url, target_indicator=domain)
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if not response or response.status_code != 200:
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raise requests.exceptions.RequestException(f"crt.sh API returned status {response.status_code if response else 'None'}")
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try:
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certificates = response.json()
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except json.JSONDecodeError:
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self.logger.logger.error(f"crt.sh returned invalid JSON for {domain}")
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return []
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if not certificates:
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return []
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return certificates
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def _process_certificates_to_result_fixed(self, query_domain: str, certificates: List[Dict[str, Any]]) -> ProviderResult:
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"""
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Process certificates to create proper domain and CA nodes.
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"""
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result = ProviderResult()
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if self._stop_event and self._stop_event.is_set():
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self.logger.logger.info(f"CrtSh processing cancelled before processing for domain: {query_domain}")
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return result
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incompleteness_warning = self._check_for_incomplete_data(query_domain, certificates)
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if incompleteness_warning:
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result.add_attribute(
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target_node=query_domain,
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name="crtsh_data_warning",
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value=incompleteness_warning,
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attr_type='metadata',
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provider=self.name,
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confidence=1.0
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)
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all_discovered_domains = set()
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processed_issuers = set()
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for i, cert_data in enumerate(certificates):
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# Check for stop event inside the loop to make it responsive.
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if i % 10 == 0 and self._stop_event and self._stop_event.is_set():
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self.logger.logger.info(f"CrtSh processing cancelled at certificate {i} for domain: {query_domain}")
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break
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# Extract all domains from this certificate
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cert_domains = self._extract_domains_from_certificate(cert_data)
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all_discovered_domains.update(cert_domains)
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# Create CA nodes for certificate issuers
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issuer_name = self._parse_issuer_organization(cert_data.get('issuer_name', ''))
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if issuer_name and issuer_name not in processed_issuers:
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result.add_relationship(
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source_node=query_domain,
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target_node=issuer_name,
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relationship_type='crtsh_cert_issuer',
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provider=self.name,
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confidence=0.95,
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raw_data={'issuer_dn': cert_data.get('issuer_name', '')}
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)
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processed_issuers.add(issuer_name)
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# Add certificate metadata to each domain in this certificate
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cert_metadata = self._extract_certificate_metadata(cert_data)
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for cert_domain in cert_domains:
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if not _is_valid_domain(cert_domain):
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continue
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for key, value in cert_metadata.items():
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if value is not None:
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result.add_attribute(
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target_node=cert_domain,
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name=f"cert_{key}",
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value=value,
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attr_type='certificate_data',
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provider=self.name,
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confidence=0.9,
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metadata={'certificate_id': cert_data.get('id')}
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)
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# Check for stop event before creating final relationships.
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if self._stop_event and self._stop_event.is_set():
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self.logger.logger.info(f"CrtSh query cancelled before relationship creation for domain: {query_domain}")
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return result
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# Create selective relationships to avoid large entities
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for discovered_domain in all_discovered_domains:
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if discovered_domain == query_domain:
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continue
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if not _is_valid_domain(discovered_domain):
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continue
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if self._should_create_relationship(query_domain, discovered_domain):
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confidence = self._calculate_domain_relationship_confidence(
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query_domain, discovered_domain, [], all_discovered_domains
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)
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result.add_relationship(
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source_node=query_domain,
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target_node=discovered_domain,
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relationship_type='crtsh_san_certificate',
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provider=self.name,
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confidence=confidence,
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raw_data={'relationship_type': 'certificate_discovery'}
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)
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self.log_relationship_discovery(
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source_node=query_domain,
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target_node=discovered_domain,
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relationship_type='crtsh_san_certificate',
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confidence_score=confidence,
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raw_data={'relationship_type': 'certificate_discovery'},
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discovery_method="certificate_transparency_analysis"
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)
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self.logger.logger.info(f"CrtSh processing completed for {query_domain}: {len(all_discovered_domains)} domains, {result.get_relationship_count()} relationships")
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return result
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def _should_create_relationship(self, source_domain: str, target_domain: str) -> bool:
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"""
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Determine if a relationship should be created between two domains.
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"""
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if target_domain.endswith(f'.{source_domain}') or source_domain.endswith(f'.{target_domain}'):
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return True
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source_parts = source_domain.split('.')
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target_parts = target_domain.split('.')
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if len(source_parts) >= 2 and len(target_parts) >= 2:
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source_root = '.'.join(source_parts[-2:])
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target_root = '.'.join(target_parts[-2:])
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return source_root == target_root
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return False
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def _extract_certificate_metadata(self, cert_data: Dict[str, Any]) -> Dict[str, Any]:
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"""Extract comprehensive metadata from certificate data."""
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raw_issuer_name = cert_data.get('issuer_name', '')
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parsed_issuer_name = self._parse_issuer_organization(raw_issuer_name)
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metadata = {
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'certificate_id': cert_data.get('id'),
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'serial_number': cert_data.get('serial_number'),
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'issuer_name': parsed_issuer_name,
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'issuer_ca_id': cert_data.get('issuer_ca_id'),
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'common_name': cert_data.get('common_name'),
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'not_before': cert_data.get('not_before'),
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'not_after': cert_data.get('not_after'),
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'entry_timestamp': cert_data.get('entry_timestamp'),
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'source': 'crtsh'
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}
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try:
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if metadata['not_before'] and metadata['not_after']:
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not_before = self._parse_certificate_date(metadata['not_before'])
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not_after = self._parse_certificate_date(metadata['not_after'])
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metadata['validity_period_days'] = (not_after - not_before).days
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metadata['is_currently_valid'] = self._is_cert_valid(cert_data)
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metadata['expires_soon'] = (not_after - datetime.now(timezone.utc)).days <= 30
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metadata['not_before'] = not_before.isoformat()
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metadata['not_after'] = not_after.isoformat()
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except Exception as e:
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self.logger.logger.debug(f"Error computing certificate metadata: {e}")
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metadata['is_currently_valid'] = False
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metadata['expires_soon'] = False
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return metadata
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def _parse_issuer_organization(self, issuer_dn: str) -> str:
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"""Parse the issuer Distinguished Name to extract just the organization name."""
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if not issuer_dn:
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return issuer_dn
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try:
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components = [comp.strip() for comp in issuer_dn.split(',')]
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for component in components:
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if component.startswith('O='):
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org_name = component[2:].strip()
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if org_name.startswith('"') and org_name.endswith('"'):
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org_name = org_name[1:-1]
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return org_name
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return issuer_dn
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except Exception as e:
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self.logger.logger.debug(f"Failed to parse issuer DN '{issuer_dn}': {e}")
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return issuer_dn
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def _parse_certificate_date(self, date_string: str) -> datetime:
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"""Parse certificate date from crt.sh format."""
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if not date_string:
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raise ValueError("Empty date string")
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try:
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if isinstance(date_string, datetime):
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return date_string.replace(tzinfo=timezone.utc)
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if date_string.endswith('Z'):
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return datetime.fromisoformat(date_string[:-1]).replace(tzinfo=timezone.utc)
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elif '+' in date_string or date_string.endswith('UTC'):
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date_string = date_string.replace('UTC', '').strip()
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if '+' in date_string:
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date_string = date_string.split('+')[0]
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return datetime.fromisoformat(date_string).replace(tzinfo=timezone.utc)
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else:
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return datetime.fromisoformat(date_string).replace(tzinfo=timezone.utc)
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except Exception as e:
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try:
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return datetime.strptime(date_string[:19], "%Y-%m-%dT%H:%M:%S").replace(tzinfo=timezone.utc)
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except Exception:
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raise ValueError(f"Unable to parse date: {date_string}") from e
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def _is_cert_valid(self, cert_data: Dict[str, Any]) -> bool:
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"""Check if a certificate is currently valid based on its expiry date."""
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try:
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not_after_str = cert_data.get('not_after')
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if not not_after_str:
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return False
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not_after_date = self._parse_certificate_date(not_after_str)
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not_before_str = cert_data.get('not_before')
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now = datetime.now(timezone.utc)
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is_not_expired = not_after_date > now
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if not_before_str:
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not_before_date = self._parse_certificate_date(not_before_str)
|
|
is_not_before_valid = not_before_date <= now
|
|
return is_not_expired and is_not_before_valid
|
|
|
|
return is_not_expired
|
|
|
|
except Exception as e:
|
|
return False
|
|
|
|
def _extract_domains_from_certificate(self, cert_data: Dict[str, Any]) -> Set[str]:
|
|
"""Extract all domains from certificate data."""
|
|
domains = set()
|
|
|
|
common_name = cert_data.get('common_name', '')
|
|
if common_name:
|
|
cleaned_cn = self._clean_domain_name(common_name)
|
|
if cleaned_cn:
|
|
domains.update(cleaned_cn)
|
|
|
|
name_value = cert_data.get('name_value', '')
|
|
if name_value:
|
|
for line in name_value.split('\n'):
|
|
cleaned_domains = self._clean_domain_name(line.strip())
|
|
if cleaned_domains:
|
|
domains.update(cleaned_domains)
|
|
|
|
return domains
|
|
|
|
def _clean_domain_name(self, domain_name: str) -> List[str]:
|
|
"""Clean and normalize domain name from certificate data."""
|
|
if not domain_name:
|
|
return []
|
|
|
|
domain = domain_name.strip().lower()
|
|
|
|
if domain.startswith(('http://', 'https://')):
|
|
domain = domain.split('://', 1)[1]
|
|
|
|
if '/' in domain:
|
|
domain = domain.split('/', 1)[0]
|
|
|
|
if ':' in domain and not domain.count(':') > 1:
|
|
domain = domain.split(':', 1)[0]
|
|
|
|
cleaned_domains = []
|
|
if domain.startswith('*.'):
|
|
cleaned_domains.append(domain)
|
|
cleaned_domains.append(domain[2:])
|
|
else:
|
|
cleaned_domains.append(domain)
|
|
|
|
final_domains = []
|
|
for d in cleaned_domains:
|
|
d = re.sub(r'[^\w\-\.]', '', d)
|
|
if d and not d.startswith(('.', '-')) and not d.endswith(('.', '-')):
|
|
final_domains.append(d)
|
|
|
|
return [d for d in final_domains if _is_valid_domain(d)]
|
|
|
|
def _calculate_domain_relationship_confidence(self, domain1: str, domain2: str,
|
|
shared_certificates: List[Dict[str, Any]],
|
|
all_discovered_domains: Set[str]) -> float:
|
|
"""Calculate confidence score for domain relationship based on various factors."""
|
|
base_confidence = 0.9
|
|
|
|
relationship_context = self._determine_relationship_context(domain2, domain1)
|
|
|
|
if relationship_context == 'exact_match':
|
|
context_bonus = 0.0
|
|
elif relationship_context == 'subdomain':
|
|
context_bonus = 0.1
|
|
elif relationship_context == 'parent_domain':
|
|
context_bonus = 0.05
|
|
else:
|
|
context_bonus = 0.0
|
|
|
|
final_confidence = base_confidence + context_bonus
|
|
return max(0.1, min(1.0, final_confidence))
|
|
|
|
def _determine_relationship_context(self, cert_domain: str, query_domain: str) -> str:
|
|
"""Determine the context of the relationship between certificate domain and query domain."""
|
|
if cert_domain == query_domain:
|
|
return 'exact_match'
|
|
elif cert_domain.endswith(f'.{query_domain}'):
|
|
return 'subdomain'
|
|
elif query_domain.endswith(f'.{cert_domain}'):
|
|
return 'parent_domain'
|
|
else:
|
|
return 'related_domain'
|
|
|
|
def _check_for_incomplete_data(self, domain: str, certificates: List[Dict[str, Any]]) -> Optional[str]:
|
|
"""
|
|
Analyzes the certificate list to heuristically detect if the data from crt.sh is incomplete.
|
|
"""
|
|
cert_count = len(certificates)
|
|
|
|
if cert_count >= 10000:
|
|
return f"Result likely truncated; received {cert_count} certificates, which may be the maximum limit."
|
|
|
|
if cert_count > 1000:
|
|
latest_expiry = None
|
|
for cert in certificates:
|
|
try:
|
|
not_after = self._parse_certificate_date(cert.get('not_after'))
|
|
if latest_expiry is None or not_after > latest_expiry:
|
|
latest_expiry = not_after
|
|
except (ValueError, TypeError):
|
|
continue
|
|
|
|
if latest_expiry and (datetime.now(timezone.utc) - latest_expiry).days > 365:
|
|
return f"Incomplete data suspected: The latest certificate expired more than a year ago ({latest_expiry.strftime('%Y-%m-%d')})."
|
|
|
|
return None |