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#!/usr/bin/env python
import argparse
from collections import deque
import datetime
import fcntl
import hashlib
import importlib
import logging
import os
import sys
import time
from flask import Flask, current_app
import requests
FILE_DELAY = 15
SCAN_DELAY = 60
LOGGING_CONFIG = {
'level': logging.INFO,
'style': '{',
'format': '{asctime} [{levelname}] {message}',
}
logging.basicConfig(**LOGGING_CONFIG)
logger = logging.getLogger('fbin-scanner')
parser = argparse.ArgumentParser()
parser.add_argument('--lock-file', default='/tmp/fbin-scanner.lock')
parser.add_argument('-c', '--config-file', default='fbin/fbin.cfg')
parser.add_argument('-p', '--poll', action='store_true')
args = parser.parse_args()
lock_file = open(args.lock_file, 'w')
try:
fcntl.flock(lock_file, fcntl.LOCK_EX | fcntl.LOCK_NB)
except OSError:
logger.error('Cannot acquire lock; another process is running')
sys.exit(1)
def get_report(dbfile, digest, fileobj):
logger.info('Fetching file report')
params = {
'apikey': app.config['VIRUSTOTAL_API_KEY'],
'resource': digest,
}
response = requests.get('https://www.virustotal.com/vtapi/v2/file/report', params=params)
response.raise_for_status()
data = response.json()
# Report found
if data['response_code'] == 1:
return data
scan_id = None
# No report, submit file for scan
if data['response_code'] == 0:
logger.info('No report, submitting file')
response = requests.post('https://www.virustotal.com/vtapi/v2/file/scan',
params={'apikey': app.config['VIRUSTOTAL_API_KEY']},
files={'file': (dbfile.filename, fileobj)},
)
response.raise_for_status()
data = response.json()
if data['response_code'] != 1:
logger.error('Scan failed')
return
scan_id = data['scan_id']
logger.info('File submitted with scan_id %s, waiting for scan report', scan_id)
params['resource'] = scan_id
# File was submitted or is queued for scan
if scan_id or data['response_code'] == -2:
# TODO: consider adding a timeout here
while True:
time.sleep(SCAN_DELAY)
response = requests.get('https://www.virustotal.com/vtapi/v2/file/report', params=params)
response.raise_for_status()
data = response.json()
if data['response_code'] == 1:
return data
logger.warning('Unknown response: %s', data)
def process_files(filters=None):
storage = importlib.import_module(current_app.config.get('STORAGE_MODULE', 'fbin.file_storage.filesystem')) \
.Storage(current_app)
files = deque(db.session.query(File).filter(*filters).all())
if not files:
return False
while len(files):
dbfile = files.pop()
if not dbfile.size:
logger.info('Ignoring file %s/%s due to unknown size', dbfile.filename, dbfile.hash)
continue
if dbfile.size > 32 * 10**6:
logger.info('Ignoring file %s/%s due to size (%s)', dbfile.filename, dbfile.hash, dbfile.formatted_size)
continue
logger.info('Checking file %s/%s (%s)', dbfile.filename, dbfile.hash, dbfile.formatted_size)
try:
with storage.temp_file(dbfile) as f:
h = hashlib.sha256()
chunk = f.read(2**10 * 16)
while chunk:
h.update(chunk)
chunk = f.read(2**10 * 16)
f.seek(0)
digest = h.hexdigest()
logger.info('SHA-256: %s', digest)
report = get_report(dbfile, digest, f)
except FileNotFoundError:
logger.error('Skipping non-existent file %s/%s', dbfile.filename, dbfile.hash)
dbfile.scanned = True
db.session.add(dbfile)
db.session.commit()
continue
except Exception:
logger.exception('Failed to get report for %s/%s', dbfile.filename, dbfile.hash)
# Most likely an error from virustotal, so just break here and retry later.
break
dbfile.scanned = True
if report and any(r.get('detected', False) for r in report['scans'].values()):
logger.warning('Positive match')
dbfile.blocked_reason = report
else:
logger.info('No match')
db.session.add(dbfile)
db.session.commit()
time.sleep(FILE_DELAY)
logger.info('No more files to scan')
return True
def poll_loop():
now = datetime.datetime(1970, 1, 1)
next_now = datetime.datetime.utcnow()
while True:
try:
process_files([File.scanned == False, File.date >= now]) # noqa: E712
now = next_now
next_now = datetime.datetime.utcnow()
except Exception:
# On errors, log the exception and retry. Don't update 'now' so that we will retry with the same files.
# This tends to happen eg. when we process a file but it's been deleted when we try to update it.
logger.exception('Error while processing files')
db.session.rollback()
time.sleep(60)
def main():
if args.poll:
poll_loop()
else:
if not process_files([File.scanned == False]): # noqa: E712
logger.info('No files to scan were found')
app = Flask('scanner')
with app.app_context():
app.config.from_pyfile(args.config_file)
from fbin.db import db, File
db.init_app(app)
config = app.config
main()
fcntl.flock(lock_file, fcntl.LOCK_UN)
lock_file.close()
os.unlink(args.lock_file)
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