From: Christian Heller Date: Wed, 25 Jan 2017 23:28:22 +0000 (+0100) Subject: Commit of work done so far. X-Git-Url: https://plomlompom.com/repos/?a=commitdiff_plain;ds=inline;h=07d3257fab88d61d28bee7202b8041576912900e;p=url-catcher Commit of work done so far. --- diff --git a/url_catcher.py b/url_catcher.py new file mode 100644 index 0000000..ac4b7a7 --- /dev/null +++ b/url_catcher.py @@ -0,0 +1,147 @@ +import bottle +import validators +import html +import os +import os.path +import time +import json +import smtplib +import email.mime.text +import tempfile +import shutil + +slowdown_reset = 60 * 60 * 24 +ips_dir = 'ips' +lists_dir = 'lists' +captchas_dir = 'captchas' +customizations_path = 'customizations.json' +messages = { + 'internalServerError': 'Internal server error.', + 'badPageName': 'Bad page name.', + 'wrongCaptcha': 'Wrong captcha.', + 'invalidURL': 'Invalid URL.', + 'recordedURL': 'Recorded URL: ', + 'pleaseWait': 'Too many attempts from your IP. Wait this many seconds: ', + 'mailSubject': '[url_catcher.py] New URL submitted', + 'mailBodyPage': 'New URL submitted for page: ', + 'mailBodyURL': 'URL is: ', +} +mail_config = { + 'from': 'foo@example.org', + 'to': 'bar@example.org', +} +if os.path.isfile(customizations_path): + customizations_file = open(customizations_path) + customizations = json.load(customizations_file) + customizations_file.close() + for key in customizations['translations']: + messages[key] = customizations['translations'][key] + for key in customizations['mailConfig']: + mail_config[key] = customizations['mailConfig'][key] + if 'slowdownReset' in customizations: + slowdown_reset = customizations['slowdownReset'] +os.makedirs(ips_dir, exist_ok=True) +os.makedirs(lists_dir, exist_ok=True) + + +def atomic_write(path, content, mode): + """Atomic write/append to file.""" + _, tmpPath = tempfile.mkstemp() + if 'a' == mode: + shutil.copy2(path, tmpPath) + f = open(tmpPath, mode) + f.write(content) + f.flush() + os.fsync(f.fileno()) + f.close() + os.rename(tmpPath, path) + + +def send_mail(page, url): + """Send mail telling about page URL list update.""" + body = messages['mailBodyPage'] + page + '\n' + messages['mailBodyURL'] + \ + url + msg = email.mime.text.MIMEText(body) + msg['Subject'] = messages['mailSubject'] + msg['From'] = mail_config['from'] + msg['To'] = mail_config['to'] + s = smtplib.SMTP('localhost') + s.send_message(msg) + s.quit() + + +@bottle.error(500) +def internal_error(error): + """If trouble, don't leak bottle.py's detailed error description.""" + return messages['internalServerError'] + + +@bottle.post('/uwsgi/post_link') +def post_link(): + """Record URL if all sane, send mail to curator.""" + + # Slow down repeat requests. + now = int(time.time()) + start_date = now + attempts = 0 + rewrite = True + ip = bottle.request.environ.get('REMOTE_ADDR') + ip_file_path = ips_dir + '/' + ip + try: + if os.path.isfile(ip_file_path): + ip_file = open(ip_file_path, 'r') + ip_data = ip_file.readlines() + ip_file.close() + old_start_date = int(ip_data[0]) + if old_start_date + slowdown_reset > now: + attempts = int(ip_data[1]) + start_date = old_start_date + wait_period = 2**attempts + if start_date + wait_period > now: + limit = min(start_date + wait_period, + start_date + slowdown_reset) + rewrite = False + remaining_wait = limit - now + msg = messages['pleaseWait'] + str(remaining_wait) + return bottle.HTTPResponse(msg, 429, + {'Retry-After': str(remaining_wait)}) + attempts += 1 + except: + raise + finally: + if rewrite: + atomic_write(ip_file_path, + str(start_date) + '\n' + str(attempts), 'w') + + # Derive page / page file name. + page = bottle.request.forms.get('page') + if '\0' in page or '/' in page or '.' in page or len(page.encode()) > 255: + return bottle.HTTPResponse(messages['badPageName'], 400) + + # Test captcha. + captcha_file = open(captchas_dir + '/' + page, 'r') + captcha_correct = captcha_file.readline().rstrip() + captcha_file.close() + captcha_input = bottle.request.forms.get('captcha') + if captcha_correct != captcha_input: + return bottle.HTTPResponse(messages['wrongCaptcha'], 400) + + # Record URL. + url = bottle.request.forms.get('url') + if not validators.url(url): + return bottle.HTTPResponse(messages['invalidURL'], 400) + send_mail(page, url) + atomic_write(lists_dir + '/' + page, url + '\n', 'a') + url_html = html.escape(url) + + # Response body. + return messages['recordedURL'] + url_html + + +bottle.debug(True) +# Non-uWSGI mode. +if __name__ == '__main__': + bottle.run(host='localhost', port=8080) +# uWSGI mode. +else: + app = application = bottle.default_app()