import re from django.conf import settings from django.http import HttpResponsePermanentRedirect from django.utils.deprecation import MiddlewareMixin class SecurityMiddleware(MiddlewareMixin): def __init__(self, get_response=None): self.sts_seconds = settings.SECURE_HSTS_SECONDS self.sts_include_subdomains = settings.SECURE_HSTS_INCLUDE_SUBDOMAINS self.sts_preload = settings.SECURE_HSTS_PRELOAD self.content_type_nosniff = settings.SECURE_CONTENT_TYPE_NOSNIFF self.xss_filter = settings.SECURE_BROWSER_XSS_FILTER self.redirect = settings.SECURE_SSL_REDIRECT self.redirect_host = settings.SECURE_SSL_HOST self.redirect_exempt = [re.compile(r) for r in settings.SECURE_REDIRECT_EXEMPT] self.referrer_policy = settings.SECURE_REFERRER_POLICY self.get_response = get_response def process_request(self, request): path = request.path.lstrip("/") if (self.redirect and not request.is_secure() and not any(pattern.search(path) for pattern in self.redirect_exempt)): host = self.redirect_host or request.get_host() return HttpResponsePermanentRedirect( "https://%s%s" % (host, request.get_full_path()) ) def process_response(self, request, response): if (self.sts_seconds and request.is_secure() and 'Strict-Transport-Security' not in response): sts_header = "max-age=%s" % self.sts_seconds if self.sts_include_subdomains: sts_header = sts_header + "; includeSubDomains" if self.sts_preload: sts_header = sts_header + "; preload" response['Strict-Transport-Security'] = sts_header if self.content_type_nosniff: response.setdefault('X-Content-Type-Options', 'nosniff') if self.xss_filter: response.setdefault('X-XSS-Protection', '1; mode=block') if self.referrer_policy: # Support a comma-separated string or iterable of values to allow # fallback. response.setdefault('Referrer-Policy', ','.join( [v.strip() for v in self.referrer_policy.split(',')] if isinstance(self.referrer_policy, str) else self.referrer_policy )) return response