django/core/checks/security/base.py
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from .. import Error, Tags, Warning, register
CROSS_ORIGIN_OPENER_POLICY_VALUES = {
"same-origin",
"same-origin-allow-popups",
"unsafe-none",
}
REFERRER_POLICY_VALUES = {
"no-referrer",
"no-referrer-when-downgrade",
"origin",
"origin-when-cross-origin",
"same-origin",
"strict-origin",
"strict-origin-when-cross-origin",
"unsafe-url",
}
SECRET_KEY_INSECURE_PREFIX = "django-insecure-"
SECRET_KEY_MIN_LENGTH = 50
SECRET_KEY_MIN_UNIQUE_CHARACTERS = 5
SECRET_KEY_WARNING_MSG = (
f"Your %s has less than {SECRET_KEY_MIN_LENGTH} characters, less than "
f"{SECRET_KEY_MIN_UNIQUE_CHARACTERS} unique characters, or it's prefixed "
f"with '{SECRET_KEY_INSECURE_PREFIX}' indicating that it was generated "
f"automatically by Django. Please generate a long and random value, "
f"otherwise many of Django's security-critical features will be "
f"vulnerable to attack."
)
W001 = Warning(
"You do not have 'django.middleware.security.SecurityMiddleware' "
"in your MIDDLEWARE so the SECURE_HSTS_SECONDS, "
"SECURE_CONTENT_TYPE_NOSNIFF, SECURE_REFERRER_POLICY, "
"SECURE_CROSS_ORIGIN_OPENER_POLICY, and SECURE_SSL_REDIRECT settings will "
"have no effect.",
id="security.W001",
)
W002 = Warning(
"You do not have "
"'django.middleware.clickjacking.XFrameOptionsMiddleware' in your "
"MIDDLEWARE, so your pages will not be served with an "
"'x-frame-options' header. Unless there is a good reason for your "
"site to be served in a frame, you should consider enabling this "
"header to help prevent clickjacking attacks.",
id="security.W002",
)
W004 = Warning(
"You have not set a value for the SECURE_HSTS_SECONDS setting. "
"If your entire site is served only over SSL, you may want to consider "
"setting a value and enabling HTTP Strict Transport Security. "
"Be sure to read the documentation first; enabling HSTS carelessly "
"can cause serious, irreversible problems.",
id="security.W004",
)
W005 = Warning(
"You have not set the SECURE_HSTS_INCLUDE_SUBDOMAINS setting to True. "
"Without this, your site is potentially vulnerable to attack "
"via an insecure connection to a subdomain. Only set this to True if "
"you are certain that all subdomains of your domain should be served "
"exclusively via SSL.",
id="security.W005",
)
W006 = Warning(
"Your SECURE_CONTENT_TYPE_NOSNIFF setting is not set to True, "
"so your pages will not be served with an "
"'X-Content-Type-Options: nosniff' header. "
"You should consider enabling this header to prevent the "
"browser from identifying content types incorrectly.",
id="security.W006",
)
W008 = Warning(
"Your SECURE_SSL_REDIRECT setting is not set to True. "
"Unless your site should be available over both SSL and non-SSL "
"connections, you may want to either set this setting True "
"or configure a load balancer or reverse-proxy server "
"to redirect all connections to HTTPS.",
id="security.W008",
)
W009 = Warning(
SECRET_KEY_WARNING_MSG % "SECRET_KEY",
id="security.W009",
)
W018 = Warning(
"You should not have DEBUG set to True in deployment.",
id="security.W018",
)
W019 = Warning(
"You have "
"'django.middleware.clickjacking.XFrameOptionsMiddleware' in your "
"MIDDLEWARE, but X_FRAME_OPTIONS is not set to 'DENY'. "
"Unless there is a good reason for your site to serve other parts of "
"itself in a frame, you should change it to 'DENY'.",
id="security.W019",
)
W020 = Warning(
"ALLOWED_HOSTS must not be empty in deployment.",
id="security.W020",
)
W021 = Warning(
"You have not set the SECURE_HSTS_PRELOAD setting to True. Without this, "
"your site cannot be submitted to the browser preload list.",
id="security.W021",
)
W022 = Warning(
"You have not set the SECURE_REFERRER_POLICY setting. Without this, your "
"site will not send a Referrer-Policy header. You should consider "
"enabling this header to protect user privacy.",
id="security.W022",
)
E023 = Error(
"You have set the SECURE_REFERRER_POLICY setting to an invalid value.",
hint="Valid values are: {}.".format(", ".join(sorted(REFERRER_POLICY_VALUES))),
id="security.E023",
)
E024 = Error(
"You have set the SECURE_CROSS_ORIGIN_OPENER_POLICY setting to an invalid "
"value.",
hint="Valid values are: {}.".format(
", ".join(sorted(CROSS_ORIGIN_OPENER_POLICY_VALUES)),
),
id="security.E024",
)
W025 = Warning(SECRET_KEY_WARNING_MSG, id="security.W025")
def _security_middleware():
return "django.middleware.security.SecurityMiddleware" in settings.MIDDLEWARE
def _xframe_middleware():
return (
"django.middleware.clickjacking.XFrameOptionsMiddleware" in settings.MIDDLEWARE
)
@register(Tags.security, deploy=True)
def check_security_middleware(app_configs, **kwargs):
passed_check = _security_middleware()
return [] if passed_check else [W001]
@register(Tags.security, deploy=True)
def check_xframe_options_middleware(app_configs, **kwargs):
passed_check = _xframe_middleware()
return [] if passed_check else [W002]
@register(Tags.security, deploy=True)
def check_sts(app_configs, **kwargs):
passed_check = not _security_middleware() or settings.SECURE_HSTS_SECONDS
return [] if passed_check else [W004]
@register(Tags.security, deploy=True)
def check_sts_include_subdomains(app_configs, **kwargs):
passed_check = (
not _security_middleware()
or not settings.SECURE_HSTS_SECONDS
or settings.SECURE_HSTS_INCLUDE_SUBDOMAINS is True
)
return [] if passed_check else [W005]
@register(Tags.security, deploy=True)
def check_sts_preload(app_configs, **kwargs):
passed_check = (
not _security_middleware()
or not settings.SECURE_HSTS_SECONDS
or settings.SECURE_HSTS_PRELOAD is True
)
return [] if passed_check else [W021]
@register(Tags.security, deploy=True)
def check_content_type_nosniff(app_configs, **kwargs):
passed_check = (
not _security_middleware() or settings.SECURE_CONTENT_TYPE_NOSNIFF is True
)
return [] if passed_check else [W006]
@register(Tags.security, deploy=True)
def check_ssl_redirect(app_configs, **kwargs):
passed_check = not _security_middleware() or settings.SECURE_SSL_REDIRECT is True
return [] if passed_check else [W008]
def _check_secret_key(secret_key):
return (
len(set(secret_key)) >= SECRET_KEY_MIN_UNIQUE_CHARACTERS
and len(secret_key) >= SECRET_KEY_MIN_LENGTH
and not secret_key.startswith(SECRET_KEY_INSECURE_PREFIX)
)
@register(Tags.security, deploy=True)
def check_secret_key(app_configs, **kwargs):
try:
secret_key = settings.SECRET_KEY
except (ImproperlyConfigured, AttributeError):
passed_check = False
else:
passed_check = _check_secret_key(secret_key)
return [] if passed_check else [W009]
@register(Tags.security, deploy=True)
def check_secret_key_fallbacks(app_configs, **kwargs):
warnings = []
try:
fallbacks = settings.SECRET_KEY_FALLBACKS
except (ImproperlyConfigured, AttributeError):
warnings.append(Warning(W025.msg % "SECRET_KEY_FALLBACKS", id=W025.id))
else:
for index, key in enumerate(fallbacks):
if not _check_secret_key(key):
warnings.append(
Warning(W025.msg % f"SECRET_KEY_FALLBACKS[{index}]", id=W025.id)
)
return warnings
@register(Tags.security, deploy=True)
def check_debug(app_configs, **kwargs):
passed_check = not settings.DEBUG
return [] if passed_check else [W018]
@register(Tags.security, deploy=True)
def check_xframe_deny(app_configs, **kwargs):
passed_check = not _xframe_middleware() or settings.X_FRAME_OPTIONS == "DENY"
return [] if passed_check else [W019]
@register(Tags.security, deploy=True)
def check_allowed_hosts(app_configs, **kwargs):
return [] if settings.ALLOWED_HOSTS else [W020]
@register(Tags.security, deploy=True)
def check_referrer_policy(app_configs, **kwargs):
if _security_middleware():
if settings.SECURE_REFERRER_POLICY is None:
return [W022]
# Support a comma-separated string or iterable of values to allow fallback.
if isinstance(settings.SECURE_REFERRER_POLICY, str):
values = {v.strip() for v in settings.SECURE_REFERRER_POLICY.split(",")}
else:
values = set(settings.SECURE_REFERRER_POLICY)
if not values <= REFERRER_POLICY_VALUES:
return [E023]
return []
@register(Tags.security, deploy=True)
def check_cross_origin_opener_policy(app_configs, **kwargs):
if (
_security_middleware()
and settings.SECURE_CROSS_ORIGIN_OPENER_POLICY is not None
and settings.SECURE_CROSS_ORIGIN_OPENER_POLICY
not in CROSS_ORIGIN_OPENER_POLICY_VALUES
):
return [E024]
return []