SSL Certificate error on SMTP Django DRF App [duplicate]
I have a Django DRF Backend that works just OK when using EMAIL_BACKEND = "django.core.mail.backends.locmem.EmailBackend".
But then, switching to SMTP powered by Google as:
EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"
EMAIL_HOST = "smtp.gmail.com"
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = config("GMAIL_APP_HOST_USER")
EMAIL_HOST_PASSWORD = config("GMAIL_APP_HOST_PASSWORD")
DEFAULT_FROM_EMAIL = "TestApp"
ACCOUNT_EMAIL_SUBJECT_PREFIX = ""
I get a [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: Basic Constraints of CA cert not marked critical
This is being tested in a Windows 11 PC.
Error details with Traceback:
Django Version: 5.2.6
Python Version: 3.13.7
Installed Applications:
['django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.sites',
'django.contrib.staticfiles',
'rest_framework',
'rest_framework.authtoken',
'rest_framework_simplejwt',
'allauth',
'allauth.account',
'allauth.headless',
'allauth.socialaccount',
'allauth.socialaccount.providers.google',
'dj_rest_auth',
'dj_rest_auth.registration',
'corsheaders',
'authentication.apps.AuthenticationConfig']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'allauth.account.middleware.AccountMiddleware',
'corsheaders.middleware.CorsMiddleware',
'django.middleware.common.CommonMiddleware']
Traceback (most recent call last):
File "C:\dev\myProject\venv\Lib\site-packages\django\core\handlers\exception.py", line 55, in inner
response = get_response(request)
^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\core\handlers\base.py", line 197, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\views\decorators\csrf.py", line 65, in _view_wrapper
return view_func(request, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\views\generic\base.py", line 105, in view
return self.dispatch(request, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\utils\decorators.py", line 48, in _wrapper
return bound_method(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\views\decorators\debug.py", line 143, in sensitive_post_parameters_wrapper
return view(request, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\dj_rest_auth\registration\views.py", line 47, in dispatch
return super().dispatch(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\rest_framework\views.py", line 515, in dispatch
response = self.handle_exception(exc)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\rest_framework\views.py", line 475, in handle_exception
self.raise_uncaught_exception(exc)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\rest_framework\views.py", line 486, in raise_uncaught_exception
raise exc
^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\rest_framework\views.py", line 512, in dispatch
response = handler(request, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\rest_framework\generics.py", line 194, in post
return self.create(request, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\dj_rest_auth\registration\views.py", line 68, in create
user = self.perform_create(serializer)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\dj_rest_auth\registration\views.py", line 92, in perform_create
complete_signup(
^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\utils.py", line 103, in complete_signup
return flows.signup.complete_signup(
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\internal\flows\signup.py", line 114, in complete_signup
return perform_login(request, login)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\internal\flows\login.py", line 93, in perform_login
return resume_login(request, login)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\internal\flows\login.py", line 102, in resume_login
response = ctrl.handle()
^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\stages.py", line 119, in handle
response, cont = stage.handle()
^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\stages.py", line 157, in handle
send_verification_email_at_login(self.request, login)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\internal\flows\email_verification.py", line 294, in send_verification_email_at_login
sent = send_verification_email_at_real_login(request, login)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\internal\flows\email_verification.py", line 308, in send_verification_email_at_real_login
return send_verification_email_to_address(request, address, signup=login.signup)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\internal\flows\email_verification.py", line 269, in send_verification_email_to_address
confirmation = address.send_confirmation(request, signup=signup)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\models.py", line 104, in send_confirmation
confirmation.send(request, signup=signup)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\models.py", line 133, in send
get_adapter().send_confirmation_mail(request, self, signup)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\adapter.py", line 676, in send_confirmation_mail
self.send_mail(email_template, emailconfirmation.email_address.email, ctx)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\allauth\account\adapter.py", line 211, in send_mail
msg.send()
^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\core\mail\message.py", line 307, in send
return self.get_connection(fail_silently).send_messages([self])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\core\mail\backends\smtp.py", line 128, in send_messages
new_conn_created = self.open()
^^^^^^^^^^^
File "C:\dev\myProject\venv\Lib\site-packages\django\core\mail\backends\smtp.py", line 93, in open
self.connection.starttls(context=self.ssl_context)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Python313\Lib\smtplib.py", line 779, in starttls
self.sock = context.wrap_socket(self.sock,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Python313\Lib\ssl.py", line 455, in wrap_socket
return self.sslsocket_class._create(
File "C:\Python313\Lib\ssl.py", line 1076, in _create
self.do_handshake()
^^^^^^^^^^^^^^^^^^^
File "C:\Python313\Lib\ssl.py", line 1372, in do_handshake
self._sslobj.do_handshake()
^^^^^^^^^^^^^^^^^^^^^^^^^^^
Exception Type: SSLCertVerificationError at /auth/register/
Exception Value: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: Basic Constraints of CA cert not marked critical (_ssl.c:1032)
Debug and Fix attempts: Trying to debug I wrote this in settings
import smtplib
import ssl
import certifi
print(certifi.where())
context = ssl.create_default_context(cafile=certifi.where())
print(context)
This prints:
C:\dev\myProject\venv\Lib\site-packages\certifi\cacert.pem
<ssl.SSLContext object at 0x0000024ACAE360D0>
And in line server.starttls(context=context) it raises ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self-signed certificate in certificate chain (_ssl.c:1032)
Also tried (but getting same error) changing email backend to a custom one as:
class EmailBackend(SMTPBackend):
@cached_property
def ssl_context(self):
if self.ssl_certfile or self.ssl_keyfile:
ssl_context = ssl.SSLContext(protocol=ssl.PROTOCOL_TLS_CLIENT)
# set verify location:
if hasattr(django_settings, 'CA_PATH') and django_settings.CA_PATH is not None:
ssl_context.load_verify_locations(capath=django_settings.CA_PATH)
ssl_context.load_cert_chain(self.ssl_certfile, self.ssl_keyfile)
return ssl_context
else:
ssl_context = ssl.create_default_context()
return ssl_context