Use normalized email address for new users

Not check email deliverability for now to allow air-gapped usage or
authenticated/multi-user setups with admin managed otp

Closes #1069

src/khoj/database/adapters/__init__.py

@@ -72,6 +72,7 @@ from khoj.utils.helpers import (
     generate_random_name,
     in_debug_mode,
     is_none_or_empty,
+    normalize_email,
     timer,
 )
 
@@ -231,17 +232,22 @@ async def acreate_user_by_phone_number(phone_number: str) -> KhojUser:
     return user
 
 
-async def aget_or_create_user_by_email(email: str) -> tuple[KhojUser, bool]:
+async def aget_or_create_user_by_email(input_email: str) -> tuple[KhojUser, bool]:
+    email, is_valid_email = normalize_email(input_email)
+    is_existing_user = await KhojUser.objects.filter(email=email).aexists()
+    # Validate email address of new users
+    if not is_existing_user and not is_valid_email:
+        logger.error(f"Account creation failed. Invalid email address: {email}")
+        return None, False
+
     user, is_new = await KhojUser.objects.filter(email=email).aupdate_or_create(
         defaults={"username": email, "email": email}
     )
-    await user.asave()
 
-    if user:
-        # Generate a secure 6-digit numeric code
-        user.email_verification_code = f"{secrets.randbelow(1000000):06}"
-        user.email_verification_code_expiry = datetime.now(tz=timezone.utc) + timedelta(minutes=5)
-        await user.asave()
+    # Generate a secure 6-digit numeric code
+    user.email_verification_code = f"{secrets.randbelow(1000000):06}"
+    user.email_verification_code_expiry = datetime.now(tz=timezone.utc) + timedelta(minutes=5)
+    await user.asave()
 
     user_subscription = await Subscription.objects.filter(user=user).afirst()
     if not user_subscription:
@@ -270,10 +276,15 @@ async def astart_trial_subscription(user: KhojUser) -> Subscription:
 
 
 async def aget_user_validated_by_email_verification_code(code: str, email: str) -> tuple[Optional[KhojUser], bool]:
-    user = await KhojUser.objects.filter(email_verification_code=code, email=email).afirst()
+    # Normalize the email address
+    normalized_email, _ = normalize_email(email)
+
+    # Check if verification code exists for the user
+    user = await KhojUser.objects.filter(email_verification_code=code, email=normalized_email).afirst()
     if not user:
         return None, False
 
+    # Check if the code has expired
     if user.email_verification_code_expiry < datetime.now(tz=timezone.utc):
         return user, True
 
@@ -348,6 +359,8 @@ async def set_user_subscription(
 ) -> tuple[Optional[Subscription], bool]:
     # Get or create the user object and their subscription
     user, is_new = await aget_or_create_user_by_email(email)
+    if not user:
+        return None, is_new
     user_subscription = await Subscription.objects.filter(user=user).afirst()
 
     # Update the user subscription state

src/khoj/routers/auth.py

@@ -86,12 +86,11 @@ async def login_magic_link(request: Request, form: MagicLinkForm):
         # Clear the session if user is already authenticated
         request.session.pop("user", None)
 
-    email = form.email
-    user, is_new = await aget_or_create_user_by_email(email)
-    unique_id = user.email_verification_code
+    user, is_new = await aget_or_create_user_by_email(form.email)
 
     if user:
-        await send_magic_link_email(email, unique_id, request.base_url)
+        unique_id = user.email_verification_code
+        await send_magic_link_email(user.email, unique_id, request.base_url)
         if is_new:
             update_telemetry_state(
                 request=request,

src/khoj/utils/helpers.py

@@ -27,6 +27,7 @@ import psutil
 import requests
 import torch
 from asgiref.sync import sync_to_async
+from email_validator import EmailNotValidError, EmailUndeliverableError, validate_email
 from magika import Magika
 from PIL import Image
 from pytz import country_names, country_timezones
@@ -614,3 +615,13 @@ def get_openai_client(api_key: str, api_base_url: str) -> Union[openai.OpenAI, o
             base_url=api_base_url,
         )
     return client
+
+
+def normalize_email(email: str, check_deliverability=False) -> tuple[str, bool]:
+    """Normalize, validate and check deliverability of email address"""
+    lower_email = email.lower()
+    try:
+        valid_email = validate_email(lower_email, check_deliverability=check_deliverability)
+        return valid_email.normalized, True
+    except (EmailNotValidError, EmailUndeliverableError):
+        return lower_email, False