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Keith SmithandClaude Sonnet 4.5 5d9c901918 Fix HIGH Security Issue: Add file upload validation for avatars
Added comprehensive validation for avatar file uploads to prevent malicious file uploads.

Validation Checks:
- File extension: Only allow jpg, jpeg, png, gif
- File size: Maximum 5MB
- Content type: Verify MIME type matches allowed image types

Changes:

users/serializers.py:
- Added MAX_AVATAR_SIZE constant (5MB)
- Created validate_avatar() method in UserSerializer
- Validates file extension against whitelist
- Checks file size and provides helpful error messages
- Verifies content-type header matches allowed image types

config/settings/base.py:
- Added FILE_UPLOAD_MAX_MEMORY_SIZE = 5MB
- Added DATA_UPLOAD_MAX_MEMORY_SIZE = 5MB
- Enforces global upload limits at Django level

Security impact:
- Prevents upload of executables, malware, or scripts
- Mitigates DoS via large file uploads
- Ensures only valid image files can be uploaded
- Protects against MIME-type confusion attacks

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2025-12-23 06:23:11 -07:00

136 lines
4.4 KiB
Python

"""
User serializers for KeepItGoing API.
"""
from django.contrib.auth import get_user_model
from django.contrib.auth.password_validation import validate_password
from django.core.validators import FileExtensionValidator
from rest_framework import serializers
from .models import DeviceToken
User = get_user_model()
# Maximum file size for avatar uploads (5MB)
MAX_AVATAR_SIZE = 5 * 1024 * 1024
class UserSerializer(serializers.ModelSerializer):
"""Serializer for user details."""
class Meta:
model = User
fields = [
'id', 'email', 'username', 'first_name', 'last_name',
'timezone', 'avatar', 'default_reminder_minutes',
'email_notifications', 'push_notifications',
'created_at', 'updated_at',
]
read_only_fields = ['id', 'email', 'created_at', 'updated_at']
def validate_avatar(self, value):
"""
Validate avatar file upload.
Checks:
- File extension (jpg, jpeg, png, gif only)
- File size (max 5MB)
- Content type
"""
if value:
# Check file extension
allowed_extensions = ['jpg', 'jpeg', 'png', 'gif']
ext = value.name.split('.')[-1].lower()
if ext not in allowed_extensions:
raise serializers.ValidationError(
f"File type '.{ext}' is not supported. "
f"Allowed types: {', '.join(allowed_extensions)}"
)
# Check file size (5MB max)
if value.size > MAX_AVATAR_SIZE:
max_size_mb = MAX_AVATAR_SIZE / (1024 * 1024)
actual_size_mb = value.size / (1024 * 1024)
raise serializers.ValidationError(
f"File size ({actual_size_mb:.1f}MB) exceeds maximum allowed size ({max_size_mb:.0f}MB)."
)
# Check content type
allowed_types = ['image/jpeg', 'image/png', 'image/gif']
if hasattr(value, 'content_type') and value.content_type not in allowed_types:
raise serializers.ValidationError(
f"Invalid image type. Allowed types: JPEG, PNG, GIF"
)
return value
class UserRegistrationSerializer(serializers.ModelSerializer):
"""Serializer for user registration."""
password = serializers.CharField(
write_only=True,
required=True,
validators=[validate_password],
style={'input_type': 'password'}
)
password_confirm = serializers.CharField(
write_only=True,
required=True,
style={'input_type': 'password'}
)
class Meta:
model = User
fields = ['email', 'username', 'password', 'password_confirm', 'first_name', 'last_name', 'timezone']
def validate(self, attrs):
if attrs['password'] != attrs['password_confirm']:
raise serializers.ValidationError({
'password_confirm': "Passwords do not match."
})
return attrs
def create(self, validated_data):
validated_data.pop('password_confirm')
user = User.objects.create_user(**validated_data)
return user
class ChangePasswordSerializer(serializers.Serializer):
"""Serializer for password change."""
old_password = serializers.CharField(
required=True,
style={'input_type': 'password'}
)
new_password = serializers.CharField(
required=True,
validators=[validate_password],
style={'input_type': 'password'}
)
def validate_old_password(self, value):
user = self.context['request'].user
if not user.check_password(value):
raise serializers.ValidationError("Current password is incorrect.")
return value
class DeviceTokenSerializer(serializers.ModelSerializer):
"""Serializer for device tokens."""
class Meta:
model = DeviceToken
fields = ['id', 'platform', 'token', 'device_name', 'is_active', 'created_at']
read_only_fields = ['id', 'created_at']
def create(self, validated_data):
validated_data['user'] = self.context['request'].user
# Update if token already exists, otherwise create
device_token, created = DeviceToken.objects.update_or_create(
user=validated_data['user'],
token=validated_data['token'],
defaults=validated_data
)
return device_token