Lightweight version of django-simple-captcha for work with django-rest-framework.
- Speed: use
cacheinstead of database - Safety: union methods for generate key and image. (You can't generate many images for one key)
- Easy: only one rest api (for generate, refresh image).
Add RestCaptchaSerializer to your protected request validator:
from rest_captcha serializer import RestCaptchaSerializer
class HumanOnlyDataSerializer(RestCaptchaSerializer):
pass
This code add to your serializer two required fields (captcha_key, captcha_value)
For provide this fields client(js code) should generate key:
> curl -X POST http:localhost:8000/api/captcha/ | python -m json.tool
{
'image_type': 'image/png',
'image_decode': 'base64',
'captcha_key': 'de67e7f3-72d9-42d8-9677-ea381610363d',
'captcha_value': '... image encoded in base64'
}
captcha_value - is base64 encoded PNG image, client should decode and show this image to human for validation and send letters from captcha to protected api.
If human have mistake - client should re generate your image.
Note: See also trottling for protect public api
> pip install django-rest-captcha
Add to installed apps:
INSTALLED_APPS = (
...
'rest_captcha',
)
Set rest_captcha settings (if you want), see defaults:
REST_CAPTCHA = {
'CAPTCHA_CACHE': 'default',
'CAPTCHA_TIMEOUT': 300, # 5 minutes
'CAPTCHA_LENGTH': 4,
'CAPTCHA_FONT_SIZE': 22,
'CAPTCHA_IMAGE_SIZE': (90, 40),
'CAPTCHA_LETTER_ROTATION': (-35, 35),
'CAPTCHA_FOREGROUND_COLOR': '#001100',
'CAPTCHA_BACKGROUND_COLOR': '#ffffff',
'CAPTCHA_FONT_PATH': FONT_PATH,
'CAPTCHA_CACHE_KEY': 'rest_captcha_{key}.{version}',
'FILTER_FUNCTION': 'rest_captcha.captcha.filter_default',
'NOISE_FUNCTION': 'rest_captcha.captcha.noise_default'
}
We recommend using redis or local memory as cache with set parameter, with bigger value of MAX_ENTRIES:
CACHES={
'default': {
'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
'LOCATION': 'rest-captcha',
'MAX_ENTRIES': 10000,
}
}
urlpatterns = [
...
url(r'api/captcha/', include('rest_captcha.urls')),
]