www-bocal/api/models.py

61 lines
1.9 KiB
Python

import hashlib
import hmac
import random
import string
from datetime import datetime, timedelta
from django.db import models
class ApiKey(models.Model):
"""An API key, to login using the API
An API key consists in a somewhat long chunk of ascii text, *not*
containing any dollar ($) sign. It is saved on the client's machine as
a string "keyId$key".
An API token (to authentify a request) is a triplet (ts, kid, hmac) of
a timestamp `ts`, the key id `kid` and
hmac = `HMAC(key, ts + data, sha256)`
where `data` is the normalized (`json.dumps(json.loads(...))`) value of
the data part of the request.
"""
key = models.CharField("API key", max_length=128)
name = models.CharField(
"Key name", max_length=256, help_text="Where is this key used from?"
)
last_used = models.DateTimeField("Last used", default=datetime.fromtimestamp(0))
def everUsed(self):
return self.last_used > datetime.fromtimestamp(0)
def initialFill(self):
if not self.key:
KEY_SIZE = 64
KEY_CHARS = string.ascii_letters + string.digits
self.key = "".join([random.choice(KEY_CHARS) for _ in range(KEY_SIZE)])
@property
def keyId(self):
return self.pk
@property
def displayValue(self):
return "{}${}".format(self.keyId, self.key)
def __str__(self):
return self.displayValue
def isCorrect(self, timestamp, inpMac, data):
claimedDate = datetime.fromtimestamp(timestamp)
if datetime.now() - timedelta(minutes=5) > claimedDate:
return False
mac = hmac.new(
self.key.encode("utf-8"),
msg=str(int(claimedDate.timestamp())).encode("utf-8"),
digestmod=hashlib.sha256,
)
mac.update(data.encode("utf-8"))
return hmac.compare_digest(mac.hexdigest(), inpMac)