Harden timing when getting order with secret check (#4177)

This commit is contained in:
Richard Schreiber
2024-05-24 14:09:18 +02:00
committed by GitHub
parent 37908bd042
commit fb3046210b

View File

@@ -111,28 +111,27 @@ class OrderQuerySet(models.QuerySet):
dummy = "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"[:secret_length]
try:
order = self.get(code=code)
if not hmac.compare_digest(
order.tagged_secret(tag, secret_length) if tag else order.secret,
received_secret[:secret_length].lower() if tag else received_secret.lower()
) and not (
# TODO: remove this clause after a while (compatibility with old secrets currently in flight)
tag and hmac.compare_digest(
hashlib.sha1(order.secret.lower().encode()).hexdigest(),
received_secret.lower()
)
):
raise Order.DoesNotExist
return order
except Order.DoesNotExist:
# Do a hash comparison as well to harden against timing attacks
if hmac.compare_digest(
hmac.compare_digest(
salted_hmac(key_salt=b"", value=tag, algorithm="sha256",
secret=dummy).hexdigest()[:secret_length],
received_secret[:secret_length]
):
raise Order.DoesNotExist
else:
raise Order.DoesNotExist
)
raise Order.DoesNotExist
if not hmac.compare_digest(
order.tagged_secret(tag, secret_length) if tag else order.secret,
received_secret[:secret_length].lower() if tag else received_secret.lower()
) and not (
# TODO: remove this clause after a while (compatibility with old secrets currently in flight)
tag and hmac.compare_digest(
hashlib.sha1(order.secret.lower().encode()).hexdigest(),
received_secret.lower()
)
):
raise Order.DoesNotExist
return order
class Order(LockModel, LoggedModel):