I am curious why bcrypt was used for hashing in the first place and not something like sha-512
Is there a reason I might be missing?
Is there a reason I might be missing?
According to the security advisory this cache was for AD/LDAP delegated authentication, so they don't have their own password database with a version field or similar for sensible invalidation.
I guess the requirements could be something like:
- different username/password combinations must have separately cached results
- mitigate a potential data leak by putting all the entropy we have available together with the password material and using a slow password hashing functionHash functions themselves are general purpose and don't protect against low entropy inputs (low entropy passwords). They also don't protect against rainbow tables (pre-calculated digests for common or popular passwords). For password hashing you want something slow and something with unique entropy for each user's password to prevent rainbow attacks.
It doesn't solve the problem of weak passwords, but it's the best that can be done with weak passwords. The only improvement is to enforce strong passwords.
> SHA-2 family of hashes was designed to be fast. BCrypt was designed to be slow.
Slow == harder to brute-force == more secure.