Comment by fc417fc802

> There is certainly good reason to do server-side hashing: you do not keep a persistent record of the customer's secret, yet keep the ability for them to authenticate with it.

That is not a property of server side hashing but rather hashing in general.

> If you are never logging a clear-text secret

Yeah good luck with that. /s

It's better not to need to worry about logging plaintext. The less of your infra that falls within any given security boundary the easier it will be to properly secure. The difference between server and client side hashing is how much of your infra touches the plaintext. Less is always better.

Sure, an insider could make direct use of hashes pulled from the logs. However if the attacker already has access to your systems then they are already inside the security boundary (or at least most of them) and likely have many other (probably better) options available to them.

It's important to keep in mind that the primary purpose behind hashing credentials is to minimize the degree to which your systems come into contact with the plaintext. The goal here is to contain the blast radius of any intrusion to only your own systems and only the immediate intrusion (ie to prevent future abuse after you've cleaned everything up) given the unfortunate reality that end users will frequently reuse credentials.

It's also important to keep in mind that hashing is cheap enough that you should probably be doing both. Hash it on the client so that you don't need to worry about logs (or snooping the LAN or whatever other way an employee might come up with to obtain plaintext passwords) and then hash it again before it enters the db so that you don't need to worry about the logs that contain hashes leaking.