DEV Community

Discussion on: Securing your express/Node.js API with Firebase auth

 
technoplato profile image
Michael Lustig - halfjew22@gmail.com

Thanks for taking the time to answer these quandaries.

Last one: even if an attacker has both access to a hash and the hash function, if that hash function is secure, they still can’t reverse that to get the password, correct?

Thread Thread
 
emeka profile image
Nwakwoke Patrick Nnaemeka

No they can’t

Thread Thread
 
v6 profile image
🦄N B🛡

if every app did authentication the same way you are suggesting then their hashed password is still all that will be needed in a case of compromise.

There are, I think, ways to mitigate this kind of hash re-use. And I think Michael is right about there being some security advantages to interception of a hash vs a plaintext password.

Ideally a variable-salted hash of the passphrase would be signed by a given client's private key specific to the user, the same one used for a mutual TLS session.

It could still be intercepted via a MITM attack, but the attack might then give evidence of tampering.