How to tell passwd to use salted passwords?

Question

I am hunting the web on how to change passwords of an existing user using a salted hash.

I found that way with adding a non-existing user:

https://stackoverflow.com/questions/2150882/how-to-automatically-add-user-account-and-password-with-a-bash-script

But I want to change the password of an existing user.

The man page of passwd is laking documentation on how to do that.

Can't be done. And it Unix has used salted passwords for as long as I remember (almost 30 years now), so... What are you really trying to do? — vonbrand, Mar 13 '13 at 11:08

score 3 · Answer 1 · answered Mar 13 '13 at 11:35

The crypt function in Linux has been using salted password hashes since before the 1.2 kernel series so this is likely a non-issue.

That said, the salt is a system-wide salt so you can't set one per-user. When you change a password it is run through crypt() again using the system-wide salt.

How to tell passwd to use salted passwords?

1 Answers1