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0 pointssaagarjha6y ago0 comments

How do you suggest implementing passwd without setuid?

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4 comments · 2 top-level

mehrdadn6y ago· 2 in thread

Off the top of my head? Ask a system service that has the privilege to change it for you after authenticating you.

saagarjhaOP6y ago

Isn’t that exactly what passwd is? A system service that has permission to change the passwords file?

mehrdadn6y ago

No, the point is that passwd should obtain its privilege by virtue of being started by a privileged process, not by virtue of being marked as a privileged program when it's run by an unprivileged user.

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JdeBP6y ago

Using the design of the LSASS is one way, as mentioned. Others include OpenWall's tcb, and Daniel Rench's userdirs.

* https://www.openwall.com/tcb/

* https://web.archive.org/web/20030919191907/http://dren.ch:80...

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