Usability issue when forced to change password when logging in to a system

Darren Tucker dtucker at
Sat Jan 24 09:27:58 AEDT 2015

On Fri, Jan 23, 2015 at 10:59 AM, Iain Morgan <imorgan at> wrote:
> As I recall, OpenSSH does not use PAM to implement password changes;

Actually it does (via pam_chauthtok() but only when you are using
keyboard-interactive and it has a reliable way to talk to to the user.

> instead, it executes the system's passwd binary.

It does that when you are not using PAM, or when you are using PAM with
"password" authentication (it can't call pam_chauthtok() in the latter case
because by the time it can talk to the user via a tty, it has long since
dropped the privilege required to actually change the password.

Darren Tucker (dtucker at
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.

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