Hot answers tagged sshd
A quick look at the source indicates that auth-passwd.c includes <pwd.h> & auth-shadow.c includes <shadow.h>. Without doing to deep of a dive, it seems that sshd does use the system calls to check the password. There was also code that allowed sshd to required and do a password change for expired passwords.
Answer is yes. You are pointing to the correct target, but you miss few pieces: Using ChallengeResponseAuthentication, you can define more authentication methods, but to make sure they are requested from user, you need to specify the list of them in AuthenticationMethods, for example like this in sshd_config (doing pam two times is just example to try how ...
Am I correct that in Linux this means that sshd directly checks the /etc/passwd and /etc/shadow files if UsePAM in sshd configuration is disabled? Yes. But currently most of distributions handle login using pam, because the sessions in todays systems are getting more and more complicated. OpenSSH can communicate with shadow using <shadow.h> header ...
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