ssh without password does not work for some users

I found the answer. It was in the permissions of the home directory of user jack. User jack had group write permissions on the home directory, while jane did not. The problem is that all of the tutorials on the web specify the permissions for the .ssh directory and the files, but fail to mention that the user directory itself needs to have write permission for group turned off.

Have you tried restricting the permission of the .ssh directory? Because in most cases that would work. Not sure though where that "strict" configuration is but I encountered the same issue several times before and changing permissions on the .ssh directory fixed the problem.

I had the same problem, but with a user ssh'ing to another user local to the same system.

All permissions the same with both users.

Experimentation showed that users A and B could log in as each other, but neither could connect as user C.

It turned out that user C (being a system user) didn't have a shadow entry although he did have a passwd entry.

Hopefully this will be helpful to someone with the same problem later on.

System: OpenIndiana oi_151a