SSH with keys issues

2009-10-22

Summary

A customer complained of problems using SSH with keys. SSH with keys had worked previously but had stopped working.

Cause

This was caused by incorrect permissions on the users home directory.

The required permissions are 755 for the home directory - e.g.

drwxr-xr-x james james 4.0K 2009-04-01 16:20 james


Other things to be aware of:-


700 permissions for the .ssh folder in the home folder

drwx------ james james 4.0K 2009-04-01 16:20 .ssh

600 for the authorized_keys

drw------- james james 1.0K 2009-04-01 16:30 authorized_keys


If you need to troubleshoot problems with the sshd & keys it is possible to run up a second instance using the following command:

sudo /usr/sbin/sshd -p 9666 -D -d -e -o PasswordAuthentication=no -o UsePAM=no

That sshd will only accept keys and produces decent error output if there is a problem.
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