Non-interactive, non-login, shells inherit the PATH from the ssh process, so we must set the PATH with ssh. Some shells, like Korn Shell (ksh, rksh, pksh), only parse user environment files in login shells, so there's no way to change the inherited environment in non-interactive, non-login shells.
Note: replace username with the login of the user. Then, optionally, lock down write access to ~/.ssh/environment:
- To set the path globally, build a custom ssh with the needed default path.
- To set the path for a particular user, first configure ssh to use custom environments by enabling "PermitUserEnvironment" in /etc/ssh/sshd_config: PermitUserEnvironment yes
- Restart sshd
- Then set the path in that user's authorized_keys file or using ~/.ssh/environment.
- Note that you need to set all of the important shell variables. The existence of ~/.ssh/environment seems to preclude the setting of default environmental variable values.
- So, for example, given a location for binaries for rksh (restricted korn shell), /usr/restricted/bin, place the following in ~/.ssh/environment:
HOME=/home/username LOGNAME=username MAIL=/var/mail/username PATH=/usr/restricted/bin PWD=/home/username SHELL=/bin/rksh SHLVL=1 USER=username
- Set the classical permissions:
- chown root:root /home/username/.ssh/environment
- chmod 644 /home/username/.ssh/environment
- Or, place file in an restricted SE Linux context and then configure an SE Linux ACL restricting access.
- Or, set a Posix ACL on the file to limit access.