Change umask for SFTP and SCP connections on RHEL and CentOS running OpenSSH

This should work on any system running OpenSSH, but this was specifically tested on RHEL 6 and CentOS 6.

Problem: When users are placing files on a server with SFTP, the umask set in /etc/profile and sticky bits set on directories are ignored.

Solution:  Modify /etc/ssh/sshd_config.  Find the line near the bottom that looks like:

Subsystem      sftp    /usr/libexec/openssh/sftp-server

Change to the following, adjusting the umask as needed.  This example sets permission to 664 for files and 775 for directories:

Subsystem      sftp  /bin/sh -c 'umask 002; /usr/libexec/openssh/sftp-server'

To fix it for SCP, you also need to add the following line to /etc/pam.d/login and /etc/pam.d/sshd

session    optional     pam_umask.so umask=0022