The ssh man page claims ~/.ssh/config This is the per-user configuration file. The file format and configuration options are described in ssh_config(5). Because of the potential for abuse, this file must have strict permissions: read/write for the user, and not accessible by others. However in fact this file must only not be writeable by others and this is what ssh checks for.
-read/write for the user, and not accessible by others. +read/write for the user, and not writable by others. committed and will be in openssh-6.3
Set all RESOLVED bugs to CLOSED with release of OpenSSH 7.1