On Linux Mint 17.1 x86_64 with kernel 3.13.0-48-generic and OpenSSL version 1.0.1f-1ubuntu2.11; whenever I try to execute any docker command (like docker login or <
docker login
In my case it was because of file /Users/user/.ssh/config has permissions 777. To check it run in terminal ssh docker@localhost
/Users/user/.ssh/config
ssh docker@localhost