/etc/salt/roster is in salt-ssh 0.17.5+ds-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 | # Sample salt-ssh config file
#web1:
#  host: 192.168.42.1 # The IP addr or DNS hostname
#  user: fred         # Remote executions will be executed as user fred
#  passwd: foobarbaz  # The password to use for login, if omitted, keys are used
#  sudo: True         # Whether to sudo to root, not enabled by default
#web2:
#  host: 192.168.42.2
 |