The following are the spec and example files for passwords.conf.

passwords.conf.spec

#   Version 9.3.0
#
# This file maintains the credential information for a given app in Splunk Enterprise.
#
# There is no global, default passwords.conf. Instead, anytime a user creates
# a new user or edit a user onwards hitting the storage endpoint
# will create this passwords.conf file which gets replicated
# in a search head clustering enviornment.
# Note that passwords.conf is only created from 6.3.0 release.
#
# You must restart Splunk Enterprise to reload manual changes to passwords.conf.
#
# To learn more about configuration files (including precedence) please see the
# documentation located at
# http://docs.splunk.com/Documentation/Splunk/latest/Admin/Aboutconfigurationfiles

passwords.conf.example

#   Version 9.3.0
#
# The following are example passwords.conf configurations. Configure properties for
# your custom application.
#
# There is NO DEFAULT passwords.conf. The file only gets created once you add/edit
# a credential information via the storage endpoint as follows.
#
# The POST request to add user1 credentials to the storage/password endpoint 
# curl -k -u admin:changeme https://localhost:8089/servicesNS/nobody/search/storage/passwords -d name=user1 -d password=changeme2
#
# The GET request to list all the credentials stored at the storage/passwords endpoint 
# curl -k -u admin:changeme https://localhost:8089/services/storage/passwords
#
# To use one or more of these configurations, copy the configuration block into
# passwords.conf in $SPLUNK_HOME/etc/<apps>/local/. You must restart Splunk to
# enable configurations.
#
# To learn more about configuration files (including precedence) please see the
# documentation located at
# http://docs.splunk.com/Documentation/Splunk/latest/Admin/Aboutconfigurationfiles
#

[credential::testuser:]
password = changeme