Describe the issue:

In the section "3.2.8.2. Configuring the Secure Token Service" we explain the usage of "rgw_sts_key" and has given an example

ceph config set RGW_CLIENT_NAME rgw_sts_key STS_KEY
ceph config set client.rgw rgw_sts_key 9a2142613c504c42a23ba2b82147dc28

But in upstream we explicitly ask the key to be 16 hex characters
===========
rgw_sts_key = {sts key for encrypting/ decrypting the session token, exactly 16 hex characters}
===========

https://docs.ceph.com/en/latest/radosgw/STSLite/


This information is missing from the document :

https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/6/html/developer_guide/ceph-object-gateway-and-the-s3-api#secure-token-service_dev


Chapter/Section Number and Title:

3.2.8.2. Configuring the Secure Token Service


Product Version:
RHCS 6

Any other versions of this document that also needs this update:

Yes, RHCS 5 
https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/5/html/developer_guide/ceph-object-gateway-and-the-s3-api#configuring-the-secure-token-service_dev