Issue while enabling sse-c on remote store

[bsrikanthreddy5]

I am enabling smart store on Splunk 7.2.6 with SSE-C. My smart store is working without SSL parameters successfully.

https://docs.splunk.com/Documentation/Splunk/7.2.5/Indexer/SmartStoresecuritystrategies

After adding below configuration to /opt/splunk/etc/_master-apps/_cluster/local/indexes.conf trying to apply the bundle to form clustermaster UI and facing an issue: Bad SSL settings for KMS leading to bad ssl context for volume=remote_store.
I am using AWS role for S3 buket access.

[volume:remote_store]
storageType = remote
path = s3://buket-name
remote.s3.access_key = 
remote.s3.secret_key = 
remote.s3.endpoint = https://s3.us-west-2.amazonaws.com
remote.s3.encryption = sse-c
remote.s3.encryption.sse-c.key_type = kms
remote.s3.encryption.sse-c.key_refresh_interval = 86400
remote.s3.kms.auth_region = us-west-2
remote.s3.kms.key_id = xxxxxxxxxxxxxxxxxxxxxxxx
remote.s3.kms.sslAltNameToCheck = s3.us-west-2.amazonaws.com
remote.s3.kms.sslVerifyServerCert = true
remote.s3.kms.sslVersions = tls1.2
remote.s3.kms.sslRootCAPath = /tmp/s3.us-west-2.amazonaws.com.pem
remote.s3.kms.cipherSuite = ECDHE-ECDSA-AES128-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256
remote.s3.kms.ecdhCurves = prime256v1,secp384r1,secp521r1

My Splunk env is running on AWS EC2 instances.
s3.us-west-2.amazonaws.com.pem is pem cert with root chain included

[bsrikanthreddy5]

Recommendation from Splunk PS:

SSE-C (Customer Managed Keys)
This is the recommended option in the documentation but this will change very soon.

Advantages
The self-managed key so there is an element of trust as the creator/generator of the key.
No KMS API operation limits to contend with.

Disadvantages
Keys are in plain text on the indexes.conf file. This would not pass a security risk assessment.
Advanced key management requires an advanced key management solution e.g. Hardware Security Modules for storage and management.
To rotate keys, you need to move the data from SmartStore back to an EBS volume and re-upload the data with the new key. Splunk cannot be running during this operation. This is by far the biggest drawback.
SSE-C while technically valid requires more due care of the customer to ensure adequate protection of the data and is subject to human error and misconfiguration. It is only appropriate for customers with specific requirements to use customer-managed keys.

SSE-KMS has Amazon manage your keys for you and is more flexible than SSE-C. There are limits that are described here: https://docs.aws.amazon.com/kms/latest/developerguide/limits.html