Fix S3 Plugin for Jenkins with this one Wierd Trick!
So this is really just here for my future reference, but it may be useful for someone else with the same issue. :D
The problem:
Jenkins S3 publisher plugin was showing this error in Manage Jenkins - > Configure System -> Amazon S3 profiles:
"Can't connect to s3 service: unable to execute http request: peer not authenticated"
Likely Cause:
OpenJDK has different cert settings out of box than Sun JDK does.
Solution for my server:
Install Sun JDK latest version (1.8_40 in my case).