I have a domain (example.com) with SSL support. I am having an issue when trying to redirect a request from www.example.com
-> https://example.com
.
You need to have your content being distributed by Cloudfront. So the content from your S3 bucket will go through Cloudfront before being served. You can find info about how to do it here: Using CloudFront with Amazon S3
Then, for the second part, to have all your data served with https, do the following: Go to CloudFront > Your distribution > behaviour tab > select the first element of the list and click Edit. Then you should be able to see an option for redirecting http to https.
I'm surprised that you're having luck with the SSL endpoints, as it's my understanding that the proper setup is to disable static website hosting on the s3 buckets and make sure all traffic to them is going through Cloudfront. Cloudfront will handle SSL itself, including redirects from HTTP to HTTPS, provided that you configure your Cloudfront origin to only allow HTTPS access via the Origin Protocol Policy
setting.
For setting up the Cloudfront-to-s3 configuration: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/DownloadDistS3AndCustomOrigins.html
For restricting s3 to be accessible only by Cloudfront: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/private-content-restricting-access-to-s3.html