Question

I’m using the C# library for AWS.
We have a scenario where a 3rd party has granted us read access to their S3 bucket. Is it possible to copy objects from their S3 bucket into one of ours without doing a round trip (i.e. GET and PUT)?

I found this in the AWS documentation:
http://docs.amazonwebservices.com/AmazonS3/latest/API/RESTObjectCOPY.html

but that seems to apply only to their REST API, not to the C# library I am using

thanks

Answer 1

Despite what bwight seems to think, it just doesn’t work that way. The only way to get this to work without an necessary round-trip is to use the exact same credentials to access BOTH buckets. So the only way to get it to work is to have the owner of the source bucket (in my case its a 3rd party) to grant access to one of your user accounts to list/read from their bucket. They just need to modify their bucket policy to include something like this:

"Principal": {
    "AWS": "arn:aws:iam::1234567890:user/someusername"
}

and then grant whatever permissions needed to it in the policy