AWS S3 – Etag Sha256 instead of Md5


I want to use Sha256 for the checksum of my objects.
But it looks like, that amazon uses md5 in the ETag.

Is there any workaround?


Unfortunately, there’s no direct way to make S3 use SHA256 for ETag. You could use S3 metadata as a workaround. For this, you can calculate the SHA256 checksum yourself and use user defined S3 object metadata to set it for each upload. User defined metadata is just a set of key-value pairs you can assign to your object. You’ll have to set the checksum when you PUT your object and compare it on GET/HEAD object.

More information is available in the S3 documentation:

AWS – Object Key and Metadata

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