When I copy files from a local directory to a fastly bucket via rclone, every transfer fails and it claims the md5 hashes do not match:
2025/06/09 19:05:26 ERROR : <FILENAME>: corrupted on transfer: md5 hashes differ src(Local file system at <PATH>) "8080a1bad182b9863ba0bb289d72736d" vs dst(S3 bucket <BUCKET>) "d63727d982bb0ab3689b281dab1a0808"
The md5 hashes are actually reversed with the first one on the local system showing up as correct against md5sum while fastly’s seems backwards.
The Fastly support team had me add “server_side_encryption = aws:kms” to my rclone config and it seemed to work after that!
To give some context for this, by default AWS returns the MD5 sum as the object’s ETag, and rclone assumes this is the case. However, if you use server-side encryption with AWS the ETags are not MD5 sums of the data, and this config option disables the assumption in rclone.
With Fastly Object Storage, server-side encryption is always enabled, ETags are not MD5 sums of the data, and this setting is needed for rclone.