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by texthompson 578 days ago
Why does it matter where the bytes are stored at rest? Isn't everything you need for SHA-256 just the results of the SHA-256 algorithm on every 4096-byte block? I think you could just calculate that as the data is streamed in.
2 comments
jiggawatts 577 days ago
The data is not necessarily "streamed" in! That's a significant design feature to allow parallel uploads of a single object using many parts ("blocks"). See: https://docs.aws.amazon.com/AmazonS3/latest/API/API_CreateMu...
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Dylan16807 577 days ago
> Isn't everything you need for SHA-256 just the results of the SHA-256 algorithm on every 4096-byte block?

No, you need the hash of the previous block before you can start processing the next block.

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