# `ExStorageServiceSdk.S3.Checksum`
[🔗](https://github.com/gsmlg-opt/ex_storage_service/blob/v0.7.1/lib/ex_storage_service_sdk/s3/checksum.ex#L1)

Incremental raw-byte S3 checksums, multipart composites and bounded checksum trailers.

# `algorithms`

# `combine`

Combines finalized CRC part checksums and byte lengths into a full-object CRC.

# `composite`

Checksums of parts in wire order, encoded as base64(digest(raw part digests))-count.

# `digest`

# `encode_trailers`

A lazy aws-chunked unsigned checksum envelope. Source chunks must obey the configured bound.

# `encoded`

# `finish`

# `header`

# `new`

# `update`

# `verify`

Verifies a full-object digest, or an explicit ordered collection of part digests.

# `verify_response`

Rejects conflicting header/trailer values; absence is reported without a verification claim.

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*Consult [api-reference.md](api-reference.md) for complete listing*