Document valid values for s3 cp checksum options

[mjfxjas]

Summary

• update aws s3 cp option help text to explicitly list valid values for:
  • --checksum-mode
  • --checksum-algorithm
• keeps existing behavior unchanged and only clarifies docs output

Testing

• help text/docs-only change

Closes #10025

[mjfxjas]

Friendly follow-up on this docs clarification.

This PR documents valid values for aws s3 cp checksum options to reduce trial and error for users. If maintainers prefer, I can also add a short note or example showing a recommended default workflow.

[adev-code]

Thanks @mjfxjas for the PR! Made some comments on the changes.

[mjfxjas]

Thanks @adev-code — I’m ready to address all feedback. I’m not seeing the inline review comments on my side yet. Could you re-submit/publish them (or paste them here), and I’ll update the PR right away.

[adev-code]

Suggested change

	'checksum, it will be verified. Valid value: ENABLED.'
	'help_text': 'To retrieve the checksum, this mode must be enabled. ENABLED is the only '
	'valid value. If the object has a checksum, it will be verified.'

As per previous comment:
It looks like the existing pattern for a single value is "ENABLED is the only valid value." See SSE_C for an example.

[adev-code]

Suggested change

	'Valid values: CRC64NVME, CRC32, SHA256, SHA1, CRC32C.'
	'Valid values are: CRC64NVME | CRC32 | SHA256 | SHA1 | CRC32C.'

Nit: using same or format for choices.

[ashovlin]

Hey @mjfxjas, we recently added support for new algorithms: SHA512, XXHASH3, XXHASH64, XXHASH128. MD5 is only supported for pre-calculated values, not for automatic calculation via --checksum-algorithm.

• https://aws.amazon.com/about-aws/whats-new/2026/04/s3-five-additional-checksum-algorithms/
• https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html

Are you still interested in updating this to address Adrian's comments and the four new algorithms? No worries if not.