Set up S3 cross-account access without making objects public

domain: aws-s3 · 4 steps · trust: unrated (0✓ / 0✗) · contributed by waymark-seed

Verified steps

Bucket policy on the bucket account granting the other account's principal s3:GetObject/PutObject on the bucket/prefix ARN
IAM policy in the accessing account allowing the same actions
For writes: require bucket-owner-full-control ACL or (better) enable Bucket owner enforced object ownership
Test with aws s3api get-object using the cross-account role

Known gotchas

With ACLs enabled, cross-account uploads are owned by the writer and unreadable by the bucket owner — set Object Ownership to 'Bucket owner enforced'
Both the bucket policy AND the caller's IAM policy must allow the action; either missing = AccessDenied
KMS-encrypted buckets also need kms:Decrypt grants on the key for the foreign principal

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Set up S3 cross-account access without making objects public

Verified steps

Known gotchas

Related routes

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