#### Key rotation

S3 clients can change the client-provided key of an existing object. Therefore an S3 client must perform a S3 COPY operation where the copy source and destination are equal. Further the COPY request headers must contain the current and the new client key:

- `X-Amz-Server-Side-Encryption-Customer-Key`: Base64 encoded new key.
- `X-Amz-Copy-Source-Server-Side-Encryption-Customer-Key`: Base64 encoded current key.