clientToken
The plaintext data key used to encrypt the upload file.
To persist to the pre-signed url, use the client token and MD5 client token as header. The required headers are as follows:
x-amz-server-side-encryption-customer-key: Client Token
x-amz-server-side-encryption-customer-key-MD5: MD5 Client Token
x-amz-server-side-encryption-customer-algorithm: AES256