Usage notes

To verify a MAC in one call, specify the ONLY keyword on the segmenting rule keyword for the rule_array parameter. For two or more calls, specify the FIRST keyword for the first input block, MIDDLE for intermediate blocks (if any), and LAST for the last block.

For a given text string, the MAC resulting from the verification process is the same regardless of how the text is segmented or how it was segmented when the original MAC was generated.