late_mac sas input input_len info info_len mac mac_len</code></p><p>Generate a message authentication code (MAC) based on the shared secret.</p><p>Takes a SAS object, the message to produce the authentication code for, the extra information to mix in when generating the MAC, as per the Matrix spec, and the buffer in which to store the generated MAC.</p><p>Returns `olm_error()` on failure. If the `mac` buffer is too small, then `olm_sas_last_error()` will be `OUTPUT_BUFFER_TOO_SMALL`.</p></dd></dl><dl><dt cl