t&gt; <strong>decrypt</strong> (span&lt;span&lt;char&gt;&gt; <em>/*receive_vec*/</em>) = 0;
</pre>
<p>decrypt the provided buffers.
returns is a tuple representing the values
(consume, produce, packet_size)</p>
<p>consume is set to the number of bytes which should be trimmed from the
head of the buffers, default is 0</p>
<p>produce is set to the number of bytes of payload which are now ready to
be sent to the upper layer. default is the number of bytes passed in receive_vec</p>
<p>packet_size is set to the 