<div class="content" name="EXCHANGE_MESSAGE" uuid="aeeaeae6-1782-4d72-af14-a320ad51f0fa"><p>The <b>EXCHANGE_MESSAGE</b> structure message is used to
encapsulate context tokens of the negotiated security mechanism for either the
initiator or the acceptor.  </p><dl>
<dd>
<div><pre> struct
 {
   MESSAGE_HEADER Header;
   AUTH_SCHEME AuthScheme;
   BYTE_VECTOR Exchange;
} EXCHANGE_MESSAGE; 
</pre></div>
</dd></dl><p><b>Header:</b> A <b>MESSAGE_HEADER</b> structure, as
specified in section <a href="1f4a4b47-6e44-4427-9028-e384a4ca1fda" data-linktype="relative-path">2.2.6.2</a>.
The Header’s <b>MessageType</b> field is set from the values of the <b>MESSAGE_TYPE</b>
enumeration, as specified in section <a href="3a77a20d-9746-4e79-8f06-b241263e3da3" data-linktype="relative-path">2.2.6.1</a>. The <b>MessageType</b>
field MUST be set to MESSAGE_TYPE_AP_REQUEST type for the initiator or
MESSAGE_TYPE_CHALLENGE type for the acceptor when context tokens are being
exchanged. The <b>MessageType</b> field MUST be set to
MESSAGE_TYPE_INITIATOR_META_DATA type for the initiator or
MESSAGE_TYPE_ACCEPTOR_META_DATA type for the acceptor when metadata tokens are
being exchanged.  </p><p><b>AuthScheme:</b> An <b>AUTH_SCHEME</b> GUID that
contains the security mechanism&#39;s ID, as specified in section <a href="fa13c53c-f15c-4506-9679-c8cd69684463" data-linktype="relative-path">2.2.2</a>.  </p><p><b>Exchange:</b> A <b>BYTE_VECTOR</b> structure,
specified in section <a href="2e9b7476-1e8b-4543-83ac-77b6f41c1e0c" data-linktype="relative-path">2.2.5.2.3</a>,
that contains the opaque handshake message for the client authentication
scheme.  </p></div>