4.6.1 Basic Authentication Sequence
For Basic authentication, the following sequence is used.

Figure 9: Basic authentication sequence
In response to a client LinkViewerToMacConnect message request, the server sends a LinkMacToViewerReportConnectedEX message with the following attributes:
The AuthenPackage field is set to BASIC.
The cbAuthenPackage field has a value of 6.
The client and server then continue their normal sequence of commands.
Eventually, the client sends a LinkViewerToMacOpenFile message request to which the server responds with a LinkMacToViewerSecurityChallenge message.
The client sends a LinkViewerToMacSecurityResponse message to the server that contains the username and password. If the credentials are correct, the server responds with a LinkMacToViewerReportOpenFile message. Otherwise, the server responds with a LinkMacToViewerSecurityChallenge message.