By default, Messenger for Mac clients use Transport Layer Security (TLS) to connect to the Office Communications Server. If TLS is unavailable, Transport Connection Protocol (TCP) is used to establish the connection.
For TLS connections, users must have an X509 certificate to authenticate the server to the Messenger for Mac client. If the server uses a certificate from one of the root certification authorities (CAs) that is preinstalled on the client computer, the user does not have to install the certificate again. When a user signs in to a TLS connection, Messenger for Mac requests a valid certificate from the server. To be valid, the certificate must be from a CA trusted by the client. If the certificate is valid, the client authenticates the server and opens the connection. If the server uses a certificate that is generated from a certification authority that the Macintosh computer does not recognize, you have to manually import the certificate to the client computers before you deploy Messenger for Mac.
To complete the certificate installation, you have to have access to the certificate file. You can issue a self-signed certificate, an identity certificate that is signed by its own creator, or you can purchase digital certificates from a certification authority. For more information about how to obtain a digital certificate from a certification authority, visit the
Office Marketplace digital ID page
on the Microsoft Office Online
Web site (office.microsoft.com).
Select one of the following procedures based on whether the Macintosh computer that you want to install the certificate on is running Mac OS X v10.4 (Tiger) or Mac OS X v10.5 (Leopard).
Install a certificate in a version of Mac OS X v10.4 (Tiger)
Double-click the certificate file (.cer) file to open it in the Keychain Access application.
On the Keychain pop-up menu, click X509Anchors, and then click OK.
If you are asked to provide a name and password, use the administrator credentials.
Click View Certificates to verify the details of the certificate.
Install a certificate in Mac OS X v10.5 (Leopard)
In Mac OS X v10.5 (Leopard), you must first add X509Anchors to Keychain Access. Then add the root certificate to X509Anchors.
To add x509Anchors to Keychain Access, do the following:
Open Keychain Access from /Applications/Utilities.
On the File menu, click Add Keychain.
Select the X509Anchors keychain from /System/Library/Keychains.
To add the root certificate to X509Anchors, do the following:
Double-click the certificate file (.cer) file to open it in the Keychain Access application.
On the Keychain pop-up menu, click X509Anchors, and then click OK.
If you are asked to provide a name and password, use the administrator credentials.
Click View Certificates to verify the details of the certificate.
