Lync 2010 Identity Client Runtime for Lync Online and Exchange Online General Reference (Lync Online 2010)

Microsoft Lync 2010 uses a pluggable identity client runtime (IDCRL) in order to authenticate with the Microsoft Lync Online and Microsoft Exchange Online services that are hosted in the cloud. Lync 2010 also supports third-party authentication redistributable binaries instead of the default Microsoft IDCRL binary. This document describes how this kind of runtime binary must be constructed for use by Lync 2010 and other applications that meet this standard.

The identity client runtime (IDCRL) library must be a 32-bit Microsoft Windows dynamic link library (DLL) that exports the IDCRL namespace C++ functions. All functions, constants, and types must be in the IDCRL namespace.

When Lync 2010 must integrate with the IDCRL, to determine whether a third-party IDCRL service is deployed, it first checks its own registry settings by checking the following keys in the 32-bit hive of the Windows registry.



The keys are used to define the following settings:




The directory where the IDCRL .dll file is located.


The name of the .dll file that Lync should use for integration.

Lync 2010 attempts to load the IDCRL library at TargetDir\TargetName and then calls LogonIdentityIdentityEx() to initialize the IDCRL library. If this call succeeds, then integration with the IDCRL library is considered successful and Lync 2010 starts to use the Microsoft Lync 2010 API to perform the necessary services authentication.