RpcBindingSetAuthInfoExA function (rpcdce.h)

The RpcBindingSetAuthInfoEx function sets a binding handle's authentication, authorization, and security quality-of-service information.


RPC_STATUS RpcBindingSetAuthInfoExA(
  RPC_BINDING_HANDLE       Binding,
  RPC_CSTR                 ServerPrincName,
  unsigned long            AuthnLevel,
  unsigned long            AuthnSvc,
  unsigned long            AuthzSvc,
  RPC_SECURITY_QOS         *SecurityQos



Server binding handle into which authentication and authorization information is set.


Pointer to the expected principal name of the server referenced by Binding. The content of the name and its syntax are defined by the authentication service in use.

Note  For the set of allowable target names for SSPs, please refer to the comments in the InitializeSecurityContext documentation.


Level of authentication to be performed on remote procedure calls made using Binding. For a list of the RPC-supported authentication levels, see Authentication-Level Constants.


Authentication service to use.

Specify RPC_C_AUTHN_NONE to turn off authentication for remote procedure calls made using Binding.

If RPC_C_AUTHN_DEFAULT is specified, the RPC run-time library uses the RPC_C_AUTHN_WINNT authentication service for remote procedure calls made using Binding.


Handle for the structure that contains the client's authentication and authorization credentials appropriate for the selected authentication and authorization service.

When using the RPC_C_AUTHN_WINNT authentication service AuthIdentity should be a pointer to a SEC_WINNT_AUTH_IDENTITY structure (defined in Rpcdce.h). Kerberos and Negotiate authentication services also use the SEC_WINNT_AUTH_IDENTITY structure.

Specify a null value to use the security login context for the current address space. Pass the value RPC_C_NO_CREDENTIALS to use an anonymous log-in context. Note that RPC_C_NO_CREDENTIALS is only valid if RPC_C_AUTHN_GSS_SCHANNEL is selected as the authentication service.


Authorization service implemented by the server for the interface of interest. The validity and trustworthiness of authorization data, like any application data, depends on the authentication service and authentication level selected. This parameter is ignored when using the RPC_C_AUTHN_WINNT authentication service. See Note.



Return value

Value Meaning
The call succeeded.
The binding handle was invalid.
This was the wrong kind of binding for the operation.
Unknown authentication service.
Note  For a list of valid error codes, see RPC Return Values.


A client application calls the RpcBindingSetAuthInfoEx function to set up a server binding handle for making authenticated remote procedure calls. This function provides the capability to set security quality-of-service information on the binding handle. It is otherwise identical to RpcBindingSetAuthInfo.

Unless a client calls RpcBindingSetAuthInfoEx, all remote procedure calls on Binding are unauthenticated. A client is not required to call this function.

The RpcBindingSetAuthInfoEx function takes a snapshot of the credentials. Therefore, the memory dedicated to the AuthIdentity parameter can be freed before the binding handle. The exception to this is when your application uses RpcBindingSetAuthInfoEx with RPC_C_QOS_IDENTITY_DYNAMIC and also specifies a non-NULL value for AuthIdentity.

Note  The RpcBindingSetAuthInfo function must not be called on a binding handle while an RPC call on the same handle is in progress. Doing so produces undefined results.
Due to the varying requirements of different versions of Microsoft RPC, Microsoft recommends that an application maintain a pointer to the AuthIdentity parameter for as long as the binding handle exists. Doing so increases the applications portability.

Windows Server 2003 with SP1 and Windows XP with SP2:  For Windows XP SP2 and Windows Server 2003 SP1, the pointer to the AuthIdentity parameter need not be maintained for the life of the binding handle. This pointer must only be maintained if subsequent calls to RpcBindingInqAuthInfo or RpcBindingInqAuthInfoEx are made.

Note  The ncalrpc protocol sequence supports only RPC_C_AUTHN_WINNT, but does support mutual authentication; supply an SPN and request mutual authentication through the SecurityQOS parameter to achieve this.


The rpcdce.h header defines RpcBindingSetAuthInfoEx as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.


Minimum supported client Windows 2000 Professional [desktop apps | UWP apps]
Minimum supported server Windows 2000 Server [desktop apps | UWP apps]
Target Platform Windows
Header rpcdce.h (include Rpc.h)
Library Rpcrt4.lib
DLL Rpcrt4.dll

See also