CoQueryProxyBlanket

Retrieves the authentication information the client uses to make calls on the specified proxy.

HRESULT CoQueryProxyBlanket(

void* pProxy,	//Location for the proxy to query
DWORD* pAuthnSvc,	//Location for the the current authorization service
DWORD* pAuthzSvc,	//Location for the the current authorization service
OLECHAR ** pServerPrincName,	//Location for the current principal name
DWORD * pAuthnLevel,	//Location for the current authentication level
DWORD * pImpLevel,	//Location for the current impersonation level
RPC_AUTH_IDENTITY_HANDLE ** ppAuthInfo,	//Location for the value passed to IClientSecurity::SetBlanket
DWORD ** pCapabilities	//Location for flags indicating further capabilities of the proxy
);

Parameters

pProxy

[in] Pointer to an interface on the proxy to query.

pAuthnSvc

[out] Pointer to a DWORD value defining the current authentication service. This will be a single value taken from the list of RPC_C_AUTHN_xxx constants. May be NULL, in which case the current authentication service is not retrieved.

pAuthzSvc

[out] Pointer to a DWORD value defining the current authorization service. This will be a single value taken from the list of RPC_C_AUTHZ_xxx constants. May be NULL, in which case the current authorization service is not retrieved.

pServerPrincName

[out] Pointer to the current principal name. The string will be allocated by the one called using CoTaskMemAlloc and must be freed by the caller using CoTaskMemFree when they are done with it. May be NULL, in which case the principal name is not retrieved.

pAuthnLevel

[out] Pointer to a DWORD value defining the current authentication level. This will be a single value taken from the list of RPC_C_AUTHN_LEVEL_xxx constants. May be NULL, in which case the current authentication level is not retrieved.

pImpLevel

[out] Pointer to a DWORD value defining the current impersonation level. This will be a single value taken from the list of RPC_C_IMP_LEVEL_xxx constants. May be NULL, in which case the current authentication level is not retrieved.

ppAuthInfo

[out] Pointer to the pointer value passed to IClientSecurity::SetBlanket indicating the identity of the client. Because this points to the value itself and is not a copy, it should not be manipulated. May be NULL, in which case the information is not retrieved.

pCapabilities

[out] Pointer to a DWORD of flags indicating further capabilities of the proxy. Currently, no flags are defined for this parameter and it will only return EOAC_NONE. May be NULL, in which case the flags indicating further capabilities are not retrieved.

Return Values

S_OK

Success.

E_INVALIDARG

One or more arguments are invalid.

E_OUTOFMEMORY

Insufficient memory to create the pasAuthnSvc out-parameter.

Remarks

CoQueryProxyBlanket is called by the client to retrieve the authentication information COM will use on calls made from the specified proxy. This function encapsulates the following sequence of common calls (error handling excluded):

pProxy->QueryInterface(IID_IClientSecurity, (void**)&pcs);
pcs->QueryBlanket(pProxy, pAuthnSvc, pAuthzSvc, pServerPrincName,
                 pAuthnLevel, pImpLevel, ppAuthInfo, pCapabilities);
pcs->Release();
 

This sequence calls QueryInterface on the proxy for IClientSecurity, and with the resulting pointer, calls IClientSecurity::QueryBlanket, and then releases the pointer.

In pProxy, you can pass any proxy, such as a proxy you get through a call to CoCreateInstance, CoUnmarshalInterface, or just passing an interface pointer as a parameter. It can be any interface. You cannot pass a pointer to something that is not a proxy. Thus you can’t pass a pointer to an interface that has the local keyword in its interface definition since no proxy is created for such an interface. IUnknown is the exception.

See Also

IClientSecurity::QueryBlanket, Security in COM