The SECPKG_SUPPLEMENTAL_CRED structure defines the name of the security package that requires supplemental credentials and the credential buffer for that package. The SECPKG_SUPPLEMENTAL_CRED structure is marshaled by RPC [MS-RPCE].

The SECPKG_SUPPLEMENTAL_CRED structure is defined as follows.

 typedef struct _SECPKG_SUPPLEMENTAL_CRED {
   RPC_UNICODE_STRING PackageName;
   ULONG CredentialSize;
   [size_is(CredentialSize)] PUCHAR Credentials;
 } SECPKG_SUPPLEMENTAL_CRED,
  *PSECPKG_SUPPLEMENTAL_CRED;

PackageName: A RPC_UNICODE_STRING structure that MUST store the name of the security protocol for which the supplemental credentials are being presented.<17>

CredentialSize: A 32-bit unsigned integer that MUST specify the length, in bytes, of the data in the Credentials member.

Credentials: A pointer that MUST reference the serialized credentials being presented to the security protocol named in PackageName.