FC_Digest - digest a block of data.
CK_RV FC_Digest( CK_SESSION_HANDLE hSession, CK_BYTE_PTR pData, CK_ULONG usDataLen, CK_BYTE_PTR pDigest, CK_ULONG_PTR pusDigestLen );
hSessionpDatausDataLenpDigestpusDigestLenFC_Digest digests a message in a single operation according to the attributes of the previous call to FC_DigestInit.
A user may call FC_Digest without logging into the token (to assume the NSS User role).