typedef struct { ... } *SilcSILCPrivateKey;

    This structure defines the SILC protocol implementation specific
    private key.  This structure isn't usually needed by the user.

    typedef struct SilcSILCPrivateKeyStruct {
      const SilcPKCSAlgorithm *pkcs;   /* PKCS algorithm */
      void *private_key;               /* PKCS algorithm specific private key */
    } *SilcSILCPrivateKey;