typedef struct { ... } *SilcPublicKey;

    This context represents any kind of PKCS public key.  It can be
    allocated by silc_pkcs_public_key_alloc and is freed by the
    silc_pkcs_public_key_free.  The PKCS specific public key context
    can be retrieved by calling silc_pkcs_get_context.

    typedef struct SilcPublicKeyStruct {
      const SilcPKCSObject *pkcs;   /* PKCS */
      void *public_key;             /* PKCS specific public key */
    } *SilcPublicKey;