extern const uschar * exim_dkim_sign(es_ctx *, hashmethod, blob *, blob *);
extern const uschar * exim_dkim_verify_init(blob *, keyformat, ev_ctx *);
extern const uschar * exim_dkim_verify(ev_ctx *, hashmethod, blob *, blob *);
extern const uschar * exim_dkim_sign(es_ctx *, hashmethod, blob *, blob *);
extern const uschar * exim_dkim_verify_init(blob *, keyformat, ev_ctx *);
extern const uschar * exim_dkim_verify(ev_ctx *, hashmethod, blob *, blob *);