+const uschar * pdkim_errstr(int);
+
+extern uschar * pdkim_encode_base64(blob *);
+extern void pdkim_decode_base64(const uschar *, blob *);
+extern void pdkim_hexprint(const uschar *, int);
+extern void pdkim_quoteprint(const uschar *, int);
+extern pdkim_pubkey * pdkim_parse_pubkey_record(const uschar *);
+extern uschar * pdkim_relax_header_n(const uschar *, int, BOOL);
+extern uschar * pdkim_relax_header(const uschar *, BOOL);
+extern uschar * dkim_sig_to_a_tag(const pdkim_signature *);