Fix build with OpenSSL >= 1.1.0

--- src/conf.C

+++ src/conf.C

@@ -554,6 +554,19 @@ configuration_parser::parse_file (const char *fname)

     }

 }

+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)

+void RSA_get0_key(const RSA *r,

+                 const BIGNUM **n, const BIGNUM **e, const BIGNUM **d)

+{

+   if (n != NULL)

+       *n = r->n;

+   if (e != NULL)

+       *e = r->e;

+   if (d != NULL)

+       *d = r->d;

+}

+#endif

+

 configuration_parser::configuration_parser (configuration &conf,

                                             bool need_keys,

                                             int argc,

@@ -649,13 +662,16 @@ configuration_parser::configuration_parser (configuration &conf,

               exit (EXIT_FAILURE);

             }

-          if (conf.rsa_key && conf.thisnode->rsa_key)

-            if (BN_cmp (conf.rsa_key->n, conf.thisnode->rsa_key->n) != 0

-                || BN_cmp (conf.rsa_key->e, conf.thisnode->rsa_key->e) != 0)

+          if (conf.rsa_key && conf.thisnode->rsa_key) {

+            const BIGNUM *n, *e, *thisnode_n, *thisnode_e;

+            RSA_get0_key(conf.rsa_key, &n, &e, NULL);

+            RSA_get0_key(conf.thisnode->rsa_key, &thisnode_n, &thisnode_e, NULL);

+            if (BN_cmp (n,thisnode_n) != 0 || BN_cmp (e, thisnode_e) != 0)

               {

                 slog (L_NOTICE, _("private hostkey and public node key mismatch: is '%s' the correct node?"), ::thisnode);

                 exit (EXIT_FAILURE);

               }

+            }

         }

     }