fix build with openssl 1.1

they finally made their structs opaque, and provided proper getters.

src/socket.c

@@ -40,6 +40,10 @@
 # include <openssl/ssl.h>
 # include <openssl/err.h>
 # include <openssl/x509v3.h>
+# if OPENSSL_VERSION_NUMBER < 0x10100000L
+#  define X509_OBJECT_get0_X509(o) ((o)->data.x509)
+#  define X509_STORE_get0_objects(o) ((o)->objs)
+# endif
 #endif
 
 enum {
@@ -171,7 +175,7 @@ verify_cert_host( const server_conf_t *conf, conn_t *sock )
 
 	trusted = (STACK_OF(X509_OBJECT) *)sock->conf->trusted_certs;
 	for (i = 0; i < sk_X509_OBJECT_num( trusted ); i++) {
-		if (!X509_cmp( cert, sk_X509_OBJECT_value( trusted, i )->data.x509 ))
+		if (!X509_cmp( cert, X509_OBJECT_get0_X509( sk_X509_OBJECT_value( trusted, i ) ) ))
 			return 0;
 	}
 
@@ -222,7 +226,7 @@ init_ssl_ctx( const server_conf_t *conf )
 		       conf->cert_file, ERR_error_string( ERR_get_error(), 0 ) );
 		return 0;
 	}
-	mconf->trusted_certs = (_STACK *)sk_X509_OBJECT_dup( SSL_CTX_get_cert_store( mconf->SSLContext )->objs );
+	mconf->trusted_certs = (_STACK *)sk_X509_OBJECT_dup( X509_STORE_get0_objects( SSL_CTX_get_cert_store( mconf->SSLContext ) ) );
 	if (mconf->system_certs && !SSL_CTX_set_default_verify_paths( mconf->SSLContext ))
 		warn( "Warning: Unable to load default certificate files: %s\n",
 		      ERR_error_string( ERR_get_error(), 0 ) );