Fix Visual Studio compiling errors

src/x509_cer.c

@@ -25,6 +25,10 @@
 #include <gmssl/x509.h>
 #include <gmssl/error.h>
 
+#ifdef WIN32
+#include "u_time.h"
+#endif
+
 
 const char *x509_version_name(int version)
 {
@@ -97,7 +101,11 @@ int x509_time_to_der(time_t tv, uint8_t **out, size_t *outlen)
 	int ret;
 	struct tm tm_val;
 
+#ifdef WIN32
+	GMSSL_gmtime(&tv, &tm_val);
+#else
 	gmtime_r(&tv, &tm_val);
+#endif
 	if (tm_val.tm_year < 2050 - 1900) {
 		if ((ret = asn1_utc_time_to_der(tv, out, outlen)) != 1) {
 			if (ret < 0) error_print();
@@ -136,7 +144,11 @@ int x509_validity_add_days(time_t *not_after, time_t not_before, int days)
 		error_print();
 		return -1;
 	}
+#ifdef WIN32
+	GMSSL_gmtime(&not_before, &tm_val);
+#else	
 	gmtime_r(&not_before, &tm_val);
+#endif
 	tm_val.tm_mday += days;
 	*not_after = mktime(&tm_val);
 	return 1;