+/*
+ * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#ifndef OSSL_INTERNAL_TIME_H
+# define OSSL_INTERNAL_TIME_H
+# pragma once
+
+# include <openssl/e_os2.h> /* uint64_t */
+# include "internal/e_os.h" /* for struct timeval */
+# include "internal/safe_math.h"
+
+/* The precision of times allows this many values per second */
+# define OSSL_TIME_SECOND 1000000000
+
+/* Macro representing the most distant future time */
+# define OSSL_TIME_INFINITY (~(OSSL_TIME)0)
+
+/*
+ * Internal type defining a time.
+ * The time datum is Unix's 1970 and at nanosecond precision, this gives
+ * a range of 584 years roughly.
+ */
+typedef uint64_t OSSL_TIME;
+
+/* Get current time */
+OSSL_TIME ossl_time_now(void);
+
+/* Convert time to timeval */
+static ossl_unused ossl_inline
+void ossl_time_time_to_timeval(OSSL_TIME t, struct timeval *out)
+{
+#ifdef _WIN32
+ out->tv_sec = (long int)(t / OSSL_TIME_SECOND);
+#else
+ out->tv_sec = (time_t)(t / OSSL_TIME_SECOND);
+#endif
+ out->tv_usec = (t % OSSL_TIME_SECOND) / (OSSL_TIME_SECOND / 1000000);
+}
+
+/* Compare two time values, return -1 if less, 1 if greater and 0 if equal */
+static ossl_unused ossl_inline
+int ossl_time_compare(OSSL_TIME a, OSSL_TIME b)
+{
+ if (a > b)
+ return 1;
+ if (a < b)
+ return -1;
+ return 0;
+}
+
+/*
+ * Arithmetic operations on times.
+ * These operations are saturating, in that an overflow or underflow returns
+ * the largest or smallest value respectively.
+ */
+OSSL_SAFE_MATH_UNSIGNED(time, OSSL_TIME)
+
+static ossl_unused ossl_inline
+OSSL_TIME ossl_time_add(OSSL_TIME a, OSSL_TIME b)
+{
+ OSSL_TIME r;
+ int err = 0;
+
+ r = safe_add_time(a, b, &err);
+ return err ? OSSL_TIME_INFINITY : r;
+}
+
+static ossl_unused ossl_inline
+OSSL_TIME ossl_time_subtract(OSSL_TIME a, OSSL_TIME b)
+{
+ OSSL_TIME r;
+ int err = 0;
+
+ r = safe_sub_time(a, b, &err);
+ return err ? 0 : r;
+}
+
+#endif