diff --git a/library/timing.c b/library/timing.c
new file mode 100644
index 0000000..1ed8863
--- /dev/null
+++ b/library/timing.c
@@ -0,0 +1,154 @@
+/*
+ *  Portable interface to the CPU cycle counter
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
+#include "ssl_misc.h"
+
+#if defined(MBEDTLS_TIMING_C)
+
+#include "mbedtls/timing.h"
+
+#if !defined(MBEDTLS_TIMING_ALT)
+
+#if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
+    !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
+    !defined(__HAIKU__) && !defined(__midipix__)
+#error "This module only works on Unix and Windows, see MBEDTLS_TIMING_C in mbedtls_config.h"
+#endif
+
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+
+#include <windows.h>
+#include <process.h>
+
+struct _hr_time {
+    LARGE_INTEGER start;
+};
+
+#else
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <signal.h>
+/* time.h should be included independently of MBEDTLS_HAVE_TIME. If the
+ * platform matches the ifdefs above, it will be used. */
+#include <time.h>
+#include <sys/time.h>
+struct _hr_time {
+    struct timeval start;
+};
+#endif /* _WIN32 && !EFIX64 && !EFI32 */
+
+/**
+ * \brief          Return the elapsed time in milliseconds
+ *
+ * \warning        May change without notice
+ *
+ * \param val      points to a timer structure
+ * \param reset    If 0, query the elapsed time. Otherwise (re)start the timer.
+ *
+ * \return         Elapsed time since the previous reset in ms. When
+ *                 restarting, this is always 0.
+ *
+ * \note           To initialize a timer, call this function with reset=1.
+ *
+ *                 Determining the elapsed time and resetting the timer is not
+ *                 atomic on all platforms, so after the sequence
+ *                 `{ get_timer(1); ...; time1 = get_timer(1); ...; time2 =
+ *                 get_timer(0) }` the value time1+time2 is only approximately
+ *                 the delay since the first reset.
+ */
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+
+unsigned long mbedtls_timing_get_timer(struct mbedtls_timing_hr_time *val, int reset)
+{
+    struct _hr_time *t = (struct _hr_time *) val;
+
+    if (reset) {
+        QueryPerformanceCounter(&t->start);
+        return 0;
+    } else {
+        unsigned long delta;
+        LARGE_INTEGER now, hfreq;
+        QueryPerformanceCounter(&now);
+        QueryPerformanceFrequency(&hfreq);
+        delta = (unsigned long) ((now.QuadPart - t->start.QuadPart) * 1000ul
+                                 / hfreq.QuadPart);
+        return delta;
+    }
+}
+
+#else /* _WIN32 && !EFIX64 && !EFI32 */
+
+unsigned long mbedtls_timing_get_timer(struct mbedtls_timing_hr_time *val, int reset)
+{
+    struct _hr_time *t = (struct _hr_time *) val;
+
+    if (reset) {
+        gettimeofday(&t->start, NULL);
+        return 0;
+    } else {
+        unsigned long delta;
+        struct timeval now;
+        gettimeofday(&now, NULL);
+        delta = (now.tv_sec  - t->start.tv_sec) * 1000ul
+                + (now.tv_usec - t->start.tv_usec) / 1000;
+        return delta;
+    }
+}
+
+#endif /* _WIN32 && !EFIX64 && !EFI32 */
+
+/*
+ * Set delays to watch
+ */
+void mbedtls_timing_set_delay(void *data, uint32_t int_ms, uint32_t fin_ms)
+{
+    mbedtls_timing_delay_context *ctx = (mbedtls_timing_delay_context *) data;
+
+    ctx->int_ms = int_ms;
+    ctx->fin_ms = fin_ms;
+
+    if (fin_ms != 0) {
+        (void) mbedtls_timing_get_timer(&ctx->timer, 1);
+    }
+}
+
+/*
+ * Get number of delays expired
+ */
+int mbedtls_timing_get_delay(void *data)
+{
+    mbedtls_timing_delay_context *ctx = (mbedtls_timing_delay_context *) data;
+    unsigned long elapsed_ms;
+
+    if (ctx->fin_ms == 0) {
+        return -1;
+    }
+
+    elapsed_ms = mbedtls_timing_get_timer(&ctx->timer, 0);
+
+    if (elapsed_ms >= ctx->fin_ms) {
+        return 2;
+    }
+
+    if (elapsed_ms >= ctx->int_ms) {
+        return 1;
+    }
+
+    return 0;
+}
+
+/*
+ * Get the final delay.
+ */
+uint32_t mbedtls_timing_get_final_delay(
+    const mbedtls_timing_delay_context *data)
+{
+    return data->fin_ms;
+}
+#endif /* !MBEDTLS_TIMING_ALT */
+#endif /* MBEDTLS_TIMING_C */