test: add test case to reliably reproduce RAND leak during POST

The FIPS provider leaks a RAND if the POST is run at initialisation time.
This test case reliably reproduces this event.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15278)

1 files changed, 82 insertions, 0 deletions

diff --git a/test/threadstest.h b/test/threadstest.h
new file mode 100644
index 0000000000..8bdedd7052
--- /dev/null
+++ b/test/threadstest.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2021 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
+ */
+
+#if defined(_WIN32)
+# include <windows.h>
+#endif
+
+#include <string.h>
+#include "testutil.h"
+
+#if !defined(OPENSSL_THREADS) || defined(CRYPTO_TDEBUG)
+
+typedef unsigned int thread_t;
+
+static int run_thread(thread_t *t, void (*f)(void))
+{
+    f();
+    return 1;
+}
+
+static int wait_for_thread(thread_t thread)
+{
+    return 1;
+}
+
+#elif defined(OPENSSL_SYS_WINDOWS)
+
+typedef HANDLE thread_t;
+
+static DWORD WINAPI thread_run(LPVOID arg)
+{
+    void (*f)(void);
+
+    *(void **) (&f) = arg;
+
+    f();
+    return 0;
+}
+
+static int run_thread(thread_t *t, void (*f)(void))
+{
+    *t = CreateThread(NULL, 0, thread_run, *(void **) &f, 0, NULL);
+    return *t != NULL;
+}
+
+static int wait_for_thread(thread_t thread)
+{
+    return WaitForSingleObject(thread, INFINITE) == 0;
+}
+
+#else
+
+typedef pthread_t thread_t;
+
+static void *thread_run(void *arg)
+{
+    void (*f)(void);
+
+    *(void **) (&f) = arg;
+
+    f();
+    return NULL;
+}
+
+static int run_thread(thread_t *t, void (*f)(void))
+{
+    return pthread_create(t, NULL, thread_run, *(void **) &f) == 0;
+}
+
+static int wait_for_thread(thread_t thread)
+{
+    return pthread_join(thread, NULL) == 0;
+}
+
+#endif
+