1 files changed, 25 insertions, 0 deletions
diff --git a/v_windows/v/vlib/crypto/rand/rand_windows.c.v b/v_windows/v/vlib/crypto/rand/rand_windows.c.v
new file mode 100644
index 0000000..075a3ed
--- /dev/null
+++ b/v_windows/v/vlib/crypto/rand/rand_windows.c.v
@@ -0,0 +1,25 @@
+// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module rand
+
+#flag windows -Llibraries/bcrypt
+#flag windows -lbcrypt
+#include <bcrypt.h>
+
+const (
+	status_success                  = 0x00000000
+	bcrypt_use_system_preferred_rng = 0x00000002
+)
+
+// read returns an array of `bytes_needed` random bytes read from the OS.
+pub fn read(bytes_needed int) ?[]byte {
+	mut buffer := []byte{len: bytes_needed}
+	// use bcrypt_use_system_preferred_rng because we passed null as algo
+	status := C.BCryptGenRandom(0, buffer.data, bytes_needed, rand.bcrypt_use_system_preferred_rng)
+	if status != rand.status_success {
+		return IError(&ReadError{})
+	}
+	return buffer
+}