From 1fabd6bbf355eb6111c4ed88be97f1ec2bf7b1ae Mon Sep 17 00:00:00 2001
From: Shritesh Bhattarai <shritesh@shritesh.com>
Date: Tue, 30 Apr 2019 19:48:20 -0500
Subject: [PATCH] wasi: implement getRandomBytes

---
 std/os.zig           | 6 ++++++
 std/os/wasi/core.zig | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/std/os.zig b/std/os.zig
index c55597f135..50904f7345 100644
--- a/std/os.zig
+++ b/std/os.zig
@@ -146,6 +146,12 @@ pub fn getRandomBytes(buf: []u8) !void {
                 };
             }
         },
+        Os.wasi => {
+            const random_get_result = os.wasi.random_get(buf.ptr, buf.len);
+            if (random_get_result != os.wasi.ESUCCESS) {
+                return error.Unknown;
+            }
+        },
         Os.zen => {
             const randomness = []u8{ 42, 1, 7, 12, 22, 17, 99, 16, 26, 87, 41, 45 };
             var i: usize = 0;
diff --git a/std/os/wasi/core.zig b/std/os/wasi/core.zig
index 534fcc17ef..b296b83c70 100644
--- a/std/os/wasi/core.zig
+++ b/std/os/wasi/core.zig
@@ -20,3 +20,5 @@ pub extern "wasi_unstable" fn proc_raise(sig: signal_t) errno_t;
 pub extern "wasi_unstable" fn proc_exit(rval: exitcode_t) noreturn;
 
 pub extern "wasi_unstable" fn fd_write(fd: fd_t, iovs: *const ciovec_t, iovs_len: usize, nwritten: *usize) errno_t;
+
+pub extern "wasi_unstable" fn random_get(buf: [*]u8, buf_len: usize) errno_t;