1 files changed, 98 insertions, 0 deletions
diff --git a/fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/random.c b/fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/random.c
new file mode 100644
index 000000000..01a1dab3a
--- /dev/null
+++ b/fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/random.c
@@ -0,0 +1,98 @@
+// Part of the Wasmtime Project, under the Apache License v2.0 with LLVM
+// Exceptions. See
+// https://github.com/bytecodealliance/wasmtime/blob/main/LICENSE for license
+// information.
+//
+// Significant parts of this file are derived from cloudabi-utils. See
+// https://github.com/bytecodealliance/wasmtime/blob/main/lib/wasi/sandboxed-system-primitives/src/LICENSE
+// for license information.
+//
+// The upstream file contains the following copyright notice:
+//
+// Copyright (c) 2016 Nuxi, https://nuxi.nl/
+
+#include "ssp_config.h"
+#include "bh_platform.h"
+#include "random.h"
+
+#if CONFIG_HAS_ARC4RANDOM_BUF
+
+void
+random_buf(void *buf, size_t len)
+{
+    arc4random_buf(buf, len);
+}
+
+#elif CONFIG_HAS_GETRANDOM
+
+#ifndef BH_PLATFORM_LINUX_SGX
+#include <sys/random.h>
+#endif
+
+void
+random_buf(void *buf, size_t len)
+{
+    for (;;) {
+        ssize_t x = getrandom(buf, len, 0);
+        if (x < 0) {
+            if (errno == EINTR)
+                continue;
+            os_printf("getrandom failed: %s", strerror(errno));
+            abort();
+        }
+        if ((size_t)x == len)
+            return;
+        buf = (void *)((unsigned char *)buf + x);
+        len -= (size_t)x;
+    }
+}
+
+#else
+
+static int urandom;
+
+static void
+open_urandom(void)
+{
+    urandom = open("/dev/urandom", O_RDONLY);
+    if (urandom < 0) {
+        os_printf("Failed to open /dev/urandom\n");
+        abort();
+    }
+}
+
+void
+random_buf(void *buf, size_t len)
+{
+    static pthread_once_t open_once = PTHREAD_ONCE_INIT;
+    pthread_once(&open_once, open_urandom);
+
+    if ((size_t)read(urandom, buf, len) != len) {
+        os_printf("Short read on /dev/urandom\n");
+        abort();
+    }
+}
+
+#endif
+
+// Calculates a random number within the range [0, upper - 1] without
+// any modulo bias.
+//
+// The function below repeatedly obtains a random number from
+// arc4random() until it lies within the range [2^k % upper, 2^k). As
+// this range has length k * upper, we can safely obtain a number
+// without any modulo bias.
+uintmax_t
+random_uniform(uintmax_t upper)
+{
+    // Compute 2^k % upper
+    //      == (2^k - upper) % upper
+    //      == -upper % upper.
+    uintmax_t lower = -upper % upper;
+    for (;;) {
+        uintmax_t value;
+        random_buf(&value, sizeof(value));
+        if (value >= lower)
+            return value % upper;
+    }
+}