From 4bacf39790df9ff21479858ce92b361a28fc9b4b Mon Sep 17 00:00:00 2001
From: Zhi Guan <guanzhi1980@gmail.com>
Date: Thu, 22 Dec 2022 21:32:06 +0800
Subject: [PATCH] Fix rand_bytes in Android

---
 CMakeLists.txt |  2 ++
 src/rand.c     | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 src/rand.c

diff --git a/CMakeLists.txt b/CMakeLists.txt
index aae0633a..fe42143a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -113,6 +113,8 @@ if (WIN32)
 	list(APPEND src src/rand_win.c)
 elseif (APPLE)
 	list(APPEND src src/rand_apple.c)
+elseif (ANDROID)
+	list(APPEND src src/rand.c)
 else()
 	list(APPEND src src/rand_unix.c)
 endif()
diff --git a/src/rand.c b/src/rand.c
new file mode 100644
index 00000000..e155aef5
--- /dev/null
+++ b/src/rand.c
@@ -0,0 +1,45 @@
+/*
+ *  Copyright 2014-2022 The GmSSL Project. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the License); you may
+ *  not use this file except in compliance with the License.
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <gmssl/rand.h>
+#include <gmssl/error.h>
+
+#define RAND_MAX_BUF_SIZE 4096
+
+int rand_bytes(uint8_t *buf, size_t len)
+{
+	FILE *fp;
+	if (!buf) {
+		error_print();
+		return -1;
+	}
+	if (len > RAND_MAX_BUF_SIZE) {
+		error_print();
+		return -1;
+	}
+	if (!len) {
+		return 0;
+	}
+
+	if (!(fp = fopen("/dev/urandom", "rb"))) {
+		error_print();
+		return -1;
+	}
+	if (fread(buf, 1, len, fp) != len) {
+		error_print();
+		fclose(fp);
+		return -1;
+	}
+	fclose(fp);
+	return 1;
+}