Add WIN32 rand

src/rand_win.c

@@ -0,0 +1,47 @@
+/*
+ *  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 <stdlib.h>
+#include <limits.h>
+#include <wincrypt.h>
+#include <gmssl/error.h>
+
+
+int rand_bytes(uint8_t *buf, size_t len)
+{
+	HCRYPTPROV hCryptProv = NULL;
+	int ret = -1;
+
+	if (!buf) {
+		error_print();
+		return -1;
+	}
+	if (len > INT_MAX) {
+		error_print();
+		return -1;
+	}
+	if (CryptAcquireContextA(&hCryptProv, NULL, NULL, PROV_RSA_FULL,
+		CRYPT_VERIFYCONTEXT|CRYPT_SILENT) != TRUE) {
+		error_print();
+		return -1;
+	}
+	if (CryptGenRandom(hCryptProv, (DWORD)len, buf) != TRUE) {
+		error_print();
+		goto end;
+	}
+	ret = 1
+end:
+	if (CryptReleaseContext(hCryptProv, 0) != TRUE) {
+		error_print();
+		ret = -1;
+	}
+	return ret;
+}