/*

 * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <openssl/opensslconf.h>

#include <stdio.h>

#include <string.h>

#include "internal/engine.h"

#include <openssl/rand.h>

#include <openssl/err.h>

#include <openssl/crypto.h>

#if (defined(__i386)   || defined(__i386__)   || defined(_M_IX86) || \

     defined(__x86_64) || defined(__x86_64__) || \

     defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ)

size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len);

static int get_random_bytes(unsigned char *buf, int num)

{

    if (num < 0) {

        return 0;

    }

    return (size_t)num == OPENSSL_ia32_rdrand_bytes(buf, (size_t)num);

}

static int random_status(void)

{

    return 1;

}

static RAND_METHOD rdrand_meth = {

    NULL,                       /* seed */

    get_random_bytes,

    NULL,                       /* cleanup */

    NULL,                       /* add */

    get_random_bytes,

    random_status,

};

static int rdrand_init(ENGINE *e)

{

    return 1;

}

static const char *engine_e_rdrand_id = "rdrand";

static const char *engine_e_rdrand_name = "Intel RDRAND engine";

static int bind_helper(ENGINE *e)

{

    if (!ENGINE_set_id(e, engine_e_rdrand_id) ||

        !ENGINE_set_name(e, engine_e_rdrand_name) ||

        !ENGINE_set_flags(e, ENGINE_FLAGS_NO_REGISTER_ALL) ||

        !ENGINE_set_init_function(e, rdrand_init) ||

        !ENGINE_set_RAND(e, &rdrand_meth))

        return 0;

    return 1;

}

static ENGINE *ENGINE_rdrand(void)

{

    ENGINE *ret = ENGINE_new();

    if (ret == NULL)

        return NULL;

    if (!bind_helper(ret)) {

        ENGINE_free(ret);

        return NULL;

    }

    return ret;

}

void engine_load_rdrand_int(void)

{

    extern unsigned int OPENSSL_ia32cap_P[];

    if (OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) {

        ENGINE *toadd = ENGINE_rdrand();

        if (!toadd)

            return;

        ENGINE_add(toadd);

        ENGINE_free(toadd);

        ERR_clear_error();

    }

}

#else

void engine_load_rdrand_int(void)

{

}

#endif