/*

 * Copyright 2020-2022 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (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 "crypto/rand.h"

#include "crypto/rand_pool.h"

#include <openssl/core_dispatch.h>

#include <openssl/err.h>

size_t ossl_rand_get_entropy(ossl_unused const OSSL_CORE_HANDLE *handle,

                             unsigned char **pout, int entropy,

                             size_t min_len, size_t max_len)

{

    size_t ret = 0;

    size_t entropy_available;

    RAND_POOL *pool;

    pool = ossl_rand_pool_new(entropy, 1, min_len, max_len);

    if (pool == NULL) {

        ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    /* Get entropy by polling system entropy sources. */

    entropy_available = ossl_pool_acquire_entropy(pool);

    if (entropy_available > 0) {

        ret   = ossl_rand_pool_length(pool);

        *pout = ossl_rand_pool_detach(pool);

    }

    ossl_rand_pool_free(pool);

    return ret;

}

void ossl_rand_cleanup_entropy(ossl_unused const OSSL_CORE_HANDLE *handle,

                               unsigned char *buf, size_t len)

{

    OPENSSL_secure_clear_free(buf, len);

}

size_t ossl_rand_get_nonce(ossl_unused const OSSL_CORE_HANDLE *handle,

                           unsigned char **pout, size_t min_len, size_t max_len,

                           const void *salt, size_t salt_len)

{

    size_t ret = 0;

    RAND_POOL *pool;

    pool = ossl_rand_pool_new(0, 0, min_len, max_len);

    if (pool == NULL) {

        ERR_raise(ERR_LIB_RAND, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    if (!ossl_pool_add_nonce_data(pool))

        goto err;

    if (salt != NULL && !ossl_rand_pool_add(pool, salt, salt_len, 0))

        goto err;

    ret   = ossl_rand_pool_length(pool);

    *pout = ossl_rand_pool_detach(pool);

 err:

    ossl_rand_pool_free(pool);

    return ret;

}

void ossl_rand_cleanup_nonce(ossl_unused const OSSL_CORE_HANDLE *handle,

                             unsigned char *buf, size_t len)

{

    OPENSSL_clear_free(buf, len);

}