// SPDX-License-Identifier: GPL-2.0-or-later
/* 32-bit compatibility syscall for 64-bit systems for DH operations
 *
 * Copyright (C) 2016 Stephan Mueller <smueller@chronox.de>
 */

#include <linux/uaccess.h>

#include "internal.h"

/*
 * Perform the DH computation or DH based key derivation.
 *
 * If successful, 0 will be returned.
 */
long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
                              char __user *buffer, size_t buflen,
                              struct compat_keyctl_kdf_params __user *kdf)
{
        struct keyctl_kdf_params kdfcopy;
        struct compat_keyctl_kdf_params compat_kdfcopy;

        if (!kdf)
                return __keyctl_dh_compute(params, buffer, buflen, NULL);

        if (copy_from_user(&compat_kdfcopy, kdf, sizeof(compat_kdfcopy)) != 0)
                return -EFAULT;

        kdfcopy.hashname = compat_ptr(compat_kdfcopy.hashname);
        kdfcopy.otherinfo = compat_ptr(compat_kdfcopy.otherinfo);
        kdfcopy.otherinfolen = compat_kdfcopy.otherinfolen;
        memcpy(kdfcopy.__spare, compat_kdfcopy.__spare,
               sizeof(kdfcopy.__spare));

        return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
}