security/keys/compat_dh.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* 32-bit compatibility syscall for 64-bit systems for DH operations
   3  *
   4  * Copyright (C) 2016 Stephan Mueller <smueller@chronox.de>
   5  */
   6
   7 #include <linux/uaccess.h>
   8
   9 #include "internal.h"
  10
  11 /*
  12  * Perform the DH computation or DH based key derivation.
  13  *
  14  * If successful, 0 will be returned.
  15  */
  16 long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
  17                               char __user *buffer, size_t buflen,
  18                               struct compat_keyctl_kdf_params __user *kdf)
  19 {
  20         struct keyctl_kdf_params kdfcopy;
  21         struct compat_keyctl_kdf_params compat_kdfcopy;
  22
  23         if (!kdf)
  24                 return __keyctl_dh_compute(params, buffer, buflen, NULL);
  25
  26         if (copy_from_user(&compat_kdfcopy, kdf, sizeof(compat_kdfcopy)) != 0)
  27                 return -EFAULT;
  28
  29         kdfcopy.hashname = compat_ptr(compat_kdfcopy.hashname);
  30         kdfcopy.otherinfo = compat_ptr(compat_kdfcopy.otherinfo);
  31         kdfcopy.otherinfolen = compat_kdfcopy.otherinfolen;
  32         memcpy(kdfcopy.__spare, compat_kdfcopy.__spare,
  33                sizeof(kdfcopy.__spare));
  34
  35         return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
  36 }