xref: /openbmc/linux/security/keys/compat_dh.c (revision e15a5365)
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 }
37