xref: /linux/security/keys/compat_dh.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
1 /* 32-bit compatibility syscall for 64-bit systems for DH operations
2  *
3  * Copyright (C) 2016 Stephan Mueller <smueller@chronox.de>
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License
7  * as published by the Free Software Foundation; either version
8  * 2 of the License, or (at your option) any later version.
9  */
10 
11 #include <linux/uaccess.h>
12 
13 #include "internal.h"
14 
15 /*
16  * Perform the DH computation or DH based key derivation.
17  *
18  * If successful, 0 will be returned.
19  */
20 long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
21 			      char __user *buffer, size_t buflen,
22 			      struct compat_keyctl_kdf_params __user *kdf)
23 {
24 	struct keyctl_kdf_params kdfcopy;
25 	struct compat_keyctl_kdf_params compat_kdfcopy;
26 
27 	if (!kdf)
28 		return __keyctl_dh_compute(params, buffer, buflen, NULL);
29 
30 	if (copy_from_user(&compat_kdfcopy, kdf, sizeof(compat_kdfcopy)) != 0)
31 		return -EFAULT;
32 
33 	kdfcopy.hashname = compat_ptr(compat_kdfcopy.hashname);
34 	kdfcopy.otherinfo = compat_ptr(compat_kdfcopy.otherinfo);
35 	kdfcopy.otherinfolen = compat_kdfcopy.otherinfolen;
36 	memcpy(kdfcopy.__spare, compat_kdfcopy.__spare,
37 	       sizeof(kdfcopy.__spare));
38 
39 	return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
40 }
41