1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (c) 2016, Intel Corporation
  4 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
 
 
 
 
 
  5 */
  6#include <linux/kernel.h>
  7#include <linux/export.h>
  8#include <linux/err.h>
  9#include <linux/string.h>
 10#include <crypto/dh.h>
 11#include <crypto/kpp.h>
 12
 13#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 4 * sizeof(int))
 14
 15static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size)
 16{
 17	if (!dst || size > end - dst)
 18		return NULL;
 19	memcpy(dst, src, size);
 20	return dst + size;
 21}
 22
 23static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
 24{
 25	memcpy(dst, src, size);
 26	return src + size;
 27}
 28
 29static inline unsigned int dh_data_size(const struct dh *p)
 30{
 31	return p->key_size + p->p_size + p->q_size + p->g_size;
 32}
 33
 34unsigned int crypto_dh_key_len(const struct dh *p)
 35{
 36	return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
 37}
 38EXPORT_SYMBOL_GPL(crypto_dh_key_len);
 39
 40int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
 41{
 42	u8 *ptr = buf;
 43	u8 * const end = ptr + len;
 44	struct kpp_secret secret = {
 45		.type = CRYPTO_KPP_SECRET_TYPE_DH,
 46		.len = len
 47	};
 48
 49	if (unlikely(!len))
 50		return -EINVAL;
 51
 52	ptr = dh_pack_data(ptr, end, &secret, sizeof(secret));
 53	ptr = dh_pack_data(ptr, end, &params->key_size,
 54			   sizeof(params->key_size));
 55	ptr = dh_pack_data(ptr, end, &params->p_size, sizeof(params->p_size));
 56	ptr = dh_pack_data(ptr, end, &params->q_size, sizeof(params->q_size));
 57	ptr = dh_pack_data(ptr, end, &params->g_size, sizeof(params->g_size));
 58	ptr = dh_pack_data(ptr, end, params->key, params->key_size);
 59	ptr = dh_pack_data(ptr, end, params->p, params->p_size);
 60	ptr = dh_pack_data(ptr, end, params->q, params->q_size);
 61	ptr = dh_pack_data(ptr, end, params->g, params->g_size);
 62	if (ptr != end)
 63		return -EINVAL;
 
 
 
 
 
 
 
 
 
 64	return 0;
 65}
 66EXPORT_SYMBOL_GPL(crypto_dh_encode_key);
 67
 68int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
 69{
 70	const u8 *ptr = buf;
 71	struct kpp_secret secret;
 72
 73	if (unlikely(!buf || len < DH_KPP_SECRET_MIN_SIZE))
 74		return -EINVAL;
 75
 76	ptr = dh_unpack_data(&secret, ptr, sizeof(secret));
 77	if (secret.type != CRYPTO_KPP_SECRET_TYPE_DH)
 78		return -EINVAL;
 79
 80	ptr = dh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
 81	ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
 82	ptr = dh_unpack_data(&params->q_size, ptr, sizeof(params->q_size));
 83	ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
 84	if (secret.len != crypto_dh_key_len(params))
 85		return -EINVAL;
 86
 87	/*
 88	 * Don't permit the buffer for 'key' or 'g' to be larger than 'p', since
 89	 * some drivers assume otherwise.
 90	 */
 91	if (params->key_size > params->p_size ||
 92	    params->g_size > params->p_size || params->q_size > params->p_size)
 93		return -EINVAL;
 94
 95	/* Don't allocate memory. Set pointers to data within
 96	 * the given buffer
 97	 */
 98	params->key = (void *)ptr;
 99	params->p = (void *)(ptr + params->key_size);
100	params->q = (void *)(ptr + params->key_size + params->p_size);
101	params->g = (void *)(ptr + params->key_size + params->p_size +
102			     params->q_size);
103
104	/*
105	 * Don't permit 'p' to be 0.  It's not a prime number, and it's subject
106	 * to corner cases such as 'mod 0' being undefined or
107	 * crypto_kpp_maxsize() returning 0.
108	 */
109	if (memchr_inv(params->p, 0, params->p_size) == NULL)
110		return -EINVAL;
111
112	/* It is permissible to not provide Q. */
113	if (params->q_size == 0)
114		params->q = NULL;
115
116	return 0;
117}
118EXPORT_SYMBOL_GPL(crypto_dh_decode_key);

 
 1/*
 2 * Copyright (c) 2016, Intel Corporation
 3 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
 4 *
 5 * This program is free software; you can redistribute it and/or
 6 * modify it under the terms of the GNU General Public Licence
 7 * as published by the Free Software Foundation; either version
 8 * 2 of the Licence, or (at your option) any later version.
 9 */
10#include <linux/kernel.h>
11#include <linux/export.h>
12#include <linux/err.h>
13#include <linux/string.h>
14#include <crypto/dh.h>
15#include <crypto/kpp.h>
16
17#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int))
18
19static inline u8 *dh_pack_data(void *dst, const void *src, size_t size)
20{
 
 
21	memcpy(dst, src, size);
22	return dst + size;
23}
24
25static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
26{
27	memcpy(dst, src, size);
28	return src + size;
29}
30
31static inline int dh_data_size(const struct dh *p)
32{
33	return p->key_size + p->p_size + p->g_size;
34}
35
36int crypto_dh_key_len(const struct dh *p)
37{
38	return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
39}
40EXPORT_SYMBOL_GPL(crypto_dh_key_len);
41
42int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
43{
44	u8 *ptr = buf;
 
45	struct kpp_secret secret = {
46		.type = CRYPTO_KPP_SECRET_TYPE_DH,
47		.len = len
48	};
49
50	if (unlikely(!buf))
51		return -EINVAL;
52
53	if (len != crypto_dh_key_len(params))
 
 
 
 
 
 
 
 
 
 
54		return -EINVAL;
55
56	ptr = dh_pack_data(ptr, &secret, sizeof(secret));
57	ptr = dh_pack_data(ptr, &params->key_size, sizeof(params->key_size));
58	ptr = dh_pack_data(ptr, &params->p_size, sizeof(params->p_size));
59	ptr = dh_pack_data(ptr, &params->g_size, sizeof(params->g_size));
60	ptr = dh_pack_data(ptr, params->key, params->key_size);
61	ptr = dh_pack_data(ptr, params->p, params->p_size);
62	dh_pack_data(ptr, params->g, params->g_size);
63
64	return 0;
65}
66EXPORT_SYMBOL_GPL(crypto_dh_encode_key);
67
68int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
69{
70	const u8 *ptr = buf;
71	struct kpp_secret secret;
72
73	if (unlikely(!buf || len < DH_KPP_SECRET_MIN_SIZE))
74		return -EINVAL;
75
76	ptr = dh_unpack_data(&secret, ptr, sizeof(secret));
77	if (secret.type != CRYPTO_KPP_SECRET_TYPE_DH)
78		return -EINVAL;
79
80	ptr = dh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
81	ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
 
82	ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
83	if (secret.len != crypto_dh_key_len(params))
84		return -EINVAL;
85
 
 
 
 
 
 
 
 
86	/* Don't allocate memory. Set pointers to data within
87	 * the given buffer
88	 */
89	params->key = (void *)ptr;
90	params->p = (void *)(ptr + params->key_size);
91	params->g = (void *)(ptr + params->key_size + params->p_size);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
92
93	return 0;
94}
95EXPORT_SYMBOL_GPL(crypto_dh_decode_key);