96 lines
2.6 KiB
C
96 lines
2.6 KiB
C
/*
|
|
* Copyright (c) 2016, Intel Corporation
|
|
* Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/export.h>
|
|
#include <linux/err.h>
|
|
#include <linux/string.h>
|
|
#include <crypto/dh.h>
|
|
#include <crypto/kpp.h>
|
|
|
|
#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int))
|
|
|
|
static inline u8 *dh_pack_data(void *dst, const void *src, size_t size)
|
|
{
|
|
memcpy(dst, src, size);
|
|
return dst + size;
|
|
}
|
|
|
|
static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
|
|
{
|
|
memcpy(dst, src, size);
|
|
return src + size;
|
|
}
|
|
|
|
static inline int dh_data_size(const struct dh *p)
|
|
{
|
|
return p->key_size + p->p_size + p->g_size;
|
|
}
|
|
|
|
int crypto_dh_key_len(const struct dh *p)
|
|
{
|
|
return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_dh_key_len);
|
|
|
|
int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
|
|
{
|
|
u8 *ptr = buf;
|
|
struct kpp_secret secret = {
|
|
.type = CRYPTO_KPP_SECRET_TYPE_DH,
|
|
.len = len
|
|
};
|
|
|
|
if (unlikely(!buf))
|
|
return -EINVAL;
|
|
|
|
if (len != crypto_dh_key_len(params))
|
|
return -EINVAL;
|
|
|
|
ptr = dh_pack_data(ptr, &secret, sizeof(secret));
|
|
ptr = dh_pack_data(ptr, ¶ms->key_size, sizeof(params->key_size));
|
|
ptr = dh_pack_data(ptr, ¶ms->p_size, sizeof(params->p_size));
|
|
ptr = dh_pack_data(ptr, ¶ms->g_size, sizeof(params->g_size));
|
|
ptr = dh_pack_data(ptr, params->key, params->key_size);
|
|
ptr = dh_pack_data(ptr, params->p, params->p_size);
|
|
dh_pack_data(ptr, params->g, params->g_size);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_dh_encode_key);
|
|
|
|
int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
|
|
{
|
|
const u8 *ptr = buf;
|
|
struct kpp_secret secret;
|
|
|
|
if (unlikely(!buf || len < DH_KPP_SECRET_MIN_SIZE))
|
|
return -EINVAL;
|
|
|
|
ptr = dh_unpack_data(&secret, ptr, sizeof(secret));
|
|
if (secret.type != CRYPTO_KPP_SECRET_TYPE_DH)
|
|
return -EINVAL;
|
|
|
|
ptr = dh_unpack_data(¶ms->key_size, ptr, sizeof(params->key_size));
|
|
ptr = dh_unpack_data(¶ms->p_size, ptr, sizeof(params->p_size));
|
|
ptr = dh_unpack_data(¶ms->g_size, ptr, sizeof(params->g_size));
|
|
if (secret.len != crypto_dh_key_len(params))
|
|
return -EINVAL;
|
|
|
|
/* Don't allocate memory. Set pointers to data within
|
|
* the given buffer
|
|
*/
|
|
params->key = (void *)ptr;
|
|
params->p = (void *)(ptr + params->key_size);
|
|
params->g = (void *)(ptr + params->key_size + params->p_size);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_dh_decode_key);
|