linux/crypto/dh_helper.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

119 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016, Intel Corporation
* Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
*/
#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) + 4 * sizeof(int))
static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size)
{
if (!dst || size > end - dst)
return NULL;
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 unsigned int dh_data_size(const struct dh *p)
{
return p->key_size + p->p_size + p->q_size + p->g_size;
}
unsigned 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;
u8 * const end = ptr + len;
struct kpp_secret secret = {
.type = CRYPTO_KPP_SECRET_TYPE_DH,
.len = len
};
if (unlikely(!len))
return -EINVAL;
ptr = dh_pack_data(ptr, end, &secret, sizeof(secret));
ptr = dh_pack_data(ptr, end, &params->key_size,
sizeof(params->key_size));
ptr = dh_pack_data(ptr, end, &params->p_size, sizeof(params->p_size));
ptr = dh_pack_data(ptr, end, &params->q_size, sizeof(params->q_size));
ptr = dh_pack_data(ptr, end, &params->g_size, sizeof(params->g_size));
ptr = dh_pack_data(ptr, end, params->key, params->key_size);
ptr = dh_pack_data(ptr, end, params->p, params->p_size);
ptr = dh_pack_data(ptr, end, params->q, params->q_size);
ptr = dh_pack_data(ptr, end, params->g, params->g_size);
if (ptr != end)
return -EINVAL;
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(&params->key_size, ptr, sizeof(params->key_size));
ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
ptr = dh_unpack_data(&params->q_size, ptr, sizeof(params->q_size));
ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
if (secret.len != crypto_dh_key_len(params))
return -EINVAL;
/*
* Don't permit the buffer for 'key' or 'g' to be larger than 'p', since
* some drivers assume otherwise.
*/
if (params->key_size > params->p_size ||
params->g_size > params->p_size || params->q_size > params->p_size)
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->q = (void *)(ptr + params->key_size + params->p_size);
params->g = (void *)(ptr + params->key_size + params->p_size +
params->q_size);
/*
* Don't permit 'p' to be 0. It's not a prime number, and it's subject
* to corner cases such as 'mod 0' being undefined or
* crypto_kpp_maxsize() returning 0.
*/
if (memchr_inv(params->p, 0, params->p_size) == NULL)
return -EINVAL;
/* It is permissible to not provide Q. */
if (params->q_size == 0)
params->q = NULL;
return 0;
}
EXPORT_SYMBOL_GPL(crypto_dh_decode_key);