mirror of
https://github.com/torvalds/linux.git
synced 2024-12-30 14:52:05 +00:00
ccd9888f14
The "qat-dh" DH implementation assumes that 'key' and 'g' can be copied
into a buffer with size 'p_size'. However it was never checked that
that was actually the case, which most likely allowed users to cause a
buffer underflow via KEYCTL_DH_COMPUTE.
Fix this by updating crypto_dh_decode_key() to verify this precondition
for all DH implementations.
Fixes: c9839143eb ("crypto: qat - Add DH support")
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
112 lines
3.1 KiB
C
112 lines
3.1 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 unsigned int dh_data_size(const struct dh *p)
|
|
{
|
|
return p->key_size + p->p_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;
|
|
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 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)
|
|
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);
|
|
|
|
/*
|
|
* 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;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_dh_decode_key);
|