Commit 13c935bb authored by Salvatore Mesoraca's avatar Salvatore Mesoraca Committed by Herbert Xu

crypto: api - laying defines and checks for statically allocated buffers

In preparation for the removal of VLAs[1] from crypto code.
We create 2 new compile-time constants: all ciphers implemented
in Linux have a block size less than or equal to 16 bytes and
the most demanding hw require 16 bytes alignment for the block
We also enforce these limits in crypto_check_alg when a new
cipher is registered.

[1] default avatarSalvatore Mesoraca <>
Signed-off-by: default avatarHerbert Xu <>
parent c4e84858
......@@ -10,6 +10,7 @@
#include <crypto/algapi.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/fips.h>
......@@ -59,6 +60,15 @@ static int crypto_check_alg(struct crypto_alg *alg)
if (alg->cra_blocksize > PAGE_SIZE / 8)
return -EINVAL;
if (!alg->cra_type && (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
if (alg->cra_alignmask > MAX_CIPHER_ALIGNMASK)
return -EINVAL;
if (alg->cra_blocksize > MAX_CIPHER_BLOCKSIZE)
return -EINVAL;
if (alg->cra_priority < 0)
return -EINVAL;
......@@ -17,6 +17,14 @@
#include <linux/kernel.h>
#include <linux/skbuff.h>
* Maximum values for blocksize and alignmask, used to allocate
* static buffers that are big enough for any combination of
* ciphers and architectures.
struct crypto_aead;
struct crypto_instance;
struct module;
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