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Commit 13c935bb authored by Salvatore Mesoraca's avatar Salvatore Mesoraca Committed by Herbert Xu
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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
buffer.
We also enforce these limits in crypto_check_alg when a new
cipher is registered.

[1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com



Signed-off-by: default avatarSalvatore Mesoraca <s.mesoraca16@gmail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent c4e84858

crypto/algapi.c

+10 −0
Original line number Diff line number Diff line
@@ -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) ==

			       CRYPTO_ALG_TYPE_CIPHER) {

		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;

include/crypto/algapi.h

+8 −0
Original line number Diff line number Diff line
@@ -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.

 */

#define MAX_CIPHER_BLOCKSIZE		16

#define MAX_CIPHER_ALIGNMASK		15



struct crypto_aead;

struct crypto_instance;

struct module;