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authorHerbert Xu <herbert@gondor.apana.org.au>2013-10-30 09:51:45 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2013-10-30 09:51:45 +0800
commitf3d53ed038944a5e785f04952170f7e239a49ae8 (patch)
tree199e6e156dae4b50b9b79ec95b3e21ea9737ede5 /crypto
parentc306a98d637613818c87c19eabf7feba02b5b618 (diff)
crypto: skcipher - Use eseqiv even on UP machines
Previously we would use eseqiv on all async ciphers in all cases, and sync ciphers if we have more than one CPU. This meant that chainiv is only used in the case of sync ciphers on a UP machine. As chainiv may aid attackers by making the IV predictable, even though this risk itself is small, the above usage pattern causes it to further leak information about the host. This patch addresses these issues by using eseqiv even if we're on a UP machine. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Acked-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/ablkcipher.c21
1 files changed, 1 insertions, 20 deletions
diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index 7d4a8d28277e..40886c489903 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -16,9 +16,7 @@
#include <crypto/internal/skcipher.h>
#include <linux/cpumask.h>
#include <linux/err.h>
-#include <linux/init.h>
#include <linux/kernel.h>
-#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
@@ -30,8 +28,6 @@
#include "internal.h"
-static const char *skcipher_default_geniv __read_mostly;
-
struct ablkcipher_buffer {
struct list_head entry;
struct scatter_walk dst;
@@ -527,8 +523,7 @@ const char *crypto_default_geniv(const struct crypto_alg *alg)
alg->cra_blocksize)
return "chainiv";
- return alg->cra_flags & CRYPTO_ALG_ASYNC ?
- "eseqiv" : skcipher_default_geniv;
+ return "eseqiv";
}
static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
@@ -709,17 +704,3 @@ err:
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
-
-static int __init skcipher_module_init(void)
-{
- skcipher_default_geniv = num_possible_cpus() > 1 ?
- "eseqiv" : "chainiv";
- return 0;
-}
-
-static void skcipher_module_exit(void)
-{
-}
-
-module_init(skcipher_module_init);
-module_exit(skcipher_module_exit);

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