crypto: sha - replace memset by memzero_explicit

Memset on a local variable may be removed when it is called just before the
variable goes out of scope.  Using memzero_explicit defeats this
optimization.  A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
type T;
@@

{
... when any
T x[...];
... when any
    when exists
- memset
+ memzero_explicit
  (x,
-0,
  ...)
... when != x
    when strict
}
// </smpl>

This change was suggested by Daniel Borkmann <dborkman@redhat.com>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Julia Lawall 2014-11-30 18:03:44 +01:00 committed by Herbert Xu
parent 8202cd7206
commit a6326ba025
2 changed files with 2 additions and 2 deletions

View File

@ -211,7 +211,7 @@ static int sha224_ssse3_final(struct shash_desc *desc, u8 *hash)
sha256_ssse3_final(desc, D);
memcpy(hash, D, SHA224_DIGEST_SIZE);
memset(D, 0, SHA256_DIGEST_SIZE);
memzero_explicit(D, SHA256_DIGEST_SIZE);
return 0;
}

View File

@ -219,7 +219,7 @@ static int sha384_ssse3_final(struct shash_desc *desc, u8 *hash)
sha512_ssse3_final(desc, D);
memcpy(hash, D, SHA384_DIGEST_SIZE);
memset(D, 0, SHA512_DIGEST_SIZE);
memzero_explicit(D, SHA512_DIGEST_SIZE);
return 0;
}