crypto: zeroization of buffers
cover crypto: zeroization of buffers
Hi Herbert,
as discussed, these patches use the memzero_explicit function that is yet to be integrated into the cryptodev-2.6 tree.
Stephan Mueller (2):
crypto: AF_ALG - zeroize message digest buffer
crypto: AF_ALG - zeroize IV buffer
crypto/algif_hash.c | 2 ++ crypto/algif_skcipher.c | 1 + 2 files changed, 3 insertions(+)
Signature · 1 line
2.1.0
PATCH 1/2 crypto: AF_ALG - zeroize message digest buffer
Zeroize the buffer holding the message digest calculated for the consumer before the buffer is released by the hash AF_ALG interface handler.
--- crypto/algif_hash.c | 2 ++ 1 file changed, 2 insertions(+)
crypto/algif_hash.c +2 -0
@@ -258,6 +258,8 @@ static void hash_sock_destruct(struct sock *sk)struct alg_sock *ask =alg_sk (sk);struct hash_ctx *ctx = ask->private; +memzero_explicit (ctx->result, +crypto_ahash_digestsize (crypto_ahash_reqtfm (&ctx->req)));sock_kfree_s (sk, ctx->result,crypto_ahash_digestsize (crypto_ahash_reqtfm (&ctx->req)));sock_kfree_s (sk, ctx, ctx->len);
Signature · 1 line
2.1.0
Re: [PATCH 1/2] crypto: AF_ALG - zeroize message digest buffer
Hi Stephan,
Quoted 14 lines · Stephan Mueller
Zeroize the buffer holding the message digest calculated for the consumer before the buffer is released by the hash
AF_ALGinterface handler.Signed-off-by Stephan Mueller <[email protected]>--- crypto/algif_hash.c | 2 ++ 1 file changed, 2 insertions(+)crypto/algif_hash.c +0
-0
crypto/algif_hash.c static void hash_sock_destruct(struct sock *sk) · line 263
Quoted 6 lines
crypto/algif_hash.c +2
-0@@ -258,6 +258,8 @@ static void hash_sock_destruct(struct sock *sk)struct alg_sock *ask =alg_sk (sk);struct hash_ctx *ctx = ask->private; +memzero_explicit (ctx->result, +crypto_ahash_digestsize (crypto_ahash_reqtfm (&ctx->req))); sock_kfree_s(sk, ctx->result,
Perhaps something like this (alternatively kzfree() would work, too) ...
static void __sock_kfree_s(struct sock *sk, void *mem, int size,
bool clear_mem)
{
if (WARN_ON_ONCE(!mem))
return;
if (clear_mem)
memzero_explicit(mem, size);
kfree(mem);
atomic_sub(size, &sk->sk_omem_alloc);
}void sock_kfree_s(struct sock *sk, void *mem, int size)
{
__sock_kfree_s(sk, mem, size, false);
}EXPORT_SYMBOL(sock_kfree_s);
void sock_kzfree_s(struct sock *sk, void *mem, int size)
{
__sock_kfree_s(sk, mem, size, true);
}EXPORT_SYMBOL(sock_kzfree_s);
... so you could then just use it as drop-in in various places:
sock_kzfree_s(sk, ctx->result, ...);
crypto/algif_hash.c static void hash_sock_destruct(struct sock *sk) · line 265
Quoted 3 lines
crypto/algif_hash.c +0
-0crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));sock_kfree_s (sk, ctx, ctx->len);
Thanks,
Daniel
PATCH 2/2 crypto: AF_ALG - zeroize IV buffer
In reply to Stephan MuellerZeroize the buffer holding the IV used for the completed cipher operation before the buffer is released by the skcipher AF_ALG interface handler.
--- crypto/algif_skcipher.c | 1 + 1 file changed, 1 insertion(+)
crypto/algif_skcipher.c +1 -0
@@ -566,6 +566,7 @@ static void skcipher_sock_destruct(struct sock *sk)struct crypto_ablkcipher *tfm =crypto_ablkcipher_reqtfm (&ctx->req);skcipher_free_sgl (sk); +memzero_explicit (ctx->iv,crypto_ablkcipher_ivsize (tfm));sock_kfree_s (sk, ctx->iv,crypto_ablkcipher_ivsize (tfm));sock_kfree_s (sk, ctx, ctx->len);af_alg_release_parent (sk);
Signature · 1 line
2.1.0
Herbert Xu
maintainerQuoted 5 lines · Stephan Mueller
Hi Herbert,
as discussed, these patches use the
memzero_explicitfunction that is yet to be integrated into the cryptodev-2.6 tree.
Quoted 7 lines
Stephan Mueller (2):
crypto:AF_ALG- zeroize message digest buffer
crypto:AF_ALG- zeroize IV buffercrypto/algif_hash.c | 2 ++ crypto/algif_skcipher.c | 1 + 2 files changed, 3 insertions(+)
All applied.
Signature · 3 lines
Email: Herbert Xu <[email protected]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt