Re: tcrypt: hmac test with keys > blocksize fail

[Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>]

Adrian-Ken R??egsegger <rueegsegger@xxxxxxxxxxx> wrote:
> 
> using the cryptodev-2.6 tree I noticed that the hmac tests that have
> keys larger than blocksize for md5 and the various sha algorithms all
> fail (tcrypt mode=10[0-5]). The other tests seem to pass just fine.
> 
> The issue seems to have come from commit
> de224c309b5631bdaae3fcd6880cfb93b52f5a53.
> 
> 
> I have tested 48c8949ea8460216783dd33640121187b9531b60 which does not
> contain this bug.  It's just before the various tcrypt-changes from
> Sebastian Siewior.

Actually this just exposed an ancient bug in hmac.  It relied
on the key to be in identity-mapped memory which has never been
guaranteed.

This patch fixes the problem for me.

Thanks,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
diff --git a/crypto/hmac.c b/crypto/hmac.c
index b60c3c7..14c6351 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -57,14 +57,35 @@ static int hmac_setkey(struct crypto_hash *parent,
 	if (keylen > bs) {
 		struct hash_desc desc;
 		struct scatterlist tmp;
+		int tmplen;
 		int err;
 
 		desc.tfm = tfm;
 		desc.flags = crypto_hash_get_flags(parent);
 		desc.flags &= CRYPTO_TFM_REQ_MAY_SLEEP;
-		sg_init_one(&tmp, inkey, keylen);
 
-		err = crypto_hash_digest(&desc, &tmp, keylen, digest);
+		err = crypto_hash_init(&desc);
+		if (err)
+			return err;
+
+		tmplen = bs * 2 + ds;
+		sg_init_one(&tmp, ipad, tmplen);
+
+		for (; keylen > tmplen; inkey += tmplen, keylen -= tmplen) {
+			memcpy(ipad, inkey, tmplen);
+			err = crypto_hash_update(&desc, &tmp, tmplen);
+			if (err)
+				return err;
+		}
+
+		if (keylen) {
+			memcpy(ipad, inkey, keylen);
+			err = crypto_hash_update(&desc, &tmp, keylen);
+			if (err)
+				return err;
+		}
+
+		err = crypto_hash_final(&desc, digest);
 		if (err)
 			return err;
 
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html