From: Herbert Xu Subject: [PATCH] crypto: hash - Fixed digest size check Date: Mon, 7 Jul 2008 20:31:31 +0800 Message-ID: <20080707123131.GA12105@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Linux Crypto Mailing List Return-path: Received: from rhun.apana.org.au ([64.62.148.172]:34688 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753344AbYGGMbe (ORCPT ); Mon, 7 Jul 2008 08:31:34 -0400 Received: from gondolin.me.apana.org.au ([192.168.0.6] ident=mail) by arnor.apana.org.au with esmtp (Exim 4.63 #1 (Debian)) id 1KFpsR-00056B-Kz for ; Mon, 07 Jul 2008 22:31:32 +1000 Received: from herbert by gondolin.me.apana.org.au with local (Exim 3.36 #1 (Debian)) id 1KFpsR-00039W-00 for ; Mon, 07 Jul 2008 20:31:31 +0800 Content-Disposition: inline Sender: linux-crypto-owner@vger.kernel.org List-ID: Hi: I'm going to add this patch to cryptodev-2.6: commit cbc5176dbb8d80d50efa515d7f8bed90b1fdc922 Author: Herbert Xu Date: Mon Jul 7 20:23:56 2008 +0800 crypto: hash - Fixed digest size check The digest size check on hash algorithms is incorrect. It's perfectly valid for hash algorithms to have a digest length longer than their block size. For example crc32c has a block size of 1 and a digest size of 4. Rather than having it lie about its block size, this patch fixes the checks to do what they really should which is to bound the digest size so that code placing the digest on the stack continue to work. HMAC however still needs to check this as it's only defined for such algorithms. Signed-off-by: Herbert Xu diff --git a/crypto/ahash.c b/crypto/ahash.c index a83e035..8c1f918 100644 --- a/crypto/ahash.c +++ b/crypto/ahash.c @@ -68,7 +68,7 @@ static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask) struct ahash_alg *alg = &tfm->__crt_alg->cra_ahash; struct ahash_tfm *crt = &tfm->crt_ahash; - if (alg->digestsize > crypto_tfm_alg_blocksize(tfm)) + if (alg->digestsize > PAGE_SIZE / 8) return -EINVAL; crt->init = alg->init; diff --git a/crypto/digest.c b/crypto/digest.c index 025c9ae..d63d5d9 100644 --- a/crypto/digest.c +++ b/crypto/digest.c @@ -141,7 +141,7 @@ int crypto_init_digest_ops(struct crypto_tfm *tfm) struct hash_tfm *ops = &tfm->crt_hash; struct digest_alg *dalg = &tfm->__crt_alg->cra_digest; - if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm)) + if (dalg->dia_digestsize > PAGE_SIZE / 8) return -EINVAL; ops->init = init; diff --git a/crypto/hash.c b/crypto/hash.c index f9400a0..0d7caa9 100644 --- a/crypto/hash.c +++ b/crypto/hash.c @@ -152,7 +152,7 @@ static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask) { struct hash_alg *alg = &tfm->__crt_alg->cra_hash; - if (alg->digestsize > crypto_tfm_alg_blocksize(tfm)) + if (alg->digestsize > PAGE_SIZE / 8) return -EINVAL; if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) != CRYPTO_ALG_TYPE_HASH_MASK) diff --git a/crypto/hmac.c b/crypto/hmac.c index 14c6351..7ff2d6a 100644 --- a/crypto/hmac.c +++ b/crypto/hmac.c @@ -226,6 +226,7 @@ static struct crypto_instance *hmac_alloc(struct rtattr **tb) struct crypto_instance *inst; struct crypto_alg *alg; int err; + int ds; err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH); if (err) @@ -236,6 +237,13 @@ static struct crypto_instance *hmac_alloc(struct rtattr **tb) if (IS_ERR(alg)) return ERR_CAST(alg); + inst = ERR_PTR(-EINVAL); + ds = (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == + CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize : + alg->cra_digest.dia_digestsize; + if (ds > alg->cra_blocksize) + goto out_put_alg; + inst = crypto_alloc_instance("hmac", alg); if (IS_ERR(inst)) goto out_put_alg; @@ -246,14 +254,10 @@ static struct crypto_instance *hmac_alloc(struct rtattr **tb) inst->alg.cra_alignmask = alg->cra_alignmask; inst->alg.cra_type = &crypto_hash_type; - inst->alg.cra_hash.digestsize = - (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == - CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize : - alg->cra_digest.dia_digestsize; + inst->alg.cra_hash.digestsize = ds; inst->alg.cra_ctxsize = sizeof(struct hmac_ctx) + - ALIGN(inst->alg.cra_blocksize * 2 + - inst->alg.cra_hash.digestsize, + ALIGN(inst->alg.cra_blocksize * 2 + ds, sizeof(void *)); inst->alg.cra_init = hmac_init_tfm; -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt