From: Kim Phillips Subject: Re: [PATCH 2/2 v2] talitos: Freescale integrated security engine (SEC) driver Date: Thu, 5 Jun 2008 16:44:15 -0500 Message-ID: <20080605164415.d486a299.kim.phillips@freescale.com> References: <20080530185830.60f4e1d4.kim.phillips@freescale.com> <20080605052224.GA23150@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-crypto@vger.kernel.org, linuxppc-dev@ozlabs.org, Evgeniy Polyakov To: Herbert Xu Return-path: Received: from de01egw02.freescale.net ([192.88.165.103]:40492 "EHLO de01egw02.freescale.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752617AbYFEVqc (ORCPT ); Thu, 5 Jun 2008 17:46:32 -0400 In-Reply-To: <20080605052224.GA23150@gondor.apana.org.au> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Thu, 5 Jun 2008 15:22:24 +1000 Herbert Xu wrote: > On Fri, May 30, 2008 at 06:58:30PM -0500, Kim Phillips wrote: > > > > + /* get random IV */ > > + get_random_bytes(req->giv, crypto_aead_ivsize(authenc)); > > Sorry but this is unworkable given our current RNG infrastructure. > Draining 16 bytes for every packet is going to make /dev/random > unuseable (if it wasn't already :). it is :). I'm working on it :). > Perhaps just use eseqiv (it should be pretty cheap sinec it just > tacks on an extra block to the encryption) for now until we have > a PRNG? the h/w has a IV out feature we should probably be using. How about something like this (UNTESTED): diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c index cf2e6f3..5ebb0f1 100644 --- a/drivers/crypto/talitos.c +++ b/drivers/crypto/talitos.c @@ -566,6 +566,7 @@ struct talitos_ctx { struct device *dev; __be32 desc_hdr_template; u8 key[TALITOS_MAX_KEY_SIZE]; + u8 iv[TALITOS_AES_IV_LENGTH]; unsigned int keylen; unsigned int enckeylen; unsigned int authkeylen; @@ -873,8 +874,9 @@ static int ipsec_esp(struct ipsec_esp_edesc *edesc, struct aead_request *areq, edesc->dma_len, DMA_BIDIRECTIONAL); } - /* optional iv out - entry points use random IVs instead */ - desc->ptr[6].len = 0; + /* iv out */ + map_single_talitos_ptr(dev, &desc->ptr[6], ivsize, ctx->iv, 0, + DMA_FROM_DEVICE); return talitos_submit(dev, desc, callback, areq); } @@ -1020,8 +1022,7 @@ static int aes_cbc_sha1_hmac_authenc_givencrypt( /* set encrypt */ edesc->desc.hdr = ctx->desc_hdr_template | DESC_HDR_MODE0_AESU_ENC; - /* get random IV */ - get_random_bytes(req->giv, crypto_aead_ivsize(authenc)); + memcpy(req->giv, ctx->iv, crypto_aead_ivsize(authenc)); return ipsec_esp(edesc, areq, req->giv, req->seq, ipsec_esp_encrypt_done); @@ -1081,6 +1082,9 @@ static int talitos_cra_init(struct crypto_tfm *tfm) /* copy descriptor header template value */ ctx->desc_hdr_template = talitos_alg->desc_hdr_template; + /* random first IV */ + get_random_bytes(ctx->iv, TALITOS_AES_IV_LENGTH); + return 0; } Kim