From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D81BBC43331 for ; Fri, 6 Sep 2019 13:12:38 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ACD49206BB for ; Fri, 6 Sep 2019 13:12:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACD49206BB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56184 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i6E2X-0006m6-P0 for qemu-devel@archiver.kernel.org; Fri, 06 Sep 2019 09:12:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33574) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i6E1l-0006J7-V9 for qemu-devel@nongnu.org; Fri, 06 Sep 2019 09:11:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i6E1k-0007JH-IK for qemu-devel@nongnu.org; Fri, 06 Sep 2019 09:11:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58906) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i6E1h-0007G3-5s; Fri, 06 Sep 2019 09:11:45 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 913A87F768; Fri, 6 Sep 2019 13:11:43 +0000 (UTC) Received: from redhat.com (ovpn-112-50.ams2.redhat.com [10.36.112.50]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 07DA7166CE; Fri, 6 Sep 2019 13:11:39 +0000 (UTC) Date: Fri, 6 Sep 2019 14:11:36 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Maxim Levitsky Message-ID: <20190906131123.GF5119@redhat.com> References: <20190826135103.22410-1-mlevitsk@redhat.com> <20190826135103.22410-10-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190826135103.22410-10-mlevitsk@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.71]); Fri, 06 Sep 2019 13:11:44 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v2 09/13] qcrypto-block: extract check and parse header X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Markus Armbruster , qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Aug 26, 2019 at 04:50:59PM +0300, Maxim Levitsky wrote: > This is just to make qcrypto_block_luks_open more > reasonable in size. > > Signed-off-by: Maxim Levitsky > --- > crypto/block-luks.c | 254 +++++++++++++++++++++++++------------------- > 1 file changed, 146 insertions(+), 108 deletions(-) > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > index b4dc6fc899..cc9a52c9af 100644 > --- a/crypto/block-luks.c > +++ b/crypto/block-luks.c > @@ -508,6 +508,148 @@ fail: > return ret; > } > > +/* > + * Does basic sanity checks on the LUKS header > + */ > +static int > +qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp) > +{ > + int ret; > + > + if (memcmp(luks->header.magic, qcrypto_block_luks_magic, > + QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { > + error_setg(errp, "Volume is not in LUKS format"); > + ret = -EINVAL; > + goto fail; > + } Just 'return -1' here immediately - don't return an errno, as we're using Error objects for reporting. > + > + if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { > + error_setg(errp, "LUKS version %" PRIu32 " is not supported", > + luks->header.version); > + ret = -ENOTSUP; > + goto fail; > + } > + > + return 0; > +fail: > + return ret; > +} > + > +/* > + * Parses the crypto parameters that are stored in the LUKS header > + */ > + > +static int > +qcrypto_block_luks_parse_header(QCryptoBlockLUKS *luks, Error **errp) > +{ > + g_autofree char *cipher_mode = g_strdup(luks->header.cipher_mode); > + char *ivgen_name, *ivhash_name; > + int ret = -1; > + Error *local_err = NULL; > + > + /* > + * The cipher_mode header contains a string that we have > + * to further parse, of the format > + * > + * -[:] > + * > + * eg cbc-essiv:sha256, cbc-plain64 > + */ > + ivgen_name = strchr(cipher_mode, '-'); > + if (!ivgen_name) { > + ret = -EINVAL; Again, don't use errnos - just return -1 in this method. > + error_setg(errp, "Unexpected cipher mode string format %s", > + luks->header.cipher_mode); > + goto out; > + } > + *ivgen_name = '\0'; > + ivgen_name++; > + > + ivhash_name = strchr(ivgen_name, ':'); > + if (!ivhash_name) { > + luks->ivgen_hash_alg = 0; > + } else { > + *ivhash_name = '\0'; > + ivhash_name++; > + > + luks->ivgen_hash_alg = qcrypto_block_luks_hash_name_lookup(ivhash_name, > + &local_err); > + if (local_err) { > + ret = -ENOTSUP; > + error_propagate(errp, local_err); > + goto out; > + } > + } > + > + luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode, > + &local_err); > + if (local_err) { > + ret = -ENOTSUP; > + error_propagate(errp, local_err); > + goto out; > + } > + > + luks->cipher_alg = > + qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, > + luks->cipher_mode, > + luks->header.master_key_len, > + &local_err); > + if (local_err) { > + ret = -ENOTSUP; > + error_propagate(errp, local_err); > + goto out; > + } > + > + luks->hash_alg = > + qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, > + &local_err); > + if (local_err) { > + ret = -ENOTSUP; > + error_propagate(errp, local_err); > + goto out; > + } > + > + luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, > + &local_err); > + if (local_err) { > + ret = -ENOTSUP; > + error_propagate(errp, local_err); > + goto out; > + } > + > + if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { > + if (!ivhash_name) { > + ret = -EINVAL; > + error_setg(errp, "Missing IV generator hash specification"); > + goto out; > + } > + luks->ivgen_cipher_alg = > + qcrypto_block_luks_essiv_cipher(luks->cipher_alg, > + luks->ivgen_hash_alg, > + &local_err); > + if (local_err) { > + ret = -ENOTSUP; > + error_propagate(errp, local_err); > + goto out; > + } > + } else { > + > + /* > + * Note we parsed the ivhash_name earlier in the cipher_mode > + * spec string even with plain/plain64 ivgens, but we > + * will ignore it, since it is irrelevant for these ivgens. > + * This is for compat with dm-crypt which will silently > + * ignore hash names with these ivgens rather than report > + * an error about the invalid usage > + */ > + luks->ivgen_cipher_alg = luks->cipher_alg; > + } > + ret = 0; > +out: > + return ret; > + > +} > + > /* > * Given a key slot, and user password, this will attempt to unlock > * the master encryption key from the key slot. > @@ -720,12 +862,9 @@ qcrypto_block_luks_open(QCryptoBlock *block, > Error **errp) > { > QCryptoBlockLUKS *luks = NULL; > - Error *local_err = NULL; > int ret = 0; > g_autofree uint8_t *masterkey = NULL; > - char *ivgen_name, *ivhash_name; > g_autofree char *password = NULL; > - g_autofree char *cipher_mode = NULL; > > if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { > if (!options->u.luks.key_secret) { > @@ -748,117 +887,16 @@ qcrypto_block_luks_open(QCryptoBlock *block, > goto fail; > } > > - > - if (memcmp(luks->header.magic, qcrypto_block_luks_magic, > - QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { > - error_setg(errp, "Volume is not in LUKS format"); > - ret = -EINVAL; I can't remember why I set ret to an errno in my original code. it is entirely pointless, as the caller of this method merely checks "ret < 0" and doesn't do anything else with the return value. IOW, we should just purge the errnors from this existing code entirely. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|