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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 EDC67C10F14 for ; Wed, 10 Apr 2019 06:48:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDA6F2083E for ; Wed, 10 Apr 2019 06:48:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554878929; bh=DSKp+hJvQwS1YK+d6ixSmvgXn1wvYr8vfysXcKoP1LE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ozy6thP9Hci7AL+zqjigxcrPMwmIIGN4T4Tv2d79e0RaglcwVMpZWJYK9mk+dRBIo vLyyYcdzWnRd+HQySH6Ein9QJT7+obUNWi16o4xt+k+gNCHSa2T636CrGhsl2FxW5Z p3PWp6BTttHp96CZADwKhLb6/zbEqBFu/tRSoWBU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728626AbfDJGss (ORCPT ); Wed, 10 Apr 2019 02:48:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:53352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728721AbfDJGss (ORCPT ); Wed, 10 Apr 2019 02:48:48 -0400 Received: from sol.localdomain (c-24-5-143-220.hsd1.ca.comcast.net [24.5.143.220]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6F5C7217F9; Wed, 10 Apr 2019 06:48:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554878927; bh=DSKp+hJvQwS1YK+d6ixSmvgXn1wvYr8vfysXcKoP1LE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QAjn1SqACpJ/2SyWVbwwr5X9yFRTgNhOQJRk8FQxzwNBzfXXjHnPQjiZEXFkE/0NN uHPyL9v76GfJoCWHhTPsSnrO+ssv13ShRzR0hHkJ3Lsy8+Dynb4b6elVTj3ZwijtC1 yESFMhF3kCvOPc80ozvRW9hB+lnb5fJySSxTdiyE= From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: stable@vger.kernel.org Subject: [PATCH v2 6/7] crypto: ccm - fix incompatibility between "ccm" and "ccm_base" Date: Tue, 9 Apr 2019 23:46:34 -0700 Message-Id: <20190410064635.11813-7-ebiggers@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190410064635.11813-1-ebiggers@kernel.org> References: <20190410064635.11813-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers CCM instances can be created by either the "ccm" template, which only allows choosing the block cipher, e.g. "ccm(aes)"; or by "ccm_base", which allows choosing the ctr and cbcmac implementations, e.g. "ccm_base(ctr(aes-generic),cbcmac(aes-generic))". However, a "ccm_base" instance prevents a "ccm" instance from being registered using the same implementations. Nor will the instance be found by lookups of "ccm". This can be used as a denial of service. Moreover, "ccm_base" instances are never tested by the crypto self-tests, even if there are compatible "ccm" tests. The root cause of these problems is that instances of the two templates use different cra_names. Therefore, fix these problems by making "ccm_base" instances set the same cra_name as "ccm" instances, e.g. "ccm(aes)" instead of "ccm_base(ctr(aes-generic),cbcmac(aes-generic))". This requires extracting the block cipher name from the name of the ctr and cbcmac algorithms. It also requires starting to verify that the algorithms are really ctr and cbcmac using the same block cipher, not something else entirely. But it would be bizarre if anyone were actually using non-ccm-compatible algorithms with ccm_base, so this shouldn't break anyone in practice. Fixes: 4a49b499dfa0 ("[CRYPTO] ccm: Added CCM mode") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers --- crypto/ccm.c | 43 +++++++++++++++++-------------------------- 1 file changed, 17 insertions(+), 26 deletions(-) diff --git a/crypto/ccm.c b/crypto/ccm.c index 50df8f001c1c9..dbb3b6d8e6136 100644 --- a/crypto/ccm.c +++ b/crypto/ccm.c @@ -458,7 +458,6 @@ static void crypto_ccm_free(struct aead_instance *inst) static int crypto_ccm_create_common(struct crypto_template *tmpl, struct rtattr **tb, - const char *full_name, const char *ctr_name, const char *mac_name) { @@ -486,7 +485,8 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl, mac = __crypto_hash_alg_common(mac_alg); err = -EINVAL; - if (mac->digestsize != 16) + if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 || + mac->digestsize != 16) goto out_put_mac; inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL); @@ -509,23 +509,26 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl, ctr = crypto_spawn_skcipher_alg(&ictx->ctr); - /* Not a stream cipher? */ + /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */ err = -EINVAL; - if (ctr->base.cra_blocksize != 1) + if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 || + crypto_skcipher_alg_ivsize(ctr) != 16) goto err_drop_ctr; - /* We want the real thing! */ - if (crypto_skcipher_alg_ivsize(ctr) != 16) + /* ctr and cbcmac must use the same underlying block cipher. */ + if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0) goto err_drop_ctr; err = -ENAMETOOLONG; + if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, + "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME) + goto err_drop_ctr; + if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)", ctr->base.cra_driver_name, mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) goto err_drop_ctr; - memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME); - inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC; inst->alg.base.cra_priority = (mac->base.cra_priority + ctr->base.cra_priority) / 2; @@ -567,7 +570,6 @@ static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb) const char *cipher_name; char ctr_name[CRYPTO_MAX_ALG_NAME]; char mac_name[CRYPTO_MAX_ALG_NAME]; - char full_name[CRYPTO_MAX_ALG_NAME]; cipher_name = crypto_attr_alg_name(tb[1]); if (IS_ERR(cipher_name)) @@ -581,35 +583,24 @@ static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb) cipher_name) >= CRYPTO_MAX_ALG_NAME) return -ENAMETOOLONG; - if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >= - CRYPTO_MAX_ALG_NAME) - return -ENAMETOOLONG; - - return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name, - mac_name); + return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name); } static int crypto_ccm_base_create(struct crypto_template *tmpl, struct rtattr **tb) { const char *ctr_name; - const char *cipher_name; - char full_name[CRYPTO_MAX_ALG_NAME]; + const char *mac_name; ctr_name = crypto_attr_alg_name(tb[1]); if (IS_ERR(ctr_name)) return PTR_ERR(ctr_name); - cipher_name = crypto_attr_alg_name(tb[2]); - if (IS_ERR(cipher_name)) - return PTR_ERR(cipher_name); - - if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)", - ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME) - return -ENAMETOOLONG; + mac_name = crypto_attr_alg_name(tb[2]); + if (IS_ERR(mac_name)) + return PTR_ERR(mac_name); - return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name, - cipher_name); + return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name); } static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key, -- 2.21.0