From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.110.172]:49760 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726030AbfFUIJi (ORCPT ); Fri, 21 Jun 2019 04:09:38 -0400 From: Ard Biesheuvel Subject: [PATCH v4 3/6] md: dm-crypt: infer ESSIV block cipher from cipher string directly Date: Fri, 21 Jun 2019 10:09:15 +0200 Message-Id: <20190621080918.22809-4-ard.biesheuvel@arm.com> In-Reply-To: <20190621080918.22809-1-ard.biesheuvel@arm.com> References: <20190621080918.22809-1-ard.biesheuvel@arm.com> Reply-To: ard.biesheuvel@linaro.org Sender: linux-fscrypt-owner@vger.kernel.org To: linux-crypto@vger.kernel.org Cc: Ard Biesheuvel , Herbert Xu , Eric Biggers , dm-devel@redhat.com, linux-fscrypt@vger.kernel.org, Gilad Ben-Yossef , Milan Broz List-ID: From: Ard Biesheuvel Instead of allocating a crypto skcipher tfm 'foo' and attempting to infer the encapsulated block cipher from the driver's 'name' field, directly parse the string that we used to allocated the tfm. These are always identical (unless the allocation failed, in which case we bail anyway), but using the string allows us to use it in the allocation, which is something we will need when switching to the 'essiv' crypto API template. Signed-off-by: Ard Biesheuvel --- drivers/md/dm-crypt.c | 35 +++++++++----------- 1 file changed, 15 insertions(+), 20 deletions(-) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 1b16d34bb785..f001f1104cb5 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -2321,25 +2321,17 @@ static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) * The cc->cipher is currently used only in ESSIV. * This should be probably done by crypto-api calls (once available...) */ -static int crypt_ctr_blkdev_cipher(struct crypt_config *cc) +static int crypt_ctr_blkdev_cipher(struct crypt_config *cc, char *alg_name) { - const char *alg_name = NULL; char *start, *end; if (crypt_integrity_aead(cc)) { - alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc))); - if (!alg_name) - return -EINVAL; if (crypt_integrity_hmac(cc)) { alg_name = strchr(alg_name, ','); if (!alg_name) return -EINVAL; } alg_name++; - } else { - alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc))); - if (!alg_name) - return -EINVAL; } start = strchr(alg_name, '('); @@ -2434,6 +2426,20 @@ static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key if (*ivmode && !strcmp(*ivmode, "lmk")) cc->tfms_count = 64; + if (crypt_integrity_aead(cc)) { + ret = crypt_ctr_auth_cipher(cc, cipher_api); + if (ret < 0) { + ti->error = "Invalid AEAD cipher spec"; + return -ENOMEM; + } + } + + ret = crypt_ctr_blkdev_cipher(cc, cipher_api); + if (ret < 0) { + ti->error = "Cannot allocate cipher string"; + return -ENOMEM; + } + cc->key_parts = cc->tfms_count; /* Allocate cipher */ @@ -2445,21 +2451,10 @@ static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key /* Alloc AEAD, can be used only in new format. */ if (crypt_integrity_aead(cc)) { - ret = crypt_ctr_auth_cipher(cc, cipher_api); - if (ret < 0) { - ti->error = "Invalid AEAD cipher spec"; - return -ENOMEM; - } cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); } else cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); - ret = crypt_ctr_blkdev_cipher(cc); - if (ret < 0) { - ti->error = "Cannot allocate cipher string"; - return -ENOMEM; - } - return 0; } -- 2.17.1