From patchwork Mon Apr 28 19:04:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 885877 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4504319ABC6; Mon, 28 Apr 2025 19:04:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745867098; cv=none; b=Rf3hQAQYnj19cJP2CSP07flIh93UVBBNSqou9G0qNgOcpXbBmkLum8vlH48ldpw6jGHsKDGZ7UY+bGRGermmoMVKKli3KcN6TGGF1LIRJO6Tp6k78dYpzyirxSU/TOxJo1VEmTFccK1LoNRDSdF5Ff1yn0525E2zKuUztb8ntXY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745867098; c=relaxed/simple; bh=yd3XTTVHcnpHFArsoHLF/KSZ5TfDWwJCeAmdln9qQkU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=M/G6bCopdcDgKTUKTeHIGVK88zvB5+4LPpcIqS3mLYn7BBYwOw7npvAo1HDRruMgMlhnsaVCktgFz5OQJZuhkI2amz9He7dDgHueFeL5iyJe1ObpoG4Fr3w6u2T5i7Xun393w8ReMsDwUWmiOMznBnUgdwifDNBKMOPMfUAQvig= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ALJYc9PR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ALJYc9PR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E886C4CEE4; Mon, 28 Apr 2025 19:04:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745867097; bh=yd3XTTVHcnpHFArsoHLF/KSZ5TfDWwJCeAmdln9qQkU=; h=From:To:Cc:Subject:Date:From; b=ALJYc9PR+AUq1lxvddH9AbDiAfljYdiuvDEbETp9zB1F3uSSjOOkV+wbgNTg4eYfu XZRQBn9i9BZ/+YyRZapwV5j6BhmvkzO83Kcq7epw/hPqbeL2zsGaOYdT/KdDmwDvIs nhqApA8jty67E5MhvES4Ktr9Ih1v7zWMTK3Uj5mjrAK8uYOu+5/dR32eZERKpSs+v9 43GlLTj6W3H2HBBUSpcTLpoNDVL5edUePZkedWJA+fgB7NF6JTqkyydNCReleYV/sE kpzr0GzI3opXLnT0ZE8fShBuBQG0YQXzesLUXufuRdpbnwYcAOiXbmS6e9mfnjBhHb E1FJS7is8lGuw== From: Eric Biggers To: John Johansen , apparmor@lists.ubuntu.com Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org Subject: [PATCH] apparmor: use SHA-256 library API instead of crypto_shash API Date: Mon, 28 Apr 2025 12:04:30 -0700 Message-ID: <20250428190430.850240-1-ebiggers@kernel.org> X-Mailer: git-send-email 2.49.0 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Eric Biggers This user of SHA-256 does not support any other algorithm, so the crypto_shash abstraction provides no value. Just use the SHA-256 library API instead, which is much simpler and easier to use. Signed-off-by: Eric Biggers --- This patch is targeting the apparmor tree for 6.16. security/apparmor/Kconfig | 3 +- security/apparmor/crypto.c | 85 ++++++-------------------------------- 2 files changed, 13 insertions(+), 75 deletions(-) base-commit: 33035b665157558254b3c21c3f049fd728e72368 diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig index 64cc3044a42ce..1e3bd44643dac 100644 --- a/security/apparmor/Kconfig +++ b/security/apparmor/Kconfig @@ -57,12 +57,11 @@ config SECURITY_APPARMOR_INTROSPECT_POLICY cpu is paramount. config SECURITY_APPARMOR_HASH bool "Enable introspection of sha256 hashes for loaded profiles" depends on SECURITY_APPARMOR_INTROSPECT_POLICY - select CRYPTO - select CRYPTO_SHA256 + select CRYPTO_LIB_SHA256 default y help This option selects whether introspection of loaded policy hashes is available to userspace via the apparmor filesystem. This option provides a light weight means of diff --git a/security/apparmor/crypto.c b/security/apparmor/crypto.c index aad486b2fca65..40e17e153f1e5 100644 --- a/security/apparmor/crypto.c +++ b/security/apparmor/crypto.c @@ -9,115 +9,54 @@ * Fns to provide a checksum of policy that has been loaded this can be * compared to userspace policy compiles to check loaded policy is what * it should be. */ -#include +#include #include "include/apparmor.h" #include "include/crypto.h" -static unsigned int apparmor_hash_size; - -static struct crypto_shash *apparmor_tfm; - unsigned int aa_hash_size(void) { - return apparmor_hash_size; + return SHA256_DIGEST_SIZE; } char *aa_calc_hash(void *data, size_t len) { - SHASH_DESC_ON_STACK(desc, apparmor_tfm); char *hash; - int error; - - if (!apparmor_tfm) - return NULL; - hash = kzalloc(apparmor_hash_size, GFP_KERNEL); + hash = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); if (!hash) return ERR_PTR(-ENOMEM); - desc->tfm = apparmor_tfm; - - error = crypto_shash_init(desc); - if (error) - goto fail; - error = crypto_shash_update(desc, (u8 *) data, len); - if (error) - goto fail; - error = crypto_shash_final(desc, hash); - if (error) - goto fail; - + sha256(data, len, hash); return hash; - -fail: - kfree(hash); - - return ERR_PTR(error); } int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, size_t len) { - SHASH_DESC_ON_STACK(desc, apparmor_tfm); - int error; + struct sha256_state state; __le32 le32_version = cpu_to_le32(version); if (!aa_g_hash_policy) return 0; - if (!apparmor_tfm) - return 0; - - profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL); + profile->hash = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); if (!profile->hash) return -ENOMEM; - desc->tfm = apparmor_tfm; - - error = crypto_shash_init(desc); - if (error) - goto fail; - error = crypto_shash_update(desc, (u8 *) &le32_version, 4); - if (error) - goto fail; - error = crypto_shash_update(desc, (u8 *) start, len); - if (error) - goto fail; - error = crypto_shash_final(desc, profile->hash); - if (error) - goto fail; - + sha256_init(&state); + sha256_update(&state, (u8 *)&le32_version, 4); + sha256_update(&state, (u8 *)start, len); + sha256_final(&state, profile->hash); return 0; - -fail: - kfree(profile->hash); - profile->hash = NULL; - - return error; } static int __init init_profile_hash(void) { - struct crypto_shash *tfm; - - if (!apparmor_initialized) - return 0; - - tfm = crypto_alloc_shash("sha256", 0, 0); - if (IS_ERR(tfm)) { - int error = PTR_ERR(tfm); - AA_ERROR("failed to setup profile sha256 hashing: %d\n", error); - return error; - } - apparmor_tfm = tfm; - apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm); - - aa_info_message("AppArmor sha256 policy hashing enabled"); - + if (apparmor_initialized) + aa_info_message("AppArmor sha256 policy hashing enabled"); return 0; } - late_initcall(init_profile_hash);