From mboxrd@z Thu Jan 1 00:00:00 1970 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 676C123ABB1; Mon, 30 Jun 2025 17:49:50 +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=1751305790; cv=none; b=CYIM0O+0WWPHCwCR+/3NUHfmgHhHg0LXcOVlSyxS5x9bez8FCvqb/vPVz2Mjb6n/kxo4sWK+Um/H2D+ksnIQRDgjO4reHEw/Hdo0Z7WJjX1Z5RCWJP/omcfm8NiU7YHR81XeZMCIrOGgrGbTh66+6trxLT1kzjn0a3RF+WK6OWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751305790; c=relaxed/simple; bh=yoi4i5n4fYavqimbjruoWqPfoDDaWyBF/Jq0f8YDWfk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=b+kZQWM3s/4j4YMrgMG7UUm1V3MP7RPHrLqwKe6YMvFGlotj8kbVPHU6H8J9L8ZtapWRwpLjiy9Sn0VjsyEHYxxBaGhAKw85YLUGOKhVOiz0932KmlLWJYfZkFO7SrEKxj0M/zFA9UhJLyDXau6Kn6+DCPXEh3I6hwn3VtkYgCg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=obBBMxy3; 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="obBBMxy3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0854C4CEE3; Mon, 30 Jun 2025 17:49:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751305790; bh=yoi4i5n4fYavqimbjruoWqPfoDDaWyBF/Jq0f8YDWfk=; h=From:To:Cc:Subject:Date:From; b=obBBMxy3BYFAIbQN+AMObBhPvreutHdvFk7yTDY8A+cNTdYBk98gSFqk4GADNqSyd sMZOT50584KhZdRUf44ZW1Ln4r+VePJl3cs+r3TMEZ86ltMHeYenz76amLMVgnU1sG uUHhQM3lFDfFjdY4cSNIc2e+kqdXzmcAoA9V3KIw+OKgTUhXQzUdkXVCKCDNVLZ/Nc 7lQs8RZs7Eyc2nNAck9+1lUBJojyJA6vbs05Dr4ipTZRyIUL9R4JlKDwPVuPMHWREr 5J7CGBabK0eGVLp/aR6suj+69CAzzk+UZdeSln7gJV51/KAIzejM1eVpjhTQ90eFun gHic5WT98P90g== From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: apparmor@lists.ubuntu.com, John Johansen , linux-kernel@vger.kernel.org, Eric Biggers Subject: [PATCH v2] apparmor: use SHA-256 library API instead of crypto_shash API Date: Mon, 30 Jun 2025 10:48:05 -0700 Message-ID: <20250630174805.59010-1-ebiggers@kernel.org> X-Mailer: git-send-email 2.50.0 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. Acked-by: John Johansen Signed-off-by: Eric Biggers --- This is the slightly revised version of https://lore.kernel.org/r/20250428190430.850240-1-ebiggers@kernel.org/ that I'm planning to apply to libcrypto-next for 6.17 to avoid a silent conflict with the sha256_state => sha256_ctx rename, as per the discussion in that thread. You can also get this patch and its dependencies from: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git apparmor-sha256-lib-v2 security/apparmor/Kconfig | 3 +- security/apparmor/crypto.c | 85 ++++++-------------------------------- 2 files changed, 13 insertions(+), 75 deletions(-) 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..227d47c149074 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_ctx sctx; __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(&sctx); + sha256_update(&sctx, (u8 *)&le32_version, 4); + sha256_update(&sctx, (u8 *)start, len); + sha256_final(&sctx, 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); base-commit: 1f7eb3c393ab9e56b5746f5fd31796a73bdd4d48 -- 2.50.0