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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF1EFC4332F for ; Fri, 4 Mar 2022 00:54:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231145AbiCDAyr (ORCPT ); Thu, 3 Mar 2022 19:54:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229918AbiCDAyq (ORCPT ); Thu, 3 Mar 2022 19:54:46 -0500 Received: from mail-pf1-f170.google.com (mail-pf1-f170.google.com [209.85.210.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0699A13DE21; Thu, 3 Mar 2022 16:54:00 -0800 (PST) Received: by mail-pf1-f170.google.com with SMTP id s11so6180638pfu.13; Thu, 03 Mar 2022 16:54:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=YJwEZHpBOkrX91NRDhiBnL9TsivdhXedQE1MEXdFkGk=; b=KLqrmsV0QMDFisEQB581pHpZA0EGa9UiO3CkbzHNOLMFnxj91kwkuw2WUOmut/cUHN nsbxWH+4ijCJTsCaBks4mFTZsPmVVsrPGEbnSfFFiR7JcRGFrYFYOruemTxwDZnCH7fJ zQtxl6g4+Rms0YodOQpQEXORNmg/g7Y1LWOGKH1+ZHo6mLNnNkzu2mxcCIBgZusZwVOx o0iVQmtj+HW8pPuljIBUiM+rD1OoJhZpUalYj15k7VwZWmAYOdbaRO7Ry2viyIDvD0vt VFB+SUc366GmdWzOLE4z897D9QcCR3/XeMJkQS8RIoQWuq76qlMsF5Od8Em1cvPuOK3z 0ksg== X-Gm-Message-State: AOAM530u1mkxOBZNGjel/zsl7R0We785t3M94/vqJ5SMjwrSlu+RgvFe Py1zLpHO+BS4SzjtAysxZaw= X-Google-Smtp-Source: ABdhPJwrunTYNLwCSAFqvfBGbiuz/Fhz9cSPhSzz+gpBillc7qLhh3XO4rOBM76VfXVVCsK+o8PRkg== X-Received: by 2002:aa7:970e:0:b0:4f6:6c73:24c3 with SMTP id a14-20020aa7970e000000b004f66c7324c3mr6208291pfg.32.1646355239206; Thu, 03 Mar 2022 16:53:59 -0800 (PST) Received: from ?IPV6:2601:647:4000:d7:feaa:14ff:fe9d:6dbd? ([2601:647:4000:d7:feaa:14ff:fe9d:6dbd]) by smtp.gmail.com with ESMTPSA id s2-20020a056a001c4200b004f41e1196fasm3699345pfw.17.2022.03.03.16.53.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 03 Mar 2022 16:53:58 -0800 (PST) Message-ID: Date: Thu, 3 Mar 2022 16:53:56 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH v5 1/3] block: add basic hardware-wrapped key support Content-Language: en-US To: Eric Biggers , linux-block@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: linux-arm-msm@vger.kernel.org, linux-scsi@vger.kernel.org, kernel-team@android.com, Gaurav Kashyap , Israel Rukshin References: <20220228070520.74082-1-ebiggers@kernel.org> <20220228070520.74082-2-ebiggers@kernel.org> From: Bart Van Assche In-Reply-To: <20220228070520.74082-2-ebiggers@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2/27/22 23:05, Eric Biggers wrote: > -static u8 blank_key[BLK_CRYPTO_MAX_KEY_SIZE]; > +static u8 blank_key[BLK_CRYPTO_MAX_STANDARD_KEY_SIZE]; > > static void blk_crypto_fallback_evict_keyslot(unsigned int slot) > { > @@ -539,7 +539,7 @@ static int blk_crypto_fallback_init(void) > if (blk_crypto_fallback_inited) > return 0; > > - prandom_bytes(blank_key, BLK_CRYPTO_MAX_KEY_SIZE); > + prandom_bytes(blank_key, BLK_CRYPTO_MAX_STANDARD_KEY_SIZE); Please use sizeof(blank_key) to make it easier for readers to verify that the length argument is correct. > +int blk_crypto_derive_sw_secret(struct blk_crypto_profile *profile, > + const u8 *wrapped_key, > + unsigned int wrapped_key_size, > + u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE]) > +{ > + int err = -EOPNOTSUPP; > + > + if (profile && > + (profile->key_types_supported & BLK_CRYPTO_KEY_TYPE_HW_WRAPPED) && > + profile->ll_ops.derive_sw_secret) { > + blk_crypto_hw_enter(profile); > + err = profile->ll_ops.derive_sw_secret(profile, wrapped_key, > + wrapped_key_size, > + sw_secret); > + blk_crypto_hw_exit(profile); > + } > + return err; > +} Please use the common kernel style: return early if the preconditions have not been met. That helps to keep the indentation level low. > @@ -68,7 +71,10 @@ static int __init bio_crypt_ctx_init(void) > > /* Sanity check that no algorithm exceeds the defined limits. */ > for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++) { > - BUG_ON(blk_crypto_modes[i].keysize > BLK_CRYPTO_MAX_KEY_SIZE); > + BUG_ON(blk_crypto_modes[i].keysize > > + BLK_CRYPTO_MAX_STANDARD_KEY_SIZE); > + BUG_ON(blk_crypto_modes[i].security_strength > > + blk_crypto_modes[i].keysize); > BUG_ON(blk_crypto_modes[i].ivsize > BLK_CRYPTO_MAX_IV_SIZE); > } Does the following advice from Linus Torvalds apply to the above code: "because there is NO EXCUSE to knowingly kill the kernel"? See also https://lkml.org/lkml/2016/10/4/1. Thanks, Bart.