From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f169.google.com (mail-yb1-f169.google.com [209.85.219.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C44E3748F for ; Thu, 4 Jul 2024 09:12:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720084359; cv=none; b=s2KBNfE5eZMN12VbD2CPDfBafRudR62L/epym3ON1luDI5QDB9zovifr24OJzDR0fH2v2/HmkMomnmQbuHdzB9ZPMKAq6Te/5qQWASDqvN5jfjaLpuu0yHUZAAu/50pK8s/I6Dz/UNKcY5KfHzypsn8b8YQUOvWaxqf4Tas2Lt4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720084359; c=relaxed/simple; bh=4Zy3A/R03Ea9KVeiTELXbEtMjlgFd5QKpAtjvYV8Ihs=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=LPIIiCT7ETt1i2paeO+hHdtlr+OGYhOWFJ27uc+PKoLZ6FWRU1PI8p3B+zPgeHOhGyVzuG4m7TFe6nAj/HPTe+q/MLFDMNXRrl+b5Tsd2mEMiWxZZ+DT1AtWhZWU3pmdOHrIkiNkzsZxA5w0EncLXXNhoEWvgwwx3FEgo/RoX/c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=GoRZSkbc; arc=none smtp.client-ip=209.85.219.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GoRZSkbc" Received: by mail-yb1-f169.google.com with SMTP id 3f1490d57ef6-e036d1ce4f7so328038276.0 for ; Thu, 04 Jul 2024 02:12:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1720084357; x=1720689157; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=cViqdyaOCwn+ROKlv4dtSt/nqrwCEFM0XP/6otHc2rI=; b=GoRZSkbcFxFvrio4Y5zb/mXr304EaQTb6Wai3j7SOIeaINL0J6mp0J6HzS7pky0mJJ Og4Z1xN7z6h+hZCLWaJj/EuASvDpZU/Zu9vpzI36PiLtwgyZo32Y8fmHn5/K+SBOK1GN QRMJbPXlPo/9uwZq4nlY8M9J8fPEeYVNkX5hK4hvnhXIdTSPu38bXT5fdlSdtkezhPF8 B4ZBhwOgB96G49TDCBfkoGEqgCwTd0vMy/ER6w6AxIBUZQ6g3XxJkO8GWy13oLmVxlav q+JXCTiedOwh0O15ZMDuCB8/VyNsgpExIn2b22YTxw8f4n84yR+QVDcGlw6SWXE2YOoj WDnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720084357; x=1720689157; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=cViqdyaOCwn+ROKlv4dtSt/nqrwCEFM0XP/6otHc2rI=; b=YQ2Y6WAkqiXswjnssEeYqM5o8JUK9dBbWoJ1c1BBYoTmGdc3Z9kSX8ZvqYTjOL3vtN 8Rjy1up6fSZpnp6qIC1f80reec91tQOSqW1zZBJuSJJZ0+wSk76Hs5V/rFNkNiVX0Xbd v9zN2CTxUwSMnGJ5UmKGha6VBhvNPLkmJFUhzUhSNBXQ7QmPaswwah/A13KyxkiFV81W krlqeQSEAobaokSK6ADscq7oizbWJZ3jHS5+uCZNvooaUCAvCfqelG1wPMyoJMxKbley bzbduE0qUkzCreYOMqwzySl+CMzjFq5MPjhqVg04GDZSuiEeaLtDuBNNBKjo/ogTMmP9 U3mA== X-Forwarded-Encrypted: i=1; AJvYcCWhu98dGIVY19UsaRuTtV71JHmzvBPuJAjVwwsdOgYF9Qb8dVS5wopGJUs/5SE7S0tOB1S7ncEYS72TAaAnQxCgY6rpOeb+V3vMQOSiWIIs6Iz2e1eB X-Gm-Message-State: AOJu0YxS7Ljr6E8xlQoFoMODmB7kByzCWNjH24H5c5CJ7EoVMQNDv1ZZ 5TqV5S6Ln2D9PR8duCGo7Ui9IqtPaUZ5MwJt3Tc4fIBaKR8Ny8o6RJOzQgI/d1SsHpoF3w9k0Ha dI1U+MCUoqmuZTEJc6k468b1vxOMk64Q1 X-Google-Smtp-Source: AGHT+IGK9cO/Y3Kx7AjnAWYe8aljVXMGzquzBsbgTcYH0VQHl/lZ4BXdt1YQTy3egddkXiJCHNq1qxeGr6bUrWVKjfk= X-Received: by 2002:a5b:b05:0:b0:e03:61d1:2b88 with SMTP id 3f1490d57ef6-e03c2a17390mr488544276.15.1720084356615; Thu, 04 Jul 2024 02:12:36 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240617220037.594792-1-luca.boccassi@gmail.com> In-Reply-To: <20240617220037.594792-1-luca.boccassi@gmail.com> From: Luca Boccassi Date: Thu, 4 Jul 2024 10:12:25 +0100 Message-ID: Subject: Re: [PATCH] dm verity: add support for signature verification with platform keyring To: dm-devel@lists.linux.dev, linux-security-module@vger.kernel.org Cc: snitzer@kernel.org, jmorris@namei.org, paul@paul-moore.com Content-Type: text/plain; charset="UTF-8" On Mon, 17 Jun 2024 at 23:00, wrote: > > From: Luca Boccassi > > Add a new configuration CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING > that enables verifying dm-verity signatures using the platform keyring, > which is populated using the UEFI DB certificates. This is useful for > self-enrolled systems that do not use MOK, as the secondary keyring which > is already used for verification, if the relevant kconfig is enabled, is > linked to the machine keyring, which gets its certificates loaded from MOK. > On datacenter/virtual/cloud deployments it is more common to deploy one's > own certificate chain directly in DB on first boot in unattended mode, > rather than relying on MOK, as the latter typically requires interactive > authentication to enroll, and is more suited for personal machines. > > Default to the same value as DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING > if not otherwise specified, as it is likely that if one wants to use > MOK certificates to verify dm-verity volumes, DB certificates are > going to be used too. Keys in DB are allowed to load a full kernel > already anyway, so they are already highly privileged. > > Signed-off-by: Luca Boccassi > --- > drivers/md/Kconfig | 10 ++++++++++ > drivers/md/dm-verity-verify-sig.c | 7 +++++++ > 2 files changed, 17 insertions(+) > > diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig > index 35b1080752cd..1e9db8e4acdf 100644 > --- a/drivers/md/Kconfig > +++ b/drivers/md/Kconfig > @@ -540,6 +540,16 @@ config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING > > If unsure, say N. > > +config DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING > + bool "Verity data device root hash signature verification with platform keyring" > + default DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING > + depends on DM_VERITY_VERIFY_ROOTHASH_SIG > + depends on INTEGRITY_PLATFORM_KEYRING > + help > + Rely also on the platform keyring to verify dm-verity signatures. > + > + If unsure, say N. > + > config DM_VERITY_FEC > bool "Verity forward error correction support" > depends on DM_VERITY > diff --git a/drivers/md/dm-verity-verify-sig.c b/drivers/md/dm-verity-verify-sig.c > index 4836508ea50c..d351d7d39c60 100644 > --- a/drivers/md/dm-verity-verify-sig.c > +++ b/drivers/md/dm-verity-verify-sig.c > @@ -126,6 +126,13 @@ int verity_verify_root_hash(const void *root_hash, size_t root_hash_len, > NULL, > #endif > VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL); > +#ifdef CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING > + if (ret == -ENOKEY) > + ret = verify_pkcs7_signature(root_hash, root_hash_len, sig_data, > + sig_len, > + VERIFY_USE_PLATFORM_KEYRING, > + VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL); > +#endif > > return ret; > } Gentle ping. Anything I can do to help move this patch forward? It fixes a gap in our dm-verity story that I'd really like to see sorted for the next release. We will use this in systemd, among other things. Thanks!